title: Toxoplasma gondii infection can regulate the expression of tumour necrosis factor-alpha receptors on human cells in vitro.
abstract: The in vitro regulation of tumour necrosis factor (TNF)-alpha receptors during Toxoplasma gondii infection of human MRC5 fibroblasts and human myelomonocytic THP-1 cells was investigated. Cells were infected with the virulent RH of T. gondii. TNFR membrane receptors were analysed by flow cytometry with biotinylated TNF-alpha. Shedding of the soluble form of TNFR1 and TNFR2 in cell culture supernatants was measured by enzyme-linked immunosorbent assay, and expression of mRNA production of TNFR1 and TNFR2 was analysed by quantitative real-time polymerase chain reaction, 1 h after infection. In the MRC5 cell line, T. gondii infection did not induce any up- or down-regulation of membrane TNFRs, soluble TNFRs or mRNA of TNFRs. However, THP-1 cell infection with living parasites induced a significant soluble TNFR1 release by THP-1 cells after 1 h. We detected an approximately 50% up-regulation (P < 0.01) of soluble TNFR1 in infected THP-1 cells compared to controls. No change in soluble TNFR2 levels was observed in the same conditions. Moreover, infection decreased the level of TNF membrane receptors, but had no effect on TNFR1 and TNFR2 mRNA levels. TNFR modulation by T. gondii infection, in vitro, depends on the cell type. Furthermore, our data suggest that living parasites control the shedding of the soluble form of TNFR1. This mechanism may influence the role of TNF-alpha in toxoplasmosis.
authors.affiliation: Interactions Cellulaiers Parasite-Hôte (EA.UJF 2940), Faculté de Médecine, Université J. Fourier, Grenoble, France. dorra.derrouich-guergour@ujf-grenonle.fr
authors.forename: Dorra
authors.initials: D
authors.lastname: Derouich-Guergour
authors.forename: Delphine
authors.initials: D
authors.lastname: Aldebert
authors.forename: Ines
authors.initials: I
authors.lastname: Vigan
authors.forename: Evelyne
authors.initials: E
authors.lastname: Jouvin-Marche
authors.forename: Patrice N
authors.initials: PN
authors.lastname: Marche
authors.forename: Dominique
authors.initials: D
authors.lastname: Aubert
authors.forename: Pierre
authors.initials: P
authors.lastname: Ambroise-Thomas
authors.forename: Hervé
authors.initials: H
authors.lastname: Pelloux
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis; D001952:Bridged-Ring Compounds / Q000378:metabolism; D002478:Cells, Cultured; D005347:Fibroblasts / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D051379:Mice; D009636:Norbornanes; D012333:RNA, Messenger / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis*; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D013859:Thiocarbamates; D013871:Thiones / Q000378:metabolism; D014122:Toxoplasma / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*; D015854:Up-Regulation
chemical_list: D015703:Antigens, CD; D001952:Bridged-Ring Compounds; D009636:Norbornanes; D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D013859:Thiocarbamates; D013871:Thiones; D014409:Tumor Necrosis Factor-alpha; C046498:tricyclodecane-9-yl-xanthogenate