title: Flavivirus induces MHC antigen on human myoblasts: a model of autoimmune myositis?
abstract: Infection of human embryonic myoblasts by West Nile virus (WNV), a flavivirus, caused significant upregulation of class I and II MHC expression as determined by flow cytometry. After 48 hours at a multiplicity of infection of 5 pfu/cell, a sixfold increase in MHC class I expression was induced from initially low levels of expression. In contrast, MHC class II was induced de novo to five times the control fluorescence level. At least 70% of the cells were infected as determined using fluorescence microscopy and anti-WNV antibody labeling. Myoblasts were > 90% pure as shown by anti--Leu-19 labeling. MHC class I (but not class II) was increased threefold after exposure to virus-inactivated supernatant from 48-hour--infected cells, indicating the presence of factor(s) contributing to the MHC class I increase. These findings may be important in establishing a link between viral infection of human cells and induction of inflammatory autoimmune disease. We discuss the possibility of using WNV as an in vivo model.
authors: Department of Anatomy, University of Sydney, New South Wales, Australia.
authors: S
authors: S
authors: Bao
authors: N J
authors: NJ
authors: King
authors: C G
authors: CG
authors: Dos Remedios
mesh_terms: D001327:Autoimmune Diseases / Q000276:immunology*; D004622:Embryo, Mammalian / Q000166:cytology / Q000276:immunology; D005434:Flow Cytometry; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D009132:Muscles / Q000166:cytology / Q000196:embryology / Q000276:immunology*; D009220:Myositis / Q000276:immunology*; D014901:West Nile Fever / Q000175:diagnosis / Q000276:immunology; D014902:West Nile virus / Q000276:immunology*
chemical_list: D006680:HLA Antigens