title: Differential signaling of cmvIL-10 through common variants of the IL-10 receptor 1.
abstract: Human IL-10 (hIL-10) signaling is mediated by receptors consisting of two subunits, IL-10 receptor 1 (IL-10R1) and IL-10 receptor 2. Two common variants of the IL-10R1 (Ser 138 Gly (single-nucleotide polymorphism 3, SNP3) and Gly 330 Arg (SNP4)) are associated with diverse disease phenotypes. Viral homologs to hIL-10, such as cmvIL-10, utilize the same IL-10 receptor complex as part of viral immune evasion strategies. For the present study we hypothesized that IL-10R1 variants alter the ability of viral IL-10 to utilize the IL-10R1 signaling pathway. HeLa cell clones expressing different IL-10R1 haplotypes (WT or any variant) were incubated with hIL-10 or cmvIL-10. In cells expressing IL-10R1-WT, cmvIL-10 (both non-glycosylated- and HeLa-expressed) resulted in equal or slightly stronger STAT3 phosphorylation compared with hIL-10. In clones expressing IL-10R1-SNP3, IL-10R1-SNP4 or IL-10R1-SNP3+4, the cmvIL-10 showed significantly less STAT3 phosphorylation, especially when HeLa-expressed cytokines were used. Time course experiments demonstrated a slower kinetic of cmvIL-10 STAT3 activation through the variant IL-10R1. Similarly, IL-10R1 variants decreased the cmvIL-10-induced SOCS3 and signaling lymphocytic activation molecule mRNA expression. These data suggest that the IL-10R1 variants differentially reduce the signaling activity of cmvIL-10 and thereby may affect CMV's ability to escape from the host's immune surveillance.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine 3, Medical University of Vienna, Vienna, Austria.
authors.forename: Sabine G
authors.initials: SG
authors.lastname: Gruber
authors.forename: Maria
authors.initials: M
authors.lastname: Gloria Luciani
authors.forename: Paul
authors.initials: P
authors.lastname: Grundtner
authors.forename: Alexander
authors.initials: A
authors.lastname: Zdanov
authors.forename: Christoph
authors.initials: C
authors.lastname: Gasche
mesh_terms: D006239:Haplotypes; D006367:HeLa Cells; D006801:Humans; D053709:Interleukin-10 Receptor alpha Subunit / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D007700:Kinetics; D008024:Ligands; D008213:Lymphocyte Activation / Q000276:immunology; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation; D050796:STAT3 Transcription Factor / Q000378:metabolism; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: C446339:CMV IL-10 protein, Cytomegalovirus; D053709:Interleukin-10 Receptor alpha Subunit; D008024:Ligands; C106644:SOCS3 protein, human; D050796:STAT3 Transcription Factor; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D014764:Viral Proteins