Thymic maturation and exportation of Innate CD8+ T cells to secondary lymphoid organs (SLO)

Tucumán

Congreso; LXVII Reunión Científica Anual de la Sociedad Argentina de Inmunología (SAI).; 2019

Sociedad Argentina de Inmunología (SAI)

Innate CD8+ T cells are a subset of CD8+ T cells that have been described in mice and human. They mature in the thymus like conventional T cells and can exert a protective effect both in neoplastic and infectious processes.Our previous work demonstrated that during the acute stage of certain infections (Trypanosoma cruzi or Candida albicans), there is an increase in Innate CD8+ T cells in the thymus. This effect is mediated by the inflammatory process since we observe similar data when we induce systemic expression of IL-12 and IL-18 by hydrodynamic injection of their cDNAs.Our recent data demonstrate that Innate CD8+ T cells generated in the thymus of T. cruzi-infected mice, that were intrathymically stained with the dye eFluor660, can be tracked in increasing numbers in SLO from day 3 to day 6 as eFluor660+ cells (p<0,05). To evaluate the reversibility of the developmental changes observed in the thymus, we analyzed cellularity and phenotype of CD8+ thymocytes at a distant time point (day 60) from the acute phase of T. cruzi infection (day 15), when the thymus are enriched with Innate CD8+ cells. At day 60, thymi of T. cruzi-infected mice show similar cellularity and subset proportions than control mice, however, CD8+ thymocytes still maintain some of the phenotypic features of Innate CD8+ T cells like high CD122 and Eomesodermin expressions (p<0,05).This data encourage us to investigate the capacity of Innate CD8+ T cells to migrate to SLO and exert protection in different pathologic settings.