Abstract available through the Journal of Investigative Medicine.

Abstract available through the Journal of Investigative Medicine.

Les particules fines atmosphériques (PF) sont capables de pénétrer dans les poumons où certains composés transportés peuvent interagir avec les cellules pulmonaires et atteindre la circulation sanguine. L'exposition aux PF affecte particulièrement les populations sensibles telles que les personnes agées. Cette thèse s'inscrit dans une démarche d'identification des effets des PF sur les lymphocytes T humains (LT) tout en visant à déterminer des biomarqueurs liés à l'exposition et à évaluer la variation de la réponse cellulaire en fonction de l'âge. Des LT ont été isolés de prélèvements sanguins de 91 volontaires appartenant à trois classes d'age (20-30, 45-55, 70-85 ans) puis exposés ex vivo pendant 72h à 45 µg/µl de PF collectées à Dunkerque. Les étapes d'isolement, purification et activation des LT ont d'abord été optimisées. Suite à la caractérisation de la population échantillonnée, une population d'étude homogène a été sélectionnée ( 10 sujets / classe d'âge). Nous avons mis en évidence une induction génique d'enzymes impliquées dans l'activation métabolique des HAP identifiés dans l'échantillon de PF. La caractérisation du profil des Lt a permis de proposer un profil mixte Th1/Th2 causé par l'exposition. L'étude transcriptomique des miARN a mis en évidence une surexpression de miR-124-3p impliqué dans la régulation de plusieurs fonctions au niveau du système immunitaire et de miR-1290 impliqué dans plusieurs types de cancer. Quant à l'influence de l'âge, une surexpression des gènes codant pour les enzymes antioxydantes (NQO1 et HMOX1), une augmentation de la concentration des cytokines (IL-4 et IL-13) ainsi qu'une modification du profil d'expression de certains miARN ont été notées chez les sujets les plus âgés. / Atmospheric fine particulate matter (FP) are able to enter the lungs where some compounds can interact with lung cells and reach the bloodstream . Exposure to FP affects in particular susceptible populations such as the elderly. This thesis is part of a project aiming to identify the effects of FP on human T lymphocytes (LT) while attempting to determine biomarkers related to exposure and to evaluate the variation of the cellular response as a function of age. LT were isolated from blood samples of 91 volunteers belonging to three age groups (20-30, 45-55, 70-85 years) then exposed ex vivo for 72h to 45 µg/µl of FP collected in Dunkirk. The steps of isolation, purification and activation of LT were first optimized. Following the characterization of the sampled population, a homogeneous study population was selected (10 subjects/age class). We have demonstrated an induction of the genes coding for the enzymes involved in the metabolic activation of PAH identified in the PF sample. Characterization of the LT profile made it possible to propose a mixed th1/th2 profile cause by the exposure. Teh transcriptomic study of miRNAs revealed an overexpression of miR-124-3p involved in the regulation of several functions in the immune system and miR-1290 involved in several types of cancer. As for the influence of age, overexpression of the genes coding for the antioxidant enzymes (NQO1 and HMOX1), an increase in the concentration of cytokines (IL-4 and IL-13) as well as a modification of the expression profile of some miRNAs were noted on the elderly.

Made available in DSpace on 2014-07-29T15:07:56Z (GMT). No. of bitstreams: 1 Dissertacao Julia de Miranda Moraes.pdf: 1781008 bytes, checksum: 240b1d82cc44d5f20591020197abd396 (MD5) Previous issue date: 2008-03-03 / The Curraleiro cattle are extremely docile and resistant to infectious diseases and parasites. They may be used in exploration of low-quality pastures, without great investments, when other breeds could show a low productivity or even survival difficulties. This genetic potential runs risk to extinction due to its replace by more productive breeds. The Curraleiro cattle resistence to illness is popularly known and many works has been published about it, although its immunologic system physiology is completely unknown. Such features are plausible reasons for the preservation of this potentially genetic resource. So, the mean aim of this study was to establish an immunological profile by marking and quantification of T and B lymphocytes in Curraleiro breed with immunocytochemistry. Thus, it was used 116 bovines, male and female, with different ages from two farms situated at Goiás State, Brazil. The animals were allotted in groups according to age, sex and origin. Blood samples were collected and processed in accordance with immunocytochemistry standard technique using lymphoid markers species-specific, anti-CD3 (MM1A BoCD3) and anti-LB (LCTB16A clone B-B14), for T and B lymphocytes counting, respectively. All procedures were accomplished at Veterinary School, Federal University of Goiás, Brazil. The data were submitted to descriptive statistics and then to Kruskall Wallis and Mann-Whitney tests. The results showed decreased levels of leukocytes, lymphocytes, T lymphocytes and B lymphocytes along the age advance. Absolute values of leukocytes, lymphocytes and T lymphocytes were higher in males than females. None of the evaluated parameters were affected by differences of the management carried out at two farms. / O gado Curraleiro é extremamente dócil, resistente às doenças e parasitas, que pode ser utilizado, sem grandes investimentos na exploração de pastagens naturais de baixa qualidade onde outras raças teriam baixa produtividade ou até mesmo dificuldades de sobrevivência. Todo esse potencial genético encontra-se em sério risco de extinção, uma vez que esses animais vêm sendo substituídos por outros com maior produtividade. A resistência do Curraleiro às enfermidades é popularmente conhecida e divulgada, porém desconhece-se por completo a fisiologia do sistema imunológico desses animais. Estas características são notáveis justificativas para conservar este recurso genético potencialmente importante. Assim, este estudo teve por objetivo traçar um perfil imunológico, através de marcação imunocitoquímica e quantificação de linfócitos T e B em bovinos da raça Curraleiro. Para tal, foram utilizados 116 animais entre machos e fêmeas, de diferentes faixas etárias, provenientes de duas propriedades de criação de gado Curraleiro do Estado de Goiás, sendo alocados em grupos conforme a faixa etária, sexo e origem. As amostras de sangue foram colhidas e processadas de acordo com o padrão da técnica de imunocitoquímica e posteriormente utilizados os marcadores linfóides espécieespecíficos, anti-CD3 (MM1A BoCD3) e anti-LB (LCTB16A clone B-B14), para a quantificação de linfócitos T e linfócitos B, respectivamente. Todo procedimento foi realizado na Escola de Veterinária da UFG. Inicialmente os dados foram submetidos à estatística descritiva e posteriormente ao teste de Kruskall Wallis e Mann-Whitney. Com o avançar da idade, diminuíram-se os níveis de leucócitos, linfócitos, linfócitos T e linfócitos B. Os valores absolutos de leucócitos, linfócitos e linfócitos T foram maiores nos machos em relação às fêmeas. Nenhum dos parâmetros avaliados sofreu influência em relação à diferença de qualidade de manejo nas duas propriedades.