title: The diversity of the structure and genomic integration sites of HTLV-1 provirus in MT-2 cell lines.
abstract: A human T-lymphotropic virus Type 1 (HTLV-1) positive cell line, MT-2, derived from human cord leukocytes co-culturing with adult T cell leukemia/lymphoma (ATL) cells is commonly used in HTLV-1 research; however, the details of provirus integrated in MT-2 genome have not yet been characterized. In this study, five types of HTLV-1 proviral sequences were detected in 11 different sites of the genome in a reference MT-2 cell line. The five types of HTLV-1 proviral sequences were one complete proviral genome, two types of proviruses with deletion of large internal viral sequences (5.3 and 3.9 kB), one provirus with a large deletion (6.2 kB) from 5'LTR to position 6257, and one provirus of LTR only. The provirus with identical deletion of large internal viral sequence (5.3 kB) was found to be integrated into six different sites (chromosomes). A complete provirus and three of four types of defective provirus were consistently detected in two other MT-2 cell lines cultured in different laboratories. Not only Tax/Rex RNA and HBZ RNA, but also the transcriptional product for a specific defective provirus, were detectable in all three MT-2 cell lines. Because it has been reported that defective provirus is frequently detected in ATL cells, these results may be important in understanding the mechanism of HTLV-1 proviral polymorphism, which may be related to leukemogenesis. In addition, the large variation in integrated HTLV-1 proviruses makes it important for researchers to exercise caution in their assessment and interpretation of results using MT-2 cell lines.
authors.affiliation: Department of Rheumatology, Infectious Diseases and Laboratory Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan.
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Hashikura
authors.affiliation: Department of Rheumatology, Infectious Diseases and Laboratory Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Umeki
authors.affiliation: Department of Rheumatology, Infectious Diseases and Laboratory Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Umekita
authors.affiliation: Department of Rheumatology, Infectious Diseases and Laboratory Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Nomura
authors.affiliation: Department of Rheumatology, Infectious Diseases and Laboratory Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Yamamoto
authors.affiliation: Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki, 852-8102, Japan.
authors.forename: Hiroo
authors.initials: H
authors.lastname: Hasegawa
authors.affiliation: Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki, 852-8102, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Yanagihara
authors.affiliation: Department of Rheumatology, Infectious Diseases and Laboratory Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki, 889-1692, Japan. okayama@med.miyazaki-u.ac.jp.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Okayama
mesh_terms: D001483:Base Sequence; D002460:Cell Line / Q000821:virology*; D018920:Coculture Techniques; D016679:Genome, Viral / Q000235:genetics*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000821:virology; D007962:Leukocytes; D011533:Proviruses / Q000235:genetics; D016662:Virus Integration / Q000235:genetics*
keywords: Defective virus; HTLV-1; MT-2 cell line