title: Identification and characterization of Kaposi's sarcoma-associated herpesvirus K8.1 virion glycoprotein.
abstract: Kaposi's sarcoma-associated herpesvirus (KSHV) has been consistently identified in Kaposi's sarcomas (KS), body cavity-based lymphomas (BCBL), and some forms of Castleman's disease. Previous serological tests with KS patient sera have detected lytic-cycle polypeptides from KSHV-infected BCBL cells. We have found that these polypeptides are predominantly encoded by the K8.1 open reading frame, which is present in the same genomic position as virion envelope glycoproteins of other gammaherpesviruses. The cDNA of K8.1 from BCBL-1 cells was found to encode a glycosylated protein with an apparent molecular mass of 37 kDa. K8.1 was found to be expressed during lytic KSHV replication in BCBL-1 cells and was localized on the surface of cells and virions. The results of immunofluorescence and immunoelectron microscopy suggest that KSHV acquires K8.1 protein on its virion surface during the process of budding at the plasma cell membrane. When KSHV K8.1 derived from mammalian cells was used as an antigen in immunoblot tests, antibodies to K8.1 were detected in 18 of 20 KS patients and in 0 of 10 KS-negative control subjects. These results demonstrate that the K8.1 gene encodes a KSHV virion-associated glycoprotein and suggest that antibodies to K8.1 may prove useful as contributory serological markers for infection by KSHV.
authors.affiliation: Department of Microbiology and Molecular Genetics, New England Regional Primate Research Center, Harvard Medical School, Southborough, Massachusetts 01772-9102, USA.
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.forename: J
authors.initials: J
authors.lastname: MacKey
authors.forename: S C
authors.initials: SC
authors.lastname: Czajak
authors.forename: R C
authors.initials: RC
authors.lastname: Desrosiers
authors.forename: A A
authors.initials: AA
authors.lastname: Lackner
authors.forename: J U
authors.initials: JU
authors.lastname: Jung
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D001483:Base Sequence; D019556:COS Cells; D003001:Cloning, Molecular; D004279:DNA, Viral; D006023:Glycoproteins / Q000235:genetics* / Q000378:metabolism; D019288:Herpesvirus 8, Human / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D015995:Prevalence; D011817:Rabbits; D012514:Sarcoma, Kaposi / Q000453:epidemiology / Q000276:immunology / Q000378:metabolism / Q000821:virology*; D017422:Sequence Analysis, DNA; D014407:Tumor Cells, Cultured; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000378:metabolism; D014764:Viral Proteins; D014771:Virion
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral; D006023:Glycoproteins; C113454:K8.1 protein, Human herpesvirus 8; D014759:Viral Envelope Proteins; D014764:Viral Proteins