Introdução: A doação de plaquetas por aférese é um método de coleta que vem aumentando em relevância. Sabe-se que esta técnica apresenta inúmeras vantagens em comparação à doação de sangue total. Observamos que há uma preocupação na qualidade dos hemocomponentes enviados ao paciente, no entanto, não se observam muitas pesquisas em busca do cuidado com o doador. Órgãos como o Food and Drug Administration (FDA) já publicaram normas mais restritivas em relação à doação de plaquetas por aférese, pois pesquisas apontaram uma diminuição de algumas células e proteínas do sistema imunológico em doadores de repetição. Objetivos: Analisar doadores de plaquetas de repetição quanto a parâmetros hematimétricos e quantificação de subpopulações linfocitárias comparando-os com um grupo controle composto por doadores de sangue total que não doam há no mínimo um ano ou doando pela primeira vez e, ainda avaliar se a frequência de doações, o tempo de procedimento e o número de plaquetas doadas influenciam na contagem de leucócitos totais e nas subpopulações de linfócitos. Metodologia: Foram analisados 88 indivíduos em um estudo caso-controle, sendo que o grupo controle (CO) incluído foi de doadores de sangue total que haviam doado pela primeira vez ou haviam doado sangue total há mais de um ano. Os casos (CA) incluídos foram os doadores de repetição de plaquetaférese (quatro ou mais doações no último ano). O pareamento foi feito por sexo e idade. As amostras de sangue periférico foram coletadas em tubos contendo EDTA e analisadas em até 6 horas por citometria de fluxo, através da utilização de anticorpos monoclonais anti-CD3, CD4, CD8, HLADR, CD19 e CD56. Resultados: Foram avaliados 44 pares de doadores (caso vs controle). Destes, 81,8% eram homens, a média de idade dos grupos foi de 46 ±13 anos nos casos e 47 ±11 nos controles. Comparando os dois grupos, observou-se diferença estatisticamente significativa (p<0,05) na média de quantificação de leucócitos absolutos CA= 6476,6/μL vs CO=7115,4/μL (p=0,017), na média de linfócitos absolutos CA= 1862,6/μL vs CO= 2239,2/μL (p=0,007) e nos marcadores: CD3+/CD8+ (absoluto) CA= 437/μL vs CO= 597/μL (p=0,01), CD3+/CD4+(%) CA= 47,3/μL vs CO= 42,77/μL (p=0,007). Conclusões: Neste estudo foi possível observar que há uma diminuição em algumas células linfoides dos doadores de repetição em relação aos doadores convencionais, no entanto essa diferença não tem relevância clínica, demonstrando que os intervalos de doações que estes doadores estão sendo submetidos é adequado. A contagem de plaquetas dos doadores de repetição se mantiveram no decorrer do ano, este dado nos auxilia para mantermos um banco de dados de doadores de repetição com uma quantificação de plaquetas adequada, podendo ser convocado sem risco de ser bloqueado por contagem inferior ao preconizado. / Introduction: The donation of platelets by apheresis as a collection method has lately grown in relevance. This technique presents several advantages when compared to total blood donation. We understand there is a concern about the quality of the hemocomponents that are administered to the patients; however, there are not many researches concerned with caring for the donor. Entities such as the Food and Drug Administration (FDA) have published more restricting regulations regarding the donation of platelets by apheresis, since researches indicate a decrease in some cells and proteins present in the immunological systems of repeat donors. Objectives: To analyze repeat donors of platelets with regards to hematimetric parameters and quantification of lymphocyte sub-populations by comparing them with a control group consisting of total blood donors that have not donated blood for the past year at least or that are donating for the first time. Additionally, to evaluate if the frequency of donations, the duration of the procedure, and the donated platelet counts influence in the total leukocyte counts and in the sub-populations of lymphocytes. Methodology: We analyzed 88 individuals in a control case study. The control group (CG) consisted of total blood donors in their first donation or that had donated for the last time more than a year before. The cases (CA) included were the repeat donors by platelet apheresis (four or more donations in the past year). We matched the individuals by gender and age. Peripheral blood samples were collected in tubes containing EDTA and analyzed up until 6 hours later by flow cytometry, through monoclonal antibodies anti-CD3, CD4, CD8, HLADR, CD19, and CD56. Results: 44 pairs of donor were evaluated (case vs control). Among them, 81.8% were men, the average age of the groups was 46 (±13) years in the cases and 47 (±11) in the controls. When comparing the two groups, we observed a statistically significant difference (p<0,05) in the average of the quantification of absolute leukocytes CA= 6476.6/μL vs CG=7115.4/μL (p=0.017), in the average of absolute lymphocytes CA= 1862.6/μL vs CG= 2239.2/μL (p=0.007), and in the markers: CD3+/CD8+ (absolute) CA= 437/μL vs CG= 597/μL (p=0,01), CD3+/CD4+(%) CA= 47.3/μL vs CG= 42.77/μL (p=0.007). Conclusions: We were able to note in this study that there is a significant decrease in some lymphoid cells of repeat donors when compared to conventional donors. This difference, however, is not clinically relevant, which demonstrates that the donation intervals to which the donors are subject are appropriate. Platelet numbers of repeat donors remained the same throughout the year. This piece of data helps us keep a database of repeat donors with an adequate platelet number. These donors can be called for without risking of their being blocked in the screening for a number lower than the recommended.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2017-05-29T14:12:30Z No. of bitstreams: 1 Luciana Florencio Vilaca.pdf: 780940 bytes, checksum: f71ece6a621a081642573fed11311887 (MD5) / Made available in DSpace on 2017-05-29T14:12:31Z (GMT). No. of bitstreams: 1 Luciana Florencio Vilaca.pdf: 780940 bytes, checksum: f71ece6a621a081642573fed11311887 (MD5) Previous issue date: 2017-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The program of selection of goats with milk aptitude has been focused on the increase in milk quantity, neglecting factors related to resistance to diseases and milk composition. This behavior has led to studies aimed at the rapid detection of microorganisms and the identification of genes or chromosomal regions related to infectious diseases of the mammary gland. The objective of the present thesis was to detect Mycoplasma agalactiae (Ma) and Mycoplasma mycoides cluster (Mmcluster) in goat milk samples and to evaluate the composition and counting of somatic cells from Ma and Mmcluster positive animals (Experiment 1). In addition, we sought to identify Goat Lymphocyte Antigen (GoLA-DRB.2) gene polymorphisms and to associate them with goat milk characteristics (Experiment 2). To perform the experiment 1, 373 samples of goat milk of different races belonging to herds located in the states of Pernambuco and Paraiba were collected. The genomic DNA of the milk samples was extracted by the silica / guanidine isothiocyanate method, followed by the generic and species-specific amplification by polymerase chain reaction. Identification of the presence or absence of gene products was performed by direct observation of the bands of the PCR products visualized on electrophoresis gel. Analysis of variance and comparison tests of averages were performed to verify the effects of positivity on somatic cell composition and counting characteristics. The frequencies for Ma and Mmcluster were 43.21% and 5.70%, respectively, in the herds evaluated. The breeding system was considered as risk factors (p <0.001) and the racial pattern (p<0.001). Ma positive samples were detected in all genetic groups, with higher occurrence in the and Marota race. Positive samples for Mmcluster were only observed in Moxotó (18.28%), Parda Sertaneja (1.92%) and SPRD (3.12%) rats. In the study of association between positivity and milk composition, a statistical difference was observed for protein, casein and somatic cell counts. The detection of Mycoplasma in samples of goat milk suggests the introduction of infected animals in the evaluated herds, as well as the possible contact with the etiological agents in fairs and exhibitions. In addition, the breeding system adopted on the property influences the spread of the infection in the herd. For the execution of Experiment 2, a total of 181 female goats of different races from the state of Pernambuco and Paraiba were selected. Milk samples were harvested and extracted from genomic DNA as described in Experiment 1. The genotyping of the animals for the 285bp fragment of the GoLA-DRB.2 gene was the result of amplification by PCR-RFLP technique, using the enzymes of Restriction PstI and TaqI. The allelic frequency found for the total population using the PstI enzyme was A equal to 0.7254 and B at 0.2746, with the frequencies of the AA, AB and BB genotypes being 0.6740, 0.0387 and 0, 2873 respectively. The allele frequencies obtained from the digestion with the TaqI enzyme were C = 0.8149 and D = 0.1851, with the frequencies of the genotypes: 0.7403 (CC), 0.1492 (CD) and 0.1105 ( DD), with predominance of the CC genotype in all the racial standards evaluated. The observed Heterozygosity values were lower than those found for expected Heterozygosity in all tested populations with herds out of Hardy-Weinberg equilibrium. There was significant genetic variation between races, among individuals of the same race and within the population. There was no significant difference between genotypes and haplotype patterns on the values of fat, protein, lactose, total solids, casein and somatic cell counts. The GoLA-DRB.2 gene was polymorphic in the evaluation with the PstI and TaqI enzymes studied but had no effect on any of the somatic cell composition and counting characteristics evaluated. / O programa de seleção de caprinos com aptidão leiteira tem sido, basicamente, voltado ao aumento na quantidade de leite, negligenciando fatores relacionados à resistência a doenças e à composição do leite. Este comportamento vem ocasionando o direcionamento a estudos voltados à rápida detecção de micro-organismos e à identificação de genes ou regiões cromossômicas relacionadas a doenças infectocontagiosas da glândula mamária. Diante do exposto, a presente tese teve como objetivo inicial, detectar Mycoplasma agalactiae (Ma) e Mycoplasma mycoides cluster (Mmcluster) em amostras de leite caprino e avaliar a composição e a contagem de células somáticas provenientes de animais positivos para Ma e Mmcluster (Experimento 1). Além disso, buscou-se identificar os polimorfismos do gene Goat Lymphocyte Antigen (GoLA-DRB.2) e associar com características do leite de cabra (Experimento 2). Para realização do Experimento 1, foram colhidas 373 amostras de leite de caprinos de diferentes raças pertencentes a rebanhos localizados nos estados de Pernambuco e da Paraíba. O DNA genômico das amostras de leite foi extraído pelo método sílica/isotiocianato de guanidina, seguida da amplificação genérica e espécie-específica por reação em cadeia da polimerase. A identificação da presença ou não de produtos gênicos foi realizada através de observação direta das bandas dos produtos de PCR visualizados em gel de eletroforese. Análises de variância e testes de comparação de médias foram realizados para verificar os efeitos da positividade sobre as características de composição e contagem de células somáticas. As frequências para Ma e Mmcluster foram de 43,21% e 5,70%, nos rebanhos avaliados, respectivamente. Foram considerados fatores de risco o sistema de criação (p<0,001) e o padrão racial (p<0,001). Em todos os grupos genéticos foram detectadas amostras positivas para Ma, sendo observada maior ocorrência na raça Marota. Amostras positivas para Mmc só foram observadas em animais das raças Moxotó (18,28%), Parda Sertaneja (1,92%) e SPRD (3,12%). No estudo de associação entre a positividade e composição do leite, observou-se diferença estatística para as médias de proteína, caseína e contagem de células somáticas. A detecção de Mycoplasma em amostras de leite caprino sugere a introdução de animais infectados nos rebanhos avaliados, como também o possível contato com os agentes etiológicos em feiras e exposições. Além disso, o sistema de criação adotado na propriedade influencia a disseminação da infecção no rebanho. Para execução do Experimento 2, um total de 181 fêmeas caprinas de diferentes raças provenientes do estado de Pernambuco e da Paraíba foram selecionadas. Amostras de leite foram colhidas e submetidas à extração do DNA genômico como descrito no Experimento 1. A genotipagem dos animais para o fragmento de 285 pb do gene GoLADRB. 2 foi resultante da amplificação pela técnica de PCR-RFLP, utilizando as enzimas de restrição PstI e TaqI. A frequência alélica encontrada para a população total com a utilização da enzima PstI foi de A igual a 0,7254 e B a 0,2746, sendo as frequências dos genótipos AA, AB e BB de 0,6740, 0,0387 e 0,2873, respectivamente. As frequências alélicas obtidas a partir da digestão com a enzima TaqI foi de C = 0,8149 e D = 0,1851, sendo as frequências dos genótipos: 0,7403 (CC), 0,1492 (CD) e 0,1105 (DD), com predominância do genótipo CC em todos os padrões raciais avaliados. Os valores da Heterozigosidade observada foram menores do que os encontrado para Heterozigosidade esperada em todas as populações testadas, com rebanhos fora do equilíbrio de Hardy-Weinberg. Houve variação genética significativa entre raças, entre indivíduos da mesma raça e dentro da população. Não houve diferença significativa entre os genótipos e os padrões de haplótipos sobre os valores de gordura, proteína, lactose, sólidos totais, caseína e contagem de células somáticas. O gene GoLA-DRB.2 foi polimórfico na avaliação com as enzimas PstI e TaqI estudadas, mas não desempenhou efeitos sobre nenhumas das características de composição e contagem de células somáticas avaliadas.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / As reaÃÃes alÃrgicas a fÃrmacos representam um terÃo das reaÃÃes adversas a medicamentos, e embora sejam pouco freqÃentes, apresentam altas taxas de morbidade e mortalidade, revelando um importante problema de saÃde pÃblica. Os principais desafios relacionados com a hipersensibilidade a fÃrmacos decorrem do fato de sua imprevisibilidade, de que nÃo existe um modelo animal para pesquisa e devido à variabilidade individual no que diz respeito ao metabolismo do fÃrmaco. As reaÃÃes alÃrgicas a medicamentos sÃo difÃceis de serem diagnosticadas, uma vez que hà carÃncia de mÃtodos laboratoriais para sua investigaÃÃo. O presente estudo teve como objetivo estabelecer alguns mÃtodos imunolÃgicos in vitro para o diagnÃstico de alergia a medicamentos. Vinte pacientes atendidos no AmbulatÃrio de Dermatologia do Hospital UniversitÃrio Walter CantÃdio, Universidade Federal do CearÃ, com manifestaÃÃes muco-cutÃneas e sistÃmicas decorrentes de hipersensibilidade a fÃrmacos foram investigados atravÃs de histÃria clÃnica, exames laboratoriais in vivo e in vitro. Foram avaliados os marcadores de ativaÃÃo de linfÃcitos CD25 e CD69 atravÃs de citometria de fluxo, em cÃlulas mononucleares do sangue perifÃrico previamente incubadas com diferentes concentraÃÃes do fÃrmaco suspeito, e anÃlise das citocinas interferon &#947; e interleucina 5 no sobrenadante da cultura atravÃs de teste imunoenzimÃtico. Dezoito pacientes foram submetidos aos testes cutÃneos, sendo que nove mostraram resultados positivos a um ou mais fÃrmacos. Quinze pacientes apresentaram positividade para pelo menos um dos marcadores de ativaÃÃo em resposta ao fÃrmaco suspeito. Os marcadores CD69 e/ou CD25 foram expressos pelas cÃlulas T CD4+ e CD8+, tanto em reaÃÃes imediatas como nas nÃo imediatas. A comparaÃÃo dos Ãndices de estimulaÃÃo desses marcadores entre pacientes e indivÃduos saudÃveis nÃo alÃrgicos, resultou em diferenÃa significativa para CD4+CD69+ nas trÃs concentraÃÃes do fÃrmaco suspeito e para CD4+CD25+ apenas na menor concentraÃÃo do fÃrmaco suspeito. Nenhuma diferenÃa significativa para as citocinas IFN-&#947; e IL-5 foi observada entre os pacientes e os indivÃduos controles. A detecÃÃo de ambos os marcadores de ativaÃÃo CD69 e CD25 aumentou a sensibilidade diagnÃstica do teste. O uso combinado dos marcadores representa uma ferramenta promissora no diagnÃstico laboratorial das reaÃÃes alÃrgicas a medicamentos. NÃo obstante, essa hipÃtese deve ser confirmada com um nÃmero maior de pacientes e controles. / Drug allergy reactions represent one third of adverse drug reactions, and although they are infrequent, they present high rates of morbidity and mortality, revealing a major public health problem. The main challenges related to drug hypersensitivity result from its unpredictability, no animal model for research and individual variability with regard to drug metabolism. Drug allergy reactions are difficult to be diagnosed once there is a lack of laboratorial tests for their investigation. The present study aimed to establish some immunological in vitro methods for diagnosing drug allergy. Patients (n=20) attending a dermatology outpatient clinic, Hospital Universitario Walter CantÃdio, Universidade Federal Ceara, with mucocutaneous and systemic manifestations due to drug hypersensitivity were investigated by clinical history, laboratory findings, and in vivo and in vitro tests. The lymphocyte activation markers, CD25 and CD69, were evaluated by flow cytometry on the peripheral blood mononuclear cells previously incubated with different concentrations of the suspected drug, and analysis of interferon &#947; and interleukin 5 was done in the culture supernatant by enzyme immunoassay. Eighteen patients were tested by skin tests; nine patients showed positive results to one or more drugs. Fifteen patients showed positivity for at least one of activation markers in response to the suspected drug. The markers CD69 and/or CD25 were expressed by T cells CD4+ and CD8+, both in immediate and delayed reactions. Comparing stimulation index of the markers between patients and healthy no allergic individuals, it was observed a significant difference for CD4+CD69+ in the three suspected drug concentrations and CD4+CD25+ only in the lower drug concentration. No significant differences were found for the cytokines IFN-&#947; and IL-5 between patients and healthy individuals. The detection of both activation markers CD69 and CD25 increased the diagnostic sensitivity of the test. The use of both markers represents a promising tool in drug allergy diagnosis. Nonetheless, this hypothesis needs to be confirmed with a greater number of patients and controls.

A abordagem imunoterapêutica do câncer tem sido cada vez mais explorada. Entre os fatores que a tornam atraente, mas também a limitam, está o uso de material antigênico do próprio paciente. Assim, pretendeu-se estabelecer condições de extração e amplificação de mRNA tumoral, como fonte renovável de antígenos. Pretendeu-se avaliar também a eficácia da vacina, com o uso de monócitos transfectados com RNA tumoral total para mimetismo das células tumorais. Diferentes concentrações (0,1 mg a 10 mg) de RNA total de SK-BR-3 e diferentes tempos (12, 24 e 48 h) foram usados para transfecção. Na avaliação do potencial linfo-estimulador dos monócitos foi usado o ensaio de proliferação linfocitária e a secreção de citocinas durante a co-cultura. Como resultado viu-se que monócitos transfectados se tornaram mais ativados e foram capazes de induzir linfoproliferação. Esses resultados indicaram ser possível o desenvolvimento de um método para avaliação das respostas celulares induzidas contra células tumorais em pacientes com câncer que foram vacinados. / The cancer immunotherapeutic approach has been increasingly exploited. Among the factors that make it attractive, but also limited, is the use of patient antigenic material. Thus, we propose to establish conditions for extraction and amplification of mRNA tumor, as renewable source of antigens. It is also intended to assess the vaccine effectiveness, using monocytes transfection with total tumor RNA for mimicry the tumor cells. Different concentrations (0.1 to 10 mg) of SK-BR-3 total RNA and different times (12, 24 and 48 h) were used in transfection. To assess the lympho-stimulator potential of transfected monocytes was used the test of lymphocyte proliferation, and cytokines secretion during co-culture. The result was that transfected monocytes became more activated and were able to induce lymphoproliferation. These results indicated that the development of a method for evaluating cellular responses induced against tumor cells in cancer patients who were vaccinated is possible.

Triptofano (TRP) é metabolizado por duas vias, a via serotonérgica e a via das quinureninas. Na via serotonérgica, TRP é metabolizado a serotonina (5-HT) e, em algumas células, à melatonina (MLT) que pode ser oxidada à N1-acetil-N2-formil-5- metoxiquinuramina (AFMK) e N1-acetil-5-metoxiquinuramina (AMK) por ação de peroxidases. Na via das quinureninas o TRP é diretamente metabolizado à N formilquinurenina (NFK) e em seguida a quinurenina (QUIN). A enzima indolamina 2, 3 dioxigenase (IDO) é uma das responsáveis por esta reação. Dada a importância da IDO na tolerância imunológica e pelo fato desta enzima ser induzível nos propusemos a avaliar a existência de uma regulação cruzada entre esta enzima e a via serotonérgica. Avaliando a interferência de AMK sobre a ação de IDO e a interferência de QUIN sobre a formação de AFMK por peroxidases, observamos uma possível interação entre as vias. AMK é um inibidor competitivo clássico de IDO e o Ki encontrado foi de 0,98 mM. QUIN é um inibidor acompetitivo linear simples da formação de AFMK e o Ki encontrado foi de 0,1 mM. A inibição da formação de AFMK também ocorre para a peroxidase humana (mieloperoxidase, MPO). Além de representarem uma regulação cruzada utilizada in vivo, as inibições encontradas podem ser relevantes para a proposta de novos inibidores de IDO e MPO na terapia imunomodulatória. Dado o nosso interesse pelas enzimas IDO e MPO, avaliamos ainda a localização intracelular destas enzimas em células de peritônio de camundongo, tanto residente como ativada com concanavalina A (Con A). O estímulo com Con A representa uma ativação de linfócitos T mediado por interferon gama (IFN-&#947;) e foi usado como modelo experimental para avaliar condições de localização em células ativadas. Por imunocitoquímica verificamos que IDO e MPO localizam-se próxima à membrana plasmática sendo que uma leve dispersão apenas de MPO foi observada em células ativadas com Con A. A localização intracelular das duas enzimas é no citoplasma, vesículas e núcleo. Curiosamente, verificamos MPO em células isoladas e também em agrupamentos celulares de duas ou mais células. Por citometria de fluxo identificamos macrófagos, linfócitos B1 e agrupamentos celulares como células que contém MPO. A mobilização de MPO durante a ativação celular, a presença de MPO em linfócitos e a presença de MPO e IDO em núcleos são informações novas que sugerem novas atividades para estas enzimas. / Tryptophan (TRP) is metabolized by two mains pathways, the serotoninergic pathway and the kynurenine pathway. In the serotoninergic pathway, TRP is metabolized to serotonin (5-HT) and, in some cells, to melatonin (MLT). The later can even be oxidized to acetyl-N1-N2-formyl-5-methoxykynuramine (AFMK) and N1-acetyl-5 -methoxykynuramine (AMK) by peroxidases. In the kynurenine pathway, TRP is metabolized to N-formylkynurenine (NFK) and to kynurenine (KYN). Indoleamine 2, 3 dioxygenase (IDO) is one of those responsible for this reaction. Since IDO is importat in immune tolerance and the fact that this enzyme is inducible by cytokines we proposed whether there is a cross regulation between this enzyme and the serotoninergic pathway. A possible interaction between MLT and TRP oxidation pathways was shown by the AMK influence on IDO activity and QUIN interference on AFMK formation by peroxidases. AMK was shown to be an IDO classical competitive inhibitor with a Ki of 0.98 mM. QUIN was a peroxidase (horseradish peroxidase, HRP) classical uncompetitive inhibitor and Ki was found to be 0,1 mM. AFMK formation inhibition was also found in human peroxidase (myeloperoxidase, MPO). Beyond the in vivo crosstalk, new IDO and MPO inhibitors in immunomodulatory therapy would be proposed by the compounds shown in this study. Given our interest in IDO and MPO, we also evaluated their intracellular localization in both resident and concanavalin A (Con A) activated mice peritoneum cells. Con A stimulation is a IFN-&#947; mediated T lymphocytes activation and was our experimental model to evaluate activated cells. In light microscopy we observed IDO and MPO localization near the membrane and MPO only had a dispersed localization in Con A activated cells. Cytoplasm, nucleus and vesicles were the intracellular localization of both enzymes. Interestingly, we found MPO in isolated cells and in cell clusters of two or more cells. MPO was founded on macrophages, B1 cells and cell clusters by flow cytometry. The MPO mobilization during cell activation, the presence of MPO in lymphocytes and the presence of MPO and IDO in nuclei are new informations to suggest new activities for these enzymes.

La synapse immunologique est une structure qui se forme à l’interface entre un lymphocyte T et une cellule présentatrice d’antigène lors de la reconnaissant d’un antigène étranger spécifique. Cette plate‑forme est actuellement considérée comme le lieu d’où est déclenchée la cascade de signalisation moléculaire conduisant à l’activation lymphocytaire. Les travaux présentés dans ce manuscrit décrivent un autre pôle de signalisation localisé sur le lymphocyte T, à l’opposé de la zone de contact. Ce pôle a été nommé antisynapse. On peut détecter cette structure dans la première minute avant le contact, avant l’apparition de la synapse immunologique. Elle contient les composants classiquement décrit à la synapse immunologique. Sa formation est indépendante de la reconnaissance d’antigène et déclenchée par l’adhésion entre les cellules. Plusieurs fonctions potentielles sont étudiés, l’antisynapse agit notamment comme un réservoir de molécules qui sont transférées à la synapse immune de manière dépendante des microtubules. L’antisynapse peut également être considérée comment une pre-synapse déclenchée avant la reconnaissance d’antigène. / The immunological synapse forms at the interface between a T cell and an antigen-presenting cell after foreign antigen recognition. The immunological synapse is considered to be the site where the signaling cascade leading to T lymphocyte activation is triggered. In this manuscript, we show that another signaling region can be detected before formation of the synapse at the opposite pole of the T cell. This pole has been named antisynapse. This structure appears during the first minute after the contact forms, is transient and contains all the classic components that have been previously described at the immunological synapse. Its formation is independent of antigen recognition but is driven by adhesion itself. Some potentials functions à discussed here, it constitutes a reservoir of signaling molecules that are potentially ready to be sent to the immunological synapse through a microtubule-dependent pathway. The antisynapse can thus be considered as a pre-synapse that is triggered independently of antigen recognition.

Cytotoxicity is the capacity for immune cells to kill infected or malignant cells in order to eliminate pathogens and tumours through different mechanisms including the exocytosis of perforin-containing cytosolic granules. This crucial property is usually restricted to specialized innate and adaptive lymphocytes such as natural killer (NK) cells and CD8 T cells. T lymphocytes differentiate in the thymus and are delivered to the peripheral blood as naive T cells committed to either the CD8 or the CD4 lineage. CD8 T cells are programmed to acquire cytotoxic effector functions under the control of the transcription factor (TF) Runx3. The fate of CD4 T cells is to acquire multiple helper functions through the action of the TF ThPOK that promotes CD4 helper functions and restricts the CD8 cytotoxic program. However, this restriction is not absolute as cytotoxic CD4 (CD4CTX) T cells differentiate in vivo, indicating that the multipotency of human naive CD4 T cells includes the ability to acquire perforin expression and potent cytotoxicity in vitro and ex vivo. This cytotoxic potential correlates with outcome in human pathology and mediates protection against viral challenge and tumour eradication in murine models. CD4CTX T cells are terminally differentiated effector memory T cells that accumulate during cytomegalovirus chronic infection and ageing. They are phenotypically and functionally related to T helper type 1 (Th1)-effector memory cells. However, whether they belong to the Th1 pathway or constitute a separate specialized helper T cell subset is unknown. In this work, we show that CD4CTX T cell differentiation is an integral part of the Th1 pathway. Indeed, CD4 T cells acquire cytotoxic potential early in the memory differentiation process as central memory Th1 but not Th2 and Th17 cells are epigenetically primed to develop a cytotoxic program. The expression of perforin and other cytotoxic genes present a stepwise increase profile that is specific of the Th1 differentiation pathway. This profile has been recapitulated in an in vitro model of effector CD4 T cell differentiation in which naive CD4 T cells acquire cytotoxicity one to two weeks after polyclonal stimulation when cultured in presence of Th1 cytokines. The molecular regulation of CD4CTX T cells is poorly understood and most available data have been generated in mice. These data include the observation of intraepithelial CD4CTX T cells in the mouse gut after loss of ThPOK expression and subsequent up-regulation of a Runx3-dependent cytotoxic program. Other candidate regulators of CD4 T cell cytotoxic function include the TF regulating Th1 and CD8CTX T cells differentiation such as Runx3, T-bet and Eomesodermin (Eomes). We show that the transcriptional program of human CD4CTX T cells is enriched in CD8-lineage genes. However, by contrast to CD4CTX T cells from the mouse intestine, human circulating CD4CTX T cells maintain the expression of ThPOK and even up-regulate this TF upon differentiation from naive CD4 T cells. Surprisingly, this sustained expression of ThPOK was compatible with the establishment of a T-bet- and Runx3-dependent cytotoxic transcriptional program. The specific knockdown of T-bet or Runx3 but not Eomes resulted in impaired cytotoxic differentiation whereas ThPOK knockdown enhanced perforin expression and cytotoxicity. We propose that CD4CTX T cells constitute the terminal stage of Th1 memory differentiation and that ThPOK, Runx3 and T-bet co-regulate this process by instructing a cytotoxic transcriptional network largely shared with CD8CTX T cells. The modulation of this network is a potential target for novel immunotherapeutic strategies in viral infections and cancer. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished

Les récepteurs du Fc des Immunoglobulines G (FcγR) sont impliqués dans de nombreuses réactions immunitaires. Deux groupes de faible affinité existent : les FcγRIIa/b/c et les FcγRIIIa/b, FcγRIIb étant le seul inhibiteur. Plusieurs polymorphismes, modifiant l’affinité au ligand et la réponse du récepteur, sont favorisés par une pression de sélection infectieuse et associés aux Maladies Auto-Immunes (MAI). Nous avons étudié l’association des polymorphismes FcγRIIa-R131H, FcγRIIb-I232T, FcγRIIIa-F158V, FcγRIIIb-Na1/Na2 aux Lupus érythémateux systémique (LES), la neuromyélite optique (NMO) et la sclérose en plaque (SEP) en Martinique. Nos résultats montrent une forte fréquence des allèles T232, V158 et des génotypes 232TT et 158VV dans la population générale, une augmentation de la fréquence de l’homozygote Na1, des allèles Na1 et 158F dans le LES, une augmentation du génotype 131RR ainsi que des allèles 131R et 158V dans le LES avec atteinte rénale, une augmentation du génotype 131RR et une diminution du NA2/NA2 dans la SEP ainsi qu’une augmentation de l’allèle 232T dans les NMO. L’étude de l’influence du FcγRIIb-I232T sur l’activation du récepteur à l’antigène des lymphocytes B (BCR) chez des lupiques et des témoins sains porteurs des formes IT, TT ou II montre que la régulation du BCR est effective même en présence de la forme TT. Ces résultats démontrent pour la première fois que la population martiniquaise possède un terrain génétique particulier qui faciliterait l’apparition de MAI avec pronostic plus sévère. / Receptors of Fc of Immunoglobulin G (FcγR) are involved in many immune responses. Two low affinity groups exist: FcγRIIa/b/c, and FcγRIIIa/b, FcγRIIb is the only inhibitor. Several polymorphisms, altering the affinity ligand and receptor response, are selected by an infectious pressure and associated with autoimmune diseases (AID). We studied the association of polymorphisms FcγRIIa-R131H, FcγRIIb-I232T, FcγRIIIa-F158V, FcγRIIIb-Na1/Na2 to systemic lupus erythematosis (SLE), neuromyelitis optica (NMO) and multiple scelrosis (MS) in Martinique. Our results show a high frequency of alleles T232, V158 and 232TT and 158VV genotypes in Martinican, an increase in the frequency of the homozygous Na1, Na1 and 158F alleles in SLE, an increase of 131RR genotype, the 131R and 158V alleles in SLE with kidney disease, an increase of 131RR genotype and a decrease of NA2 / NA2 in MS but an increase in the 232T allele in NMO. Study of the influence of FcγRIIb-I232T on the activation of the B cells receptor (BCR) in lupus and healthy controls controls exibiting IT, TT or II forms, shows that the regulation of BCR is effective even in the presence TT form. These results show for the first time Martinican population has a particular genetic background which would facilitate the appearance of MAI particularly serious.

Lors de la reconnaissance de leur antigène spécifique, les lymphocytes B vont s’activer et interagir avec les autres cellules des organes lymphoïdes secondaires (cellules folliculaires dendritiques, lymphocytes T, …) pour former un centre germinatif où le locus IgH va être remanié afin d’accroitre l’affinité des immunoglobulines pour l’antigène (grâce à l’hypermutation somatique des régions variables (SHM) et de décliner l’activité effectrice des anticorps selon plusieurs types de fonction grâce à la commutation de classe des régions constantes ou « switch u CSR», afin d’éliminer selon diverses stratégies l’antigène . Ces deux mécanismes sont initiés par l’Activation Induced Deaminase (AID) qui cible l’ADN au niveau des cytosines pour les changer en uracile, aboutissant à des cassures simple brin ou double brin lorsque que les mésappariements sont proches les uns des autres.Il a été montré qu’AID est capable de cibler la région régulatrice en 3’ du locus IgH au niveau de régions LS, action qui aboutit à la délétion complète des gènes C du locus, à la perte de l’expression du BCR et à la mort cellulaire lors de la recombinaison suicide du locus (LSR). Dans notre étude, nous avons réalisé un modèle knock-in du gène Cμ humain en aval de la dernière région LS dans le but de sauver les cellules B réalisant la LSR sur les dernières régions LS par l’expression d’un BCR humanisé (modèle LSR-μKI). Notre modèle indique que l’insertion du gène Cμ humain en aval de l’élément hs4 de la 3’RRpermet en effet de remplacer certaines recombinaisons LSR par un switch vers l’expression d’IgM humanisée », et module en outre qualitativement certains aspects de la réponse immunitaire humorale. Notre modèle « rapporteur » de la LSR suggère aussi que l’évènement de LSR est un phénomène régulé qui augmente avec l’activation B. L’étude ex vivo de cellules B issues du modèle suggère que la LSR est possible lors d’une réponse T indépendante comme T dépendante. Elle se montre aussi inductible par les ligands TLR4 mais non TLR9. L’étude du répertoire des IgM humaines indique une utilisation biaisée des familles de VH, avec notamment sur utilisation de la famille VH5murine, suggérant donc que l’incidence de la LSR varie avec la structure des régions variables du BCR et pourrait donc être dépendante de l’affinité contre des antigènes/ligands qui restent à caractériser. / After antigen recognition, B cells are activated and interact with other cells within secondarylymphoid organs (dendritic cells, T lymphocytes …) to form a germinal center. In the GC, the IgH locusis reorganized in order to increase the affinity of immunoglobulins for antigen through somatichypermutation (SHM) of V(D)J regions and to configure them into several forms harboring diversifiedmodes of action after “class switc recombination” (CSR). Both mechanisms are initiated by ActivationInduced Deaminase (AID) which targets DNA cytosines to convert them into uracil, then causing singleor double strand breaks in DNA when the mismatchs are located close to each other. It has been shownthat AID can target the IgH locus 3’ regulatory region on specific regions called LS, then leading to thetotal deletion of IgH locus C genes, loss of BCR expression and cell death by locus suicide recombination(LSR). In our study, we created a human Cμ knock-in model distal to the hs4 element of the 3’RR, in anattempt to rescue cells after the LSR event. Our model showed that this insertion indeed succeededinto replacing LSR by “class switching to humanized IgM” and also qualitatively modulated someaspects of the humoral response. This new LSR reporter model additionally supports the hypothesisthat LSR is regulated and increases with B cell activation. Studies of ex vivo B cells from the modelsuggest that LSR can occur in T dependent and independent manners, but is induced by triggering TLR4but not TLR9. Studies of the human IgM repertoire showed a biased use of VH families, and notably themouse VH5 family was used more frequently than in the control group. The BCR repertoire bias stronglysuggests that LSR is at least in part a matter of affinity of the BCR variable regions for antigens andligands that remain to be characterized.

Doctorat en Sciences / info:eu-repo/semantics/nonPublished