INNATE IMMUNITY AGAINST TRYPANOSOMA CRUZI IN IMMUNIZED ANIMALS IS AFFECTED BY SEXUAL DIMORPHISM

CAMILA BULFONI BALBI; MARÍA FLORENCIA PACINI; BRENDA DINATALE; FLORENCIA BELÉN GONZÁLEZ; ELIANA BORGNA; ESTEFANÍA PROCHETTO; CECILIA FARRÉ; GUSTAVO CHAPO; IVÁN MARCIPAR; GABRIEL CABRERA; ANA ROSA PÉREZ

Mar del Plata

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

Vaccine efficacy may be modulated by different parameters like sex, among others; so, the inclusion of both sexes becomes relevant. Typically, vaccine studies against T. cruzi (Tc) have been focused on adaptive response evaluation. We previously showed that a nasal vaccine formulated with Trans-sialidase (TS) plus c-di-AMP was immunogenic, in terms of adaptive response, while females (F) showed better responses than males (M). Here we aim to evaluate possible variations in the innate response induced in F and M infected BALB/c mice previously immunized with our vaccine. We mainly focused on cells resembling myeloid-derived suppressor cells (rMDSC). For this, mice (n=5/group) were intranasally immunized in 3 doses, one every 2 weeks with 10 µg of TS emulsified in c-di-AMP adjuvant (TS+c-di-AMP). Other groups of mice were treated with saline (S), TS or c-di-AMP alone. Fifteen days after the last immunization, mice were orally challenged with 3000 Tc. Both rMDSC lineages (rG-MDSC: CD11b+Ly6C+/lowLy6G+; rM-MDSC: CD11b+Ly6C+/ lowLy6G-) were evaluated at 21 days post-infection (dpi) by flow cytometry. Parasitemia and clinical score were recorded until 50 dpi. Overall, M mice showed increased parasitemias compared to the analogous groups of F (i.e.,17 dpi TS+c-di-AMP, p