Alterations in thymocytes populations during infectious/inflammatory conditions

NATALIA BAEZ; FABIO CERBAN; CONSTANZA SAVID FRONTERA; M CECILIA RODRIGUEZ GALAN

Congreso; REUNIÓN DE LA SOCIEDAD ARGENTINA DE INMUNOLOGÍA; 2014

Our previous work demonstrated that during the acute phase of Trypanosoma cruzi infection, where a strong Th1 immune component is present, mature peripheral cells that express CD44, a marker of activated or memory T cells, are able to re-enter the thymus. Our recent immunofluorescence analysis demonstrated that CD44+ T cells in the thymus localized both in the thymic medullary and cortical areas. Besides, under this infectious process, we have observed that CD4+ and CD8+ simple positive (SP) thymocytes adopt a phenotype similar to mature T cells that localize in secondary lymphoid organs (SLO), based on the expression of the markers Qa2 and CD24 evaluated by flow cytometry (inmature: Qa2lo CD24hi more mature: Qa2hi CD24lo). Moreover, recent studies in our group, using intrathymic staining with eFLUOR dye, suggested that conversion to a more mature phenotype occur mainly in the resident CD44lo SP thymocytes in T. cruzi infected mice (control vs infected, p