OMP19 as a promising adjuvant for immunotherapy in acute Chagas disease.

URBANO K; CASASCO A; BRUNO L; PETRAY PB; CASSATARO J; FRANK FM

Congreso; XXXI Reunión Anual de la Sociedad Argentina de Protozoologia; 2019

SAP SAIC SAFE SAB AACyTAL NANOMED-ar HCS

OMP19, a membrane protein for Brucella abortus, showed to be a good enhancer in the development of prophylactic immunity. Although experimental vaccines are able to reduce parasitic load, they allow parasites to survive within the host, modulating and evading the immune response. Immunotherapy attempts to modify this response, presenting the antigens in a different way and counteracting parasitic evasion strategies. We study the combination of OMP19 with parasite antigens (Ag) as an immunotherapy for Chagas disease. Groups of six female C3H mice were infected with a lethal dose of trypomastigotes of the RA strain of T. cruzi and treated with: 1) Ag+OMP19, 2) Ag, 3) OMP19, 4) control (PBS) at the 1st and 7th d.p.i or 5) benznidazole (Bnz) during 14 consecutive days. During the acute phase of the infection we observed a significant reduction of parasitemia in group 1 vs groups 2, 3 and 4. Control mice (4) lost more than 50% of their body mass, conducing to a mortality of only 66%, while group 1 had a 100% survival. Animals treated with Omp19+Ags had a significantly greater in vivo (DTH) and in vitro (proliferation) cellular immune response than the other groups (p