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