title: Suppression of TLR9 immunostimulatory motifs in the genome of a gammaherpesvirus.
abstract: Multiple receptors within the innate immune system have evolved to recognize nucleic acids as signatures of viral infection. It is believed that this specificity is essential for viral detection, as viruses often lack other invariant features that can serve as suitable targets for innate receptors. One such innate receptor, TLR9, has been implicated in the detection of many dsDNA viruses. In this study, we investigate the detection of murine gammaherpesvirus 68 (MHV68) by TLR9. We find that the genomic DNA of the murine CMV, a very potent inducer of innate responses. Genome-wide analysis of the number of stimulatory versus nonstimulatory CpG motifs present in the genome of each virus reveals that the MHV68 genome contains only a fraction of the number of immunostimulatory motifs present in murine CMV. Notably, MHV68 appears to have selectively suppressed the number of stimulatory motifs through cytosine to thymine conversion. These data suggest that certain viruses may have evolved and modified their genomic content to avoid recognition by nucleic acid-sensing receptors of the innate immune system.
authors.affiliation: Division of Immunology and Pathogenesis, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Pezda
authors.forename: Alex
authors.initials: A
authors.lastname: Penn
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Barton
authors.forename: Laurent
authors.initials: L
authors.lastname: Coscoy
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics / Q000276:immunology; D000818:Animals; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism / Q000821:virology; D016679:Genome, Viral / Q000276:immunology*; D057809:HEK293 Cells; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018146:Muromegalovirus / Q000235:genetics / Q000276:immunology*; D018144:Rhadinovirus / Q000235:genetics / Q000276:immunology*; D051217:Toll-Like Receptor 9 / Q000037:antagonists & inhibitors* / Q000235:genetics* / Q000378:metabolism
chemical_list: C495370:Tlr9 protein, mouse; D051217:Toll-Like Receptor 9