ASSESSING THE IMMUNOPROPHYLACTIC PROPERTIES OF A NOVEL CHIMERIC ANTIGEN CANDIDATE TO CONTROL TRYPANOSOMA CRUZI INFECTION

VAZQUEZ, MARIA ELISA; ZABALA, BRENDA ANDREA; ANDREA C. MESIAS; NATALIA CORBALAN; BLADIMIRO LENIS; LUCIA BISCARI; ANDRES ALLOATTI; CECILIA PEREZ BRANDAN; ACUÑA LEANDRO

Encuentro; REUNIÓN CONJUNTA SAIC SAI&FAIC SAFIS 2022; 2022

Chagas disease (CD) is a neglected tropical disease, affecting more than 8 million people worldwide. Patients with CD develop myocarditis and/or digestive clinical manifestations. The agent responsible for this disease is Trypanosoma cruzi, a parasite that can persist in its mammalian host because it has evolved multiple strategies to evade the immune response. This persistence is considered the main factor contributing to the late symptoms of CD. The aim ofthe present work is to depict the immunological outcome of a new antigen candidate in a prime/boost/challenge mouse model of infection. For this, animals were given three doses, in conjunction with a saponin type adjuvant, of a chimeric antigen composed of fragments of two immunogenic defined proteins of the parasites. Around day 20 post boost serum samples were taken to measure specific antibodies response and half of them were later sacrificed for spleenremoval. Cytokines production after in vitro splenocytes re-stimulation and memory T cells subsets were analyzed. The other half of animals were challenged with virulent T. cruzi parasites. During infection period parasite load in blood was recorded twice a week to test vaccine efficiency. After that animals were sacrificed and heart, colon and skeletal muscle were taken to analyze parasite burden and histological damage. Briefly, mice vaccinated with the chimera were capable to produce specific antibodies. Regarding memory T-cells, no significative differences were found among experimental groups; however, IL-10 levels were lower in vaccinated animals than in control groups. Interestingly, mice inoculated with our chimera were able to control parasite load in blood during the first days of infection and dimmish parasite burden in targeted tissues exhibiting minor inflammation and preventing parasite nesting. This study reveals the immunological potential of this chimeric protein as new immunogen to use in vaccine formulations to defeat T. cruzi infection.