Effect of elevated temperature on human immunoglobulin synthesis, lymphokine production and lymphocyte proliferation in vitro.

Fever in infections is mediated by endogenous pyrogen, a protein inseparable from interleukin 1 (IL-1). It remains unclear what the role of fever in host defence is. We studied the effect of elevated temperature on mitogen-induced human lymphocyte stimulation in vitro. Lymphocyte proliferation, elaboration of leukocyte migration inhibiting factor (LIF) and immunoglobulin production were measured at normal and elevated temperatures. Pokeweed mitogen-(PWM) driven responses were quantitated with a plaque-forming cell assay and by measuring secreted immunoglobulins in culture medium. The responses at 38, 39 or 40 degrees C were, if anything, lower than those at 37 degrees C. The production of LIF after stimulation with PWM was not augmented at elevated temperatures. In contrast, the proliferative responses to PWM, phytohaemagglutinin (PHA) and concanavalin A (ConA) were increased at 38 degrees C. These results indicated that elevated temperature has diverse effects on mitogen-induced lymphocyte functions in vitro.