Different profile and distribution of antigen specific T cells induced by intranasal and intrarectal immunization with rotavirus 2/6-VLP with and without LT-R192G.

In this study, we compared both the profile and distribution of antigen specific primed T cells after intrarectal (IR) and intranasal (IN) immunization with rotavirus (RV) 2/6-VLP, alone or in the presence of LT-R192G, in order to highlight the differences between the two routes and the impact of the adjuvant. Adult BALB/c mice were immunized once with 2/6-VLP with or without adjuvant and the T cell response was analyzed in lymphoid tissues after in vitro restimulation with the antigen. IN, but not IR, immunization of mice with 2/6-VLP alone induced antigen-specific IL-10 and IL-17 secreting T cells. IL-10-, in contrast to IL-17-, secreting T cells did not migrate to the mesenteric lymph nodes (MLN) whereas they were detected in cervical lymph nodes (CLN) and spleen. With the IN route, the adjuvant allowed to complete this profile with the secretion of IL-2 and IL-4, increased IL-17 secretion and induced antigen specific CD4+CD25+Foxp3+ and Foxp3- T cells in all studied organs (CLN, spleen and MLN) but did not impact on IL-10 secreting T cells. With the IR route, the adjuvant induced IL-2 and IL-17 secretion but, in contrast to the IN route, did not allow IL-4 production. These results show that, for a same antigen, T cell priming not only depends on the presence of adjuvant but also on the mucosal route of administration. Moreover, they show a different dissemination of IL-10 secreting T cells compared to other subtypes.