Korean J Parasitol. 2008 Sep;46(3):145-51
Suppressed Production of Pro-inflammatory Cytokines by LPS-Activated Macrophages after Treatment with Toxoplasma gondii Lysate
Lee EJ, Heo YM, Choi JH, Song HO, Ryu JS, Ahn MH.
Department of Parasitology and Institute of Biomedical Science, Hanyang University College of Medicine, Seoul 133-791, Korea. email@example.com.
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.
PMID: 18830053 [PubMed - in process]