The protein moiety of the Brucella Omp19 lipoprotein, co-administered as oral adjuvant, induces a Th1 immune response

IBAÑEZ A.; CORIA L.; PASQUEVICH, K.; BARRIONUEVO P.; DELPINO M. V.; GIAMBARTOLOMEI G. H.; CASSATARO JULIANA

Buenos Aires

Congreso; LVIII Reunión Anual de la Sociedad Argentina de Inmunología; 2010

Sociedad Argentina de Inmunologia

Previous results demonstrate that the protein moiety of the Brucella Omp19 lipoprotein (U-Omp19) administered by the oral route has self-adjuvant properties. In this study we evaluated its mucosal adjuvant capacity using as model antigen (Ag) ovalbumin (OVA). For this purpose mice were immunized orally with OVA, U-Omp19+OVA, or choleric toxin (CT)+OVA. By flow cytometry we determined that the percentage of CD4+ and CD8+ T cells expressing α4β7 integrin increased in those mesenteric lymph nodes from U-Omp19+OVA in comparison with OVA immunized mice. We also observed a significant DTH response to OVA injection in U-Omp19+OVA while OVA group did not. Similarly, we observed that mice immunized with U-Omp19+OVA induced significant production of IFN-γ in response to OVA. By flow cytometry we determined that the percentage of CD4+ and CD8+ T cells producing intracellular IFN-γ -in response to OVA- increased in U-Omp19+OVA in comparison with CT+OVA and OVA vaccinated mice. We also observed that U-Omp19 immunization induces Ag internalization by CD11b+ cells and the recruitment of dendritic cells (DCs) CD11c+CD8+. In conclusion, U-Omp19 as oral adjuvant induces the migration of CD4+ and CD8+ T cells to gastrointestinal lamina propria, T cells responses in vivo and CD4+ and CD8+ T cells that produce IFN-γ in response to OVA, and the recruitment of DCs wich are involved in the initiation of adaptative immune response.