PD-1 regulates CXCR5 + CD4 T cell-mediated proinflammatory functions in non-small cell lung cancer patients.

•CXCR5+ CD4 T cells presented higher PD-1 expression than CXCR5− CD4 T cells.•PD-1+ CXCR5+ CD4 T cells expressed IL-21, IL-10, and CXCL13 at a reduced potency.•PD-1+ CXCR5+ CD4 T cells relatively promoted IgM and IgG from B cells.•PD-1 inhibition elevated the effector function of PD-1+ CXCR5+ CD4 T cells.