title: Orf virus IL-10 reduces monocyte, dendritic cell and mast cell recruitment to inflamed skin.
abstract: Orf virus (ORFV) is a zoonotic parapoxvirus that causes pustular dermatitis of sheep, and occasionally humans. Despite causing sustained infections, ORFV induces only a transient increase in pro-inflammatory signalling and the trafficking of innate immune cells within the skin seems to be impaired. An explanation for this tempered response to ORFV infection may lie in its expression of a homolog of the anti-inflammatory cytokine, interleukin (IL)-10. Using a murine model in which inflammation was induced by bacterial lipopolysaccharide, we examined the effects of the ORFV-IL-10 protein on immune cell trafficking to and from the skin. ORFV-IL-10 limited the recruitment of blood-derived Gr-1(int)/CD11b(int) monocytes, CD11c(+ve)/MHC-II(+ve) dendritic cells and c-kit(+ve)/FcεR1(+ve) mature mast cells into inflamed skin. ORFV-IL-10 also suppressed the activation of CD11c(+ve)/MHC-II(+ve) dendritic cells within the skin, reducing their trafficking to the draining lymph node. These findings suggest that expression of IL-10 by ORFV may contribute to the impaired trafficking of innate immune cells within infected skin.
authors.affiliation: Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
authors.forename: Jared R
authors.initials: JR
authors.lastname: Bennett
authors.affiliation: Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
authors.forename: Zabeen
authors.initials: Z
authors.lastname: Lateef
authors.affiliation: Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Fleming
authors.affiliation: Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Mercer
authors.affiliation: Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand. Electronic address: lyn.wise@otago.ac.nz.
authors.forename: Lyn M
authors.initials: LM
authors.lastname: Wise
mesh_terms: D000818:Animals; D003713:Dendritic Cells / Q000276:immunology*; D003872:Dermatitis / Q000473:pathology; D004195:Disease Models, Animal; D054884:Host-Pathogen Interactions; D007108:Immune Tolerance; D016753:Interleukin-10 / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000633:toxicity; D008407:Mast Cells / Q000276:immunology*; D051379:Mice; D009000:Monocytes / Q000276:immunology*; D009923:Orf virus / Q000276:immunology*; D012867:Skin / Q000473:pathology* / Q000821:virology; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D008070:Lipopolysaccharides; D014764:Viral Proteins; D016753:Interleukin-10
keywords: Cell trafficking; IL-10; Inflammation; Orf virus; Parapoxvirus