CD4 and autoimmune disease: Furthermore, as NKT cells (CD3+, CD4+, NK1.1+) play an important role in the pathogenesis of autoimmune diseases like SLE [36], we analyzed NK1.1+, CD4+ T cells in the secondary lymphoid organs of C57BL/6 mice that produce IgG anti-NPA antibodies, and found a significant increase in the number of these cells in the spleen and mesenteric lymph nodes.