Human macrophage tumor necrosis factor (TNF)-alpha production induced by Trypanosoma brucei gambiense and the role of TNF-alpha in parasite control.
Trypanosoma brucei gambiense, a causative agent of sleeping sickness, induced a dose-dependent production of tumor necrosis factor (TNF)-alpha by human macrophages in vitro. TNF-alpha was also induced in the Mono Mac 6 cell line, which indicates a direct effect of parasite components on macrophages. Parasite-soluble factors were also potent inducers of TNF-alpha. The addition of anti-TNF-alpha to cocultures of macrophages and parasites increased the number of trypanosomes and their life span, whereas irrelevant antibodies had no effect. TNF-alpha may have a direct role (i.e., direct trypanolytic activity) and/or an indirect one, such as TNF-alpha-mediated induction of cytotoxic molecules. A direct dose-dependent lytic effect of TNF-alpha on purified parasites was observed. This lytic effect was inhibited by anti-TNF-alpha. These data suggest that, as in experimental trypanosomiasis, TNF-alpha is involved in parasite growth control in human African trypanosomiasis.
Laboratoire de Parasitologie, Université Bordeaux II, Bordeaux, France.
S
S
Daulouède
B
B
Bouteille
D
D
Moynet
P
P
De Baetselier
P
P
Courtois
J L
JL
Lemesre
A
A
Buguet
R
R
Cespuglio
P
P
Vincendeau
D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology; D002460:Cell Line; D002478:Cells, Cultured; D003601:Cytotoxicity Tests, Immunologic; D006801:Humans; D008264:Macrophages / Q000276:immunology*; D014347:Trypanosoma brucei gambiense / Q000187:drug effects / Q000254:growth & development / Q000276:immunology*; D014353:Trypanosomiasis, African / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000494:pharmacology / Q000502:physiology*
D000953:Antigens, Protozoan; D014409:Tumor Necrosis Factor-alpha