Serum antibodies and cytokines in C4-deficient mice and their responses to exercise.

Psychological stress is believed to be one of the predisposing factors for systemic lupus erythematosus (SLE), whereas physical stress such as exercise has never been reported to be related. We measured the circulating levels of antibodies (IgM, IgG, anti-dsDNA IgG), Th1 (IFN-gamma), Th2 (IL-4, IL-6), and of pro-inflammatory (TNF-alpha, IL-1beta) and anti-inflammatory (TGF-beta) cytokines of C4(-l-) female mice at rest, after acute exercise and after exercise training, using an antibody-capture ELISA. Prior to the exercise, the C4(-l-) mice had higher levels of IgG and anti-dsDNA IgG but lower levels of IFN-gamma, IL-1beta, IL-6 and IL-4 than wild-type C57BL/6 (B6) mice. A single bout of exercise to exhaustion increased serum IgG, TNF-alpha, IL-1beta and TGF-beta in the B6 mice but only TGF-beta in the C4(-l-) mice was increased. We conclude that exhaustive or moderate exercise has no effect on the levels of serum antibodies and cytokines and is thus unlikely to promote the onset of SLE.