fMLP receptor stimulated activation of macrophage: its effect on killing of intracellular Leishmania donovani

Abstract

The fMLP receptor of peritoneal macrophages stimulated by fMLP graftedliposomes as ligand, was analysed and compared with respective controlsfor its ability to promote killing of intracellular Leishmaniaparasites. fMLP grafted liposomes show greater efficacy in killingintracellular L. donovani (MHOM/IN/1983/AG83) parasites in a timedependent manner than free fMLP. fMLP grafted liposomes also releasemore active oxygen intermediates and reactive nitrogen intermediates(O^–₂, H₂O₂, NO) than free fMLP. The key enzymes PKCand PTK for the respiratory burst and nitric oxide generation werefound to be important in this fMLP receptor mediated signaling processas the enzyme specific inhibitors viz. staurosporine, genistein andAG126 suppressed the leishmanicidal effect of fMLP graftedliposomes. The above findings suggest that the fMLP receptorof macrophages activates PKC and PTK mediated signalling thatis responsible for the intracellular parasite killing.