title: Bovine milk RNases modulate pro-inflammatory responses induced by nucleic acids in cultured immune and epithelial cells.
abstract: Activation of innate immune receptors by exogenous substances is crucial for the detection of microbial pathogens and a subsequent inflammatory response. The inflammatory response to microbial lipopolysaccharide via Toll-like receptor 4 (TLR4) is facilitated by soluble accessory proteins, but the role of such proteins in the activation of other pathogen recognition receptors for microbial nucleic acid is not well understood. Here we demonstrate that RNase4 and RNase5 purified from bovine milk bind to Salmonella typhimurium DNA and stimulate pro-inflammatory responses induced by nucleic acid mimetics and S. typhimurium DNA in an established mouse macrophage cell culture model, RAW264.7, as well as in primary bovine mammary epithelial cells. RNase4 and 5 also modulated pro-inflammatory signalling in response to nucleic acids in bovine peripheral blood mononuclear cells, although producing a distinct response. These results support a role for RNase4 and RNase5 in mediating inflammatory signals in both immune and epithelial cells, involving mechanisms that are cell-type specific.
authors.affiliation: Dairy Foods, AgResearch, Ruakura Research Centre, Hamilton, New Zealand; Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand; Leibniz-Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Dummerstorf, Germany. Electronic address: sandeep.gupta@agresearch.co.nz.
authors.forename: Sandeep K
authors.initials: SK
authors.lastname: Gupta
authors.affiliation: Dairy Foods, AgResearch, Ruakura Research Centre, Hamilton, New Zealand. Electronic address: brendan.haigh@agresearch.co.nz.
authors.forename: Brendan J
authors.initials: BJ
authors.lastname: Haigh
authors.affiliation: Leibniz-Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Dummerstorf, Germany. Electronic address: seyfert@fbn-dummerstorf.de.
authors.forename: Hans-Martin
authors.initials: HM
authors.lastname: Seyfert
authors.affiliation: Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand. Electronic address: frank.griffin@otago.ac.nz.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Griffin
authors.affiliation: Cawthron Institute, Nelson, New Zealand. Electronic address: tom.wheeler@cawthron.org.nz.
authors.forename: Thomas T
authors.initials: TT
authors.lastname: Wheeler
mesh_terms: D000818:Animals; D002417:Cattle; D004269:DNA, Bacterial / Q000276:immunology; D004722:Endoribonucleases / Q000276:immunology / Q000378:metabolism*; D004847:Epithelial Cells / Q000276:immunology*; D005260:Female; D056747:Immunomodulation; D007249:Inflammation / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D008321:Mammary Glands, Animal / Q000473:pathology; D051379:Mice; D008892:Milk / Q000276:immunology / Q000378:metabolism*; D000067996:RAW 264.7 Cells; D012259:Ribonuclease, Pancreatic / Q000276:immunology / Q000378:metabolism*; D012480:Salmonella Infections / Q000276:immunology; D012486:Salmonella typhimurium / Q000235:genetics / Q000276:immunology*; D015398:Signal Transduction; D051197:Toll-Like Receptor 4 / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D051197:Toll-Like Receptor 4; D004722:Endoribonucleases; C497715:Rnase4 protein, mouse; C099439:Ang2 protein, mouse; D012259:Ribonuclease, Pancreatic
keywords: Bovine PBMCs; Host defence; Immune modulation; Macrophage; Mastitis; RNase