Total Leishmania antigens with Poly(I:C) induce Th1 protective response

SANCHEZ, MARIA VICTORIA; GERMANÓ, M. JOSE; SALOMÓN, MARIA CRISTINA; DI GENARO,SILVIA; BUSTOS GARCÍA, MARÍA FERNANDA; CARGNELUTTI, DIEGO ESTEBAN; ELICABE, RICARDO JAVIER; GEA,SUSANA; SCODELLER, EDUARDO ALBERTO

PARASITE IMMUNOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2017

0141-9838

Aims: Our proposal was to develop a vaccine based on total Leishmania antigens (TLA) adjuvanted with polyinosinic-polycytidylic acid [Poly(I:C)] able to induce a Th1 response which can provide protection against Leishmania infection.Methods and Results: Mice were vaccinated with two doses of TLA-Poly(I:C) administered by subcutaneous route at three week interval. Humoral and cellular immune responses induced by the immunization were measured. The protective efficacy of the vaccine was evaluated by challenging mice with infective promastigotes of Leishmania (Leishmania) amazonensis into the footpad. Mice vaccinated with TLA-Poly(I:C) showed a high anti-Leishmania IgG titer, as well as increased IgG1 and IgG2a subclass titers compared with mice vaccinated with the TLA alone. The high IgG2a indicated a Th1 bias response induced by the TLA-Poly(I:C) immunization. Accordingly, the cellular immune response elicited by the formulation was characterized by an increased production of IFN-γ and no significant production of IL-4. The TLA-Poly(I:C) immunization elicited good protection, which was associated with decreased footpad swelling, a lower parasite load and a reduced histopathological alteration in the footpad. Conclusion: Our findings demonstrate a promising vaccine against cutaneous leishmaniasis that is relatively economic and easy to develop and which should be taken into account for preventing leishmaniasis in developing countries.