Sla-Pgn-Primed Dendritic Cell-Based Vaccination Induces Th17-Mediated Protective Immunity Against Experimental Visceral Leishmaniasis: A Crucial Role Of Pkc Beta

Emergence of drug resistance during visceral leishmaniasis (VL) is a major obstacle imposed during successful therapy. An effective vaccine strategy against this disease is therefore necessary. Our present study exploited the SLA (soluble leishmanial antigen) and PGN (peptidoglycan) stimulated bone marrow-derived dendritic cells (DCs) as a suitable vaccine candidate during experimental VL. SLA-PGN-stimulated DCs showed a significant decrease in hepatic and splenic parasite burden, which were associated with increased production of nitric oxide and pro-inflammatory cytokines such as IL-12, IFN-gamma and IL-17. Elevated level of IL-17 was accompanied with the generation of more Th17 cells. Further studies on DC provided the evidence that these SLA-PGN-stimulated DCs played an important role in providing necessary cytokines such as IL-6, IL-23 and TGF-beta for the generation of Th17 cells. Interestingly, inhibition of protein kinase C-beta (PKC beta) in DCs led to decreased production of Th17 polarizing cytokines, causing reduction of the Th17 population size. Altogether, our finding highlighted the important role of DC-based PKC beta in regulation of the function and generation of Th17 cells.