B CELL DEPLETION COMPROMISES CD8+ T CELL RESPONSE DURING Trypanosoma cruzi INFECTION.

FIOCCA VERNENGO, FACUNDO; BECCARIA, CRISTIAN G; TOSELLO BOARI, JIMENA; GOROSITO SERRAN, MELISA; ARAUJO FURLAN, CINTIA; MONTES, CAROLINA L; ACOSTA RODRIGUEZ E V; GRUPPI, ADRIANA

Congreso; IV LASID Meeting, LXIII Argentinean Immunology Society Meeting ? II French Argentinean Immunology Meeting-; 2015

B CELL DEPLETION COMPROMISES CD8+ T CELL RESPONSE DURING Trypanosoma cruzi INFECTIONFiocca Vernengo, Facundo; Beccaría, Cristian Gabriel; Tosello Boari, Jimena; Gorosito Serrán Melisa; Araujo Furlán Cintia; Montes, Carolina; Acosta Rodriguez, Eva; Gruppi, Adriana. Departamento de Bioquímica Clínica eInmunología, FCQ, UNCConsidering that CD8+T cells play a major role in protective immunity against T. cruzi, the factors that promote the generation and maintenance of CD8+T cell responses need to be identified. B cells have been reported as critical for optimal CD8+T cell responses in cancer and infection. Based on this, the aim of our work was to analyze the role of B cell in the induction and maintenance of the CD8+T cell response during T. cruzi infection. For that, C57BL/6 mice were intraperitoneally injected with anti-CD20 (5ug/mL) to deplete B cells or an IgG2A control antibody. Seven days after treatment, mice were infected with 5.000 trypomastigotes (Tulahuén strain) and the CD8+T cell response was analyzed at different days post infection (pi) by flow citometry using tetramers containing the parasite peptide TSKB20 and by immunofluorescence.We observed that B-cell depletion did not affected T cell structures in the spleen of T. cruzi infected mice. However, in comparison to B cell-sufficient mice, B cell-deficient mice showed in the spleen and liver, a tendency to lower numbers of total TCD8+ that were significantly different on day 14pi as well as lower numbers of parasite-specific CD8+T cells. Furthermore, B cell-depleted mice showed higher percentages of naïve T cells (CD44-CD62L+) and lower frequency of effector memory cells (CD44-CD62L+). Accordingly, a high percentage of CD8+T cells from depleted mice was CD127+, reflecting their naïve state.The results suggest that B cells could be necessary for the generation/maintenance of specific CD8+T cells and may also regulate effector function.