title: Neuraminidase enhances the initial steps of human T-cell leukemia virus type 1 replication.
abstract: Human T-cell leukemia virus type 1 (HTLV-1) infection is involved in the development of adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis. A high HTLV-1 proviral load in circulating lymphocytes of HTLV-1 carriers is a risk factor for HTLV-1-related diseases. The virus-cell interaction is linked to viral tropism and pathogenesis. Characterization of the factors that affect HTLV-1 infection is important for preventing HTLV-1 infection. HTLV-1 virions are believed to be weakly infectious under cell culture conditions; however, we found that the treatment of HTLV-1 virions with microbial neuraminidase, an enzyme catalyzing the removal of sialic acid residues from various glycoconjugates, enhanced the number of proviral DNAs in infected cells in a dose-dependent manner. Neuraminidase treatment of virions, but not target cells, enhanced viral binding and entry into cells and viral infectivity; treatment of target cells prior to infection had no effect. Moreover, the number of HTLV-1-mediated syncytia was higher in the presence of neuraminidase. Our results suggest a possible contribution of microbial agents carrying neuraminidase activity to HTLV-1 pathogenesis.
authors.affiliation: Graduate School of Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga 526-0829, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Tanaka
authors.forename: Binlian
authors.initials: B
authors.lastname: Sun
authors.forename: Kenta
authors.initials: K
authors.lastname: Tezuka
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Fujisawa
authors.forename: Yuetsu
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Hiroo
authors.initials: H
authors.lastname: Hoshino
authors.forename: Masanao
authors.initials: M
authors.lastname: Miwa
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism / Q000494:pharmacology; D002415:Cats; D002460:Cell Line; D015726:Giant Cells / Q000187:drug effects; D006023:Glycoproteins / Q000187:drug effects / Q000378:metabolism; D015368:Human T-lymphotropic virus 1 / Q000187:drug effects / Q000472:pathogenicity* / Q000502:physiology; D006801:Humans; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D009439:Neuraminidase / Q000378:metabolism / Q000494:pharmacology*; D014759:Viral Envelope Proteins / Q000187:drug effects / Q000378:metabolism; D014771:Virion / Q000187:drug effects / Q000201:enzymology; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D001426:Bacterial Proteins; D006023:Glycoproteins; D014759:Viral Envelope Proteins; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid