CD5 levels define functionally heterogeneous populations of naïve human CD4+ T cells

Studies from mouse models show that differences in self-reactivity, as read-out by CD5 levels, identifies naïve T cell subsets with distinct functional properties during an immune response. Whether CD5 levels can also be used to parse functional biases in naive human CD4+ T cells is incompletely understood. Our study establishes CD5 as a reliable marker of T cell self-reactivity and functional heterogeneity in human CD4+ T cells. Naïve CD4+ T cells from peripheral blood mononuclear cells of 2 human donors were sorted on top and bottom 15% of CD5 expression. (2 biological replicates; 4 conditions: CD5lo and CD5hi for each donor).