title: Suppressed production of pro-inflammatory cytokines by LPS-activated macrophages after treatment with Toxoplasma gondii lysate.
abstract: During Toxoplasma gondii infection, macrophages, dendritic cells, and neutrophils are important sources of pro-inflammatory cytokines from the host. To counteract the pro-inflammatory activities, T. gondii is known to have several mechanisms inducing down-regulation of the host immunity. In the present study, we analyzed the production of proand anti-inflammatory cytokines from a human myelomonocytic cell line, THP-1 cells, in response to treatment with T. gondii lysate or lipopolysaccharide (LPS). Treatment of THP-1 cells with LPS induced production of IL-12, TNF-alpha, IL-8, and IL-10. Co-treatment of THP-1 cells with T. gondii lysate inhibited the LPS-induced IL-12, IL-8 and TNF-alpha expression, but increased the level of IL-10 synergistically. IL-12 and IL-10 production was down-regulated by anti-human toll-like receptor (TLR)-2 and TLR4 antibodies. T. gondii lysate triggered nuclear factor (NF)-kappaB-dependent IL-8 expression in HEK293 cells transfected with TLR2. It is suggested that immunosuppression induced by T. gondii lysate treatment might occur via TLR2-mediated NF-kappaB activation.
authors.affiliation: Department of Parasitology and Institute of Biomedical Science, Hanyang University College of Medicine, Seoul 133-791, Korea.
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Lee
authors.forename: Yoo-Mi
authors.initials: YM
authors.lastname: Heo
authors.forename: Jong-Hak
authors.initials: JH
authors.lastname: Choi
authors.forename: Hyun-Ouk
authors.initials: HO
authors.lastname: Song
authors.forename: Jae-Sook
authors.initials: JS
authors.lastname: Ryu
authors.forename: Myoung-Hee
authors.initials: MH
authors.lastname: Ahn
mesh_terms: D000818:Animals; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis*; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism*; D014122:Toxoplasma
chemical_list: D016207:Cytokines; D008070:Lipopolysaccharides