ANTI-TRYPANOSOMA CRUZI PROPHYLACTIC VACCINE DECREASES HEART TISSUE DAMAGE AND IMPROVES CARDIAC FUNCTION IN MICE

FLORENCIA PACINI; CAMILA BULFONI BALBI; BRENDA DINATALE; FLORENCIA B. GONZALEZ; CECILIA FARRÉ; GUSTAVO CHAPO; OSCAR ADELMO BOTTASSO; PAULA INÉS CACIK; ESTEFANIA PROCHETTO; IVAN MARCIPAR; ANA R. PÉREZ

San Luis

Congreso; LXXI ANNUAL MEETING OF THE ARGENTINEAN SOCIETY OF IMMUNOLOGY (SAI); 2023

Sociedad Argentina de Inmunologia

Currently there are no prophylactic vaccines to combat Chagas disease.We previously showed that a nasal vaccine formulated with a N-terminalfragment of Trans-sialidase (TS) combined with c-di-AMP(A), generatedspecific humoral and cellular immunogenicity and protects against theparasite during acute phase. Given that an effective anti-T. cruzi vaccinemight avoid or attenuate myocardialdamage, here, we aim to evaluate atmyocardial level the prophylactic efficacy during the acute (17 days postinfection–dpi-) and the chronic (110 dpi) phases. For this, BALB/c femalemice, were intranasal immunized with the TS+A vaccine(3 doses, one every2 weeks). As controls, groups of mice were also immunizedwith salinesolution (SS) or TS and A alone. After immunization, animals were orallychallenged with 3000 Tulahuen strain/mice. A group of mice not immunizedand not infected (NI) was also included. Hearts were removed at the differentdpi and longitudinally dissected, afterwards part of tissue was fixed inbuffered formalin and later paraffin-embedded and 5-mm tissue sectionswere stained withboth hematoxylin/eosin (for the evaluation of intensity andmagnitude of inflammatory infiltrates), and picrosirius red (for fibrosisevaluation). The rest of tissue was cryopreserved for cytokine expressionevaluation by RT-qPCR (IL10,TGF-β, IFN-, TNF-α, IL17a). Additionally,chronic functional impairment was determined by electrocardiogram (ECG),and different parameters (corrected QTinterval –QTc-, QRS) were analysed.Acute and chronic myocarditis showed mildinfiltrates in TS+A group, whileSS, TS and A groups showed moderated or severe damage(overall,p