Virus Genes

, Volume 46, Issue 1, pp 39–46

Human T cell leukemia virus type 2 (HTLV-2) Tax2 has a dominant activity over HTLV-1 Tax1 to immortalize human CD4+ T cells

  • Michitaka Imai
  • Masaya Higuchi
  • Hiroki Kawamura
  • Manami Yoshita
  • Masahiko Takahashi
  • Masayasu Oie
  • Hideaki Matsuki
  • Yuetsu Tanaka
  • Yutaka Aoyagi
  • Masahiro Fujii
Article

DOI: 10.1007/s11262-012-0831-9

Cite this article as:
Imai, M., Higuchi, M., Kawamura, H. et al. Virus Genes (2013) 46: 39. doi:10.1007/s11262-012-0831-9

Abstract

While human T cell leukemia virus type 1 (HTLV-1) is the causative agent of adult T cell leukemia, a close relative, HTLV-2, is not associated with any leukemia. HTLV-1 and HTLV-2 encode the Tax1 and Tax2 proteins, respectively, which are essential for the immortalization of human T cells by the respective viruses, thereby causing persistent infection. In this study, we compared Tax1 and Tax2 with respect to their immortalization activity in human T cells. Lentivirus-mediated transduction of the tax2 gene into human peripheral blood mononuclear cells stimulated with phytohemagglutinin and interleukin-2 in 96-well plates induced outgrowing T cells in most wells, but the cells infected with the control viruses died within 3 weeks. Surprisingly, the number of outgrowing cells induced by Tax2 was much higher than that induced by Tax1, and the appearance of outgrowing cells by Tax2 was earlier than that induced by Tax1. Nevertheless, both Tax2 and Tax1 preferentially immortalized CD4+ T cells, but not CD8+ T cells. Our study showed that HTLV-2 Tax2 can immortalize human CD4+ T cells, and the activity is much higher than that of Tax1. The distinct T cell immortalization activities of Tax2 and Tax1 might therefore play a role in the different pathogeneses observed for these two viruses.

Keywords

HTLV-1HTLV-2Tax2CD4ATL

Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  • Michitaka Imai
    • 1
    • 2
  • Masaya Higuchi
    • 1
  • Hiroki Kawamura
    • 3
  • Manami Yoshita
    • 1
  • Masahiko Takahashi
    • 1
  • Masayasu Oie
    • 1
  • Hideaki Matsuki
    • 1
  • Yuetsu Tanaka
    • 4
  • Yutaka Aoyagi
    • 2
  • Masahiro Fujii
    • 1
  1. 1.Division of VirologyNiigata University Graduate School of Medical and Dental SciencesNiigataJapan
  2. 2.Division of Gastroenterology and HepatologyNiigata University Graduate School of Medical and Dental SciencesNiigataJapan
  3. 3.Department of ImmunologyNiigata University Graduate School of Medical and Dental SciencesNiigataJapan
  4. 4.Department of Immunology, Graduate School and Faculty of MedicineUniversity of the RyukyusOkinawaJapan