Interleukin-1 beta and muramyl dipeptide can prevent decreased antibody response associated with sleep deprivation.

A single, brief (8 h) period of sleep deprivation (DEP) was found to suppress secondary antibody response to sheep red blood cells in rats. This decrease could be totally prevented if either interleukin-1 beta (IL-1) or muramyl dipeptide (MDP) was administered at the beginning of the DEP vigil. Twenty-five units of IL-1 or 250 micrograms/kg MDP was found to be immunosuppressive in sleeping rats but, paradoxically, the combination of such doses with DEP alleviated this effect. Increased colonic temperatures associated with antigen and/or adjuvant administration were not related to the differences in antibody levels between sleeping and DEP animals. Activation of hypothalamic dopamine in IL-1-treated rats following DEP suggests that this monoamine transmitter system may participate in the observed protective activity of IL-1. The present findings extend the immune adjuvant effects of both IL-1 and MDP to protection of the host against behaviorally induced immunosuppression.