title: Requirements for the induction of interleukin-6 by herpes simplex virus-infected leukocytes.
abstract: Cytokines play important roles in the clearance of herpes simplex virus (HSV) infections and in virus-induced immunopathology. One cytokine known to contribute to resistance against HSV is interleukin-6 (IL-6). Here we have investigated virus-cell interactions responsible for IL-6 induction by HSV in leukocytes. Both HSV type 1 and type 2 are potent inducers of IL-6, and this phenomenon is augmented in the presence of gamma interferon. The ability to induce IL-6 is dependent on de novo protein synthesis and is sensitive to UV irradiation of the virus. Virus mutants lacking the virion-transactivating protein VP16 or any of the immediate-early proteins ICP0, ICP4, or ICP27 displayed unaltered capacities to induce IL-6. However, wild-type virus was unable to induce IL-6 in a macrophage cell line overexpressing a mutant of double-stranded RNA-activated protein kinase (PKR). This suggests a role for PKR in HSV-induced IL-6 expression. HSV infection led to enhanced binding to the kappaB, CRE, and AP-1 sites of the IL-6 promoter, and inhibitors against NF-kappaB and the p38 kinase strongly reduced accumulation of IL-6 mRNA in infected cells. Moreover, macrophage cell lines expressing dominant negative mutants of IkappaBalpha and p38 responded to HSV-1 infection with reduced IL-6 expression compared to the control-vector-transfected cell line. The results show that induction of IL-6 by HSV in leukocytes is dependent on PKR and cellular signaling through NF-kappaB and a p38-dependent pathway.
authors.affiliation: Department of Medical Microbiology and Immunology, University of Aarhus, Aarhus, Denmark. srp@microbiology.au.dk
authors.forename: S R
authors.initials: SR
authors.lastname: Paludan
mesh_terms: D000328:Adult; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D018258:Herpesvirus 2, Human / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000821:virology*; D017737:Macrophages, Peritoneal / Q000276:immunology / Q000821:virology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012330:RNA, Double-Stranded / Q000378:metabolism; D015398:Signal Transduction; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D019892:eIF-2 Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D015850:Interleukin-6; D016328:NF-kappa B; D012330:RNA, Double-Stranded; D014764:Viral Proteins; D019892:eIF-2 Kinase; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases