Restraint stress-induced suppression of major histocompatibility complex class II expression by murine peritoneal macrophages.

The macrophage plays a central role in the development of immune responses. Macrophages take up and process antigen which is presented to antigen-responsive T lymphocytes in association with major histocompatibility complex class II (Ia) glycoproteins. We have investigated the effect of restraint stress on Ia expression by murine peritoneal macrophages. Stress resulted in a suppression of Ia expression which coincided with an increase in plasma corticosterone levels. In vitro experiments indicate that suppression of Ia expression can occur within 2 h after exposure to corticosterone. The suppression of this important aspect of macrophage function by stressors has important implications regarding the possible immunosuppressive effects of stress on the response of lymphocytes to antigens that depend on intact macrophage function.