Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
Double negative (DN) T cells are expanded in patients with systemic lupus erythematosus (SLE) and stimulate autoantibody production as efficiently as CD4(+) T cells. In this study, we demonstrate that DN T cells from patients with SLE produce significant amounts of IL-17 and IFN-gamma, and expand when stimulated in vitro with an anti-CD3 Ab in the presence of accessory cells. Furthermore, IL-17(+) and DN T cells are found in kidney biopsies of patients with lupus nephritis. Our findings establish that DN T cells produce the inflammatory cytokines IL-17 and IFN-gamma, and suggest that they contribute to the pathogenesis of kidney damage in patients with SLE.