title: Role of dendritic cells infected with human herpesvirus 6 in virus transmission to CD4(+) T cells.
abstract: Human herpesvirus 6 (HHV-6) is a ubiquitous betaherpesvirus that predominantly infects and replicates in CD4(+) T lymphocytes. However, the mechanism of HHV-6 transmission to T cells from the peripheral mucosa is unknown. Here we found that dendritic cells (DCs) can transmit HHV-6 to T cells, resulting in productive infection. In immature monocyte-derived DCs (MDDCs) infected with HHV-6, viral early and late antigens were expressed, and nucleocapsids containing a DNA core were observed, although few virions were detected in the cytoplasm by electron microscopy, indicating that the maturation of HHV-6 virions may be incomplete in MDDCs. However, HHV-6 transmission from MDDCs to stimulated CD4(+) T cells occurred efficiently in coculture of these cells, but not from MDDCs culture supernatants. This transmission was partially inhibited by treating the DCs with a viral DNA synthesis blocker, indicating that viral replication in MDDCs is required for this transmission. Furthermore, myeloid DCs and plasmacytoid DCs infected with HHV-6 could also transmit the virus to stimulated T cells. Thus, DCs may be the first cell population targeted by HHV-6 and could play an important role in the virus' transmission to T cells for their further propagation.
authors.affiliation: Laboratory of Virology and Vaccinology, National Institute of Biomedical Innovation, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Takemoto
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Imasawa
authors.forename: Koichi
authors.initials: K
authors.lastname: Yamanishi
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Mori
mesh_terms: D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000821:virology*; D002454:Cell Differentiation; D002478:Cells, Cultured; D003593:Cytoplasm / Q000821:virology; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000821:virology*; D005786:Gene Expression Regulation; D015654:Herpesvirus 6, Human / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008264:Macrophages / Q000821:virology; D008854:Microscopy, Electron; D019349:Roseolovirus Infections / Q000276:immunology / Q000635:transmission*
chemical_list: D000911:Antibodies, Monoclonal; D000956:Antigens, Viral