Induction of heat-shock proteins and phagocytic function of chicken macrophage following in vitro heat exposure

Abstract

The protein profiles and phagocytic ability of Sephadex-elicited chicken peritoneal macrophages were examined following heat-shock exposure. Macrophage cultures were exposed to various temperatures, time exposures and recovery periods. Densitometric analysis of SDS-PAGE autoradiographs revealed that heat-induced macrophages synthesized three major (23, 70 and 90 kD) heat-shock proteins (HSPs). The optimal temperature and time for induction of these HSPs was 45–46°C for 1 h, with a variable recovery period for each HSP. Macrophages exposed to 45°C for 30 and 60 min were significantly depressed in phagocytosis of uncoated sheep erythrocytes (SE) under 45°C incubation conditions. However, phagocytosis of antibody-coated SE was not affected when compared to 41°C control cultures. Macrophages allowed to recover at 41°C following heat-shock exhibited no alterations in their phagocytic ability for either antibody-coated or uncoated SE. This study suggests that heat shock induces three major HSPs in chicken peritoneal macrophages in addition to maintaining their Fc-mediated phagocytic function while significantly depressing their nonspecific phagocytosis.