title: Characterization of entry mechanisms of human herpesvirus 8 by using an Rta-dependent reporter cell line.
abstract: To analyze the mechanisms of entry of human herpesvirus 8 (HHV-8), we established a reporter cell line T1H6 that contains the lacZ gene under the control of the polyadenylated nuclear RNA promoter, known to be strongly activated by a viral transactivator, Rta. We found that infection with cell-free virus, as well as cocultivation with HHV-8-positive primary effusion lymphoma cell lines, activated the lacZ gene of T1H6 in a sensitive and dose-dependent manner. Addition of Polybrene and centrifugation enhanced, but polysulfonate compounds inhibited, the HHV-8 infectivity. RGD-motif-containing polypeptides and integrins did not decrease the infectivity, suggesting the presence of an additional cellular receptor other than the reported one. The entry was dependent on pH acidification but not on the clathrin pathway. Although conditioned media obtained from human immunodeficiency virus (HIV)-infected cells did not have any effect on the early steps of HHV-8 infection, intracellular expression of a proviral HIV type 1, but not of Tat alone, increased the HHV-8-dependent reporter activation slightly, suggesting a potential of HIV-mediated enhancement of an early step of HHV-8 infection.
authors.affiliation: Division of Viral and Rickettsial Disease, Centers for Disease Control and Prevention. Winship Cancer Center, Emory University, 1600 Clifton Road, Atlanta, GA 30333, USA. nai0@cdc.gov
authors.forename: Naoki
authors.initials: N
authors.lastname: Inoue
authors.forename: Jörn
authors.initials: J
authors.lastname: Winter
authors.forename: Renu B
authors.initials: RB
authors.lastname: Lal
authors.forename: Margaret K
authors.initials: MK
authors.lastname: Offermann
authors.forename: Shin
authors.initials: S
authors.lastname: Koyano
mesh_terms: D002460:Cell Line; D017930:Genes, Reporter; D006497:Heparan Sulfate / Q000494:pharmacology; D019288:Herpesvirus 8, Human / Q000472:pathogenicity*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D007763:Lac Operon; D012680:Sensitivity and Specificity; D013498:Suramin / Q000494:pharmacology; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014773:Virology / Q000379:methods
chemical_list: D006497:Heparan Sulfate; D017874:Immediate-Early Proteins; D013498:Suramin; D015534:Trans-Activators; D014764:Viral Proteins; C417604:Rta protein, Human herpesvirus 8