Abstract

T cells are selected on the thymus on class I and class II MHC molecules to respectively yield conventional CD8 and CD4 T cells. The CD4 and CD8 co-receptors are thought to be involved in the thymocyte selection process, by facilitating both TCR binding to the respective MHC molecules as well as TCR signalling. Over the past decade, we have been investigating T cells that lack both CD4 and CD8 co-receptor expression, which have been dubbed double negative (DN) T cells. In this presentation, I will discuss our most recent observations regarding the thymic selection process of DN T cells. We have identified a unique thymic selection process for DN T cells, on the opposite spectrum to agonist selection. Our results suggest that an MHC -independent thymic selection can yield functional immunoregulatory DN T cells.