Academic literature on the topic 'Humoral immune system'

Nature over millions of years has found innovative, robust and effective methods through evolution for helping organisms deal with the challenges they face when attempting to survive in hostile and uncertain environments. Two critical natural mechanisms in this evolutionary process are variation and selection, which form the basis of "evolutionary computing" (EC). EC has proved successful when dealing with complex problems, such as classification, clustering and optimization. In recent years, as our knowledge of microbiology has deepened, researchers have turned to micro-level biology for inspiration to help solve complex problems. This paper describes a novel supervised learning algorithm inspired by the humoral mediated response triggered by the adaptive immune system. The proposed algorithm uses core immune system concepts such as memory cells, plasma cells and B-cells as well as parameters and processes inspired by our knowledge of the microbiology of immune systems, such as negative clonal selection and affinity thresholds. In particular, we show how local and global similarity based measures based on affinity threshold can help to avoid over-fitting data. The novelty of the proposed algorithm is discussed in the context of existing immune system-based supervised learning algorithms. The performance of the proposed algorithm is tested on well-known benchmarked real world datasets and the results indicate performance not worse than existing techniques in most cases and improvement over previously reported results in some. The role of memory cells is highlighted as a key feature in AIS-based supervised learning that deserves further exploration and evaluation.

The immune system recognises a transplanted kidney as foreign body and mounts immune response through cellular and humoral mechanisms leading to acute or chronic rejection, which ultimately results in graft loss. Over the last five decades, there have been significant advances in the understanding of the immune responses to transplanted organs in both experimental and clinical transplant settings. Modulation of the immune response by using immunosuppressive agents has led to successful outcomes after kidney transplantation. The paper provides an overview of the general organisation and function of human immune system, immune response to kidney transplantation, and the current practice of immunosuppressive therapy in kidney transplantation in the United Kingdom.

The body’s humoral immune response plays a larger role in the body’s defenses beyond screening for invading pathogens. Modulation of this response is also vital for tissue regeneration, drug delivery, and vaccine development. The immune system operates within a complicated feedback loop and as such, altering the strength of the immune response can be approached from an engineering perspective. While a strong initial input can direct the response to either a pro- or anti-inflammatory bias, extreme responses can be deleterious, as in the case of allergic reactions or sepsis. Therefore, the objective of this thesis was to develop a novel biomaterials platform that can be used to alter the immune response in a tunable manner. Antibodies are not only the workhorses of the adaptive immune response but are also powerful immunomodulators through their Fc (constant fragment) regions. By coating microparticles with Fc ligands in variable surface densities, we were able to utilize the sensitivity of multivalent signaling to tune the response of the immune response. Microparticle size was also varied to decouple the effects of physical versus biochemical signaling. The goal of this thesis was to analyze the effects of Fc coated particles on two major components of the humoral immune responses: macrophages and the complement system. We first looked at the mechanical response of macrophages through phagocytosis and found that both Fc density and microparticle size had significant impacts on macrophage phagocytosis. These results also provide a particle delivery “toolbox” for future applications. We then analyzed the downstream effects of Fc particles on macrophage phenotype and on phenotype plasticity. This showed that the addition of Fc particles lead to increased production of TNFα and IL-12 and inverted the response of LPS treated macrophages. Finally, we applied our particles to activate the complement system, an often overlooked cascade of serum protein activation that results in bacterial cell lysis. Cleaved components of the complement system are also powerful chemokines and can act as a vaccine adjuvant. Fc density on particles played a large role in complement system activation, both through the classical and alternative pathway, as it lead to a binary response for smaller particles and a tunable response for larger particles. We then applied these results to create a novel form of antibiotic by using Fc particles to direct complement-mediated bacterial cytotoxicity. The use of immune activation by Fc particles was also applied to better understand and improve the tuberculosis vaccine. Our findings are significant to the biomaterials and immunology fields as we showed that Fc microparticles can generally be used to alter the immune response in a tunable manner for a broad range of applications, as well answering fundamental immunology questions.

Orientador: Margareth Castro Ozelo
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
Made available in DSpace on 2018-08-24T11:38:04Z (GMT). No. of bitstreams: 1 Montalvao_Silmara_M.pdf: 5511908 bytes, checksum: e7e6cf52da6e5f3fb92bce534c8e27ec (MD5) Previous issue date: 2014
Resumo: Os principais problemas relacionados ao tratamento de pacientes portadores de hemofilia A estão relacionados ao uso terapêutico de fator VIII (FVIII), sendo estes o desenvolvimento de anticorpos neutralizantes anti-FVIII (inibidores), e o desenvolvimento de reações anafiláticas, que são eventos raros, no entanto potencialmente graves. As informações quanto aos isotipos de imunoglobulinas associados a estas duas situações clínicas ainda é limitado. O objetivo deste projeto foi avaliar as características da resposta imune humoral em pacientes com hemofilia A que apresentam inibidor e/ou em condição de reação alérgica ao FVIII. Para estas análises três metodologias foram aplicadas, (1) determinação de anticorpos inibitórios por método de Bethesda-Nijmegen, (2) determinação do isotipo de imunoglobulinas envolvidas subclasses da IgG, IgM e IgE anti-FVIII, por método de ELISA e (3) determinação de citocinas por método multiplex BDTM CBA® (cytometric bead array). Esse projeto foi dividido em três estudos. No primeiro estudo, foram analisadas amostras de 25 pacientes brasileiros com hemofilia A, sendo 44% destes afrodescendentes. Todos os pacientes receberam exclusivamente terapia de reposição com concentrado de FVIII derivado de plasma (pdFVIII) e produtos bypass após o desenvolvimento de inibidor. Cinco pacientes deste grupo foram acompanhados por uma análise longitudinal no período de até três anos. No segundo estudo, 4 pacientes com hemofilia A com inibidor foram avaliados no período em que foram tratados através do protocolo de indução de imunotolerância (ITI) para erradicação do inibidor, também em análise longitudinal. O terceiro consistiu da avaliação de incidência de reação alérgica em pacientes com hemofilia A. Três de 322 pacientes (0,9%) apresentaram reação alérgica após a exposição exclusivamente para pdFVIII durante os últimos quinze anos em nosso centro. Os resultados evidenciaram que a subclasse IgG4 é a principal na modulação em presença de anticorpos inibitórios, enquanto a IgG1 na maior parte das análises estava presente junto a baixos títulos de inibidor.Durante o tratamento de ITI os níveis das interleucinas anti-inflamatórias IL-4 e IL-6 acompanharam o decaimento dos títulos de inibidor e IgG4 nos pacientes que obtiveram sucesso ao tratamento. Além disso, no decorrer do protocolo observou-se uma resposta polarizada para o tipo Th1 como padrão de resposta na conquista da tolerância completa ao FVIII. No contexto da reação alérgica, apenas um dos três pacientes apresentou reatividade da IgE que foi exclusiva ao pdFVIII, sendo negativa no ensaio do IgE anti-rFVIII (anti-fator VIII recombinante), demonstrando que a reatividade não foi específica ao FVIII. O entendimento resposta imune humoral em pacientes com hemofilia A, incluindo a participação da IgG4 e IgG1 no mecanismos envolvendo a presença e erradicação dos inibidores e da IgE na reação alérgica, possibilita ampliar conceitos estabelecidos dos mecanismos envolvidos nessas duas situações. Isso poderá auxiliar no desenvolvimento de novos produtos menos imunogênicos e de novas estratégias para a indução de tolerância ao FVIII, que tenham maior eficiência e melhor custo benefício
Abstract: The main problems related to the treatment of hemophilia A patients are linked to the use of therapeutic factor VIII (FVIII). First, the development of neutralizing antibodies against FVIII (inhibitors), and second development of anaphylactic reactions, which are rare, however potencialy severe. The knowledge about the immunoglobulin isotypes associated with these two clinical situations is still limited.The aim of this project was to evaluate the characteristics of the humoral immune response in patients with hemophilia A who have inhibitors and/or allergic reaction to FVIII. For these analyzes three methods were used (1) inhibitory anti-FVIII antibodies assay by Bethesda-Nijmegen (2) immunoglobulins isotype ELISA assay for anti-FVIII IgG subclasses, IgM and IgE and (3) cytokines assay by BDTM Cytometric bead array (BD CBA®) multiplex method. This project was divided in three studies. In the first study, we analyzed samples from 25 Brazilian hemophilia A patients with 44% African-descents. All patients received exclusively replacement therapy with plasma-derived (pdFVIII) concentrates, and bypassing agents after the development of inhibitors. Five patients from this group were followed for a longitudinal analysis in a period up to three years. In the second study, 4 hemophilia A patients with inhibitor were evaluated also in longitudinal analyses, during the induction of immunotolerance (ITI) treatment for the eradication of the inhibitor. The third study included the evaluation of the incidence of allergic reaction among hemophilia A patients. Three out of 322 patients (0.9%) had allergic reaction after exclusively exposure to pdFVIII during the last fifteen years in our center. The results of these studies demonstrated that IgG4 subclass is the main immunoglobulin involved in the modulation of the inhibitory antibodies, while IgG1 is associated with low-titer inhibitors. During the ITI protocol, the anti- inflammatory interleukins, IL-4 and IL-6 decreased following the IgG4 reduction among the patients that achieved success in the ITI treatment. In addition, during the ITI protocol it was observed a polarized Th1 immune response after the complete success achievement. In the context of allergic reaction, only one out of three patients presented IgE reactivity that was exclusively to pdFVIII, and the assay IgE anti-rFVIII (anti-recombinant FVIII) was negative, confirming that the reativity was not specific to FVIII. The understanding of the humoral immune response in hemophilia A patients, including the role of IgG4 and IgG1 in the mechanisms involving the presence and eradication of inhibitors, and the participation of IgE in allergic reaction, allows to better understand the established concepts of the mechanisms involved in these two situations. This may help the development of less immunogenic new products and new strategies for induction of tolerance to FVIII, with higher efficiency and best value
Mestrado
Clinica Medica
Mestra em Clínica Médica

The immune system is critical for the maintenance of homeostasis. Due to the fact that a coordinated effort between organ systems is required for internal stability, it has been postulated that the immune system interacts with the neuroendocrine system. Clinical, anatomical, and receptor studies have provided evidence for a bi-directional communication between the nervous and immune systems. The goal of the present studies was to determine the potential influence of the sympathetic nervous system (SNS) on the primary antibody forming cell (AFC) response. The adrenergic neurotoxin, 6-hydroxydopamine (6-OHDA), has been utilized extensively by researchers to explore the possible relationship between SNS and the antibody response. However, the literature describing the humoral effects observed following 6-OHDA treatment is irresolute. In an attempt to provide insight into these apparent discrepancies, studies were conducted comparing the effects of 6-OHDA and its non-neurotoxic congener, 5-hydroxydopamine (5-OHDA). Both chemicals, when added directly into cultures containing naive splenocytes, suppressed the in vitro AFC response. Analysis following in vivo treatment with 6-OHDA or 5-OHDA revealed that while both chemical treatments resulted in suppression of the AFC response following in viva sensitization, only the splenocytes from 6-OHDA treated mice were suppressed when subsequently sensitized in vitro. Pretreatment with desmethylimipramine (DMI) blocked the observed 6-OHDA- and 5-OHDA-induced immunosuppression displayed in vivo, indicating that the uptake of the chemicals into adrenergic neurons was required. As an alternative method for removing the sympathetic influence in the spleen, studies were conducted with chlorisondamine, a non-competitive ganglionic blocker. While direct addition of chlorisondamine was without effect in the in vitro-in vitro AFC response, the in viva AFC response following chlorisondamine treatment was significantly suppressed. In addition to the suppression of the primary AFC response, 6-OHDA and chlorisondamine treatment resulted in a time dependent increase in the level of DNA fragmentation in the thymus. Analysis of serum corticosterone levels in 6-OHDA- and chlorisondamine-treated mice revealed that both treatments elevated levels of serum corticosterone. Given the potential role of corticosterone in the 6-OHDA- and chlorisondamine-induced immunosuppression, studies were conducted to determine if the glucocorticoid receptor antagonist, RU-486, was able to block the DNA fragmentation in the thymus and the suppression of the AFC response demonstrated after 6-OHDA or chlorisondamine treatment. While RU-486 was effective at blocking the 6-OHDA- and chlorisondamine-induced thymic effects, it was unable to block the suppression of the primary AFC response. Collectively, these studies reveal that removal of the peripheral SNS by either sympathectomy with 6-OHDA or ganglionic blockade with chlorisondamine can result in 1) thymic alterations which are mediated by increased levels of corticosterone and 2) suppression of the primary AFC response which is independent of the elevated corticosterone levels. Importantly, these results provide evidence for positive modulation of the humoral immune response by the sympathetic nervous system.

RESUMO:Aterosclerose é uma das principais causas de morbilidade e mortalidade no mundo ocidental. É responsável, direta ou indiretamente, pela maior percentagem de gastos com a saúde na maioria dos países europeus. A “teoria lipídica” da aterosclerose, que se baseia na dislipidemia como causa primária para a doença vascular tem algumas implicações práticas importantes: permite a definição de linhas de orientação e protocolos simples e ainda estabelece alvos terapêuticos que podem ser atingidos na maior parte dos casos com a atual intervenção farmacológica. A associação da aterosclerose com o sistema imunológico (a “teoria imunológica”), forneceu por sua vez novas formas de explorar os mecanismos envolvidos e abriu novas perspetivas para um conhecimento mais completo da doença. No entanto, levanta dificuldades evidentes no que diz respeito às possibilidades terapêuticas. De todos os intervenientes no processo aterosclerótico (bioquímicos, imunológicos e anatómicos), as lipoproteínas de elevada densidade (HDL) são atualmente reconhecidas como um dos fatores mais importantes na aterogénese. Isto é baseado no reconhecimento das múltiplas propriedades anti-aterogénicas das HDL como por exemplo: a anti-oxidante, a anti-inflamatória e a antitrombótica, bem como o seu importante papel na melhoraria da função endotelial. Atualmente, é consensual que as funções anti-aterogénicas das HDL vão além do seu papel no transporte reverso do colesterol (RCT) e a importância das HDL no processo aterosclerótico baseia-se não apenas no seu papel protetor impedindo a formação da placa de ateroma, mas também na estabilização destas, prevenindo a sua ruptura e, consequentemente o evento trombótico. Como fundamentais no processo aterosclerótico estão reconhecidos dois principais conjuntos de eventos: um caracterizado por alterações no metabolismo das lipoproteínas que resultam em lipoproteínas pró-inflamatórias e pró-oxidantes que interagem com os componentes celulares da parede arterial e que conduzem à formação da placa de ateroma; o outro evento é a resposta imunológica desencadeada contra um novo conjunto de antigénios que por sua vez leva à produção de citoquinas pró-inflamatórias. Dada a complexidade da HDL e das suas múltiplas funções estas lipoproteínas tornaram-se um potencial alvo para a resposta auto-imune, e cujas consequências podem explicar algumas das associações identificados em estudos clínicos e epidemiológicos. Contudo esta interação entre o sistema imunológico e HDL nunca foi exaustivamente estudada. Portanto, pomos a hipótese de que em condições oxidativas e pró-inflamatórias, um aumento do antigénio (HDL) conduz a um consequente acréscimo na produção de anticorpos anti-HDL (aHDL) responsáveis pela alteração quantitativa e / ou qualitativa das HDL. O conceito de que estes anticorpos podem contribuir tanto para a evolução a longo prazo do processo aterosclerótico, como para o desencadeamento de eventos clínicos pode também explicar a heterogeneidade encontrada em cada doente e nos grandes estudos clínicos, no que diz respeito aos fatores de risco e outcomes clínicos. Para além disso, a confirmação desta hipótese pode permitir explicar porque é que as intervenções terapêuticas atualmente em desenvolvimento para aumentar os níveis de HDL, não conseguem mostrar a tão esperada redução do risco vascular. O objetivo geral desta tese foi identificar e caracterizar a resposta humoral contra os componentes da HDL, e avaliar possíveis mecanismos que possam contribuir para a modificação das propriedades anti-aterogénicas das HDL. Para alcançar este objetivo investigou-se: 1) A presença de anticorpos aHDL em doentes com lúpus eritematoso sistémico (SLE) e em doentes com manifestações clínicas de aterosclerose, como os doentes com doença arterial coronária (CAD), acidente vascular cerebral isquémico (IS) e diabetes tipo 2; 2) Os principais alvos antigénicos dentro do complexo das HDL e a associação entre os títulos de anticorpos aHDL e diferentes características clínicas destas doenças; 3) As modificações das funções normais associadas às HDL, em particular da função anti-oxidante e anti-inflamatória; 4) A atividade biológica dos anticorpos aHDL isolados do soro de doentes através de um conjunto de experiências in vitro de inibição da atividade da paraoxonase 1 (PON1) e da expressão de moléculas de adesão em culturas de células endoteliais. Para tal foi necessário estabelecer um método de isolamento dos anticorpos. Os anticorpos aHDL isolados do soro de doentes foram utilizados de forma a identificar as potenciais alterações dos sistemas celulares utilizados; 5) O efeito de fármacos usados no tratamento das dislipidemias, em particular o ácido nicotínico e as estatinas, na variação dos títulos de anticorpos aHDL através de ensaios clínicos randomizados, controlados com placebo e em dupla ocultação. Os métodos utilizados neste trabalho incluíram: técnicas imunológicas (como por exemplo, enzyme-linked immunoabsorbent assay - ELISA, ensaio imunoturbidimetrico e cromatografia de imuno-afinidade) técnicas bioquímicas (tais como a quantificação de atividade enzimática por espectrofotometria e por luminescência), experiências com cultura de células e citometria de fluxo. Os nossos resultados mostram que: 1) A presença de anticorpos aHDL, e mais especificamente anticorpos contra alguns do seus principais componentes como a apolipoproteína A-I (ApoA-I, principal apolipoproteína presente nas HDL) e a PON1 (o enzima que mais contribui para a propriedade anti-oxidante das HDL), quer em doentes com doenças auto-imunes, como o SLE, quer em doentes com manifestações clínicas de aterosclerose, como CAD, IS e diabetes tipo 2. Os doentes apresentaram títulos de anticorpos IgG aHDL, aApoA-I e aPON1 significativamente mais elevados do que controlos saudáveis com a mesma idade e sexo. 2) A correlação positiva estatisticamente significativa entre os títulos de aHDL e aApoA-I e aPON1 sugere que estes sejam dois dos principais alvos antigénicos dentro do complexo das HDL. Os anticorpos encontrados nestes doentes estão associados com a diminuição da atividade da PON1 e a uma redução da capacidade anti-oxidante total (TAC) do soro, um aumento dos biomarcadores de disfunção endotelial (como por exemplo dos metabolitos do óxido nítrico - NO2- e NO3-, as moléculas de adesão vascular e intracelular - VCAM-1 e ICAM-1 e os níveis de 3-nitrotirosina). Nos doentes com SLE os títulos destes estão associados a um aumento do dano cardiovascular e à atividade global da doença avaliados pelas escalas SLICC/ACR DI e BILAG score, respetivamente. Enquanto que nos doentes com diabetes tipo 2 estes anticorpos estão associados com um aumento dos níveis de glicemia em jejum (FGP) e hemoglobina glicada (HbA1c). 3) Após se ter estabelecido um método de isolamento dos anticorpos que permite isolar quantidades significativas de anticorpos do soro de doentes sem perder a sua especificidade, foi identificada a capacidade dos anticorpos isolados do soro de doentes inibirem de uma forma dependente da concentração a atividade da PON1 até um máximo de 70% no caso dos doentes com SLE e ente 7-52% no caso dos anticorpos isolados de doentes com CAD e IS. 4) O efeito anti-inflamatório das HDL na inibição da produção de VCAM-1 induzida por citoquinas (como o TNF-) foi revertido em mais de 80% pelos anticorpos aHDL isolados do soro de doentes. 5) A angiogenesis induzida por HDL através do aumento do fator de crescimento do endotélio vascular (VEGF) foi anulada em 65% pelos anticorpos aHDL isolados do soro de doentes. 6) Os atuais agentes farmacológicos disponíveis para aumentar as concentrações de HDL-C estão associados a um aumento dos títulos de anticorpos.-------- ABSTRACTAtherosclerosis is the major cause of morbidity and mortality in the western world. It is also responsible, directly or indirectly, for the highest percentage of health costs in most European countries. Despite the use of new technologies for the diagnosis of vascular disease and regardless of the major advances in treatment, the atherosclerosis-related clinical burden is still raising. The “lipid theory” of atherogenesis, which identifies dyslipidemia as the primary cause of this vascular disease has some important practical implications: it allows the definition of simple guidelines and establishes therapeutic targets which can be generally met with current pharmacologic intervention. The association between atherosclerosis an the immune system (the immune concept) has in turn provided new ways of exploring the mechanisms involved in this condition and has opened new perspectives in the understanding of the disease. However, it raises obvious difficulties when it comes to treatment options. Of all the players (biochemical, immunological and anatomical) involved in this matter, high-density lipoproteins (HDL) are currently recognised as one of the most important factors in atherogenesis. This is based on the recognition of HDL's multiple anti-atherogenic properties: anti-oxidant, anti-inflammatory and antithrombotic, as well as its capacity to improve endothelial function. Nowadays, it is widely recognized that the anti-atherogenic functions of HDL go beyond reverse cholesterol transport (RCT), and the importance of HDL is based not just on its ability to reduce atheroma formation but also on its ability to stabilise plaques, therefore preventing their rupture and ultimately thrombosis. Two main set of events have been recognised as fundamental in atherogenesis: one, characterized by lipoprotein metabolism alterations, resulting in pro-inflammatory and pro-oxidative lipoproteins, which interact with the normal cellular elements of the arterial wall leading to atheroma formation; the other, the immune cellular response towards new sets of antigens which lead to the production of pro-inflammatory cytokines. Given to HDL complexity and multiple functions this lipoprotein has became a potential target for an auto-immune response, the consequences of which may explain some of the association identified in epidemiological and clinical studies, though the interaction between the immune system and HDL has never been thoroughly addressed. Therefore, we hypothesized that under oxidative and pro-inflammatory conditions, the increase in the antigen (HDL) would lead to a consequent increase in the production of anti-HDL (aHDL) antibodies be responsible for quantitative and/or qualitative changes of HDL. The concept that these antibodies may contribute either to the long-term evolution of atherosclerosis or to the triggering of clinical events may also explain the heterogeneity found in individual patients and in large cohorts regarding risk factors and clinical outcomes. Moreover this may be a major breakthrough in understanding why therapeutic interventions that increase HDL levels, failed to show the anticipated reduction in vascular risk. The overall aims of this thesis were to identified and characterize the humoral response towards HDL components and to evaluate the possible mechanisms that may contribute to the modifications of the anti-atherogenic properties of HDL. To achieve this objective we investigated: 1) the presence of aHDL antibodies in patients with systemic lupus erythematosus (SLE) and in patients with atherosclerosis-related clinical events, such as coronary artery disease (CAD), ischemic stroke (IS) and type 2 diabetes; 2) the association between the titres of aHDL antibodies and different clinical features of these diseases; 3) the modifications of the anti-atherogenic properties of HDL; 4) the biologic effect of aHDL antibodies isolated from serum of patients on the anti-oxidant and anti-inflammatory properties of HDL; 5) the effect of different pharmacologic treatments for dyslipidemia on the prevalence and activity of aHDL antibodies. The methodologies used in this work included immunologic-related techniques (e.g. enzyme-linked immunoabsorbent assay – ELISA, immunoturbidimetric immunoassay and immunoaffinity chromatography), biochemical techniques (enzymatic assays with quantification by spectrophotometry and luminescence methods), cell culture experiments and flow cytometry. Our results indicate that: 1) The titres of IgG aHDL, anti-apolipoprotein A-I (aApoA-I) and anti-paraoxonase 1 (aPON1) antibodies were higher in patients with SLE, CAD, IS and type 2 diabetes when compared with age and sex matched healthy controls. 2) The antibodies found in these patients were associated with decreased PON1 activity, (the enzyme responsible for most of the anti-oxidant effect of HDL), reduced total anti-oxidant capacity (TAC) of serum and increased biomarkers of endothelial dysfunction (nitric oxide metabolites, adhesion molecules, nitrotyrosine). In patients with SLE the antibody titres were associated with an increase in disease-related cardiovascular damage and activity whereas in patients with type 2 diabetes they were directly related with the fasting glucose plasma (FGP) levels and the glycosylated haemoglobin (HbA1c). 3) The antibodies isolated from serum of our patients, directly inhibited HDL-associated PON1 activity in a dose dependent way ranging from 7 to 52%. 4) The anti-inflammatory effect of HDL, measured by the percentage of inhibition of the cytokine-induced production of vascular adhesion molecules (VCAM-1), was reduced in more than 80% by aHDL antibodies isolated from our patients. 5) The HDL-induced angiogenesis by increasing vascular endothelial growth factor (VEGF) levels was abrogated in 65% by the antibodies isolated from serum of patients. 6) The current available pharmacologic agents for increasing HDL-C concentrations were associated with an increase in the titres of IgG aApoA-I antibodies. This increase was higher in the extended release niacin when compared to statins probably due to their dampening effect on oxidative stress. In conclusion, aHDL antibodies are present in different pathologic conditions. aHDL antibodies represent a family of self-reacting immunoglobulins, of which ApoA-I and PON1 might be the most relevant targets. These antibodies are biologically active, interfering with the HDL anti-oxidant and anti-inflammatory properties and, consequently, with the atherosclerotic process. The pathogenic potential of these antibodies may lead to the identification of a new biomarker for vascular disease, whilst presenting itself as a novel target for a different treatment approach which may redefine the treatment strategies and clinical trials design for HDL interventions in the future.

Equine protozoal myeloencephalitis (EPM), caused by the protozoan parasite Sarcocystis neurona, is one of the most important neurological diseases of horses in the Americas. While seroprevalence of S. neurona in horses is high, clinical manifestation of EPM occurs in less than 1% of infected horses. Factors governing the occurrence and severity of EPM are largely unknown, although horse immunity might play an important role in clinical outcome. We hypothesize that EPM occurs due to an aberrant immune response, which will be discernable in the equine IgG subisotypes a, b, and (T) that recognize S. neurona in infected diseased horses versus infected but clinically healthy horses. Based on previously-established serum antibody concentrations for IgG subisotypes in healthy horses, standard curves were generated and served to establish the concentration of antigen-specific IgG subisotypes in equine serum and CSF in infected diseased and infected normal horses. The subisotype concentrations and ratios between subisotypes were analyzed to assess whether neurological disease is associated with detectable differences in the antibody response elicited by infection. Results indicate a type I biased immune response in infected diseased horses, implicating the role of immunity in the development of EPM.

There are many studies done to determine factors what can cause susceptibility to Sjögren's syndrome. Despite intensive research of the immune system, the model of the Sjögren's syndrome pathogenesis is not completely clear. Lymphopenia is a common symptom found in the pSS patients. Numerous studies are performed in order to determine the causes of lymphopenia, but there is a lack of detailed studies to reveal which cell population counts increase or decrease. Scarce studies are done to associate the changes in the immune cell population and the expression of humoral factors in the peripheral blood of pSS patients. The aim of dissertation work was to investigate the changes of the components of the systemic immune response in the peripheral blood of patients with primary Sjögren's syndrome (pSS) with different manifestations of the disease. In this study, a comprehensive analysis of B, NK and T cell populations and humoral factors in the peripheral blood of pSS patients was performed. For the first time the expression of CD57 and CD27 markers on CD8+ T cell population was analyzed. For the first time Th17/Th1-like cells in the peripheral blood of pSS patients were identified and imbalance in the distribution of T helper cell population was revealed. It can be explained by the significant increase of Th17/Th1-like lymphocyte population. The levels of IL-27 and IL-35 in sera of pSS patients were measured (not in the model system) for the first time as well. Primary Sjögren’s... [to full text]
Pastaruoju metu ypatingai intensyviai tiriami veiksniai, kurie gali paskatinti išsivystyti sindromą. Nepaisant intensyvių imuninės sistemos tyrimų, Sjögreno sindromo (SS) patogenezės modelis nėra pilnai aiškus. Pirminiu Sjögreno sindromu (pSS) sergančiųjų kraujyje būdinga limfopenija. Siekiant nustatyti to priežastis atlikta nemažai tyrimų, tačiau trūksta detalesnių tyrimų, atskleidžiančių kokių ląstelių populiacijų padaugėja/sumažėja, bei kokių ląstelių subpopuliacijų sąskaita, tai vyksta. Trūksta tyrimų, kurie susietų imuninės sistemos ląstelių populiacijų pokyčius ir humoralinių veiksnių raišką. Šio darbo tikslas buvo įvertinti pirminiu Sjögreno sindromu sergančių pacientų su skirtinga ligos raiška sisteminio imuninio atsako komponentų pokyčius periferiniame kraujyje. Darbe buvo atlikta kompleksinė, detali B, NK, T limfocitų populiacijų, jų subpopuliacijų ir humoralinių veiksnių analizė sergančių pSS pacientų periferiniame kraujyje. Pirmą kartą pSS pacientų periferiniame kraujyje tirtos CD8+ limfocitų populiacijos pagal jų ekspresuojamus CD57 ir CD27 žymenis. Pirmą kartą pSS pacientuose, o ne modelinėse sistemose, ištirta IL-27 ir IL-35 raiška kraujo serume. Pirmą kartą identifikuoti Th17/Th1-like limfocitai pSS pacientų periferiniame kraujyje. Nustatyta, kad pacientų sergančių pSS periferiniame kraujyje Th limfocitų populiacijų pusiausvyra yra sutrikusi, ir to priežastimi reikšmingas Th17/Th1-like limfocitų populiacijos pagausėjimas. Sergantiesiems pirminiu Sjögreno... [toliau žr. visą tekstą]

The immune system in relation to dentistry is the topic of this chapter. Non-specific body defences are explored. Then follows specific body defences, humoral and cell mediated responses; antibody types and their mechanisms of action and the clinical application in immunization. Inflammation, both acute and chronic, is explored in relation to infections of dental origin and their complications. Problems with the immune system and hypersensitivity follow. Normal oral flora and dental plaque and the body’s response in periodontal inflammation are explored. The final section deals with the implications of what has gone before for infection control in the dental surgery.

This chapter reviews the functions of the immune system, which has evolved to provide a defence mechanism against microbial challenges, and is divided into two main branches, innate and adaptive. In addition, there are physical and chemical barriers, including skin, mucous membrane, mucous secretions, saliva, and various enzymes, and these contribute to the first line of defence against pathogens. The innate immune system provides the initial quick response for rapid recognition and elimination of pathogens, as opposed to the adaptive immune system, which has evolved to provide a more definitive and finely tuned response. The common central feature of both of these systems is the ability to distinguish between self and non-self. The recognition of non-self or ‘foreign’ pathogens and the subsequent immune response is orchestrated by a whole range of cells and soluble (humoral) factors in both innate and adaptive immune systems.

The gastrointestinal (GI) system is responsible for digestion and absorption, but also has important endocrine, immune and barrier functions. Additionally, the GI system plays a major role in fluid, electrolyte and acid-base balance. The GI system is regulated by complex myogenic, neural and humoral mechanisms, and, in health, these are affected by the presence of luminal nutrient, thereby modulating function of the GI system. Accordingly, GI function varies depending on whether a person is fasted or in the postprandial state. Adequate fasting and postprandial perfusion, motility and exocrine secretion are required for ‘normal’ functioning. The protective mechanisms of the GI system consist of physical (intact gut mucosa), non-immune (gastric acid, intestinal mucin, bile and peristalsis) and immune (gut-associated lymphoid tissue, GALT) elements. Disruption of GI protection is a putative mechanism underlying the development of multiple-organ dysfunction syndrome. Maintenance of GI function is increasingly recognised as an important factor underlying survival in critical illness.

Enteroviruses (EVs) comprise a genus in the Picornaviridae family. They are single-stranded RNA viruses and are common causes of human infection. Polioviruses, the prototypic EVs, were historically responsible for widespread outbreaks of paralytic poliomyelitis; now they are on the verge of global elimination through vaccination. More than 100 serotypes of nonpoliovirus EVs are described and are associated with a wide variety of diseases, ranging from respiratory infections, nonspecific febrile illnesses, herpangina, and hand-foot-and-mouth disease to meningitis, encephalitis, paralytic disease, myocarditis, chronic or disseminated infection in immunocompromised hosts (particularly those with defects in the humoral immune response), and severe disease in neonates. This chapter reviews disease manifestations during pregnancy and in neonates, with an emphasis on clinical presentation, diagnosis, and management. The newly emerging parechoviruses, important causes of central nervous system (CNS) disease, are also reviewed.

The chapter focuses on the role of immunity and inflammation in established cancer. From the evidence reviewed it is clear that immune and inflammatory responses, innate, humoral and adaptive, local and systemic, are intimately linked to the tumour and themselves and impact on cancer survival. It is also possible to identify key mediators that may be targeted in the cancer patient. However, further work is required to elucidate the mechanisms by which these immune and inflammatory responses are activated, maintained, and interact. Therapeutic intervention using non-selective anti-inflammatory agents is widely advocated and likely to become part of routine clinical practice in the near future. Selective therapeutic intervention directed at the immune and inflammatory responses in cancer is in its infancy. Therefore, it would appear that, at least in non-hereditary disease, immune and inflammatory responses are of key, if not of prime, importance in tumour progression and dissemination.

The analysis of the variation in the number, intensity and direction of correlations between the immune system and the gut microbiota of rats revealed that the T-, B-system and humoral immunity changes as well as cellular and humoral factors of an organism nonspecific defense are accompanied by changes of the Intestinal microbiota of intact and experimental rats