Human neutrophils activated by interferon-gamma and tumour necrosis factor-alpha kill Entamoeba histolytica trophozoites in vitro.
The interaction between cytokine-activated human neutrophils and Entamoeba histolytica trophozoites was studied as well as the mechanism(s) involved. Treatment of neutrophils with rIFN-gamma alone allowed them to kill 30% of E. histolytica trophozoites; however, rIFN-gamma and rTNF-alpha pretreatments in combination increased neutrophil killing to 70%. In the absence of direct contact between neutrophils and amebae, rIFN-gamma-treated neutrophils were shown to kill 70% of amebae, and rIFN-gamma- and rTNF-alpha-treated neutrophils killed 97% of amebae. Neutrophil enhancement of amebicidal activity following cytokine treatments was correlated with increased neutrophil resistance to amebic contact-dependent killing and was shown to be 73% H2O2 dependent.
Denis
M
M
Institute of Parasitology of McGill University, Macdonald College, Ste-Anne de Bellevue, Quebec, Canada.
Chadee
K
K
D000818:Animals; D002470:Cell Survival; D010450:Endopeptidases / Q000502:physiology; D004748:Entamoeba histolytica / Q000276:immunology*; D005609:Free Radicals; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000494:pharmacology*; D009504:Neutrophils / Q000201:enzymology / Q000502:physiology*; D010100:Oxygen / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D005609:Free Radicals; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D010450:Endopeptidases; D010100:Oxygen