Regulation by protein kinase of phagocytosis of Mycobacterium leprae by macrophages

Mycobacterium leprae multiplies within host macrophages. The mechanism of i nternalisation of the bacteria by the phagocytic cells is unknown. In this study, M. leprae was purified from the foot pads of experimentally infected nu/nu mice, Peritoneal macrophages were harvested from BALB/c mice or C57 beige (bg/bg) mice. The effect of protein kinase inhibitors (erbstatin, gen istein or staurosporine for BALB/c and bg/bg mice, plus herbimycin for bg/b g mice) on phagocytosis of the mycobacteria by the macrophage monolayers wa s tested. The untreated (control) macrophages phagocytosed M, leprae, Phago cytosis by BALB/c macrophages was inhibited by erbstatin and staurosporine but not by genistein; all the protein kinase inhibitors prevented uptake of M, leprae by bg/bg cells. The results demonstrate that protein kinase regu lates phagocytosis of M, leprae by macrophages, The mechanism might prove t o be a rational drug target for mycobacteria that multiply intracellularly.