Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Estudos em diferentes populaÃÃes tÃm mostrado que a vacinaÃÃo com a BCG concede proteÃÃo parcial contra a hansenÃase. Entretanto, a necessidade da revacinaÃÃo e seu impacto na resposta imune contra antÃgenos do Mycobacterium leprae à pouco compreendida, principalmente nas crianÃas que sÃo contatos destes pacientes com hansenÃase, e constituem uma populaÃÃo de risco para o adoecimento. Neste estudo, investigamos o papel da revacinaÃÃo com a BCG na modulaÃÃo da resposta imune em contatos menores de quinze anos de pacientes com hansenÃase. Amostras de sangue perifÃrico de vinte e cinco crianÃas, vacinadas com a BCG ao nascer, foram coletas antes e dois meses apÃs a revacinaÃÃo com a BCG. Suas cÃlulas mononucleares (PBMC) foram estimuladas com proteÃnas e peptÃdeos do M. leprae, dosando-se as quantidades de IFN-γ e IL-10 por ELISA. Anteriormente a revacinaÃÃo, foram coletas amostras para dosagem de IgM e IgG anti-PGL-1 e realizado o teste tuberculÃnico (PPD) para avaliaÃÃo da eficÃcia vacinal apÃs a revacinaÃÃo. Identificamos o potencial papel da BCG em estimular a produÃÃo de IFN-γ e/ou IL-10 dependendo do antÃgeno e da idade do contato, sem relaÃÃo com o PPD e sorologia anti-PGL-1. Estes resultados sugerem que a BCG modula a resposta imune dos contatos frente aos antÃgenos do M. leprae, com o frequente aumento nos nÃveis de IFN-γ, frente ao MLT, nas crianÃas com idade entre 1 a 4 anos (4.203 + 539,2 pg/mL prÃ-BCG x 9.141 + 860,9 pg/mL pÃs-BCG, p=0,001). Jà os contatos entre 5 a 9 anos mostram aumento na produÃÃo de IL-10 (210 +39,4 pg/mL prÃ-BCG x 680 + 76,74 pg/mL pÃs-BCG, p=0,001) e IFN-γ (4.912 + 1.065 pg/mL x 9.249 + 1.171 pg/mL, p=0,024). Estes achados sÃo acompanhados com o aumento dos casos de hansenÃase em crianÃas entre 5 a 9 anos na comunidade. Entretanto, nos contatos entre 10 a 15 anos a revacinaÃÃo falha em induzir o aumento de IFN-γ e IL-10. Os contatos de MB produziram, simultaneamente, altos nÃveis de IFN-γ e IL-10 em resposta ao MLT, enquanto que os contatos de PB somente produziram altos nÃveis de IFN-γ apÃs a revacinaÃÃo. A produÃÃo de IFN-γ e IL-10 frente aos peptÃdeos sintÃticos p38 e p69 indica que estes antÃgenos podem ser possÃveis marcadores de infecÃÃo. Assim, a BCG pode ser protetora, sendo eficiente em induzir o aumento da resposta por IFN-γ nestes contatos, frente aos antÃgenos do M. leprae. / Studies in different populations have shown that vaccination with BCG provides partial protection against leprosy. However, need of boost BCG vaccination and your impact in response immune against antigens of Mycobacterium leprae is poorly understood, mainly in children who are contacts of these patients with leprosy, and constitute population of risk for illness. This study, we investigated the paper a second dose of BCG given to contacts of leprosy patients under the age of fifteen years in modulate the response imune. Blood samples of twenty five children, who received a first dose of BCG at birth, were collected immediately before and two months after BCG revaccination. Your peripheral blood mononuclear cells (PBMC) stimulated by proteins and peptides of M. leprae, were measured IFN-γ and IL-10 by an ELISA assay. Before revaccination the serum anti-PGL1 IgG and IgM isotypes were measured by ELISA assays performed with native PGL1- coated microplates, and PPD-skin reaction was measured 2 to 3 months after revaccination. The study was approved by the local Ethic Committee, number 006-08, May 7th, 2008. BCG revaccination can induces IFN-gamma and/or IL-10 production related to antigen and age, but did not correlated with PPD-skin reaction or anti-PGL1 levels. The PBMCâs production of IFN-gamma against MLT (total M. leprae antigen) after BCG was higher on children under 4 years old (N= 8, 4203,0  539,2 pg/mL before BCG x 9141,0  860,9 pg/mL after BCG, p=0,015, Mann-Whitneyâs test). Children between 5 and 9 years old showed an increase either of IFN-gama levels (N=11, 4912  1065 pg/mL x 9249,0  1171 pg/mL, p=0,024, Mann-Whitneyâs test) or IL-10 levels (N=11, 210,6  39,4 pg/mL x 680,3  76,74 pg/mL, p=0, 0,001, Mann-Whitneyâs test). However children between 10 and 15 years old failed to increase the cytokines levels after BCG booster. Contacts of multibacillary patients produced higher IFN-gamma levels (N= 13, 4536,0  543,1 pg/mL x 9263,0  989,0 pg/mL, p=0,0012, Mann-Whitneyâs test) and IL-10 levels (N= 13, 235,9  46,5 pg/mL x 743,5  87,8, p=0,0012, Mann-Whitneyâs test) against MLT after BCG, but only IFN-gamma levels (N=12, 4975,0  995,8 pg/mL x 8126,0  788,6, p=0,0342, Mann-Whitneyâs test) increased after BCG on contacts of paucibacillary patients. The production of IFN-gamma and IL-10 against two synthetic peptides (p38 and p67), before and after BCG vaccine, were similar as seen with MLT antigen, but the absence of cytokine production against p69 help to identify this peptide as a effective diagnostic marker.

Kawasaki disease (KD) is an acute febrile vasculitic syndrome of unknown etiology that preferentially affects the coronary artery. Several lines of evidence point to an important role of genetic variation in KD susceptibility. Acute KD is associated with systemic immune activation, including elevated serum levels of IL-1, IL-4, IL-6, IL-8, IL-10, TNF£\, and decreased serum levels of TGF£], as well as a variety of other cytokines that are believed to play important roles in the onset of KD. This study aims to investigate the association of 14 various polymorphisms of nine cytokine genes (IL-1A, IL-1B, IL-1RN, IL-4, IL-6, IL-8, IL-10, TNFA and TGFB) with the risk of KD. A total of 213 KD children and 226 sex-matched infection disease-free adult controls were recruited in the hospital-based case-control study. The polymorphisms of IL-1 RN intron2 VNTR and IL-4 intron3 VNTR were determined by PCR. The polymorphisms of IL-1B T-31C and IL-1B C-511T were determined by PCR-RFLP. The other single nucleotide polymorphisms (SNPs) of IL-1A C-889T, IL-4 T-590C, IL-6 G-174C, IL-8 T-251A, IL-8 C+781T, IL-10 A-1082G, IL-10 T-819C, IL-10 A-592C, TNFA G-308A and TGFB C-509T were determined by TaqMan real-time PCR method. We found that there were no associations between the 14 polymorphisms and risk of KD, either in the single locus genetypic analysis or in the multiple loci haplotypic analysis. However, in the combined analysis, subjects with four and five ¡§at risk¡¨ genotypes combined from IL-1A, IL-1B, IL-1RN, IL-4, IL-6, IL-8, IL-10, TNFA and TGFB genetic polymorphisms were with 1.85 fold risk of KD as compared to those with less or equl to four ¡§at risk¡¨ genotypes (AOR=1.85; 95% CI, 1.16-2.97; P=0.011). Additionally, subjects with six and seven ¡§at risk¡¨ genetic polymorphisms were with 2.34 fold risk as compared to those with less or equal to four ¡§at risk¡¨ genotypes (AOR=2.34; 95% CI, 1.45-3.76; P=0.001). In conclusion, no association was found between cytokine genetic polymorphisms and KD risk, except in the combined analysis.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Nineteen yearling Quarter Horses were utilized in a randomized, complete block design to evaluate systemic cytokine gene expression and circulating leukocyte population in young horses following an intra-articular lipopolysaccharide (LPS) challenge. Horses were administered an injection of 0.25 ng (n = 7) or 0.50 ng (n = 6) of LPS or lactated Ringer?s solution (n = 6; control). Blood was collected via jugular catheter at pre-injection h 0 and at 2, 6, 12, and 24 h following aseptic injection of the left radiocarpal joint. Aseptic arthrocentesis was performed at the same times to sample synovial fluid for a companion study. Total RNA was isolated from leukocytes using a commercially available kit and real-time PCR was used to determine relative gene expression of the cytokines; interleukin (IL)-1beta (beta), IL-6, IL-8, IL-10, and tumor necrosis factor-alpha (TNF-alpha). Determination of total leukocyte subpopulations and differentials was performed by Texas Veterinary Medical Diagnostic Laboratory. Data were analyzed using the PROC MIX procedure of SAS. Gene expression of all cytokines analyzed was unaffected by treatment. However, changes over time were observed in some cytokines. Interleukin-1? was increased above baseline at 6, 12, and 24 h (P = 0.04), IL-6 was decreased slightly at 6 and 12 h and then increased at 24 h (P = 0.002), and TNF-alpha was increased at 6 and 12 h (P = 0.01). Only IL-8 exceeded a 2-fold change in expression (P = 0.01), peaking at 12 h and indicating greater responsiveness to arthrocentesis than was observed in the other cytokines. No treatment effects on the leukocyte population were observed; however, total circulating leukocytes increased over time (P = 0.04), peaking at 6 h post-injection. Similarly, an increase over time was observed in monocytes (P = 0.002) and in platelets (P = 0.01) at 24 h post-injection. The results indicate that regardless of treatment, a mild immune response was elicited, likely due to repeated arthrocentesis. Future experiments should consider the effects of arthrocentesis and potential systemic inflammatory response, even in control animals, when administering intra-articular LPS to young horses.

No description available.

Universiẗat, Diss.--Jena, 2004.

Stuttgart, Univ., Diss., 2003.

Stuttgart, Univ., Diss., 2002.

Thesis (doctoral)--Eberhard-Karls-Universität zu Tübingen, 2002.