The effect of oligopeptides on the C3b receptor-mediated functions of rat macrophages

Effects of various substances known to influence macrophage functions on the adherence of C3b-coated sheep erythrocytes (E-C3b) and their phagocytosis by elicited rat peritoneal macrophages (PM) has been studied. Different oligopeptides (OP) having a chemotactic effect, such as tuftsin, angiotensin II (At II) and the OP-fraction of a lymphokine preparation (LK-OP) increased both adherence and phagocytosis of E-C3b in a concentration-dependent fashion. In contrast, neither substances influencing the membrane cation transport nor prostaglandins (PG) and cyclic nucleotides significantly changed the C3b receptor (C3bR)-dependent effector functions of macrophages. Enhanced functions of the C3bR were not associated with an increased capability of PMs for intracellular killing of Candida albicans.