IL-10 inhibits parasite killing and nitrogen oxide production by IFN-gamma-activated macrophages.

• DOI: 10.4049/jimmunol.148.6.1792
• Publication Date: 2022-12-31T09:41:06Z
• Authors: R T Gazzinelli; I P Oswald; S L James; A Sher
• Keywords: Intracellular parasite

Abstract IL-10, a cytokine produced by CD4+ T lymphocytes belonging to the Th-2 subset, has previously been shown inhibit synthesis of IFN-gamma both cells and NK cells. We now demonstrate that IL-10 can also down-regulate IFN-gamma-dependent immunity blocking ability lymphokine activate macrophages. Thus, in dose-dependent manner, inhibits microbicidal activity IFN-gamma-treated inflammatory macrophages against intracellular Toxoplasma gondii as well extracellular killing schistosomula Schistosoma mansoni. This suppression correlates with inhibition IFN-gamma-induced production toxic nitrogen oxide metabolites, an effector mechanism implicated parasite targets. nitric was occur when is given before or together IFN-gamma-activating stimulus, but not after its removal from cultures require 12 h contact for maximal suppressive effect on macrophage function. These results, taken previous findings down-regulation Th1 indicate induction may be important strategy which parasites evade IFN-gamma-dependent, cell-mediated immune destruction.