Restraint stress augments antibody production in cyclophosphamide-treated mice.

These studies evaluated the effects of a psychological stressor (restraint, RST) on antibody production in male BALB/cByJ mice. In Experiment 1, mice were immunized with keyhole limpet hemocyanin (KLH, 100 microg i.p.) 8 h prior to 15 h of RST or food and water deprivation (FWD). RST mice exhibited higher serum anti-KLH IgM and IgG antibodies than FWD mice. In Experiment 2, mice were given either cyclophosphamide (CY, 15 mg/kg) or saline (SAL) prior to immunization with KLH and RST or FWD. ANOVA revealed serum anti-KLH IgG antibody titers in CY+RST animals to be significantly higher than in CY+FWD, SAL+FWD, and SAL+RST mice. Anti-KLH IgM titers of CY+RST mice were higher than those of other groups before and after a second immunization with KLH. In Experiment 3, we show that these changes in antibody production are not likely to be mediated via CY-induced alterations in the reactivity of the hypothalamo-pituitary-adrenal axis to RST. Together, these results indicate two potentially immunomodulatory parameters (RST and CY) can interact to alter a humoral immune response. In addition, these data support the hypothesis that humoral immune response of mice can be more reactive to stress when the mice are given a low dose of an immunomodulatory drug prior to stressor exposure.