title: Major histocompatibility complex class I molecules are down-regulated at the cell surface by the K5 protein encoded by Kaposi's sarcoma-associated herpesvirus/human herpesvirus-8.
abstract: The expression of major histocompatibility complex class I (MHC-I) molecules at the cell surface was down-regulated in BC-3 cells infected with Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus-8 at early times after treatment with 12-O-tetradecanoylphorbol acetate (TPA), and in HeLa cells transfected with the K5 gene of KSHV. However, an immunoprecipitation study on these cells with anti-MHC-I monoclonal antibody revealed that there was no significant reduction in the synthesis of MHC-I molecules. A pulse-chase analysis followed by endoglycosidase H digestion also demonstrated the stability and transport of MHC-I molecules from the endoplasmic reticulum to at least the medial-GOLGI: K5 antigen was clearly detected by immunohistological examination of samples from Kaposi's sarcoma, primary effusion lymphoma and Castleman's disease. These results suggest that the down-regulation of MHC-I molecules by K5 gene expression during reactivation may be important for evading immunological surveillance in the host.
authors: Department of Microbiology, Osaka University Medical School, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan1.
authors: Muzammel
authors: M
authors: Haque
authors: Department of Microbiology, Osaka University Medical School, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan1.
authors: Keiji
authors: K
authors: Ueda
authors: Department of Microbiology, Osaka University Medical School, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan1.
authors: Kazushi
authors: K
authors: Nakano
authors: Department of Microbiology, Osaka University Medical School, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan1.
authors: Yuko
authors: Y
authors: Hirata
authors: Department of Pathology2 and Institute of Infectious Diseases3, University of Milan, 'L. Sacco' Hospital, Milan, Italy.
authors: Carlo
authors: C
authors: Parravicini
authors: Department of Pathology2 and Institute of Infectious Diseases3, University of Milan, 'L. Sacco' Hospital, Milan, Italy.
authors: Mario
authors: M
authors: Corbellino
authors: Department of Microbiology, Osaka University Medical School, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan1.
authors: Koichi
authors: K
authors: Yamanishi
mesh_terms: D000956:Antigens, Viral / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D005871:Castleman Disease / Q000276:immunology / Q000378:metabolism / Q000473:pathology / Q000821:virology; D002462:Cell Membrane; D015536:Down-Regulation; D006367:HeLa Cells; D019288:Herpesvirus 8, Human / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D017874:Immediate-Early Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D012514:Sarcoma, Kaposi / Q000276:immunology / Q000378:metabolism / Q000473:pathology / Q000821:virology; D014764:Viral Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*
chemical_list: D000956:Antigens, Viral; D015395:Histocompatibility Antigens Class I; D017874:Immediate-Early Proteins; C405867:K5 protein, Human herpesvirus 8; D014764:Viral Proteins