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Escudier, J. L., B. Gillery, H. Ojeda, and et F. Etchebarne. "Maitrise de la salinité des eaux d'irrigation pour la viticulture." BIO Web of Conferences 12 (2019): 01010. http://dx.doi.org/10.1051/bioconf/20191201010.
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Même si la vigne reste parmi les plantes cultivées une des plus économes en eau, se pose maintenant la question de la disponibilité et de l'accessibilité à la ressource en eau naturelle de qualité: eaux souterraines (infiltration, nappes), eaux de surface stagnantes (lacs, retenues de barrages) ou en écoulement (rivières, fleuves), eaux de mer, eaux usées traitées (REUT). Certaines de ces eaux peuvent contenir des composés d'intérêts nutritionnels pour les plantes, mais aussi être riches en sels dissous. L'objet de cette communication est d'étudier les technologies permettant d'affiner la teneur en sel de l'eau d'irrigation pour la vigne, quel que soit son origine et son niveau initial. Les techniques membranaires, osmose inverse, nanofiltration et électrodialyse sont ainsi comparées techniquement et évaluées économiquement. Les unes, nanofiltration et osmose inverse, à partir de membranes poreuses ou denses sous pression, consiste en une séparation de quasi tous les éléments dissous de l'eau (anions, cations, mais y compris les nutriments azotés, et minéraux) et ce quel que soit, pour l'osmose inverse, la salinité de l'eau initiale (e.g. eau de mer). L'autre l'électrodialyse, à partir de membranes denses ne filtre pas l'eau, mais extrait une quantité pilotable en ligne, de sels dissous (Na+ et Cl− en particulier sélectionnables) sous l'effet d'un champ électrique, afin de l'adapter aux sols ou plantes concernés
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Asslouj, Jaouad El, Sanae Kholtei, Namira El Amrani-Paaza, and Abderrauf Hilali. "Impact des activités anthropiques sur la qualité des eaux souterraines de la communauté Mzamza (Chaouia, Maroc)**." Revue des sciences de l'eau 20, no. 3 (October 1, 2007): 309–21. http://dx.doi.org/10.7202/016505ar.
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Résumé L’étude des caractéristiques physico-chimiques des eaux souterraines de la communauté Mzamza, soumises aux rejets liquides de la ville de Settat à partir de l’oued Boummoussa, montre que la qualité des eaux des différents puits est variable et dépend d’un certain nombre de facteurs tels que l’emplacement des puits par rapport aux eaux usées et l’activité agricole. L’interprétation des données d’analyse, la corrélation existante entre eaux usées et eaux de puits, et la répartition des eaux souterraines en groupes sont réalisées en utilisant l’Analyse en Composante Principale Normée. L’étude a révélé des origines différentes de la contamination des eaux souterraines, à savoir, la contamination par la matière organique due essentiellement à l’utilisation des eaux usées à des fins d’irrigation et à leur infiltration continue, et finalement le retour des eaux d’irrigation (chargées en engrais azotés) qui est considéré comme étant la principale origine de la minéralisation et de la pollution des eaux. Plusieurs facteurs conditionnent la progression de cette pollution : les concentrations des polluants dans les eaux usées, la nature des sols, la lithologie, la perméabilité de l’aquifère exploité et la profondeur de la nappe. Les résultats acquis dans cette étude font ressortir également l’influence primordiale des variations saisonnières, ainsi que le rôle bénéfique des précipitations.
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El Ghali, Tibari, Mohamed Qurtobi, Fatima Raibi, Hamid Marah, and Bouâbid El Mansouri. "Détermination de l'origine de recharge et du temps de séjour des eaux souterraines de l'aquifère de Berrechid à l'aide des traceurs isotopiques (18O et 3H)." La Houille Blanche, no. 5 (October 2020): 75–87. http://dx.doi.org/10.1051/lhb/2020044.
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Le bassin de Berrechid situé au Sud de Casablanca, caractérisé par un climat semi-aride, est intensément exploité pour l'alimentation en eau potable et l'irrigation. Les traits géologiques de cette région ont confié à l'aquifère de Berrechid des caractéristiques hydrogéologiques importantes. Afin d'améliorer la compréhension du fonctionnement hydrogéologique de ce bassin, des mesures des concentrations de l'oxygène 18 et du tritium dans 71 échantillons d'eau souterraine et 8 échantillons d'eau de surface ont été réalisées pour étudier l'origine de recharge et l'âge des eaux souterraines de l'aquifère. Les données isotopiques de l'18O ont montré l'existence de deux principales composantes de la recharge de la nappe de Berrechid : une recharge par des eaux non évaporées provenant de l'abouchement latéral à partir du plateau de phosphates et de l'infiltration rapide de la pluie au Nord de la plaine et une recharge par infiltration des eaux de surface fortement évaporées dans le reste de la plaine. L'évaluation des temps de transit de l'eau a été calculée à partir de l'application des modèles d'écoulement exponentiel et de dispersion du programme Boxmodel aux données isotopiques d'entrée et de sortie. Ainsi, l'interprétation des teneurs en tritium et les temps de séjour estimés à l'aide du modèle empirique (moins de 20 ans) ont révélé que les eaux des secteurs Nord et Sud sont récentes, ce qui traduit une recharge récente et continue dans cette zone. Par contre, les eaux anciennes issues d'une recharge locale dans le reste du bassin reflètent la présence d'une lithologie peu perméable.
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Montoroi, J. P., O. Grünberger, and S. Nasri. "Utilisation de l'hydrochimie d'un bassin versant de lac collinaire tunisien pour l'étude de la recharge de la nappe alluviale." Revue des sciences de l'eau 17, no. 2 (April 12, 2005): 245–63. http://dx.doi.org/10.7202/705533ar.
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En climat méditerranéen, les ressources en eau des bassins sédimentaires sont rares. Pour limiter les écoulement de surface et recharger les nappes souterraines, des lacs collinaires ont été construits sous une pluviométrie annuelle comprise entre 250 et 500 mm. Des échantillons d'eau ont été prélevés dans le bassin versant d'El Gouazine, situé en Tunisie centrale, pour mieux expliciter le fonctionnement hydrochimique et la recharge de la nappe phréatique d'un lac collinaire très filtrant. Les eaux ont été échantillonnées à deux périodes distinctes (retenue presque asséchée et retenue pleine), en amont de la retenue dans le bassin versant et en aval dans l'aquifère alluvial. Trois faciès chimiques (bicarbonaté calcique, chloruré sodique et sulfaté calcique) caractérisent les eaux de nappe, l'eau de la retenue étant sulfatée calcique. La roche-mère et la nappe phréatique sont chimiquement très dépendantes. Les isotopes stables de l'eau montre que la nappe amont est peu profonde et d'origine météorique. L'eau de la retenue se mélange avec les eaux souterraines en conservant un caractère météorique en période d'écoulement et en acquérant un caractère évaporé en période d'assèchement. La nappe alluviale aval est alimentée par les eaux mélangées de la retenue. L'altération d'un affleurement gréseux forme un aquifère en rive gauche du lac expliquant en partie les pertes par infiltration. Les principaux processus géochimiques, qui se produisent au cours de l'écoulement de la nappe dans les formations superficielles, permettent une compréhension partielle du fonctionnement hydrochimique de la retenue et de son bassin versant.
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Achak, Mounia, Naïla Ouazzani, and Laila Mandi. "Traitement des margines d’une huilerie moderne par infiltration-percolation sur un filtre à sable." Revue des sciences de l'eau 22, no. 3 (August 3, 2009): 421–33. http://dx.doi.org/10.7202/037780ar.
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Résumé Les différentes techniques d’extraction d’huile d’olive aboutissent à la formation des margines en quantités variables, allant de 400 à 500 L•t‑1 d’olives pour les unités traditionnelles et une tonne de margines•t‑1 d’olives pour les unités modernes. L’objectif de notre travail est de montrer la faisabilité du traitement des margines par la technique d’infiltration-percolation sur filtre à sable et d’étudier l’effet de la dilution des margines par des eaux usées urbaines à 50 % sur la stimulation de la biodégradation dans le filtre et sur les performances épuratoires de cette technique. Les effluents testés ont un pH très acide (4,93) et sont très chargés en matières organiques, en demande chimique en oxygène (DCO) (28 g d’O2•L‑1) et en polyphénols (1,42 g•L‑1). Après dilution à 50 % par les eaux usées urbaines, le pH augmente à 5,01, la DCO et les polyphénols diminuent respectivement à 25,58 g d’O2•L‑1 et 1,39 g•L‑1. Le traitement des margines brutes par le filtre à sable a permis une élimination de 36 % de la DCO brute, 33 % de la DCO dissoute, 53 % des polyphénols, 67 % de l’azote Kjeldahl (NTK) et 75 % de l’azote ammoniacal. Les essais de percolation des margines mélangées à 50 % avec les eaux usées urbaines dans une colonne de sable montrent une amélioration de l’efficacité quant à l’élimination de la DCO brute (76 %), de la DCO dissoute (92 %), des polyphénols (90 %), de NTK (50 %) et de l’ammonium (87 %).
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Jemli, Meryem, and Sonia Sabbahi. "Une porphyrine comme photosensibilisant des eaux d'irrigation, photostabilité et efficacité." Revue des sciences de l’eau 31, no. 1 (June 5, 2018): 1–11. http://dx.doi.org/10.7202/1047049ar.
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Le processus de photosensibilisation (phototraitement) de l'eau suscite beaucoup d'intérêt, car il implique trois composants qui sont individuellement inoffensifs pour le milieu biologique, à savoir le photosensibilisant, la lumière et l'oxygène moléculaire. La photostabilité de la porphyrine tétra-méso-cationique (T4MPyP) dans l'eau usée et l’efficacité du phototraitement dépend de la concentration du photosensibilisant, de la qualité de l'eau (contaminants organiques, turbidité, pH, taux d'oxygène dissous et épaisseur de la lame d'eau) ainsi que de l'intensité et de la nature du rayonnement lumineux. L’étude expérimentale consistait à apporter à un sol sableux i) de l’eau usée secondaire traitée par boues activées, ii) la même eau usée, mais phototraitée avec 5 μM∙L-1 de T4MPyP pendant 6 h d’ensoleillement, et iii) une eau de puits. L’eau usée phototraitée était conforme aux normes tunisiennes (NT 106.03) pour l’irrigation sans restriction au niveau du taux de bactéries indicatrices de pollution fécale (l’abattement des coliformes fécaux avoisinait 99,99 %), mais renfermait encore une concentration résiduelle de porphyrine (environ 35 % de la concentration initiale). À la fin de l’expérimentation, la configuration saline du sol dépendait de la qualité des eaux d’irrigation. Dans le cas des eaux usées secondaires, la couche de surface (0-5 cm) se caractérisait par une concentration élevée de sels solubles et par une prolifération d’algues contribuant ainsi au colmatage superficiel et à un manque de continuité des macropores. En revanche, le colmatage chimique et biologique était réduit suite à l’utilisation des eaux usées phototraitées. La salinité était plus importante au niveau de la couche profonde (5-15 cm) due à une importante mobilité des ions chlorures et sodium suivie des sulfates et du calcium de la couche 0-5 cm vers la couche 5-15 cm, ce qui peut être attribué à une oxydation plus élevée de la matière organique induite par la présence de porphyrine. Il ressort de cette étude que la valorisation des eaux usées avec des concentrations micromolaires de T4MPyP dans le domaine agricole inhiberait le développement d'algues à la surface du sol et conduirait à une meilleure infiltration des sels vers les profondeurs évitant ainsi l’installation du colmatage à la surface. En outre, une meilleure rétention des ions ammonium et orthophosphates a été observée dans le sol sableux lors de la percolation des eaux usées phototraiteées.
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Tiglyene, S., L. Mandi, and A. E. Jaouad. "Enlèvement du chrome par infiltration verticale sur lits de Phragmites australis (Cav.) Steudel." Revue des sciences de l'eau 18, no. 2 (April 12, 2005): 177–98. http://dx.doi.org/10.7202/705555ar.
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L'objectif de la présente étude est de mettre en évidence les potentialités d'un hélophyte : Phragmites australis (Cav.) Steudel à épurer l'effluent du tannage riche en chrome sous un régime d'écoulement vertical et les comparer à celles d'un sol non planté sous climat aride. Le pilote expérimental est constitué de pots de capacité 120 litres, remplis sur une épaisseur de 15 cm de graviers et de 60 cm de sol (texture : limono - argilo- sableuse). Trois pots sont plantés de jeunes tiges de Phragmites australis (36 tiges /m2). Trois autres pots non plantés sont pris comme témoin. L'alimentation du système se fait par l'eau du tannage au chrome diluée à 50%. L’alimentation des systèmes se fait par bâchées de 10 litres/jour pendant 3 jours successifs suivie d’une période de repos de 4 jours. L'écoulement se fait par translation verticale à travers le substrat. L'étude du fonctionnement hydrologique des pilotes testés a montré que le débit moyen à la sortie du système planté est trois fois plus élevé que celui du lit non planté, ce qui permet de traiter un volume d’eau usée plus important ou bien de réduire la superficie nécessaire par équivalent habitant. Aucun signe de colmatage n’a été détecté aussi bien dans les pots plantés de Phragmites australis que dans les pots non plantés. Le suivi des performances épuratoires du système à Phragmites australis montre que le pH à la sortie des deux systèmes pilotes augmente de deux à trois unités par rapport à celui des rejets du tannage. La conductivité électrique des effluents traités augmente respectivement pour les deux systèmes. L’élimination moyenne de la DCO totale est de 74% pour le système planté et de 60,5% pour le système non planté. La différence entre les performances épuratoires des deux systèmes pour l’abattement de la DCO totale est statistiquement significative (p<0,05). Le Cr total subit globalement un abattement de 99% pour les deux pilotes qui fournissent des eaux épurées limpides. En effet, la concentration moyenne en chrome total dans les eaux usées brutes appliquées à l'entrée des différents pilotes varie de 534 mg/l à 1000 mg/l avec une concentration moyenne de 780±196 mg/l. Les teneurs de chrome total enregistrées à la sortie du lit à Phragmites varient de 2,2 mg/l à 3 mg/l avec une concentration moyenne de 2±0,5 mg/l. La concentration en chrome total des eaux usées à la sortie du sol non planté varie de 2,5 mg/l à 4 mg/l avec une valeur moyenne de 2,4±1,3 mg/l. La présence de Phragmites australis dans le système planté permet de maintenir une porosité suffisante pour assurer la percolation des eaux en traitement et réduire les risques de colmatage. Avec des temps de résidence hydraulique trois fois plus réduit, le système planté assure un abattement du chrome total comparable à celui du système non planté.
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Moussima Yaka, Diane Armelle, Ange Alex Tiemeni, Bertrand Zing Zing, Thérèse Line Laure Jokam Nenkam, Amina Aboubakar, Aline Beatrice Nzeket, Brice Hermann Fokouong Tcholong, and Yvette Clarisse Mfopou Mewouo. "Qualité physico-chimique et bactériologique des eaux souterraines et risques sanitaires dans quelques quartiers de Yaoundé VII, Cameroun." International Journal of Biological and Chemical Sciences 14, no. 5 (September 14, 2020): 1902–20. http://dx.doi.org/10.4314/ijbcs.v14i5.32.
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Au Cameroun, l’accès aux systèmes d’alimentation en eau potable en milieu urbain apparaît sélectif. Les populations des quartiers situés en périphérie ont recours aux puits et sources pour assouvir leurs besoins. La présente étude a pour objectif d’évaluer la qualité physico-chimique et bactériologique des eaux souterraines couramment utilisées dans quelques quartiers de l’arrondissement de Yaoundé VII. 24 échantillons d’eaux prélevés dans 6 sources (S1 à S6) et 2 puits (W1 et W2) ont été analysés suivant des méthodes normalisées. Les températures relevées, proches de celle de l’air, révèlent le caractère libre des nappes étudiées. Celles-ci subiraient l’influence directe des eaux d’infiltration. Les stations S1, W1 et W2 présentent des valeurs en nitrates supérieures à 50 mg/l (norme OMS). La consommation de leurs eaux expose la population jeune à la méthémoglobinémie. Contrairement aux recommandations de la norme camerounaise, les indicateurs de pollution fécale et les bactéries du genre Salmonella, ont été isolées dans les eaux analysées. Une analyse en composante principale ainsi qu’un dendrogramme ont permis de classer les points d’échantillonnage, selon l’ordre croissant de pollution organique suivant : {S6}, (S3, S4, S5), (S1, S2), {W1}, {W2}. Cependant, du point de vue pathogénique, S6, S3, S4, S5 sont les plus à craindre.Mots clés : Qualité des eaux, puits, sources, Yaoundé, risques sanitaires.
English Title: Physico-chemical and bacteriological quality of groundwater and health risks in some districts of Yaoundé VII, CameroonIn Cameroon, access to drinking water supply systems in urban areas appears to be selective. The populations located in the peripheral zone use wells and springs to satisfy their needs. This study aims to assess the physico-chemical and bacteriological quality of the groundwater commonly used in some districts of Yaoundé VII. 24 water samples taken from 6 sources (S1 to S6) and 2 wells (W1 and W2) were analyzed according to standardized methods. The temperatures recorded, close to that of the air, reveal the free nature of the aquifers studied which are directly influenced by the infiltration waters. Samples points S1, W1 and W2 presented concentration of nitrate above 50 mg/l (WHO standard). The consumption of their waters exposes young people to methemoglobinemia. On contrary to the recommendations of the cameroonian standard, the indicators of faecal pollution and bacteria of the genus Salmonella, were isolated in the waters analyzed. A principal component analysis as well as a dendrogram permit to classify the sampling points, according to the following increasing order of organic pollution: {S6}, (S3, S4, S5), (S1, S2), {W1}, {W2}. However, from a pathogenic point of view, S6, S3, S4, S5, are the most to be feared.Keywords: Water quality, Dug wells, spring, Yaoundé, sanitary risks.
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TEDOLDI, D., G. CHEBBO, D. PIERLOT, Y. KOVACS, and M. C. GROMAIRE. "Accumulation de métaux et HAP dans le sol de différents ouvrages d’infiltration." Techniques Sciences Méthodes, no. 12 (January 20, 2020): 89–111. http://dx.doi.org/10.36904/tsm/201912089.
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Le développement du contrôle à la source des eaux pluviales urbaines et, notamment, le recours croissant à des dispositifs d’infiltration suscitent des interrogations sur la capacité du sol à jouer le rôle de «filtre» vis-à-vis des polluants présents dans le ruissellement. Cette question a été abordée en couplant campagnes de terrain et approche de modélisation. Sur 11 dispositifs d’infiltration aux caractéristiques contrastées, le sol a été échantillonné en deux phases successives, conduisant à des cartographies de la contamination superficielle en métaux, puis à des profils verticaux de métaux et hydrocarbures aromatiques polycycliques (HAP), accompagnés de différentes variables explicatives. Les résultats ont démontré une bonne rétention des contaminants sur la plupart des sites d’étude, grâce à la combinaison de processus mécaniques (filtration) et physico-chimiques (adsorption). La distribution spatiale des métaux en surface, qui présente une structure caractéristique par rapport à la zone d’arrivée de l’eau, révèle le caractère non uniforme de l’infiltration lors des événements pluvieux courants. Dans la zone la plus polluée des ouvrages, métaux et HAP présentent un enrichissement significatif sur 10 à 40cm de profondeur. La contrepartie de cette rétention est une contamination qui, sur sept sites, excède localement les teneurs maximales admissibles –telles que définies par différentes normes internationales– dans le sol de zones résidentielles; toutefois, cela représente un volume de terres polluées relativement limité. L’approche de modélisation a permis de montrer que la durée de vie d’un dispositif d’infiltration pouvait être significativement améliorée en apportant un amendement organique à l’horizon superficiel, ce qui accroît la rétention de la pollution dissoute, ou en privilégiant une arrivée d’eau la plus répartie possible à la surface des ouvrages. La réduction des volumes d’eau de ruissellement en entrée d’ouvrage –par exemple, en déraccordant les eaux «propres» générées par le bassin versant– y participe également.
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Tahar, Ayadat. "Dispositifs De Prévention Contre Le Risque D’infiltration Des Eaux Souterraines Dans Les Ouvrafes De Constructions." European Scientific Journal, ESJ 13, no. 15 (May 31, 2017): 162. http://dx.doi.org/10.19044/esj.2017.v13n15p162.
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For constructing sustainable geotechnical structures, it is recommended to design these structures within a perspective of performance, adaptability and durability. This article briefly describes the various geotechnical risks and the actions to be taken to reduce or eliminate these risks. It examines in more detail the problem of risks associated with groundwater infiltration in construction structures. It discusses the various causes and the measures to be taken to eliminate this risk. Finally, the article introduces the preventive measures against groundwater infiltration for two case studies, namely a sports complex and a residential building. The study also includes precautions to be taken for protecting buildings against ground swelling caused by shale rock.
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DELLINGER, F., and T. MORONNOZ. "L’eau pluviale dans la rénovation de nos cités, étude de cas : l’Arlequin de la Villeneuve à Grenoble." Techniques Sciences Méthodes, no. 3 (March 20, 2020): 71–77. http://dx.doi.org/10.36904/tsm/202003071.
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L’objet du projet présenté, support de réflexion et d’expérimentation, est la prise en compte de la gestion des eaux pluviales par infiltration dans le cadre de la rénovation urbaine d’un quartier en politique de la ville où, jusqu’à présent, toutes les eaux collectées étaient renvoyées aux réseaux. L’étude de cas est celle de la rénovation des espaces publics sur une surface de 7 ha du quartier de l’Arlequin de la Villeneuve à Grenoble en 2017 et 2018, pour un montant d’investissement de 6,50 M€ HT. En partenariat avec les services de la métropole de Grenoble, les espaces réaménagés sont progressivement déconnectés du réseau, qui, en conséquence, est pour partie abandonné. Le travail porte autant sur les expérimentations des systèmes de gestion hydrauliques en renouvellement urbain que sur le développement conjoint d’un projet urbain et paysager, sur l’évolution des palettes végétales, sur le confort des espaces publics et la réduction des îlots de chaleur, sur la sécurité et sur la gestion de la voiture dans le quartier.
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Assemien François Yao, Kouadio, Kouassi Ernest Ahoussi, Yao Blaise Koffi, Lou Moin Sandrine Tivoli, David Salze, and Miguel Lopez-Ferber. "Caractérisation Hydro-Chimique et Évaluation de la Qualité des Eaux Souterraines de l’Environnement Minier du Canton Afema (Sud-Est de la Côte d’Ivoire)." European Scientific Journal, ESJ 19, no. 6 (February 28, 2023): 248. http://dx.doi.org/10.19044/esj.2023.v19n6p248.
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Le Canton Afema situé dans le département d’Aboisso a connu une exploitation minière de 1992 à 1998. A la fin de l’exploitation les sites n’ont pas subi de réels travaux de réhabilitation. Afin de déterminer l’impact de ces activités minières sur les caractéristiques physico-chimiques et la qualité des eaux souterraines, cette étude a été entreprise. Les résultats des analyses d’eaux collectées dans la zone minière ont été traités à l’aide du diagramme triangulaire de Piper et de l’Analyse en Composantes Principales (ACP). L’approche méthodologique a consisté d’abord à déterminer les hydro-faciès des eaux étudiées puis à les repartir en différents groupes sur la base de leur ressemblance hydro-chimique et à identifier les facteurs susceptibles d’expliquer à la fois l’origine des paramètres étudiés et leur corrélation. Enfin, la qualité globale de ces eaux a été estimée à partir du calcul de l’indice de qualité. Les résultats ont montré que les eaux étudiées étaient réparties en deux grandes familles : les eaux chlorurées calciques et magnésiennes et les eaux bicarbonatées calciques et magnésiennes. Elles étaient dans l’ensemble faiblement minéralisées, avec une conductivité électrique moyenne de 195,76 μS.cm-1. Cette minéralisation était contrôlée par deux phénomènes essentiels, le temps de séjour de l’eau dans les aquifères et l’infiltration superficielle et le lessivage des terrains non saturés. La qualité physico-chimique des eaux souterraines étudiées était conforme aux normes de potabilité recommandées par l’OMS. Cependant, les résultats ont aussi montré de fortes teneurs en cadmium (0,052 mg.L-1) et en plomb (0,058 mg.L-1) ; ce qui était responsable de la mauvaise qualité globale de ces eaux selon l’indice de qualité. Ainsi, la consommation des eaux étudiées par les populations locales constitue un danger pour leur santé.
Afema Township, located in the department of Aboisso, was mined from 1992 to 1998. At the end of the exploitation, the sites did not undergo any real rehabilitation work. In order to determine the impact of these mining activities on the physicochemical characteristics and quality of groundwater, this study was undertaken. The results of the water analyses collected in the mining area were processed using Piper's triangular diagram and Principal Component Analysis (PCA). The methodological approach consisted, first of all, in determining the hydro-facies of the waters studied, then in dividing them into different groups on the basis of their hydro-chemical similarity and in identifying the factors likely to explain both the origin of the parameters studied and their correlation. Finally, the overall quality of these waters was estimated from the calculation of the quality index. The results showed that the waters studied were divided into two main families: chloride-calcium-magnesium waters and bicarbonate-calcium-magnesium waters. They were on the whole weakly mineralized, with an average electrical conductivity of 195.76 μS.cm-1. This mineralization was controlled by two essential phenomena, the residence time of water in the aquifers and surface infiltration and leaching from unsaturated ground. The physico-chemical quality of the groundwater studied complied with the standards of potability recommended by the WHO. However, the results also showed high levels of cadmium (0.052 mg.L-1) and lead (0.058 mg.L-1); this explained the overall poor quality of these waters according to the water quality index. Thus, the studied waters presented a real risk for human consumption. The consumption of these waters by local communities exposes them to health risks.
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Wanko, A., R. Mose, and A. Liénard. "Capacités de traitement d'un effluent de synthèse en infiltration percolation." Revue des sciences de l'eau 18, no. 2 (April 12, 2005): 165–75. http://dx.doi.org/10.7202/705554ar.
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Dans cet article, nous présentons des travaux mettant en évidence les capacités de traitement biologique des eaux résiduaires urbaines au sein des milieux poreux de textures différentes. Une étude comparative du développement de la biomasse couplé aux mécanismes généraux de transferts gazeux à travers deux réacteurs biologiques est menée. Des lits d’infiltration percolation sont simulés par des colonnes garnies de sables d’origine et de structures différentes. Ils sont alimentés périodiquement via un automate de commande avec un influent d’une charge de 525 mgDCO/l et de 54 mgNK/l. Les résultats obtenus établissent le fait qu’un développement équilibré de la biomasse incluant les phases de croissance et de régression est intrinsèquement lié à la nature physique du matériau support. A l’aide des carottes prélevées sur les massifs filtrants et des sondes d’oxymétrie introduites à différentes hauteurs des lits d’infiltration, nous montrons que la répartition verticale du biofilm dans les colonnes ainsi que l’oxygénation des milieux poreux lors des périodes de repos sont également corrélées à la structure des supports pourtant de diamètres moyens similaires. L’efficacité de traitement biologique du carbone est supérieure pour un sable d’origine alluvionnaire comparativement à un sable concassé ; la tendance s’inversant significativement lorsqu’il s’agit de la diminution de l’azote.
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Perrodin, Yves, Cécile Delolme, Thierry Winiarski, Jean-Philippe Bedell, Sylvie Barraud, Jean-Pascal Bardin, Magali Dechesne, et al. "Projet « MGD Infiltration ». Maîtrise et gestion durable des ouvrages d'infiltration des eaux pluviales en milieu urbain." Revue française de génie civil 7, no. 1 (January 28, 2003): 81–88. http://dx.doi.org/10.3166/rfgc.7.81-88.
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Wanko, Adrien, Robert Mose, and Antoine Sadowski. "Simulation des transferts réactifs multi-constituants au sein des lits d’infiltration percolation – évaluation des capacités d’oxygénation." Revue des sciences de l'eau 19, no. 3 (September 13, 2006): 199–212. http://dx.doi.org/10.7202/013538ar.
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Résumé L’assainissement des eaux usées par infiltration percolation appartient à la filière de traitement des rejets polluants à cultures fixées. Dans un contexte géographique spécifique et pour une population avoisinant 500 à 1 000 équivalents habitants, elle paraît bien indiquée. Filière dite rustique, elle n’en est pas moins complexe. L’objectif de cette étude est de contribuer, à travers une simulation numérique, à la compréhension des phénomènes physiques et biochimiques qui s’établissent au sein d’un lit d’infiltration percolation. Les aspects essentiels à l’activité bactérienne que sont l’hydrodynamique du milieu poreux, le développement de la biomasse active, le transport, la consommation et les transferts d’oxygène y sont abordés. À travers des essais d’une vérification méthodique du modèle effectuée à partir des solutions analytiques, il ressort principalement que la dispersion hydrodynamique et le taux de dégradation ont des effets contraires sur le rendement d’abattement des charges polluantes. En outre, un résultat significatif obtenu est la comparaison qualitative et quantitative des apports convectifs et diffusifs en oxygène au sein des lits d’infiltration percolation qui sont à aération naturelle.
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Denimal, Sophie, Florent Barbecot, Laurent Dever, Nicolas Tribovillard, and Francis Meilliez. "Tracage chimique et isotopique des eaux souterraines en relation avec les eaux de lixiviation de terrils, bassin minier du Nord-Pas-de-Calais (France)." Bulletin de la Société Géologique de France 172, no. 1 (January 1, 2001): 111–20. http://dx.doi.org/10.2113/172.1.111.
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Abstract Introduction. - In the Nord-Pas-de-Calais region (northern France), the mining activity linked to the coal extraction resulted in the existence of many mine spoils. Most of the time, the choice of the mine spoil location has been made without knowing the potential contamination of the aquifers contained in the underlying formations by substances which can be solubilized and released in relation with the weathering of these mine spoils. The aim of this study is to determine the possible role of the mine spoils in the sulfate mineralization of the chalk aquifer. Previous works [Bernard, 1979; Droz, 1985] allow to consider several possible sources of sulfate in the coal basin: the dissolution of evaporitic minerals present in the Carboniferous limestones Formation which can locally contaminate per ascensum the chalk aquifer; the dissolution of gypsum contained in the Tertiary formations (Argiles de Louvil, Sables d'Ostricourt); sulfates of anthropic origin linked to the waste water discharge and/or to the agricultural practices; finally, the weathering of mine spoils which leads to the oxydation of the pyrite contained in the Carboniferous shales, and can release sulfate ions that may be transferred to the aquifer. Two sites have been selected 30 km to the south of Lille: site 1 lies directly on the Senonian-Turonian chalk while site 2 lies on the sandy-clayey Tertiary formations overlying the chalk formations (fig. 1-3). Geology and hydrogeology. - The waters have been sampled within the chalk aquifer (fig. 2). This water table forms the main resource in drinking water, currently exploited. The chalk aquifer is a free water table except where the Tertiary formations make this water table confined, as is the case for site 2. The recharge of the chalk aquifer is made by the percolation of the impluvium through the microporosity of the chalk with an infiltration velocity of 0.5 to 0.7 m per year [Vachier et al., 1979]. The chalk aquifer flow is schematically SW-NE to the Orchies basin (fig. 1). This flow is caused by the piezometric depression in the Orchies basin linked to industrial pumpage. Since the decrease of these pumpages, we can observe a rise of the chalk aquifer piezometric level evaluated to 10 m in the studied area. Material and methods. - Rock samples have been collected on the surface of the two sites and below it at site 1. Mineralogical analyses have been carried out on the bulk fraction as on the clayey fraction, the elementary analysis of total carbon and total sulphur has also been performed. Two water sampling surveys have been carried out on 19 sites. Sampling has been made from piezometers which reach the chalk aquifer and that are placed close to the mine spoils but also in a radius of 5 to 10 km around. Chemical and isotopic analyses have been made on the waters sampled at hydraulic upstream and dowstream of the mine spoils. In situ measurements have been carried out during the sampling. Piezometric levels have been taken at all the sampling sites. Results and discussion. - The carbon and sulphur contents have shown a superficial leaching of these elements on the mine spoils (fig. 9). The use of isotopic geochemistry and in particular the sulphur isotopes as tracers of the sulfate origin has permitted to identify two contribution sources at the two sites: a "mine spoil" source with a delta 34 S weakly negative (delta 34 S = -2,8 per mil, -3,9 per mil) which corresponds to the oxidation of sulfides contained by the Carboniferous shales and another source (delta 34 S = -20 per mil) corresponding to the gypsum of the "Sables d'Ostricourt" which is present only at site 2 (fig. 7, 10 & 11). This study has revealed the different behaviour of the two sites: for site 1, with a free water-table zone, the mine spoil leaching carries sulfate ions directly to the table whereas in the second site, with a confined aquifer zone, a part of the sulfate ions are reduced once exported to the table (the redox potential presents negative values; fig. 6). This bacterial reduction is made possible by the organic carbon leaching concomitant to the sulphur leaching on the mine spoils. This carbon contribution has been confirmed by the 14 C activity analysis: 14 C activity is characteristic of the chalk aquifer waters at the upstream of the mine spoil and noticeably lower downstream, this decrease can be linked to the "dead carbon" supply from the mine spoils (fig. 8). This organic carbon is involved in bacterially-mediated sulfate reduction (2CH 2 O + SO 4 (super 2-) --> 2HSO 3 (super -) + H (super +) + HS (super -) ). Conclusion. - Both studied mine spoils release sulfate ions to the Chalk aquifer, in response to the weathering and leaching of their surficial part. Using an isotope study-grounded approach, the influence of the mine spoils upon the sulfate enrichment of the water table can be distinguished from that of Cenozoic formations sometimes present between the chalk aquifer and the mine spoil basis. No other sulfate source seems to be involved in the studied area. Together with sulfate ions, the mine spoils export dissolved organic carbon. Both chemical species sustain bacterial activity (sulfate reducers) that develops where the water table is made confined by overlying, almost impervious, Cenozoic deposits. In that case, reducing conditions in the aquifer decrease the amount of sulfate ions present. Thus the simultaneous supply of sulfate and carbon by the mine spoils leads to a self-purification process where the aquifer is confined.
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Tfeil, Hasni, Mohamed Mahfoudh, Baba Aînina Moulay Mhamed, Ahmed Aliyen, Lemhaba Yarba, and Abdellahi Mohamed Vall Hmeyada. "Caractérisation Physico-Chimique Des Eaux De Surface Et Étude De La Diversité Ichtyologique De Quelques Zones Humides Continentales En Mauritanie." European Scientific Journal, ESJ 14, no. 6 (February 28, 2018): 83. http://dx.doi.org/10.19044/esj.2018.v14n6p83.
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The aim of this study is to characterize the physicochemical parameters of the waters of certain continental wetlands and to determine the fish population diversity of this aquatic habitat in Mauritania. Physico-chemical analyses carried out in 2015-2016 (wet-fresh, hot-dry) suggest the qualities of good water, favorable to aquatic life at any time of the year. The highest values were recorded in the warm season (from 26.6 to 34.4 °C for the temperature, from 8 to 9.2 for the pH, from 170 to 591 μs/cm for the conductivity, from 3, 23 to 8.2 mg / l for dissolved oxygen and 169 to 590 mg / l TDS). The lowest values were found in the cold season (from 18.0 to 27.0 ° C for temperature, from 7.5 to 9.0 for pH, from 99.5 to 358 μs/cm for conductivity, 2.70 to 4.80 mg/l for dissolved oxygen and 100 to 360 mg/l of TDS). The establishment and development of biodiversity in these wetlands were at their peak during the hot and dry periods. 15 species belonging to 8 families were identified in these sites where there is a significant fishing activity. It is during this period that fish biodiversity and fishery potential increase as water decreases under the pressure of evaporation, infiltration and anthropozoogenic consumption. The ecosystem services of these continental wetlands, which survive the impacts of climate change, require urgent management, preservation and development measures.
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Kone, Martine, Lucien Bonou, Jean Koulidiati, Pierre Joly, Soumaïla Sodre, and Yvette Bouvet. "Traitement d'eaux usées urbaines par infiltration-percolation sur sable et sur substrat de coco après un bassin anaérobie de lagune sous climat tropical." Revue des sciences de l’eau 25, no. 2 (August 7, 2012): 139–51. http://dx.doi.org/10.7202/1011604ar.
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Au Burkina Faso, l’un des soucis majeurs demeure la gestion des eaux résiduaires dans les villes. Notre objectif a été d’étudier des procédés biologiques alternatifs destinés aux petites et moyennes collectivités et particulièrement adaptés aux conditions climatiques tropicales. Nous avons examiné les performances épuratoires de deux matériaux de filtration que sont le sable et un substrat de coco concassé (fibres de coco), sur des systèmes pilotes recevant des effluents issus d’un bassin anaérobie de lagunage. Les résultats montrent des performances croissantes de 93 % à 95 % sur la DCO (Demande Chimique en Oxygène) et un abattement moyen sur la DBO5 (Demande Biochimique en Oxygène) atteignant 99 %, avec la colonisation progressive du massif de sable par la biomasse. Avec le substrat de coco les rendements moyens sur la DCO passent successivement de 15 % à 51 % lorsque les charges hydrauliques varient de 20 à 60 L•m-2•j-1, du fait de l’extraction de composés phénoliques du substrat. Cependant, il présente la même efficacité que le sable pour l’élimination de la pollution biodégradable. Les rendements en azote Kjeldahl sont de 75 % et 84 % pour le substrat de coco et le sable respectivement, alors que le filtrat issu du substrat de coco n’a donné que 7 mg•L-1 en moyenne de nitrates. Dans le même temps, les concentrations en nitrates atteignent 40 mg•L-1 pour le massif de sable. Ce comportement du substrat de coco pourrait être attribué à la formation de complexes entre composés azotés et les tanins issus de ce matériau.
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Orou, Rodrigue Kotchi, Gbombélé Soro, Drissa Tanina Soro, Rosine Marie N’guessan Fossou, Oscar Zahibo Onetie, Ernest Kouassi Ahoussi, and Nagnin Soro. "Variation Saisonnière De La Qualité Physico-Chimique Des Eaux Souterraines Des Aquifères d’Altérites Du Département d’Agboville (Sud-Est De La Côte d’Ivoire)." European Scientific Journal, ESJ 12, no. 17 (June 29, 2016): 213. http://dx.doi.org/10.19044/esj.2016.v12n17p213.
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The main objective of this study was to evaluate the seasonal quality to explain the phenomena at the origin of the mineralization of groundwater in the department of Agboville. Hydrochemical analysis was performed in 24 wells located throughout the study area. Hydrochemical different methods and techniques of multivariate statistical analysis were used to study these waters. The physicochemical analyzes show that the water is acidic with an average pH of 6.09 in the rainy season and 6.29 in the dry season. Overall, these waters are soft and slightly mineralized with an average electrical conductivity of 172.92 μS / cm in the rainy season and 196.71 μS / cm in the dry season. These waters are mineralized in the dry season than rainy. The hydrochemical classification of water from the Piper diagram showed one hydrofacies is calcium chloride-facies. Quality chemical parameters are mostly below the WHO (2011) guideline values, except for some points (29.17%) where levels of nitrites and ammonium sometimes exceed the guide values. The various processes responsible for the acquisition of the chemistry of groundwater are studied: the residence time of water in contact with the host rock, the redox infiltration of substances linked to human activities and litter decomposition. In the mineralization mechanisms, hydrolysis of silicates is the dominant process.
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Joseph, C., C. Rodier, M. Soulie, F. Sinegre, and R. Baylet. "Approche des transferts de pollution bactérienne dans une crue karstique par l'étude des paramètres physico-chimiques." Revue des sciences de l'eau 1, no. 1-2 (April 12, 2005): 73–106. http://dx.doi.org/10.7202/705004ar.
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L'exploitation des systèmes aquifères karstiques est toujours effectuée sous des contraintes liées à leur forte vulnérabilité. Une étude complète d'un épisode de crue de la source du Lez a été réalisée grâce à une coopération entre les Services de Santé et l'Université. Cette étude comporte une observation des paramètres physico-chimiques et bactériologiques sur une période de 15 jours, correspondant à une réponse hydrodynamique impulsionnelle sur la totalité du bassin. Les pas de temps d'échantillonnage varient de 4 à 24 heures. L'interprétation des résultats physico-chimiques met en évidence une disjonction nette entre les variations piézométriques et le passage de différents volumes d'eau. L'écoulement des eaux plus chaudes (16,5 °C) observé lors de l'étiage, eaux d'origine profonde plus chargées chimiquement se poursuit jusque vers le milieu de la décrue pour faire place à l'arrivée d'eaux plus froides correspondant à des infiltrations rapides puis retardées. Les eaux les plus chaudes sont caractérisées par des variations des teneurs en magnésium, les teneurs en calcium restant à peu prés constantes. Inversement; les eaux froides de l'infiltration retardée ont de faibles variations des teneurs en magnésium et sont tracées par une forte augmentation des valeurs en calcium. Le risque sanitaire maximal est lié au début de l'arrivée des eaux froides. Les eaux d'étiage et les eaux profondes sont légèrement contaminées. Les eaux d'infiltration retardée sont peu contaminées. En dehors des zones de perte du réseau hydrographique et des axes d'infiltration rapide, la vulnérabilité de l'aquifère est faible à l'échelle du bassin.
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Heissigerova, Jarmila, Petra Seidler Stangova, Aneta Klimova, Petra Svozilkova, Tomas Hrncir, Renata Stepankova, Miloslav Kverka, Helena Tlaskalova-Hogenova, and John V. Forrester. "The Microbiota Determines Susceptibility to Experimental Autoimmune Uveoretinitis." Journal of Immunology Research 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/5065703.
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The microbiota is a crucial modulator of the immune system. Here, we evaluated how its absence or reduction modifies the inflammatory response in the murine model of experimental autoimmune uveoretinitis (EAU). We induced EAU in germ-free (GF) or conventionally housed (CV) mice and in CV mice treated with a combination of broad-spectrum antibiotics either from the day of EAU induction or from one week prior to induction of disease. The severity of the inflammation was assessed by fundus biomicroscopy or by histology, including immunohistology. The immunophenotyping of T cells in local and distant lymph nodes was performed by flow cytometry. We found that GF mice and mice where the microbiota was reduced one week before EAU induction were protected from severe autoimmune inflammation. GF mice had lower numbers of infiltrating macrophages and significantly less T cell infiltration in the retina than CV mice with EAU. GF mice also had reduced numbers of IFN-γand IL-17-producing T cells and increased numbers of regulatory T cells in the eye-draining lymph nodes. These data suggest that the presence of microbiota during autoantigen recognition regulates the inflammatory response by influencing the adaptive immune response.
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Miall, Andrew D. "Geoscience of Climate and Energy 13. The Environmental Hydrogeology of the Oil Sands, Lower Athabasca Area, Alberta." Geoscience Canada 40, no. 3 (October 31, 2013): 215. http://dx.doi.org/10.12789/geocanj.2013.40.016.
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Shallow fresh groundwater and deep saline groundwater are used together with surface water in the extraction of bitumen from the Athabasca Oil Sands both in the surface mining and in situ operations. However, increasing efficiencies in processing technologies have reduced water use substantially and currently at least 75% of the water used in most operations is recycled water. Much concern has been expressed regarding contamination of surface waters by seepage from tailings ponds, but hydrogeological studies indicate that this is not happening; that seepage capture design is effective. Oil sands mining and in situ project licensing and operation regulations include Environmental Impact Assessments that mandate considerable hydrogeological measurement and monitoring work. However, little of this is independently evaluated for accuracy or synthesized and interpreted for the public. Recent changes in Alberta environmental regulation, including the establishment of the Alberta Environmental Monitoring Management Board (in October 2012) are expected to bring new transparency to environmental management of Oil Sands operations.SOMMAIREOn utilise conjointement des eaux douce de faibles profondeur, des eaux souterraines salines profondes avec des eaux de surface dans l'extraction du bitume des sables bitumineux de l'Athabasca, tant dans le procédé d’extraction in situ qu’en surface. Par ailleurs, l’accroissement de l'efficacité des technologies de traitement a considérablement réduit la consommation d'eau et, à l’heure actuelle, au moins 75% de l'eau utilisée dans la majorité des opérations est de l'eau recyclée. Beaucoup d’inquiétude a été exprimée concernant la contamination des eaux de surface par la percolation des eaux des bassins de décantation des résidus, mais des études hydrogéologiques indiquent que ce n'est pas le cas, et que le concept de capture des infiltrations est efficace. L’octroi de permis d’exploitation ainsi que les procédés d’exploitation des sables bitumineux, par extraction en surface ou in situ, comportent des évaluations d’impact sur les milieux de vie, est assorti de mandats élaborés de mesures hydrologiques et de suivi. Cela dit, peu de ces mesures sont évaluées de manière indépendante quant à leur exactitude, leur mise en forme et leur interprétation pour le grand public. Les changements récents dans la réglementation environnementale en Alberta, y compris la mise en place du Alberta Environmental Monitoring Management Board (en Octobre 2012) devraient aboutir à une nouvelle transparence de la gestion environnementale de l'exploitation des sables bitumineux.DOI: http://dx.doi.org/10.12789/geocanj.2013.40.016
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Okunuki, Yoko, Ryo Mukai, Takeshi Nakao, Steven J. Tabor, Oleg Butovsky, Reza Dana, Bruce R. Ksander, and Kip M. Connor. "Retinal microglia initiate neuroinflammation in ocular autoimmunity." Proceedings of the National Academy of Sciences 116, no. 20 (April 25, 2019): 9989–98. http://dx.doi.org/10.1073/pnas.1820387116.
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Autoimmune uveitis is a sight-threatening ocular inflammatory condition in which the retina and uveal tissues become a target of autoreactive immune cells. While microglia have been studied extensively in autoimmune uveitis, their exact function remains uncertain. The objective of the current study was to determine whether resident microglia are necessary and sufficient to initiate and amplify retinal inflammation in autoimmune uveitis. In this study, we clearly demonstrate that microglia are essential for initiating infiltration of immune cells utilizing a murine model of experimental autoimmune uveoretinitis (EAU) and the recently identified microglia-specific marker P2ry12. Initiating disease is the primary function of microglia in EAU, since eliminating microglia during the later stages of EAU had little effect, indicating that the function of circulating leukocytes is to amplify and sustain destructive inflammation once microglia have triggered disease. In the absence of microglia, uveitis does not develop, since leukocytes cannot gain entry through the blood-retinal barrier, illustrating that microglia play a critical role in regulating infiltration of inflammatory cells into the retina.
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Li, Jinying, Chen Qiu, Zheng Zhang, Weixin Yuan, Zhen Ge, Bing Tan, Pengjie Yang, et al. "Subretinal Transplantation of Human Amniotic Epithelial Cells in the Treatment of Autoimmune Uveitis in Rats." Cell Transplantation 27, no. 10 (August 31, 2018): 1504–14. http://dx.doi.org/10.1177/0963689718796196.
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As a featured ocular inflammatory disease, autoimmune uveitis is the major cause of blindness in the clinic. Although current immunosuppressive regimens can alleviate the progression of autoimmune uveitis, they have serious side effects. Therefore, an alternative therapeutic strategy is urgently required. The present study investigated the therapeutic efficacy of human amniotic epithelial cells (hAECs) on autoimmune uveitis in a rat model. Herein, experimental autoimmune uveitis (EAU) was induced in rats via a subcutaneous injection of interphotoreceptor retinoid-binding protein. EAU rats were treated with hAECs or the vehicle solution via a subretinal injection on day 0 and day 6 after immunization, and rats were sacrificed on day 12 and day 18 for further analysis. The pathological development of EAU was evaluated by slit lamp microscopy. Immune cell infiltration and retinal structure damage were examined by histological examination of hematoxylin and eosin (H&E) and immunofluorescence staining. T-cell subsets were detected by flow cytometry, and the levels of inflammatory cytokines were quantified by enzyme-linked immunosorbent assay (ELISA). hAEC treatment ameliorated the pathological progression of EAU and preserved the retinal structure organization and thickness, especially in the preventive group that received a subretinal injection on day 0. Moreover, hAECs inhibited the retinal infiltration of macrophages and T-cells. Mechanistically, hAECs modulated the balance of T-cell subsets by downregulating T helper (Th)17 cells and upregulating T regulatory (Treg) cells, as confirmed by decreased interleukin (IL)-17 and increased IL-10 levels in the spleens and lymph nodes of EAU rats. Furthermore, hAECs improved the local cytokine environment in EAU rats by suppressing the monocyte chemoattractant protein (MCP)-1, IL-17 and interferon (IFN)-γ levels and enhancing the IL-10 in the aqueous humor. Therefore, subretinal transplantation of hAECs in EAU rats ameliorated ocular inflammation, preserved the retinal structure and coordinated the immune balance. The current study provides a novel therapeutic strategy for autoimmune uveitis and related ocular inflammatory diseases in the clinic.
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Shen, Chia-Rui, Wei-Cheng Yang, Yih-Shiou Hwang, Wei-Hsin Hong, and Chao-Lin Liu. "More roles of IL-4 than being as an antagonist of IFN-γ in experimental autoimmune uveitis." Journal of Immunology 204, no. 1_Supplement (May 1, 2020): 142.4. http://dx.doi.org/10.4049/jimmunol.204.supp.142.4.
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Abstract IL-4 appears to be beneficial for some autoimmune diseases. Despite its role in antagonizing pathogenic Th1 response, our recent work has demonstrated IL-4 possesses functions affecting the regulatory T (Treg) cells. Here we aimed to identify the role of IL-4 in the development of experimental autoimmune uveitis (EAU). EAU was induced in WT and IL-4 KO mice via active interphotoreceptor retinoid binding protein (IRBP) immunization, and the disease development was monitored by funduscopic and histology analysis as well as the IRBP-specific immune responses by flow cytometric analysis and ELISA. It showed that the onset of disease, if the clinical score equals to 1, was day 14 and 20 in IL-4KO and WT mice, respectively. The fundoscopic images demonstrated the more and bigger size of lesions, increased leukocyte infiltration, vasculitis and neovascularization in IL-4KO mice. The histological analysis also confirmed the mononuclear cell infiltration. Moreover, Th1 effector is known as the dominant pathogenic mediators, whereas Treg cells play an important and indispensable role in control of EAU progression and disease remission. The splenic T cells from IL-4 KO EAU animals produced significantly elevated level of IFN-γ in responding to IRBP stimulation. However, there seems no significant but some alternation in the presence of Treg cells (Foxp3+) among CD4+CD25+ T cells in the spleens and lymph nodes of IL-4 KO and WT mice. These results demonstrate the lack of IL-4 disrupting the induction of EAU and leading to an increased disease severity through not only antagonizing IFN-γ but also involved mechanisms of immune-regulation. Therefore, IL-4 might play more roles than being just an antagonist of IFN-γ in autoimmune uveitis.
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Horai, Reiko, So Jin Bing, Phyllis B. Silver, Yingyos Jittayasothorn, Chi-Chao Chan, and Rachel R. Caspi. "GM-CSF mediates development of eosinophil-dominant autoimmune uveitis in the absence of both IFN-γ and IL-17A." Journal of Immunology 204, no. 1_Supplement (May 1, 2020): 142.6. http://dx.doi.org/10.4049/jimmunol.204.supp.142.6.
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Abstract Autoimmune uveitis is a group of blinding diseases triggered by activated retina-specific T cells. Studies in uveitis patients and experiments in animal models of experimental autoimmune uveitis (EAU) support the notion that Th1 and Th17 cells are both pathogenic effectors and each can elicit ocular autoimmunity independently of the other. Since absence of IFN-γ or IL-17A individually failed to abolish pathology of EAU, we examined EAU development in the absence of both cytokines. Ifng−/−Il17a−/− mice were fully susceptible to EAU and displayed eosinophil-dominant ocular infiltrates, as opposed to mononuclear infiltrates in WT mice. EAU was ameliorated in double-deficient mice when eosinophils were genetically absent or their migration was blocked, supporting a pathogenic role of eosinophils in the absence of both IFN-γ and IL-17A. In Ifng−/−Il17a−/− mice immunized for EAU, ocular infiltrates contained increased GM-CSF-producing CD4 T cells, and supernatants of antigen-recalled splenocytes contained enhanced levels of GM-CSF that contributed to activation and migration of eosinophils in vitro. Systemic or local blockade of GM-CSF ameliorated EAU in Ifng−/−Il17a−/− mice. Neutralization of GM-CSF during the induction phase of EAU decreased eosinophil infiltration to the eye and eosinophil peroxidase levels in the eye and in the serum. These results support the interpretation that, in the concurrent absence of IFN-γ and IL-17A, GM-CSF takes on a major role as a pathogenic effector cytokine and induces an eosinophil-dominant pathology. This may impact therapeutic strategies aiming to target IFN-γ and IL-17A in autoimmune uveitis.
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Yang, Jee Myung, KyungA Yun, Jehwi Jeon, Hae Young Yang, Bora Kim, Sunhong Jeong, Junyeop Lee, et al. "Multimodal evaluation of an interphotoreceptor retinoid-binding protein-induced mouse model of experimental autoimmune uveitis." Experimental & Molecular Medicine 54, no. 3 (March 2022): 252–62. http://dx.doi.org/10.1038/s12276-022-00733-z.
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AbstractWe aimed to characterize the vascular phenotypes of an experimental autoimmune retinal uveitis (EAU) model induced by interphotoreceptor retinoid-binding protein (IRBP) using multimodal imaging techniques. We systemically administered IRBP or vehicle to adult C57BL/6 mice. Fundus photography, optical coherence tomography (OCT), in vivo live confocal imaging using different tracers, OCT angiography (OCTA), and electroretinography (ERG) were performed after IRBP immunization. Hematoxylin and eosin and immunofluorescence staining were performed to characterize the immune response and vascular permeability. Mice with EAU exhibited perivascular inflammation, vitritis, and superficial retinal inflammation on fundus photography and OCT. H&E revealed immune cell infiltration in the perivascular area of the retina and choroid accompanied by a significant degree of perivasculitis that subsequently damaged photoreceptors 3 weeks postimmunization. Immunofluorescence staining showed subsequent transcytosis induction after local microglial activation followed by neutrophil recruitment in the perivascular area. Transcytosis in the superficial and deep vascular areas was improved by immune cell suppression. Intravital in vivo confocal imaging showed signs of neutrophil infiltration and obstructive vasculitis with perivascular leakage 3 weeks postimmunization. OCTA revealed a significant decrease in vascular flow in the deep capillary layer of the retina. Functional analysis showed that scotopic responses were intact at 2 weeks; however, normal photopic and scotopic responses were hardly detected in mice with EAU mice at 3 weeks postimmunization. Our data suggest that inflammatory cell activation and subsequent transcytosis induction in endothelial cells might be a major pathogenic factor for vascular leakage in uveitis, providing new insights into the pathophysiology of retinal vasculitis in noninfectious uveitis.
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Bing, So Jin, Phyllis B. Silver, Yingyos Jittayasothorn, Reiko Horai, and Rachel R. Caspi. "Ocular autoimmunity develops despite concurrent absence of Th1 and Th17 signature cytokines." Journal of Immunology 200, no. 1_Supplement (May 1, 2018): 163.15. http://dx.doi.org/10.4049/jimmunol.200.supp.163.15.
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Abstract Th1 and Th17 cells are each a standalone effector phenotype, and each can elicit ocular autoimmunity independently of the other. In this study, we used mice deficient in IL-17A, or IFN-gamma (GKO), or both (DKO) to dissect the role of Th1 and Th17 cytokines in experimental autoimmune uveitis (EAU). EAU was induced by active immunization with the retinal autoantigen IRBP. Previous studies showed that EAU in GKO mice was exacerbated, whereas it was attenuated in IL-17A KO mice. Surprisingly, DKO mice were fully susceptible to EAU with scores similar to wild type (WT) controls, and displayed eosinophil-dominant infiltration along with enhancement of IL-17F, Th2, and proinflammatory cytokines. To test which cytokines contributed to pathology, EAU-challenged DKO mice were treated with blocking antibodies to IL-17F, TNF-a, GM-CSF or IL-4Ra (a shared subunit of receptor for IL-4 and IL-13). Blockade of IL-17F or TNF-a in DKO mice did not affect the severity of EAU. Treatment with an anti-GM-CSF antibody during both induction and expression stages significantly suppressed disease severity in DKO, but not in WT mice. By contrast, treatment of DKO mice with an anti-IL-4Ra antibody worsened EAU. Importantly, a single intravitreal injection of an anti-GM-CSF antibody after the disease onset reduced EAU severity in both WT and DKO mice. These results suggest that, in the absence of both IFN-gamma and IL-17A, (a) GM-CSF plays a major and nonredundant role as a pathogenic cytokine, (b) the Th2 cytokines IL-4 and/or IL-13 are protective, and (c) IL-17F and TNF-a may be dispensable. Our results highlight that ‘classical’ Th1 and Th17 cells are not the only pathogenic effectors, and that other inflammatory cytokine(s) can contribute to uveitis.
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SHAO, HUI, Yang Bian, Yan Ke, Yali Wang, Henry J. Kaplan, and Deming Sun. "Interphotoreceptor retinoid-binding protein (IRBP)-specific Th1 and Th17 cells in monophasic and recurrent experimental autoimmune uveitis (EAU) (99.10)." Journal of Immunology 182, no. 1_Supplement (April 1, 2009): 99.10. http://dx.doi.org/10.4049/jimmunol.182.supp.99.10.
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Abstract Emerging evidence supports the notion that the IL-17 producing T cells (Th17 cells) play an important role in the inflammatory response of autoimmune diseases. We wished to determine whether eye-infiltrating autoreactive T cells differ between monophasic and relapsing uveitis, and whether Th1 and Th17 autoreactive T cells play distinctive roles in monophasic versus recurrent uveitis. Analysis of the cellular components of eye-infiltrating cells revealed that within the inflamed eye of m-EAU, Th17 cells were dominant in the earlier stage, and declined gradually with disease resolution. In contrast; the number of Th1 cells was lower than Th17 cells in the early stages of disease but gradually increased during the peak and remission of eye inflammation. During r-EAU, abundant IFN-r single positive cells and IFN-rIL-17 double positive T cells were found in the early stage of disease; the double positive cells gradually declined, while the IFN-r T cells persisted in the entire disease process. Only a few IL-17 single positive T cells were found in the inflamed eye during the entire disease episode. Our studies indicate that a change in the ratio of autoreactive T cell subsets between Th17 and Th1 appears to correlate with disease recovery of m-EAU. The appearance of IFN-rIL-17 double positive autoreactive T cells may correlate with the acute attack of eye inflammation in r-EAU. The pathogenic and immunoregulatory function of single positive and double positive autoreactive T cells remain to be further investigated.
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Shome, Avik, Odunayo O. Mugisho, Rachael L. Niederer, and Ilva D. Rupenthal. "Comprehensive Grading System for Experimental Autoimmune Uveitis in Mice." Biomedicines 11, no. 7 (July 18, 2023): 2022. http://dx.doi.org/10.3390/biomedicines11072022.
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Experimental autoimmune uveitis (EAU) is the most commonly used animal model to study the progression of chronic uveitis and to test various therapies to treat the disease. However, to accurately evaluate the effectiveness of such treatments, a grading system that combines the latest imaging techniques with definitive quantitative grading thresholds is required. This study aimed to develop a comprehensive grading system that objectively evaluates EAU progression in C57BL/6J mice. EAU was induced following immunisation with interphotoreceptor retinoid-binding protein (IRBP) and pertussis toxin. Weekly fundus and optical coherence tomography (OCT) images were acquired over 12 weeks using a Micron IV imaging system. Each mouse was graded (between 0 to 4) based on changes seen on both the fundus (optic disc, retinal blood vessels and retinal tissue) and OCT (vitreous and retinal layers) images. A total EAU response (with a maximum score of 48) was calculated for each mouse based on the sum of the individual scores each week. Analysis of the clinical scores depicted a gradual increase in inflammatory signs including optic disc and vascular swelling, leukocyte infiltration in the vitreous, lesions in the retina and formation of granulomas and hyper-reflective foci in the retinal layers in EAU mice, with most signs reaching a plateau towards the end of the study period. Development of these signs into sight-threatening complications such as optic disc atrophy, structural damage to the retina and subretinal oedema were noted in 80–90% of mice suggesting consistent disease induction. Overall, a comprehensive and objective grading system encompassing all pathologies occurring in EAU mice was developed to enhance the preclinical evaluation of novel uveitis treatments.
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Caspi, Rachel, Mary Mattapallil, Rachael Rigden, Carlos Zarate-Blades, Phyllis Silver, Dror Luger, and Chi Chao Chan. "Neuroprotective effects of IL-22 during CNS inflammation (CCR4P.203)." Journal of Immunology 194, no. 1_Supplement (May 1, 2015): 118.3. http://dx.doi.org/10.4049/jimmunol.194.supp.118.3.
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Abstract IL-22 has opposing effects in different tissues, from pro-inflammatory (skin, joints) to protective (liver, intestine) but little is known about its effects on neuronal tissue. We examined this using the induced models of experimental autoimmune uveitis (EAU) and experimental autoimmune encephalomyelitis (EAE). During EAU, IL-22 was produced by CD4+ eye-infiltrating cells, most of which co-produced IL-17. IL-22-/- mice immunized for EAU or for EAE had exacerbated disease, as did wild type mice treated with anti-IL-22 systemically or intraocularly during the expression phase of EAU. Retinal glial Müller cells in uveitic eyes had upregulated IL-22rα1 expression. Furthermore, IL-22 upregulated IL-22rα1 on Müller cells in culture and enhanced their ability to suppress effector T cells. Finally, IL-22 injected concurrently with IL-1β into the eye inhibited IL-1-induced expression of multiple proinflammatory and proapoptotic genes in retinal tissue. Our results suggest that IL-22 can function locally within the CNS to ameliorate inflammatory damage and provide neuroprotection by affecting multiple molecular and cellular pathways.
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Giraud, F., C. Chevallier, H. Medion, and R. Fleury. "Bilan hydrologique d'un marais littoral à vocation agricole : Le marais de Moëze (Charente-Maritime, France)." Revue des sciences de l'eau 4, no. 4 (April 12, 2005): 521–42. http://dx.doi.org/10.7202/705114ar.
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En France, les sécheresses consécutives des années 1985, 1986, 1989 et 1990 ont mis en lumière les problèmes relatifs à l'alimentation en eau potable, l'irrigation des terres agricoles et la préservation des écosystèmes aquatiques. Dans le cas des zones humides, continentales et littorales, caractérisées par une compartimentation hydraulique souvent complexe, le manque de connaissance se fait particulièrement sentir. Bien que de nombreux travaux aient permis d'évaluer l'évaporation des masses d'eau et l'évapotranspiration de certaines espèces d'hydrophytes et d'hélophytes, les études débouchant sur des bilans quantitatifs restent peu fréquentes. Le bilan hydrologique du marais de Moëze (2250 ha) a été calculé par décade entre le 11/06/89 et le 31/08/89. Il prend en compte le débit au droit de l'ouvrage d'alimentation, les volumes prélevés pour l'irrigation hors marais, les infiltrations et l'évapotransplration sur les 318 km de canaux. L'estimation de la consommation d'eau des parcelles est globalisée au niveau des mesures d'infiltration. Les pertes par infiltration sont secondaires (9,4 %) au regard des volumes prélevés pour l'irrigation (38,0 %) et évapotransplrés par les canaux (43,7 %) dont 51,1 % uniquement par les 28,6 % des plans d'eau colonisés par Typha latifolia. L'optimisation de la gestion estivale de l'eau d'un marais littoral agricole nécessite dans un premier temps de minimiser les pertes. C'est essentiellement sur la consommation d'eau des canaux colonisés par les hélophytes que l'on peut intervenir. Nous proposons un abaque qui permet d'évaluer l'importance des économies d'eau réalisées en fonction de plusieurs scénarios d'aménagement du réseau hydraulique.
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Liu, Xuebin, Yunsang Lee, Cheng-rong Yu, Phyllis Silver, Rachel Caspi, Gery Igal, and Egwuagu E. Charles. "Loss of STAT3 in CD4+ T cells prevents development of experimental autoimmune uveoretinitis (EAU) and recruitment of pathogenic ThIL17 and Th1 cells into the retina (85.29)." Journal of Immunology 178, no. 1_Supplement (April 1, 2007): S123. http://dx.doi.org/10.4049/jimmunol.178.supp.85.29.
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Abstract ThIL17 cells are implicated in etiology of several inflammatory and autoimmune diseases. Although recent reports have emphasized essential roles of IL-6 and TGF-β1 in promoting commitment of naive CD4+ cells into ThIL17 lineage, their exact roles or contributions to development of ThIL17 cells is not well understood. IL-6 is a pleiotropic cytokine that mediates some of its biological activities through STAT3. In this study we have used a mouse with targeted deletion of STAT3 in CD4+ cells to investigate whether ThIL17 development or their involvement in pathogenic mechanisms of experimental autoimmune uveoretinitis (EAU) requires STAT3. In wild type (WT) mice, EAU is characterized by infiltration into the retina of ThIL17 and Th1 cells that express high levels of VLA-4 and LFA-1. In contrast, STAT3 conditional knockout (STAT3KO) mice do not develop EAU, fail to differentiate into ThIL17 cells, express low levels of VLA-4/LFA-1 integrins and do not enter the eye. Moreover, TGF-β1 and IL-6 or IL-23 are unable to induce naive STAT3KO T cells to differentiate into ThIL17 cells, providing further evidence that STAT3 is indispensable for commitment to the ThIL17 lineage. The requirement of STAT3 for integrin expression and the defective recruitment of IRBP-primed STAT3KO Th1 and ThIL17 cells into the eye during EAU, suggest that STAT3 is a potential target for therapeutic modulation of uveitis and other CNS inflammatory diseases.
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Wu, Sihan, Rui Ma, Yajie Zhong, Zilin Chen, Hongyan Zhou, Minyi Zhou, Waipo Chong, and Jun Chen. "Deficiency of IL-27 Signaling Exacerbates Experimental Autoimmune Uveitis with Elevated Uveitogenic Th1 and Th17 Responses." International Journal of Molecular Sciences 22, no. 14 (July 14, 2021): 7517. http://dx.doi.org/10.3390/ijms22147517.
Full textAbstract:
Human uveitis is an autoimmune disease of the central nervous system that is characterized by ocular inflammation with the involvement of uveitogenic Th1 and Th17 responses. In experimental autoimmune uveitis (EAU), the animal model for human uveitis, both responses are proven to be critical in disease development. Therefore, targeting both Th1 and Th17 cells has therapeutic implication for disease resolution. IL-27 is a multifunctional cytokine that can either promote or inhibit T cell responses and is implicated in both autoimmune and infectious diseases. The aim of this study is to characterize the role of IL-27/IL-27R signaling in regulating uveitogenic Th1/Th17 responses in EAU. By immunizing IL-27Rα−/− mice and their wild-type (WT) littermates for EAU, we demonstrated that IL-27 signaling deficiency exacerbated EAU with severe ocular inflammation and impairment of visual function. Furthermore, there was a significant increase in the eye-infiltrating Th1 and Th17 cells in IL-27Rα−/− EAU mice compared to WT. Their retinal antigen-specific Th1 and Th17 responses were also significantly increased, as represented by the elevation of their signature cytokines, IFN-γ and IL-17A, respectively. We also observed the upregulation of another pathogenic cytokine, granulocyte-macrophage colony-stimulating factor (GM-CSF), from effector T cells in IL-27Rα−/− EAU mice. Mechanistic studies confirmed that IL-27 inhibited GM-CSF production from Th17 cells. In addition, the induction of IL-10 producing type 1 regulatory T (Tr1) cells was impaired in IL-27Rα−/− EAU mice. These results identified that IL-27 signaling plays a suppressive role in EAU by regulating multiple CD4+ cell subsets, including the effector Th1 and Th17 cells and the regulatory Tr1 cells. Our findings provide new insights for therapeutic potential in controlling uveitis by enhancing IL-27 signaling.
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Chong, Wai Po, Reiko Horai, Phyllis Silver, Mary Mattapallil, Jun Chen, and Rachel Caspi. "IL27p28 inhibits induction and expression of experimental autoimmune uveitis by concurrently antagonizing autoaggressive Th1 and Th17 responses. (123.43)." Journal of Immunology 188, no. 1_Supplement (May 1, 2012): 123.43. http://dx.doi.org/10.4049/jimmunol.188.supp.123.43.
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Abstract Human autoimmune uveitis is accompanied by elevated Th1 and Th17 responses. In experimental autoimmune uveitis (EAU) induced in mice with the retinal antigen IRBP, both responses are present and each effector lineage can mediate disease independently. A therapeutic approach that targets both Th1 and Th17 would therefore be attractive. IL27p28 is an antagonist of gp130, which is required for IL-6 and for IL-27 signaling. Since IL-6 and IL 27 promote Th17 and Th1 responses respectively, we hypothesized that IL27p28 would regulate EAU by affecting both responses concurrently. Overexpression of IL27p28 reduced IFN-γ and IL-17A production from eye-infiltrating CD4+ T cells and ameliorated EAU induced by active immunization. Mechanistic studies revealed that IL27p28 suppressed IL6-mediated STAT3 and IL27-mediated STAT1 phosphorylation during Th17 and Th1 polarization, respectively. Furthermore, overexpression of IL27p28 ameliorated EAU induced by passive transfer of uveitogenic effector Th1 or Th17 cells obtained from donors expressing an IRBP-specific TCR. Donor TCR-transgenic T cells recovered from these mice expressed reduced levels of Th17 and Th1 signature cytokines, IL-17A and IFN-γ, and of their corresponding transcription factors, RORγt and Tbet. The ability of IL27p28 to inhibit both Th1 and Th17 responses and to ameliorate not only the induction, but also the effector phase of EAU, bodes well for clinical usefulness of IL27p28 augmentation to control autoimmunity.
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Makabe, Kenichi, Sunao Sugita, Yoko Futatsugi, and Masayo Takahashi. "Dynamics of Cyclooxygenase-1 Positive Microglia/Macrophage in the Retina of Pathological Model Mice as a Biomarker of the Retinal Inflammatory Diseases." International Journal of Molecular Sciences 22, no. 7 (March 25, 2021): 3396. http://dx.doi.org/10.3390/ijms22073396.
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In an intraocular inflammatory state, microglia residing in the retina become active and migrate inside the retina. In this study, we investigated whether cyclooxygenase-1 (COX-1) expressed by retinal microglia/macrophage can be a biomarker for the diagnosis of retinal diseases. COX-1 was immunopositive in microglia/macrophage and neutrophils, while COX-2 was immunopositive in astrocytes and neurons in the inner layer of normal retina. The number of COX-1 positive cells per section of the retinal tissue was 14 ± 2.8 (mean ± standard deviation) in normal mice, which showed significant increase in the lipopolysaccharide (LPS)-administrated model (62 ± 5.0, p = 8.7 × 10−9). In addition to microglia, we found neutrophils that were positive for COX-1. In the early stage of inflammation in the experimental autoimmune uveoretinitis (EAU), COX-1 positive cells, infiltrating from the ciliary body into the retinal outer nuclear layer, were observed. The number of infiltrating COX-1 positive cells correlated with the severity of EAU. Taken together, the increased number of COX-1 positive microglia/macrophage with morphological changes were observed in the retinas of retinal inflammatory disease models. This suggests that COX-1 can be a marker of disease-related activities of microglia/macrophage, which should be useful for the diagnosis of retinal diseases.
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Crabtree, Elizabeth, Katy Uribe, Sara M. Smith, Darby Roberts, Jacklyn H. Salmon, Jacquelyn J. Bower, Liujiang Song, Prabhakar Bastola, Matthew L. Hirsch, and Brian C. Gilger. "Inhibition of experimental autoimmune uveitis by intravitreal AAV-Equine-IL10 gene therapy." PLOS ONE 17, no. 8 (August 18, 2022): e0270972. http://dx.doi.org/10.1371/journal.pone.0270972.
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Equine recurrent uveitis (ERU) is a spontaneous, painful, and vision threatening disease affecting up to 25% of equine populations worldwide. Current treatments of ERU are non-specific and have many side effects which limits them to short-term use. In order to develop an effective therapy for ERU, we investigated the use of adeno-associated virus (AAV) gene therapy, exploiting a natural immune tolerance mechanism induced by equine interleukin-10 (Equine-IL10). The purpose of this study was to evaluate the therapeutic efficacy of a single intravitreal (IVT) dose of AAV8-Equine-IL10 gene therapy for inhibition of experimental autoimmune uveitis (EAU) in rats. Each rat was dosed intravitreally (IVT) in both eyes with either balanced salt solution (BSS) (control; n = 4), AAV8-Equine-IL10 at a low dose (2.4x109 vg; n = 5) or high dose (2.4x1010 vg; n = 5). EAU was induced in all groups of rats 7 days after IVT injections and euthanized 21 days post-injection. Ophthalmic examination and aqueous humor (AH) cell counts were recorded with the observer blinded to the treatment groups. Histopathology and qPCR were performed on selected ocular tissues. Data presented herein demonstrate that AAV8-Equine-IL10 treated rats exhibited a significant decrease in clinical inflammatory scores and AH cell counts compared to BSS-treated EAU eyes on days 10, 12 and 14 post EAU induction at both administered vector doses. Mean cellular histologic infiltrative scores were also significantly less in AAV8-Equine-IL10 dosed rats compared to the BSS group. Intravitreal injection of AAV8-Equine-IL10 resulted in Equine-IL10 cDNA expression in the ciliary body, retina, cornea, and optic nerve in a dose-dependent manner. A single IVT injection of AAV8-Equine-IL10 appeared to be well-tolerated and inhibited EAU even at the lowest administered dose. These results demonstrate safety and efficacy of AAV8-Equine-IL10 to prevent EAU and support continued exploration of AAV gene therapy for the treatment of equine and perhaps human recurrent uveitis.
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Bing, So Jin, Itay Shemesh, Wai Po Chong, Yingyos Jittayasothorn, Phyllis B. Silver, Benjamin Sredni, and Rachel R. Caspi. "AS101 ameliorates experimental autoimmune uveitis by regulating Th1 and Th17 responses and inducing Treg cells." Journal of Immunology 202, no. 1_Supplement (May 1, 2019): 193.1. http://dx.doi.org/10.4049/jimmunol.202.supp.193.1.
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Abstract AS101 is an organotellurium compound with multifaceted immunoregulatory properties that is remarkable for its lack of toxicity. We tested the therapeutic effect of AS101 in experimental autoimmune uveitis (EAU), a model for human autoimmune uveitis. Unexpectedly, treatment with AS101 elicited Treg generation in vivo in otherwise unmanipulated mice. Mice immunized for EAU with the retinal antigen IRBP and treated with AS101 developed attenuated disease, as did recipients of retina-specific T cells activated in vitro in the presence of AS101. In both settings, eye-infiltrating effector T cells were decreased, whereas regulatory T (Treg) cells in the spleen were increased. Mechanistic studies in vitro revealed that AS101 restricted polarization of retina-specific T cells towards Th1 or Th17 lineage by repressing activation of their respective lineage-specific transcription factors and downstream signals. Retina-specific T cells polarized in vitro towards Th1 or Th17 in the presence of AS101 had impaired ability to induce EAU in naïve recipients. Finally, AS101 promoted differentiation of retina-specific T cells to Tregs in vitro independently of TGF-β. We conclude that AS101 modulates autoimmune T cells by inhibiting acquisition and expression of effector function and by promoting Treg generation, and suggest that AS101 could be useful as a therapeutic approach for autoimmune uveitis.
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Xu, Linxinyu, Tianshu Yang, Shaobo Su, and Fang Wang. "2-Methoxyestradiol Alleviates Experimental Autoimmune Uveitis by Inhibiting Lymphocytes Proliferation and T Cell Differentiation." BioMed Research International 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/7948345.
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Purpose. To investigate the effect of 2-Methoxyestradiol (2ME2) on experimental autoimmune uveitis (EAU) and the mechanism.Method. C57BL/6 male mice were used to establish the EAU model. 2ME2 was abdominal administrated in D0–D13, D0–D6, and D7–D13 and control group was given vehicle from D0–D13. At D14, pathological severity was scored. Lymphocyte reaction was measured using MTT assay. T cell differentiation in draining lymph nodes and eye-infiltrating cells was tested by flow cytometry. Proinflammatory cytokines production from lymphocytes was determined by ELISA.Result. The disease scores from 2ME2 D0–D13, 2ME2 D0–D6, 2ME2 D7–D13, and vehicle groups were0.20±0.12,1.42±0.24,2.25±0.32, and2.42±0.24. Cells from all 2ME2 treated groups responded weaker than control (p<0.05). The inhibitory effect of 2ME2 on lymphocyte proliferation attenuated from 2ME2 D0–D13 to 2ME2 D0–D6 and to 2ME2 D7–D13 groups (p<0.05). 2ME2 treated mice developed fewer Th1 and Th17 cells both in draining lymph nodes and in eyes than control (p<0.05). Lymphocytes from 2ME2 group secreted less IFN-γand IL-17A than those from control (p<0.05).Conclusion. 2ME2 ameliorated EAU progression and presented a better effect at priming phase. The possible mechanism could be the inhibitory impact on IRBP specific lymphocyte proliferation and Th1 and Th17 cell differentiation.
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Hoey, S., P. S. Grabowski, S. H. Ralston, J. V. Forrester, and J. Liversidge. "Nitric oxide accelerates the onset and increases the severity of experimental autoimmune uveoretinitis through an IFN-gamma-dependent mechanism." Journal of Immunology 159, no. 10 (November 15, 1997): 5132–42. http://dx.doi.org/10.4049/jimmunol.159.10.5132.
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Abstract The production of large amounts of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) has been described as a double-edged sword eliciting pro- or anti-inflammatory effects in different immune situations. Our aim, therefore, was to investigate its role in experimental autoimmune uveoretinitis (EAU), a model of ocular inflammation, induced in the Lewis rat following a single footpad injection of retinal Ags. iNOS enzyme was not detected in the normal Lewis rat eye, but was strongly expressed by infiltrating ED1+ macrophages during the acute inflammatory stages of EAU. Treating immunized animals with L-arginine increased urinary NO metabolite (NOx) levels, accelerated the inflammatory response, and increased disease severity, whereas treatment with the NOS inhibitor, N(G)-nitro-L-arginine methyl ester, reduced NOx excretion, delayed the onset, and reduced the clinical signs of EAU. Reverse transcription-PCR analysis of ocular tissue from untreated and treated animals detected iNOS mRNA at all stages of disease, and expression was up-regulated during peak disease. L-arginine treatment enhanced cytokine mRNA expression, particularly of IFN-gamma, which was detected earlier than in control animals, corresponding with the more rapid onset of disease and increased disease severity observed in this group. N(G)-nitro-L-arginine methyl ester had little or no effect on iNOS or inflammatory cytokine mRNA expression. These results suggest NO is central to the pathogenesis of EAU and highlight the importance of the macrophage as an effector cell in what is considered a CD4+ T cell-dependent disease. Furthermore, this study demonstrates the therapeutic potential of NOS inhibitors in the treatment of inflammatory and autoimmune mediated disease.
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Zhang, Xuan, Cuiping Hu, Yajie Zhong, Dijie Qiao, Wei Chi, Huangxuan Shen, and Waipo Chong. "Multifunctional Interleukin-24 Resolves Neuroretina Autoimmunity via Diverse Mechanisms." International Journal of Molecular Sciences 23, no. 19 (October 9, 2022): 11988. http://dx.doi.org/10.3390/ijms231911988.
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IL-24 is a multifunctional cytokine that regulates both immune cells and epithelial cells. Although its elevation is associated with a number of autoimmune diseases, its tolerogenic properties against autoreactive T cells have recently been revealed in an animal model of central nervous system (CNS) autoimmunity by inhibiting the pathogenic Th17 response. To explore the potential of IL-24 as a therapeutic agent in CNS autoimmunity, we induced experimental autoimmune uveitis (EAU) in wildtype mice and intravitreally injected IL-24 into the inflamed eye after disease onset. We found that the progression of ocular inflammation was significantly inhibited in the IL-24-treated eye when compared to the control eye. More importantly, IL-24 treatment suppressed cytokine production from ocular-infiltrating, pathogenic Th1 and Th17 cells. In vitro experiments confirmed that IL-24 suppressed both Th1 and Th17 differentiation by regulating their master transcription factors T-bet and RORγt, respectively. In addition, we found that intravitreal injection of IL-24 suppressed the production of proinflammatory cytokines and chemokines from the retinas of the EAU-inflamed eyes. This observation appears to be applicable in humans, as IL-24 similarly inhibits human retinal pigment epithelium cells ARPE-19. In conclusion, we report here that IL-24, as a multifunctional cytokine, is capable of resolving ocular inflammation in EAU mice by targeting both uveitogenic T cells and RPE cells. This study sheds new light on IL-24 as a potential therapeutic candidate for autoimmune uveitis.
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Ridley, Raela B., Brianna M. Young, Jieun Lee, Erin Walsh, Chulbul M. Ahmed, Alfred S. Lewin, and Cristhian J. Ildefonso. "AAV Mediated Delivery of Myxoma Virus M013 Gene Protects the Retina against Autoimmune Uveitis." Journal of Clinical Medicine 8, no. 12 (November 29, 2019): 2082. http://dx.doi.org/10.3390/jcm8122082.
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Uveoretinitis is an ocular autoimmune disease caused by the activation of autoreactive T- cells targeting retinal antigens. The myxoma M013 gene is known to block NF-κB (Nuclear Factor kappa-light-chain-enhancer of activated B cells) and inflammasome activation, and its gene delivery has been demonstrated to protect the retina against lipopolysaccharide (LPS)-induced uveitis. In this report we tested the efficacy of M013 in an experimental autoimmune uveoretinitis (EAU) mouse model. B10RIII mice were injected intravitreally with AAV (adeno associated virus) vectors delivering either secreted GFP (sGFP) or sGFP-TatM013. Mice were immunized with interphotorecptor retinoid binding protein residues 161–180 (IRBP161–180) peptide in complete Freund’s adjuvant a month later. Mice were evaluated by fundoscopy and spectral domain optical coherence tomography (SD-OCT) at 14 days post immunization. Eyes were evaluated by histology and retina gene expression changes were measured by reverse transcribed quantitative PCR (RT-qPCR). No significant difference in ERG or retina layer thickness was observed between sGFP and sGFP-TatM013 treated non-uveitic mice, indicating safety of the vector. In EAU mice, expression of sGFP-TatM013 strongly lowered the clinical score and number of infiltrative cells within the vitreous humor when compared to sGFP treated eyes. Retina structure was protected, and pro-inflammatory genes expression was significantly decreased. These results indicate that gene delivery of myxoma M013 could be of clinical benefit against autoimmune diseases.
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Gellens, D., and B. Schädler. "Comparaison des réponses du bilan hydrique de bassins situés en Belgique et en Suisse à un changement de climat." Revue des sciences de l'eau 10, no. 3 (April 12, 2005): 395–414. http://dx.doi.org/10.7202/705286ar.
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Les impacts possibles d'un changement de climat induit par l'augmentation de la concentration des gaz à effet de serre sur le bilan hydrique ont été simulés sur un ensemble de bassins hydrographiques situés en Belgique et en Suisse. Le modèle hydrologique conceptuel IRMB à pas de temps journalier a été utilisé à cette fin et les paramètres du modèle ont été optimisés sur chaque bassin. Les bassins ont une taille comprise entre 100 km2 et 1200 km2 et couvrent des régions de plaine aussi bien que de moyenne montagne. Un même scénario climatique a été adopté pour tous les bassins. Il est principalement caractérisé par une augmentation de la température de près de 3·C et par une légère augmentation des précipitations annuelles. Cette méthodologie a été adoptée afin de montrer les sensibilités respectives des différents termes du bilan hydrique et de les mettre en rapport avec les caractéristiques des bassins étudiés. L'étude s'est focalisée sur l'évolution de l'évapotranspiration et de l'humidité du sol, de l'enneigement, des débits à l'exutoire et des réserves en eau souterraine. Les impacts sont également abordés en termes d'événements extrêmes. Outre des évolutions qui sont prévisibles pour l'ensemble des bassins étudiés, telles une augmentation de l'évapotranspiration, une diminution légère de l'humidité du sol et une réduction de l'enneigement, les réponses de certains termes du bilan hydrique régis par les caractéristiques du sous-sol des bassins peuvent être sensiblement différentes d'une région à une autre. Ainsi, les bassins caractérisés par une infiltration importante subiraient une évolution favorable de leurs réserves en eau souterraine et des débits de base, alors que les bassins où le ruissellement de surface prédomine verraient une diminution se produire. L'altitude des bassins semble aussi jouer un rôle non négligeable. Tous les bassins de plaine présenteraient une augmentation des débits de crues extrêmes, alors que les bassins de moyenne montagne ne subiraient pour ainsi dire pas ces conséquences négatives.
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Giulianelli, Roberto, Barbara Cristina Gentile, Gabriella Mirabile, Luca Albanesi, Paola Tariciotti, Giorgio Rizzo, Maurizio Buscarini, and Mauro Vermiglio. "Can re-cTURBT be useful in pT1HG disease as a risk indicator of recurrence and progression? A single centre experience." Archivio Italiano di Urologia e Andrologia 89, no. 4 (December 31, 2017): 272. http://dx.doi.org/10.4081/aiua.2017.4.272.
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Introduction: Understaging after initial transurethral resection is common in patients with high-risk non muscle infiltrating bladder cancer (NMIBC) and can delay accurate diagnosis and definitive treatment. The rate of upstaging from T1 to T2 disease after repeated transurethral resection ranges from 0 to 28%, although the rate of upstaging may be even higher up to 49% when muscularis propria is absent in the first specimen. A restaging classic transurethral resection of bladder tumour (re-cTURBT) is the better predictor of early stage progression. According to some reports, the rate of positivity for tumor in re-cTURBT performed within eight weeks after initial cTURBT was as high as 18-77%, and in about 40% of the patients a change in tumor stage was reported. We aimed to investigate, in high risk group, the presence of residual tumor following white light classical transurethral resection of bladder tumor (WLre-cTURBT) and the different recurrence and progression rate between patients with persistent or negative (pT0) oncological disease after WLre-cTURBT. Materials and methods: A cohort of 285 patients presenting with primitive bladder cancer underwent to WLcTURBT from January 2011 to December 2015; out of them 92 (32.28%) were T1HG. In according to EAU guidelines 2011, after 4-6 weeks all HG bladder cancer patients underwent a WL recTURBT . All patients were submitted to a subsequent followup including cystoscopy every 3 months with multiple biopsies, randomly and in the previous zone of resection; urinary citology on 3 specimens and kidney/bladder ultrasound every 6 months. The average follow-up was 48 months. Results: Following WLre-cTURBT we observed a persistent disease in 18 (15.2%) patients: 14 (77.7%) with a HG-NMIBC and 4 (22.2%) with a high grade (HG) muscle invasive bladder cancer (pT2HG). After follow up of all 92 patients according to the guidelines EAU, we observed recurrence in 36/92 (39.1%) and progression in 14/92 (15.2%). Of 14 NMIBC with persistent disease, 10 patients (71.4%) showed recurrence: 4 patients (40%) were pT1HG with concomitant carcinoma in situ (CIS), 3 patients (30%) multifocal pTaHG, 2 (20%) patients CIS and one patient (10%) a muscle invasive neoplasm (pT2HG). Instead of the group of 48 patients pT0 following WL recTURBT, we observed recurrence in 26 patients (54.1%) and in two patients (4.1%) progressions, who presented after 3 months in association with CIS. The remaining 22 patients (45.9%) with initial pT1HG are still progression free. Multivariate analysis showed that the most important variable of early progression were persistent neoplasm and histopathological findings at WLre-cTURBt (p = 0.01), followed by the Summary No conflict of interest declared. INTRODUCTION Bladder cancer is a common genito-urinary malignancy, with transitional cell carcinoma comprising nearly 90% of all primary bladder tumours. At the first diagnosis 70% to 80% of urothelial tumours are confined to the epithelium, the remainder is characterized by muscle invasion. A significant number of patients with high risk non-muscle invasive bladder tumours (HG-NMIBT) treated with white light classic transurethral resection of bladder tumours (WLcTURBT) and intravesical BCG will progress to invasive disease (1-3). Progression to muscle invasion (pT2) mandates immediate radical cystectomy (4). WLcTURBT is the standard initial therapy for NMIBT, but the high percentage of recurrence after surgery is still an unresolved problem (5). High grade pT1 bladder neoplasm (pT1HG) really represents a therapeutic challenge due to the high risk of progression (about 15-30%) to muscle-invasive disease, usually within 5 years (6). However, no consensus exists regarding the treatment of patients with recurrent bladder tumours that invade the lamina propria (pT1) (7-9). Recent studies suggested that the first cTURBT may be incomplete in a significant number of cases (10). Understaging at the time of the initial transurethral resection is common for patients with high-risk NMIBC and can delay accurate diagnosis and definitive treatment. It is therefore recommended for patients with high-risk disease and in those with large or multiple tumors or when the initial transurethral resection is incomplete, to repeat WLre-cTURBT within 2-6 DOI: 10.4081/aiua.2017.4.272 result of the first cystoscopy (p = 0.002) and presence of CIS (p = 0.02). Discussion: Following WLre-cTURBt in HG-NMIBC patients we identified in 15% of cases a persistent disease with a 4.3% of MIBC. In the high risk persistent bladder neoplasms group we observed recurrent and progression rate higher than in T0 bladder tumours group (Δ = + 17.3% and = Δ + 62.5%, p < 0.05
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Gnissien, Moussa, Kalifa Coulibaly, Moussa Barro, Jean-Marie Douzet, Laurent Cournac, Harun Cicek, and Hassan B. Nacro. "Effets longue-durée de différentes densités de <i>Piliostigma reticulatum</i> (DC) Hochst sur le stockage et la dynamique du carbone et de l’eau dans un Plinthosol épipétrique en zone nord-soudanienne du Burkina Faso." International Journal of Biological and Chemical Sciences 17, no. 3 (August 24, 2023): 1220–36. http://dx.doi.org/10.4314/ijbcs.v17i3.36.
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L’agroforesterie demeure l’une des stratégies d’amélioration de la fertilité des sols les plus accessibles aux producteurs des pays sahéliens. L’objectif de nos travaux était de déterminer les effets de densités de Piliostigma reticulatum suivant deux types de travail du sol sur le statut et la dynamique du carbone organique et de l’eau du sol en zone nord-soudanienne du Burkina Faso. Le dispositif expérimental est constitué de blocs de Fisher à deux facteurs (travail du sol et densité d’arbustes) comprenant huit traitements et quatre répétitions. Sur la profondeur 0-10 cm, le stock de carbone augmentait de 20,45% et 26,29% respectivement pour les densités de 1000 et 2000 pieds / ha comparativement à celle de 0 pieds / ha en zaï ; et de 38,59% et 57,34% pour la densité de 2000 pieds / ha respectivement en système de culture (SC) et en mise en défends comparativement à celle de 500 pieds / ha en semis direct (SD). Sur la même profondeur, la réserve utile en eau du sol a été plus élevée avec 2000 pieds / ha (13,05 ± 0,66 mm) en zaï, et avec 500 pieds / ha (11,05 ± 1,13 mm) en SD. Le rapport carbone labile sur carbone organique est plus faible sur la couche 0-10 cm (9% à 12%) que sur 20-30 cm (49% à 72%) en présence d’arbustes. La vitesse d’infiltration augmentait de 54,20% et 31% respectivement pour les densités de 1000 et 2000 pieds / ha comparativement à celle de 0 pieds / ha en zaï ; et de 140,32 et 232,23% respectivement pour la densité de 2000 pieds / ha sous SC et sous jachère comparativement à la densité de 500 pieds / ha en SD. Globalement, les densités de 1000 et 2000 pieds / ha améliorent le plus le stockage du carbone, de l’eau et la perméabilité du sol. Le zaï et le SD bien qu’ayant des effets similaires sur le stockage des deux pools de carbone, se distinguent par le fait que le zaï semble plus améliorer le stockage de l’eau alors que le SD améliore plus la perméabilité du sol.
English title: Long term effects of Piliostigma reticulatum (DC) Hochst’ densities on carbon and water storage and dynamics of an epipetal Plinthosol in Burkina Faso’s northern Sudanian area
Agroforestry remains one of the most accessible soil fertility improvement strategies for farmers in Sahelian countries. The objective of our work was to determine the effects of different planting densities of Piliostigma reticulatum, evolving on two tillages, on the status and dynamics of soil organic carbon and water in Burkina Faso’s northern Sudanian. The experimental design is a two-factor Fisher block design (tillage and shrub density) with eight treatments and four replications. At a depth of 0-10 cm, carbon stock increased by 20.45% and 26.29% respectively for the 1000 and 2000 shrubs / ha compared to 0 shrubs / ha in zaï; and by 38.59% and 57.34% for the 2000 shrubs / ha respectively in cropping system (CS) and in fallow compared to the 500 shrubs / ha density in no-till (NT). Over the same depth, the useful soil water holding capacity was higher with 2000 shrubs / ha (13.05 ± 0.66 mm) in zaï, and with 500 shrubs / ha (11.05 ± 1.13 mm) in NT. The ratio of labile carbon to organic carbon was lower on the 0-10 cm layer (9% to 12%) than on the 20-30 cm layer (49% to 72%) in the presence of shrubs. Infiltration rate increased by 54.20% and 31% respectively for 1000 and 2000 shrubs / ha densities compared to 0 shrubs / ha in zaï; and by 140.32 and 232.23% respectively for 2000 shrubs / ha density under CS and fallow compared to 500 shrubs / ha density in NT. Overall, the densities of 1000 and 2000 shrubs / ha improve the most carbon storage, water storage and soil permeability. Zaï and NT, while having similar effects on the storage of both carbon pools, differ in that zaï seems to improve water storage more while NT improves soil permeability more.
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Remini, Boualem, Bachir Achour, and Rabah Kechad. "La foggara en Algérie : un patrimoine hydraulique mondial." 23, no. 2 (June 7, 2010): 105–17. http://dx.doi.org/10.7202/039903ar.
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Localisée dans les régions arides, la foggara en Algérie, le qanat en Iran, la khettara au Maroc et le falj au sultanat d’Oman constituent des procédés d’acquisition et de distribution d’eau, basé sur des galeries horizontales drainantes. Cependant, ces techniques traditionnelles, si elles présentent des similitudes au niveau du système de captage (galeries et puits), montrent des différences au niveau de la source de captage et de la technique de partage de l’eau. À travers cette étude, basée sur des sorties de prospection dans cinq oasis du Sahara algérien et des enquêtes menées au niveau des oasiens, on a pu recenser sept types de foggaras. Il s’agit de foggaras qui captent les eaux de la nappe phréatique au pied d’un djebel ou de la nappe du Continental Intercalaire, d’une source de la nappe du Grand Erg Occidental, de drainage et des infiltrations, et enfin, uniquement les eaux de crues (foggara de Mzab) ou drainent les eaux des oueds.
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Zhu, Lei, He Li, Xuening Peng, Zhaohuai Li, Sichen Zhao, Dongting Wu, Jialing Chen, et al. "Beneficial mechanisms of dimethyl fumarate in autoimmune uveitis: insights from single-cell RNA sequencing." Journal of Neuroinflammation 21, no. 1 (April 29, 2024). http://dx.doi.org/10.1186/s12974-024-03096-6.
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Abstract Background Dimethyl fumarate (DMF) is a fumaric acid ester that exhibits immunoregulatory and anti-inflammatory properties. However, the function of DMF in autoimmune uveitis (AU) is incompletely understood, and studies comprehensively exploring the impact of DMF on immune cells are still lacking. Methods To explore the function of DMF in uveitis and its underlying mechanisms, we conducted single-cell RNA sequencing (scRNA-seq) on the cervical draining lymph node (CDLN) cells of normal, experimental autoimmune uveitis (EAU), and DMF-treated EAU mice. Additionally, we integrated scRNA-seq data of the retina and CDLNs to identify the potential impact of DMF on ocular immune cell infiltration. Flow cytometry was conducted to verify the potential target molecules of DMF. Results Our study showed that DMF treatment effectively ameliorated EAU symptoms. The proportional and transcriptional alterations in each immune cell type during EAU were reversed by DMF treatment. Bioinformatics analysis in our study indicated that the enhanced expression of Pim1 and Cxcr4 in EAU was reversed by DMF treatment. Further experiments demonstrated that DMF restored the balance between effector T (Teff) /regulatory T (Treg) cells through inhibiting the pathway of PIM1-protein kinase B (AKT)-Forkhead box O1 (FOXO1). By incorporating the scRNA-seq data of the retina from EAU mice into analysis, our study identified that T cells highly expressing Pim1 and Cxcr4 were enriched in the retina. DMF repressed the ocular infiltration of Teff cells, and this effect might depend on its inhibition of PIM1 and CXCR4 expression. Additionally, our study indicated that DMF might reduce the proportion of plasma cells by inhibiting PIM1 expression in B cells. Conclusions DMF effectively attenuated EAU symptoms. During EAU, DMF reversed the Teff/Treg cell imbalance and suppressed the ocular infiltration of Teff cells by inhibiting PIM1 and CXCR4 expression. Thus, DMF may act as a new drug option for the treatment of AU.
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Peters, Kayleigh, Trisha McDonald, Fauziyya Muhammad, Adrien Brady, John Dostal, and Darren J. Lee. "TIGIT Stimulation Suppresses Autoimmune Uveitis by Inhibiting Th17 Cell Infiltration." Journal of Leukocyte Biology, May 24, 2024. http://dx.doi.org/10.1093/jleuko/qiae116.
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Abstract T cell immunoglobulin and ITIM domain (TIGIT) is an immune checkpoint molecule that suppresses T cell activation and promotes an immunosuppressive environment to suppress autoimmune diseases. However, the impact of a TIGIT agonist as a treatment for ocular autoimmune disease has not been investigated. We examined TIGIT expression on Th17 and Treg cells, the role of TIGIT on experimental autoimmune uveitis (EAU) and Th17 cells, and the impact of Treg generation following TIGIT stimulation. TIGIT stimulation at the onset of clinical symptoms reduced the severity of uveitis and suppressed infiltration of Th17 cells into the eye. Further, Tregs from mice treated with the TIGIT agonist were capable of suppressing EAU in recipient mice. This report demonstrates that stimulation of TIGIT at onset of disease suppresses symptoms and allows for induction of regulatory immunity that provides resistance to uveitis.
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Hu, Kaijiao, Longbao Lv, Hui Huang, Guangnian Yin, Jie Gao, Jianping Liu, Yaying Yang, et al. "A Novel Tree Shrew Model of Chronic Experimental Autoimmune Uveitis and Its Disruptive Application." Frontiers in Immunology 13 (May 27, 2022). http://dx.doi.org/10.3389/fimmu.2022.889596.
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BackgroundPrevious studies have established several animal models for experimental autoimmune uveitis (EAU) in rodents without the fovea centralis in the human retina. This study aimed to develop and explore the application of a novel EAU model in tree shrews with a cone-dominated retina resembling the human fovea.MethodsTree shrews were clinically and pathologically evaluated for the development and characteristics of EAU immunized with six inter-photoreceptor retinoid-binding proteins (IRBPs). IRBP-specific T-cell proliferation and serum cytokine of tree shrews were evaluated to determine the immune responses. Differentially expressed genes (DEGs) were identified in the eyes of tree shrews with EAU by RNA-sequencing. The disruptive effects of the DEG RGS4 inhibitor CCG 203769 and dihydroartemisinin on the EAU were investigated to evaluate the potential application of tree shrew EAU.ResultsIRBP1197–1211 and R14 successfully induced chronic EAU with subretinal deposits and retinal damage in the tree shrews. The immunological characteristics presented the predominant infiltration of microglia/macrophages, dendritic cells, and CD4-T-cells into the uvea and retina and pathogenic T helper (Th) 1 and Th17 responses. The subretinal deposits positively expressed amyloid β-protein (Aβ), CD8, and P2Y purinoceptor 12 (P2RY12). The crucial DEGs in R14-induced EAU, such as P2RY2 and adenylate cyclase 4 (ADCY4), were enriched for several pathways, including inflammatory mediator regulation of transient receptor potential (TRP) channels. The upregulated RGS4 in IRBP-induced EAU was associated with mitogen-activated protein kinase (MAPK) activity. RGS4 inhibition and dihydroartemisinin could significantly alleviate the retinal pathological injuries of IRBP1197-1211-induced EAU by decreasing the expression of CD4 T-cells.ConclusionOur study provides a novel chronic EAU in tree shrews elicited by bovine R14 and tree shrew IRBP1197-1211 characterized by retinal degeneration, retinal damage with subretinal Aβ deposits and microglia/macrophage infiltration, and T-cell response, probably by altering important pathways and genes related to bacterial invasion, inflammatory pain, microglial phagocytosis, and lipid and glucose metabolism. The findings advance the knowledge of the pathogenesis and therapeutics of the fovea-involved visual disturbance in human uveitis.
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Skrlova, Eva, Eva Uherkova, Katerina Palacka, Barbora Hermankova, Vladimir Holan, and Jarmila Heissigerová. "Intravitreal application of stem cells and their products does not ameliorate experimental autoimmune uveitis." Acta Ophthalmologica 102, S279 (January 2024). http://dx.doi.org/10.1111/aos.16257.
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Aims/Purpose: Stem cell therapy has demonstrated potential therapeutic benefits in various medical disciplines. This study evaluated therapeutic effects of mesenchymal stem cells (MSCs) or their by‐products on intraocular inflammation in experimental autoimmune uveitis (EAU) model.Methods: EAU was induced in C57BL/6J mouse strain through administration of IRBP, Freund's adjuvant and pertussis toxin. Conditioned medium was procured through cultivation of MSCs in serum‐free medium, while MSC supernatant was obtained via MSC centrifugation and membrane removal. Either conditioned medium or MSC supernatant was intravitreally administered unilaterally, typically on day 14 post‐EAU induction. Ocular fundus of mice was documented regularly. Experiments were generally concluded on day 28, with eyes processed for FACS and PCR analysis. Infiltration of retina by inflammatory cells (F4/80, CD11c, CD45, CD80, CD86, CD206) and gene expression of pro‐inflammatory factors (Gfap, Iba‐1, IL‐1, iNOS) were quantified.Results: Across all experiments, clinical grading, FACS, and PCR analysis indicated exacerbation of intraocular inflammation. Post‐intravitreal administration of MSC by‐products into eyes with EAU, increased infiltration of retina by inflammatory cells and upregulation in gene expression of pro‐inflammatory factors were observed. These findings were corroborated in vitro, where co‐culturing of retina with EAU in presence of MSCs or their supernatant did not significantly reduce gene expression of pro‐inflammatory factors. Upsurge in pro‐inflammatory factors was also noted in control experiments on healthy eyes post‐intravitreal injection of no substance, serum‐free medium, PBS, or conditioned medium.Conclusions: No improvement in EAU was observed following application of MSC products, both in vivo and in vitro. Instead, inflammation was more severe. Trauma induced by intravitreal application itself significantly influenced outcome.Financial support: GA UK 309621, SVV UK 260631.