Phagocytosis and killing of the protozoan Leishmania donovani by human polymorphonuclear leukocytes.

摘要: The role of polymorphonuclear leukocytes (PMN) in host defense against Leishmania donovani, the protozoan that causes visceral leishmaniasis, is unknown. To assess ability PMN to ingest and kill infecting promastigote stage organism, cytocentrifuge preparations were made from tumbled suspensions 5 X 10(6) PMN, an equal number promastigotes, fresh human serum deficient 6th component complement. 53 +/- 9% found have 1 or more associated 81 14 promastigotes per 100 after 15 min at 37 degrees C. There was a corresponding decrease extracellular x ml 2.7 10(4)/ml. Superoxide anion generated during phagocytosis. Ingetion saturable with respect concentration, required heat labile factors, minimal when incubated ice water. Intracellular killing indicated by decline cell-associated organisms without concomitant increase promastigotes. Light electron microscopy showed disintegration intracellular Oxidative mechanisms appear be for this since there no donor chronic granulomatous disease. Promastigotes studied phagocyte-free system susceptible H2O2 glucose oxidase added directly greater than 10(-5) M. Killing enhanced addition lactoperoxidase (50 mU/ml) KI (0.05 mM) inhibited fresh, but not boiled catalase glucose-glucose system. These studies demonstrate can L. donovani H2O2-peroxidase-halide may capable providing invading, pathogen.