Distinct Functions of HTLV-1 Tax1 From HTLV-2 Tax2 Contribute Key Roles to Viral Pathogenesis

Retrovirology. 2009 Dec 17;6:117. doi: 10.1186/1742-4690-6-117.


While the human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia/lymphoma (ATL), to date, its close relative HTLV-2 is not associated with ATL or other types of malignancies. Accumulating evidence shows that HTLV-1 Tax1 and HTLV-2 Tax2 have many shared activities, but the two proteins have a limited number of significantly distinct activities, and these distinctions appear to play key roles in HTLV-1 specific pathogenesis. In this review, we summarize the functions of Tax1 associated with cell survival, cell proliferation, persistent infection as well as pathogenesis. We emphasize special attention to distinctions between Tax1 and Tax2.

Publication types

  • Review

MeSH terms

  • Cell Proliferation
  • Cell Survival
  • Gene Products, tax / genetics
  • Gene Products, tax / physiology*
  • HTLV-II Infections / virology*
  • Host-Pathogen Interactions
  • Human T-lymphotropic virus 1 / genetics
  • Human T-lymphotropic virus 1 / pathogenicity*
  • Human T-lymphotropic virus 2 / genetics
  • Human T-lymphotropic virus 2 / pathogenicity*
  • Humans
  • Leukemia-Lymphoma, Adult T-Cell / virology*
  • Signal Transduction
  • Virulence


  • Gene Products, tax