IL-10 up-regulates nitric oxide (NO) synthesis by lipopolysaccharide (LPS)-activated macrophages: improved control of Trypanosoma cruzi infection.
We examined the effects of IL-10 on tumour necrosis factor-alpha (TNF-alpha) and NO production by LPS-activated macrophages and on the ability of these cells to control Trypanosoma cruzi infection. We first observed that the addition of rIL-10 to macrophages of the J774 cell line decreased their synthesis of TNF-alpha but increased their release of NO in a dose-dependent manner. In parallel, treatment of J774 cells with rIL-10 resulted in a better control of T. cruzi infection involving up-regulation of NO synthesis, as it was not observed in presence of N-nitro-L-arginine methyl ester (L-NAME), a competitive inhibitor of NO synthase. The enhancing effect of rIL-10 on NO production was not observed on peritoneal macrophages from wild-type C57Bl/6 mice, but well on macrophages from IL-10 knock-out mice. The control of NO production by endogenous IL-10 was confirmed by the demonstration that neutralization of IL-10 secreted by LPS-activated macrophages from wild-type mice inhibited their production of NO and, in parallel, their ability to control T. cruzi infection. Taken together, these data demonstrate that both exogenous and endogenous IL-10 up-regulate the production of NO by LPS-activated macrophages and improve thereby their ability to clear T. cruzi infection.
Laboratoire d'Immunologie Expérimentale, Faculté de Médecine, Université Libre de Bruxelles, Brussels, Belgium.
F
F
Jacobs
D
D
Chaussabel
C
C
Truyens
V
V
Leclerq
Y
Y
Carlier
M
M
Goldman
B
B
Vray
D000818:Animals; D014355:Chagas Disease / Q000378:metabolism / Q000517:prevention & control*; D016753:Interleukin-10 / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects*; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009569:Nitric Oxide / Q000096:biosynthesis*; D014349:Trypanosoma cruzi; D015854:Up-Regulation
D008070:Lipopolysaccharides; D016753:Interleukin-10; D009569:Nitric Oxide