Comparative virology of HTLV-1 and HTLV-2

Retrovirology. 2019 Aug 7;16(1):21. doi: 10.1186/s12977-019-0483-0.


Human T cell leukemia virus type 1 (HTLV-1) was the first discovered human retrovirus and the etiologic agent of adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis. Shortly after the discovery of HTLV-1, human T-cell leukemia virus type 2 (HTLV-2) was isolated from a patient with hairy cell leukemia. Despite possession of similar structural features to HTLV-1, HTLV-2 has not been definitively associated with lymphoproliferative disease. Since their discovery, studies have been performed with the goal of highlighting the differences between HTLV-1 and HTLV-2. A better understanding of these differences will shed light on the specific pathogenic mechanisms of HTLV-1 and lead to novel therapeutic targets. This review will compare and contrast the two oldest human retroviruses with regards to epidemiology, genomic structure, gene products, and pathobiology.

Keywords: APH-2; ATL; Adult T-cell leukemia; HAM/TSP; HBZ; HTLV-1; HTLV-1 associated myelopathy/tropical spastic paraparesis; HTLV-2; Tax.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • HTLV-I Infections / virology
  • HTLV-II Infections / virology
  • 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
  • Leukocytes, Mononuclear / virology
  • Paraparesis, Tropical Spastic / virology