The role of T lymphocytes in immunity to Plasmodium falciparum. Enhancement of neutrophil-mediated parasite killing by lymphotoxin and IFN-gamma: comparisons with tumor necrosis factor effects.
Human neutrophils were treated with IFN-gamma or lymphotoxin and their interaction with the asexual blood forms of Plasmodium falciparum was studied by a radiometric assay and microscopy. The results showed that human neutrophils inhibited the growth of P. falciparum and killed the parasite via a phagocytic mechanism. The cytokines significantly augmented the neutrophil-mediated killing of the parasite. When compared with the effects of TNF-alpha similar results were seen although IFN-gamma and TNF-alpha were effective at 10-fold less the concentration of lymphotoxin. The maximum neutrophil-mediated parasite killing was seen in the presence of immune serum and the cytokines. These findings suggest that T cells regulate the antimalarial activity of neutrophils.
Kumaratilake
L M
LM
Department of Immunology, Adelaide Children's Hospital, South Australia.
Ferrante
A
A
Rzepczyk
C
C
D000818:Animals; D004912:Erythrocytes / Q000469:parasitology; D006801:Humans; D007371:Interferon-gamma / Q000502:physiology*; D008233:Lymphotoxin-alpha / Q000502:physiology*; D009504:Neutrophils / Q000276:immunology; D010963:Plasmodium falciparum / Q000254:growth & development / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology
D008233:Lymphotoxin-alpha; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma