Academic literature on the topic 'Cellule multi-Passages'

Chronic Hepatitis C virus (HCV) infection still constitutes a major global health problem with almost half a million deaths per year. To date, the human hepatoma cell line Huh7 and its derivatives is the only cell line that robustly replicates HCV. However, even different subclones and passages of this single cell line exhibit tremendous differences in HCV replication efficiency. By comparative gene expression profiling using a multi-pronged correlation analysis across eight different Huh7 variants, we identified 34 candidate host factors possibly affecting HCV permissiveness. For seven of the candidates, we could show by knock-down studies their implication in HCV replication. Notably, for at least four of them, we furthermore found that overexpression boosted HCV replication in lowly permissive Huh7 cells, most prominently for the histone-binding transcriptional repressor THAP7 and the nuclear receptor NR0B2. For NR0B2, our results suggest a finely balanced expression optimum reached in highly permissive Huh7 cells, with even higher levels leading to a nearly complete breakdown of HCV replication, likely due to a dysregulation of bile acid and cholesterol metabolism. Our unbiased expression-profiling approach, hence, led to the identification of four host cellular genes that contribute to HCV permissiveness in Huh7 cells. These findings add to an improved understanding of the molecular underpinnings of the strict host cell tropism of HCV.

Abstract Background: Mesenchymal Stem Cells (MSC) can be isolated from bone marrow, adipose and fetal tissues, but their presence in Mobilized Peripheral Blood (MPB) and in Umbilical Cord Blood (UCB) remains controversial. Methods: In this study we evaluated whether MPB (n=6) and UCB (n=8) could be two other sources of MSC beside Bone Marrow (BM). CD133 positive cell fraction was isolated through immunomagnetic system and MNC were seeded in medium supplemented or not with 5% of conditioned medium durong the first 48 hours of adhesion. MSC derived from MPB or UCB were identified by their expression of mesenchymal (SH2, SH3) and hematopoietic markers (CD14, CD34, CD45 and CD62-E). MPB and CB-MSC were also tested for their capacity to generate CFU-F (Fibroblast colony-forming units) and to differentiate into adipocytes, osteocytes, chondrocytes and neuronal/glial cells after specific induction. Finally we tested through RT-PCR the gene expression of Oct4, a transcriptional binding factor present in undifferentiated cells with high proliferative capacity. Results: Through CFU-F, we observed that the selection of CD133 positive cells allows to obtain a great amount of MSC in comparison with the MNC fraction seeded (MPB-MSC, 139 versus 72 and UCB-MSC 165 versus 8 after the primoculture). After four passages, more than 1.108 cells were obtained by the cell expansion assays from 1.106 cells seeded in primoculture. During the first culture, whatever the medium used or cell fraction seeded, the cell population was composed of osteoblasts, osteoclasts, marcophages and hematopoietic cells with less than 5%SH3 positive cells. After two passages, cells derived from MPB or UCB expressed mesenchymal markers (SH3 and SH2) and Oct4. Under appropriate conditions these cells were able to differentiate into adipocytes, osteocytes, chondrocytes and neuronal/glial cells. Conclusion: These results indicate that MSC are present in MPB and UCB, with similar characteristics to bone marrow (self-renewal capacity and multi-diffentiation potential), and may have a major clinical importance due to their accessibility. They could be an attractive target for cellular and gene therapies Mesenchymal marker expression (%) T0 (%) second passage (%) MPB SH2 2,7±1,1 96,1±2,9 SH3 4,9±1,5 95,7±3,3 UCB SH2 1,4±0,6 98±0,7 SH3 5,2±1,8 96,5±2,5

Cultivated meat is a fast-growing research field and an industry with great potential to overcome the limitations of traditional meat production. Cultivated meat utilizes cell culture and tissue engineering technologies to culture a vast number of cells in vitro and grow/assemble them into structures mimicking the muscle tissues of livestock animals. Stem cells with self-renewal and lineage-specific differentiation abilities have been considered one of the key cell sources for cultivated meats. However, the extensive in vitro culturing/expansion of stem cells results in a reduction in their abilities to proliferate and differentiate. Extracellular matrix (ECM) has been used as a culturing substrate to support cell expansion for cell-based therapies in regenerative medicine due to its resemblance to the native microenvironment of cells. In this study, the effect of the ECM on the expansion of bovine umbilical cord stromal cells (BUSC) in vitro was evaluated and characterized. BUSCs with multi-lineage differentiation potentials were isolated from bovine placental tissue. Decellularized ECM prepared from a confluent monolayer of bovine fibroblasts (BF) is free of cellular components but contains major ECM proteins such as fibronectin and type I collagen and ECM-associated growth factors. Expansion of BUSC on ECM for three passages (around three weeks) resulted in about 500-fold amplification, while cells were amplified less than 10-fold when cultured on standard tissue culture plates (TCP). Moreover, the presence of ECM reduced the requirement for serum in the culture medium. Importantly, the cells amplified on ECM retained their differentiation abilities better than cells cultured on TCP. The results of our study support the notion that monolayer cell-derived ECM may be a strategy to expand bovine cells in vitro effectively and efficiently.

Abstract Mesenchymal stem cells (MSC) are multipotent cells that are considered one of the most promising product for cellular therapy in regenerative medicine. MSC have been obtained and expanded from bone marrow and umbilical cord blood in adequate amounts for clinical applications. Under the right conditions, MSC could migrate from bone marrow into the peripheral circulation; however MSC have not been routinely isolated from peripheral blood, and studies are rare and not conclusive. The aim of the present study was to evaluate mobilised peripheral blood (MPB), obtained from patients undergoing apheresis collection of circulating hematopoietic progenitor cells, as a potential source of MSC for clinical applications. MPB samples (500–900 × 106 cells, N = 17) were separated by negative lineage-depletion immunoselection (RosetteSep). Selected cells were seeded in multi-well plates at low density in MesenCult Basal Medium without and with different combinations of growth factors (EGF, PDGF-BB, b-FGF). On reaching confluence, adherent cells were detached by 0.25% trypsin-EDTA treatment and replated for at least two passages. At each passage, surface antigen expression was analyzed by flowcytometry (CD45, CD34, CD105, CD44, CD73, CD166, CD31, HLA-DR and VE-caderine). Following immunoselection 9.5–17.1 × 106 cells were recovered from MPB samples. Cultured cells reached confluency in 3–4 weeks on first passage and in two weeks thereafter. Immunophenotyping showed negativity for CD45 antigen. The absence of growth factors in culture medium conditioned MSC growth capability, while the addition of PDGF-BB+EGF or b-FGF was able to boost the number of CD45−/CD73+/CD90+ cells in culture (see figure). However expansion remains still sub-optimal, having been reached in 8/17 samples. In conclusion, we demonstrate that MSC can be obtained from MPB, but expansion requires longer time period and appears more difficult compared to bone marrow. Therefore, further studies need to be conducted to find better culture conditions and optimal growth factor combinations to support MPB-derived MSC expansion. Figure Figure

Abstract Pancreatic Ductal Adenocarcinoma (PDAC) is a lethal disease with a five-year survival rate of 11%. PDAC develops from pancreatic precursor lesions, including intraductal papillary mucinous neoplasm (IPMN); studying these lesions is important to understand the multi-step process of pancreatic tumorigenesis. Development of model systems and associated tools is a critical step that is 1) scientifically necessary to understand IPMN biology and 2) clinically important for improving patient outcome. To date, only one patient-derived IPMN cell line that grows in a monolayer has been reported, illustrating the challenges of growing precancerous cells in this format. While protocols have previously been established to generate patient-derived IPMN models, the majority of these cell-based models utilize 3D organoids. To date, no study has successfully converted patient-derived IPMN organoids into 2D culture. Converting these cellular models to propagate and divide in a monolayer allows us to expand our in vitro toolbox to perform experimental methods that are less efficient or not practical in 3D culture. In this study, we optimized the conversion of a high-grade IPMN patient-derived organoid model into a monolayer culture. We considered conditions that could recapitulate an extracellular matrix as well as growth factors and/or inhibitors that could promote IPMN cell growth. In total, we tested 15 different conditions and were able to successfully culture the human high-grade IPMN cells in a monolayer culture for up to 5 passages (~1 month). Additionally, while human IPMN cellular models exists, genetic modification of these in vitro models has not been reported. Such approaches allow direct interrogation of the role of specific genes in premalignant pancreatic tumorigenesis. In this study, we report successful transduction of IPMN cells via lentivirus. By first converting the organoid into a monolayer culture, transducing them in 2D, and then converting them back into 3D culture as spheroids, we were able to successfully express EGFP into our IPMN cellular model. In summary, we optimized culture conditions to temporarily grow a patient derived 3D IPMN model in a 2D monolayer form, genetically modified this IPMN cell line model, and successfully converted it back into a 3D spheroid. These protocols have potential to be replicated in other IPMN models and can provide further insight into overall IPMN biology and pancreatic tumorigenesis. Citation Format: Raymond M. Paranal, Julie Schlanz, Maria A. Trujillo, Nicholas J. Roberts, Laura D. Wood. Optimizing an in vitro toolbox to interrogate pancreatic tumorigenesis from a patient-derived intraductal papillary mucinous neoplasm sample [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6511.

Abstract Intratumoral heterogeneity poses a significant hurdle for cancer treatment, yet is under-characterized in the context of tumor invasion. Cancer cells from solid tumors can invade through two predominant modes: collective invasion, whereby cancer cells invade in multi-cellular packs or streams marked by intact cell-cell junctions; and single-cell invasion, whereby cells invade independently without intercellular adhesion. We have observed that collective and single-cell invasion co-occur within the same tumor microenvironment in triple-negative breast cancer, suggesting that invasive heterogeneity supports cooperative behavior between tumor subpopulations. To test this, we used a novel, published technique developed by the lab (SaGA) to isolate pure subpopulations of 4T1 cells that collectively invade (collectives) or single cells that invade alone (singles). 3-D spheroids of SaGA-purified collectives and singles exhibited almost exclusively collective and single-cell invasion, respectively, and these invasive phenotypes were retained over multiple passages. Integration of RNA sequencing and methylation array data obtained from RNA and DNA isolates, respectively, of collectives and singles revealed that collectives exhibit drastic overexpression and promoter hypomethylation of two laminin genes that form the laminin-332 complex, Lama3 and Lamc2. Additionally, an unbiased proteomic analysis of secreted proteins also revealed an overabundance of these laminins in collectives media. We found that singles have increased expression of integrin α6 and β4, which together have been found to specifically bind to laminin-332 to activate the Rac1 GTPase. Interestingly, our RNA sequencing data revealed a binary overexpression of a Rac1 GTPase, Prex1 in singles, suggesting that singles have enhanced Rac1 activation when compared to collectives with the potential for hyperactivation upon laminin-332 binding. Indeed, laminin-332 resulted in higher GTP-bound Rac1 in singles and subsequently increased invasion of singles in 3-D models. Additionally, laminin-332 induced cell elongation at the leading edge of singles spheroids, which was reversable by treatment with a Rac1 inhibitor. Together, our data suggests that distinct subpopulations amidst a heterogeneous tumor cooperate via laminin-332 and Rac1 to facilitate tumor invasion in metastatic triple-negative breast cancer. Citation Format: Sung Bo (Joseph) Yoon, Janna Mouw, Luxiao Chen, Hao Wu, Adam Marcus. Invasively distinct subpopulations cooperate via a laminin-332/Rac1 axis in triple-negative breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-14-01.

Introduction:The mesenchymal stromal cells (MSCs) have gained considerable popularity owing to the vast possibilities and lack of ethical constraints. MSCs serve as multipotent progenitors for several niche components in the bone marrow (BM) and play an essential role in the quiescence, proliferation, and differentiation of hematopoietic stem cells. Recently, MSCs from BM (BM-MSCs) represent an attractive cell source for tissue engineering, thanks to their immunomodulatory property, self-renewing and high proliferative capability. BM-MSCs have multi-lineages (adipogenesis, chondrogenesis, osteogenesis) potential and in combination with biomaterials, well support cell-attachments and stimulate extracellular matrix synthesis. For these reasons, BM-MSCs have a great potential for regenerative medicine applications. The present research aims to evaluate the ability of BM-MSCs to proliferate and differentiate toward the osteogenic lineage into innovative three-dimensional bioresorbable scaffold based on gelatin-chitosan hydrogel with a poly(lactic acid) lattice structure (PLA-CH) for regenerative medicine applications in the presence of fetal bovine serum (FBS) or human platelet lysate (HPL) with or without the osteogenic medium (OM). Methods: BM-MSCs were expanded to the passages 3 or 4 and seeded into the PLA-CH, in dry state, at a cellular density of 7x10 5 cells/scaffolds in growth medium (GM). For inducing osteogenic differentiation, cells/scaffolds constructs were cultured in 24-well plates for 4 weeks with OM consisting of a high-glucose DMEM supplemented with 10% FBS or 5% HPL, 10 −7M Dex, 25 mg/ml l-ascorbic acid, and 3mM NaH 2PO 4. For histomorphological analysis at optical microscope, scaffolds were embedded in paraffin using an automatic processor Donatello series 2 (Diapath S.p.A., Bergamo, Italy). Serial paraffin sections (5 µm thick) of each sample were cut, deparaffinized, and rehydrated, according to standard procedures and stained with hematoxylin-eosin stain for general morphology and Von Kossa (Bio-Optica, Milan, Italy) for calcium deposition. Immunohistochemistry for the osteogenic marker Osteocalcin (OSC) (Santa Cruz Biotechnologies, USA) was also performed. For Scanning Electron Microscopy (SEM) (EVO LS-10 manufactured by ZEISS) observation, samples have been progressively dehydrated through immersion in alcohol solutions. The local changes in elemental composition were investigated using the Energy Dispersive X-ray (EDX) analyzer. Results: The results showed that BM-MSCs have higher affinity to attachment, migrate and differentiate toward the osteogenic lineage inside the novel scaffold PLA-CH both with HPL and FBS as supplement in the culture media. The use of HPL for cell expansion offers the possibility to obtain a safer cellular products without xenogenic contaminants. Cells develop a large spreading area with elongated fibroblast-like morphology preferentially inside the hydrogel pores, showing great affinity with the scaffold. This is confirmed also by histomorphological analyses at optical microscope, showing homogeneous colonization of cells inside the hydrogel pores (figure 1a). The results showed the presence of calcium deposits in the mash of the scaffold with Von Kossa stain (figure 1b), moreover cells appeared well integrated with a positivity for OSC showing a clear differentiation state as osteoblasts (figure 1c). Calcium and phosphorous were detected with SEM-EDX on the samples incubated in osteogenic medium (figure 1 d,e). Conclusion: MSCs, derived from bone marrow, associated with scaffold PLA-CH proved to be biocompatible and promising for personalized medicine. In fact, BM-MSCs were able to growth, colonize and osteo-differentiate throughout the hydrogel, demonstrating their potential application for bone regenerative medicine. Figure 1. Histomorphological analysis at the optical microscope of PLA-CH with BM-hMSCs in the GM at 100 m m ( a), Von Kossa stain showing calcium deposit distribution on PLA-CH with BM-hMSCs in the OM at 30 m m ( b), immunohistochemistry for OCN with BM-hMSCs differentiated to osteoblast in the OM at 10 m m ( c). Evaluation of calcium (Ca) and phosphorous (P) with SEM-EDX of PLA-CH with BM-hMSCs in OM day 28 ( d,e).

Abstract Abstract 3639 Poster Board III-575 Purpose Total body irradiation (TBI) is routinely used before allogeneic transplantation to kill the leukemic cells as well as to suppress the immunity of recipient to ensure donor hematopoietic stem cell engraftment. TBI is associated with a lot of long-term adverse effects on normal cells, including radiation-induced sarcoma. Mesenchymal stem cells (MSCs) are the stromal stem cells in the bone marrow (BM) and other mesenchymal tissue and are extensively studied in the clinical application as cell therapy for tissue repair. Nevertheless, some in vitro and animal studies had pointed out that sarcoma could be derived from cultured or in vitro manipulated MSCs. We therefore conduct this study to see whether irradiation using the dosing schedule similar to TBI can induce malignant transformation of BM-MSCs. Materials & Methods Ex vivo expanded (passage 3 to 5) BM-MSCs from two normal adults were irradiated with 1200 cGy (200cGy twice a day for consecutive 3 days, mimicking TBI clinically). Each of them was kept ex vivo culture for 6 and 12 passages respectively. The cells were then subjected to investigate morphology, phenotype, differentiation potential, and cytogenetic analysis using traditional G-banding technique and also spectral karyotyping (SKY). Ex vivo expanded (passage 3 to 5) BM-MSCs from five leukemic patients obtained before and after TBI (1200cGy)-conditioned allogeneic transplantation were also examined in the same way. The differences in the characteristic of BM-MSCs before and after irradiation (or TBI) were evaluated and the effects of TBI on MSCs were determined. Results BM-MSCs from normal adults or transplant patients after irradiation or TBI are still fibroblast-like and are CD29+, CD44+, CD73+, CD90+, CD105+, CD166+, CD14-, CD34-, and CD45-, which are just the same to normal BM-MSCs. However, the proliferation and multi-differentiation ability are markedly decreased in BM-MSCs after irradiation or TBI. Of the Two BM-MSCs obtained from normal adults and having normal karyotype, cytogenetic abnormalities can be easily identified on SKY after irradiation with 1200cGy. Besides, the same cytogenetic abnormality can be detected in both passage 6 and passage 12 MSCs. Interestingly, cytogenetic clonal evolution was detected in 1 of them. In sex-mismatched allogeneic transplant, the cytogenetic studies showed all the BM-MSCs remain recipient-origin after transplant. Nevertheless, of the five BM-MSCs isolated from transplant patients who had received TBI conditioning, cytogenetic abnormalities were detected in all of them. More importantly, cytogenetic clonal evolution was also found in 1 of them. Conclusions BM-MSCs can not be eradicated by myeloablative, TBI-based conditioning chemoradiotherapy and they remain recipient-origin. The cellular morphology and surface antigen expression did not differed significantly after irradiation. However, TBI significantly reduced the proliferation and differentiation potential of BM-MSCs. Most important of all, TBI induced clonal cytogenetic abnormality on BM-MSCs, which is evident not only from ex vivo irradiation study but also from clinical patients' specimens. Besides, cytogenetic clonal evolution, a unique feature of malignant process, was found in some of them. TBI is known to be an important risk factor for soft tissue sarcoma in transplant survivors, our study further provides the direct evidence that TBI-exposed BM-MSCs may have clonal cytogenetic abnormality and the tumorigenic potential of these cells merits extensive study. Taking together, the BM-MSCs isolated from patients who had received TBI have defective proliferation and differentiation potential. Moreover, because of cytogenetic abnormality, these cells should not be considered for any clinical application. Disclosures: No relevant conflicts of interest to declare.

Intestinal goblet cells maintain the protective epithelial barrier through mucus secretion and yet sample lumenal substances for immune processing through formation of goblet cell associated antigen passages (GAPs). The cellular biology of GAPs and how these divergent processes are balanced and regulated by goblet cells remains unknown. Using high-resolution light and electron microscopy, we found that in mice, GAPs were formed by an acetylcholine (ACh)-dependent endocytic event remarkable for delivery of fluid-phase cargo retrograde into the trans-golgi network and across the cell by transcytosis – in addition to the expected transport of fluid-phase cargo by endosomes to multi-vesicular bodies and lysosomes. While ACh also induced goblet cells to secrete mucins, ACh-induced GAP formation and mucin secretion were functionally independent and mediated by different receptors and signaling pathways, enabling goblet cells to differentially regulate these processes to accommodate the dynamically changing demands of the mucosal environment for barrier maintenance and sampling of lumenal substances.

The past decade has witnessed tremendous endeavors to deliver novel preclinical in vitro lung models for pulmonary research endpoints, including foremost with the advent of organ- and lung-on-chips. With growing interest in aerosol transmission and infection of respiratory viruses within a host, most notably the SARS-CoV-2 virus amidst the global COVID-19 pandemic, the importance of crosstalk between the different lung regions (i.e., extra-thoracic, conductive and respiratory), with distinct cellular makeups and physiology, are acknowledged to play an important role in the progression of the disease from the initial onset of infection. In the present Methods article, we designed and fabricated to the best of our knowledge the first multi-compartment human airway-on-chip platform to serve as a preclinical in vitro benchmark underlining regional lung crosstalk for viral infection pathways. Combining microfabrication and 3D printing techniques, our platform mimics key elements of the respiratory system spanning (i) nasal passages that serve as the alleged origin of infections, (ii) the mid-bronchial airway region and (iii) the deep acinar region, distinct with alveolated airways. Crosstalk between the three components was exemplified in various assays. First, viral-load (including SARS-CoV-2) injected into the apical partition of the nasal compartment was detected in distal bronchial and acinar components upon applying physiological airflow across the connected compartment models. Secondly, nebulized viral-like dsRNA, poly I:C aerosols were administered to the nasal apical compartment, transmitted to downstream compartments via respiratory airflows and leading to an elevation in inflammatory cytokine levels secreted by distinct epithelial cells in each respective compartment. Overall, our assays establish an in vitro methodology that supports the hypothesis for viral-laden airflow mediated transmission through the respiratory system cellular landscape. With a keen eye for broader end user applications, we share detailed methodologies for fabricating, assembling, calibrating, and using our multi-compartment platform, including open-source fabrication files. Our platform serves as an early proof-of-concept that can be readily designed and adapted to specific preclinical pulmonary research endpoints.

Lors de la phase aiguë d'un accident SEVESO, une évaluation précise de la qualité de l'air à proximité du site est nécessaire afin de mettre en place des mesures d'urgence vouées à protéger les populations environnantes. Il existe aujourd'hui de nombreux détecteurs de gaz commerciaux et transportables permettant d'effectuer ce type d'analyses sur le terrain. Toutefois, ces détecteurs présentent certains inconvénients, notamment dans le cas de l'analyse d'un panache de fumée. En effet, ces derniers, principalement basés sur des technologies de type : infrarouge non dispersif, électrochimique, semi-conducteur, sont souvent limités en termes de nombre de gaz détectables et peuvent présenter des problèmes de sensibilité croisée. Pour contourner ces limitations, il peut donc être nécessaire d'effectuer des prélèvements sur sites qui seront par la suite analysés en laboratoire au moyen d'instruments plus précis mais difficilement utilisables sur le terrain. Cette thèse, qui s'inscrit dans le cadre du projet SAFESIDE, vise à contribuer au développement d'un analyseur multi-gaz transportable basé sur un spectromètre laser infrarouge et capable d'effectuer des mesures localement et à distance. La détection de plusieurs gaz par spectroscopie laser infrarouge nécessitant la mise en œuvre d'une source laser largement accordable, les travaux réalisés durant cette thèse ont consisté à mettre en place un spectromètre laser à partir d'un Oscillateur Paramétrique Optique développé dans le cadre du projet. Plusieurs tests de cette source ont donc été effectués en laboratoire afin de mettre en œuvre les techniques d'absorption directe et de Wavelength Modulation Spectroscopy. En parallèle, un travail de développement de cellule de Herriott à "motif dense" a également été réalisé dans le but d'accroître la sensibilité des mesures locales. Les différentes briques technologiques développées ont finalement pu être mises en œuvre lors d'essais à grande échelle en environnement extérieur. Durant ces deux campagnes, des mesures locales de concentrations de CO2 et des mesures à distance de NH3 ont pu être réalisées
During the acute phase of a SEVESO accident, a precise assessment of air quality near the site is necessary to implement emergency measures aimed at protecting the surrounding populations. There are currently many commercial and portable gas detectors that can be used to carry out this type of analysis in the field. However, these detectors have certain drawbacks, especially when analyzing a smoke plume. Indeed, these devices, mainly based on technologies such as non-dispersive infrared, electrochemical, and semiconductor, are often limited in terms of the number of detectable gases and may encounter cross-sensitivity issues. To overcome these limitations, it may be necessary to take on-site samples that will later be analyzed in the laboratory using more accurate but less field-friendly instruments. This thesis, part of the SAFESIDE project, aims to contribute to the development of a portable multi-gas analyzer based on an infrared laser spectrometer capable of performing measurements locally and remotely. Detecting multiple gases using infrared laser spectroscopy requires the implementation of a widely tunable laser source. The work carried out during this thesis involved setting up a laser spectrometer using an Optical Parametric Oscillator developed as part of the project. Several tests of this source were conducted in the laboratory to implement direct absorption and Wavelength Modulation Spectroscopy techniques. In parallel, development work on a dense-pattern Herriott cell was also carried out with the aim of increasing the sensitivity of local measurements. The various technological components developed were finally implemented during large-scale outdoor tests. During these two campaigns, local measurements of CO2 concentrations and remote measurements of NH3 were carried out