OMP19S coadministered as adjuvant induces antigen cross presentation and elicites CD8 T cells responses in vivo

LM CORIA, AE IBÁÑEZ, KA PASQUEVICH, P BERGUER, J CASSATARO

Viña del Mar, Chile

Congreso; IX Congreso Latinoamericano de Inmunología (ALAI); 2009

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> In previous studies we have shown that the protein moiety of Omp19 from Brucella spp.(Omp19S) as adjuvant induces CD4+ T cell responses. In this study, we evaluate the adjuvant capacity on CD8+ T cell responses using chicken ovoalbumin (OVA) as an antigen model. C57BL/6 mice were adoptively transferred with CFSE- labeled OT-1 T cells, which recognize a class I epitope of OVA. One day later they were immunized s.c. with OVA coadministered with: Omp19S, Omp19SPK (digested with Proteinase K), LPS or PBS. Immunization with Omp19S as adjuvant induced greater OT-I cell proliferation (CFSE dilution) than immunization with OVA without adjuvant or OVA+Omp19SPK, and similar to the control LPS group. Moreover, the percentage of OVA-specific IFN-g producing CD8+ T cells was significantly enhanced in the OVA+Omp19S (0.73%) than in the OVA group (0.14%). Whereas immunization with OVA+Omp19SPK failed to induce IFN-g producing CD8+ T cells, confirming that the adjuvant capacity resides in the protein. In conclusion, we demonstrate that Omp19S co administered adjuvant facilitates antigen cross-presentation and induces IFN-g producing CD8+ T cells.