title: Efficient propagation of human herpesvirus 6B in a T-cell line derived from a patient with adult T-cell leukemia/lymphoma.
abstract: The efficient propagation of the OK strain of the B variant of human herpesvirus 6 (HHV-6B) was demonstrated in a line of T cells, TaY, established from the peripheral blood lymphocytes of a patient with adult T-cell leukemia/lymphoma (ATL). Growth of TaY cells depends on the presence of IL-2 and the cells harbor HTLV-I genomes. A severe cytopathic effect (CPE) was observed in many HHV-6B(OK)-infected TaY cells one week after infection. The release of virus from HHV-6B(OK)-infected TaY cells [TaY(OK)] was first detected after three days and increased rapidly for up to seven days after infection, as demonstrated by PCR. The titer of HHV-6B(OK) in the supernatant was comparable to the value of 10(3.5) TCID50/ml obtained with PHA-activated cord blood lymphocytes (CBL) that had been infected with HHV-6B(OK). The replication of the virus was shown to depend to a considerable extent on cell viability. Electron microscopy revealed many herpesvirus-type capsid- and enveloped-viruses in the nuclei and cytoplasm of degenerated cells in TaY(OK) cultures. The U1102 strain of HHV-6A and the Z29 strain of HHV-6B also infected TaY cells productively, as detected by PCR and an immunofluorescence test. These results suggest that the activation of CD4+ T lymphocytes with mitogens such as PHA or IL-2 and the expression of some cellular gene or the HTLV-I gene might be essential for efficient propagation of HHV-6B. TaY cells should play an important role in future investigations of cell-virus interactions and genetic variations or cell tropism of HHV-6 isolates since no cell line that shows propagation of both HHV-6A and HHV-6B has been reported to date.
authors.affiliation: Department of Virology, Medical Research Institute, Tokyo Medical and Dental University, Japan.
authors.forename: C F
authors.initials: CF
authors.lastname: Zhou
authors.forename: K
authors.initials: K
authors.lastname: Abe
authors.forename: P
authors.initials: P
authors.lastname: Wang
authors.forename: T
authors.initials: T
authors.lastname: Ojima
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D001483:Base Sequence; D003588:Cytopathogenic Effect, Viral; D017931:DNA Primers; D015342:DNA Probes; D004279:DNA, Viral / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay; D016355:Genes, pX; D014644:Genetic Variation; D015654:Herpesvirus 6, Human / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D015368:Human T-lymphotropic virus 1 / Q000235:genetics; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000473:pathology / Q000821:virology*; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000821:virology; D014407:Tumor Cells, Cultured; D016662:Virus Integration
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D017931:DNA Primers; D015342:DNA Probes; D004279:DNA, Viral