IMPROVED IMMUNE RESPONSE TO TOTAL LEISHMANIA ANTIGEN FORMULATED WITH A TOLL LIKE RECEPTOR AGONIST

GERMANO MARIA JOSE; LOCHEDINO SOSA, ARIANA; SANCHEZ VICTORIA; MACKERN- OBERTI, JUAN PABLO; CARGNELUTTI DIEGO; LOZANO ESTEBAN; SALOMON, CRISTINA

Congreso; XXXVI Reunión Anual de la Sociedad de Biología de Cuyo; 2018

A proper adjuvant has a relevant role in vaccine formulations to generate an effective immune response. Our proposal was to develop a first generation vaccine adjuvanted with a toll like receptor agonist, polyinosinic-polycytidylic acid [Poly (I:C)], able to induce a Th1 response. Total Leishmania antigens (TLA) were obtaining by a sonication process. Mice were vaccinated with two doses of TLA-Poly(I:C) administered by subcutaneous route at 3-week interval. Humoral and cellular immune responses induced by the immunization were measured. Mice vaccinated with TLA-Poly (I:C) showed a high anti-Leishmania IgG levels, as well as increased IgG1 and IgG2a subclass levels compared with mice vaccinated with the TLA alone. The high IgG2a levels 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, delayed-type hypersensitivity and cell proliferation. Our findings demonstrate a promising vaccine formulation against leishmaniasis that improved the Th1 immune response to TLA and which should be taken into account for preventing leishmaniasis in developing countries.