TRYPANOSOMA CRUZI INFECTION ENHANCED THE THYMIC OUTPUT AND INDUCE ALTERATIONS IN THE CENTRAL AND PERIPHERAL V-β TCR REPERTOIRE

BRENDA DINATALE; FLORENCIA BELÉN GONZÁLEZ; ITAUÁ LESTON ARAUJO; CAMILA BULFONI BALBI; MARÍA FLORENCIA PACINI; OSCAR BOTTASSO; WILSON SAVINO; EDUARDO ROGGERO; ANA ROSA PÉREZ

Mar del Plata

Congreso; LXX REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INMUNOLOGÍA (SAI) & 3ER CONGRESO FRANCO-ARGENTINO DE INMUNOLOGÍA (FAIC); 2022

The thymus is a central organ in the shaping of the peripheral T-cellrepertoire. Earlier work in a murine model of Chagas disease revealed progressive thymus atrophy, characterized by CD4+CD8+(DP) loss by apoptosis. Since alterations in the normal developmentof T-cells or in their repertoire could influence the outcome of thisinfectious disease, here, we evaluated the thymic output and theV-β repertoire after T. cruzi (Tc) infection. C57BL/6 mice (n=5/group)were infected with 1000 Tc and evaluated after 17 days post-infection (dpi). Non-infected (NI) mice act as controls. The thymic output was estimated by the quantification of recent thymic emigrants(RTEs) by intrathymic injection of fluorescein (FITC), and 24 h later,thymus and subcutaneous lymph nodes (SLN) were removed andmonitored for FITC+ cells occurrence. T-cell receptor excision circles(TRECs) were analyzed in blood by qPCR as RTEs markers. Repertoire screening was carried out by V-β family (5, 6, 8.1-8.2 and14) detection by flow cytometry. In Tc mice, thymic depletion wascoupled with adenomegaly. An increase in the counts of FITC+CD4+,FITC+CD8+, as well as immature and potentially autoreactiveFITC+DP T-cells was observed in the SLN after 17 dpi (p