Oxygen-dependent Leishmanicidal activity of stimulated macrophages

Abstract

Peritoneal macrophages pretreated with different stimulants were analysed and compared with their respective controls for their ability to kill intracellular pathogenic L. donovani, (MHOM/IN/1983/AG83) an isolate from Indian subcontinent. Stimulation of macrophages by zymosan showed a higher microbicidal activity as compared to that by PMA. A correlation between microbicidal activity of the macrophages and the parameters related to respiratory burst activity such as liberation of O₂^–, production of H₂O₂ and consumption of O₂ was sought. All the parameters showed a decrease in case of infected macrophages in comparison to those of the non-infected ones. Thus, it is possible that the impairment of macrophage activation by intracellular Leishmania contributes to their survival in the toxic environment of the host.