EVALUATION OF LAST GENERATION ADJUVANTS ON IMMUNOGENICITY AND EFFICACY OF A PROTEIN SUBUNIT VACCINE CANDIDATE AGAINST TRYPANOSOMA CRUZI

DELFINO, MARÍA ALICIA; TRINITARIO, SEBASTIÁN NICOLÁS; RUSSO, MELISSA; DZVONYK, POLINA; CARDOSO, ALEJANDRO C.; CERNY, NATACHA; MALCHIODI, EMILIO L.; BIVONA, AUGUSTO ERNESTO; SANCHEZ ALBERTI, ANDRÉS

Buenos Aires

Congreso; REUNIÓN ANUAL DE SOCIEDADES DE BIOCIENCIAS SAIC - SAI - SAFIS; 2021

BACKGROUND AND AIMS:Chagas Disease is a potentially life-threatening illness caused by the protozoan parasite Trypanosoma cruzi. Currently there is no effective vaccine to prevent or treat the infection. Previously, we have developed Traspain, a chimeric trivalent immunogen. To assess new adjuvants that might improve protection induced by vaccination, we evaluated the TLR3, TLR9 and STING ligands Poly (I:C), CpG oligodeoxynucleotide and Cyclic-di-AMP (CDA) respectively by the subcutaneous route.METHODS:Groups of 6-8 weeks old, female C3H mice (n=6/group) were vaccinated with 3 doses of 10 µg of Traspain plus 25 µg of adjuvant or PBS as placebo. Exploratory bleeding was performed and 20-30 days after the last dose, antigen specific immune responses were evaluated by ELISA, proliferation, and flow cytometry. Additionally, for efficacy assessment, immunized mice were challenged with the RA strain of T. cruzi (DTU VI). Parasitemia and weight loss were employed as readouts.RESULTS:Significant Traspain-specific IgG levels were detected in sera from CDA and Poly(I:C) groups (IgG titres: 167117*, 60970* respectively, *p