Deficiency of programmed cell death 4 affects the balance of T cell subsets in hyperlipidemic mice.

•Pdcd4 deficiency decreased the number of systemic CD8+ T cells and increased that of Tregs in hyperlipidemic mice•Pdcd4 deficiency also decreased the number of CD8+ T cells and increased that of Tregs in atherosclerotic plaques.•Pdcd4 deficiency decreased the proliferation of CD8+ T cells in vitro.•Pdcd4 deficiency regulated the expression of co-stimulatory and co-inhibitory molecules in proliferated T cells in vitro.