Lymphocytes, cytokines, inflammation, and immune trafficking

During the past year several novel reports have added new knowledge to our understanding of the pathogenesis of system lupus erythematosus (a) a novel pathway for the presentation of autoantigens to autoreactive T cells was revealed. Universally binding nucleosomal epitopes are productively recognized by autoreactive T cells by binding to the T-cell receptor-alpha chain; (b) circulating T cells from patients with lupus commonly display a deficiency of the T-cell receptor zeta chain, and upon ligation of their cell-surface antigen receptor overproduce tyrosine phosphorylated proteins; (c) lupus and lupus nephritis are associated with a low-binding FcgammaRIIIA (CD16) polymorphism that crosses ethnic barriers; (d) the pathogenetic role of the cytokine interleukin-10 is expanding, because it is reportedly overproduced not only by cells from lupus patients but also by cells from their healthy relatives, and its overproduction in vitro is correlated with increased apoptotic cell death and with lymphopenia.