Increased expression of alpha 4 beta 1 and alpha 5 beta 1 integrins on HTLV-I-infected lymphocytes

Virology. 1993 Dec;197(2):778-81. doi: 10.1006/viro.1993.1656.


T cells interact with the extracellular matrix via integrin receptors and these interactions affect both cellular localization and proliferation. The importance of these interactions in retrovirus-induced diseases, however, remains less clear. In the present study, we investigated changes in T cell adhesion to extracellular matrix proteins by HTLV-I expressing cell lines and human peripheral blood lymphocytes infected with HTLV-I by cocultivation. Cell lines and acutely infected primary peripheral blood lymphocytes demonstrated enhanced adhesion to fibronectin. Acute infection of peripheral blood lymphocytes increased the expression of alpha 5 beta 1 and alpha 4 beta 1 integrins. Antibodies to the alpha 4, alpha 5, and beta 1 subunits inhibited attachment of infected cells to fibronectin. We conclude that HTLV-I infection is associated with an increase in the expression of both the classical fibronectin receptor and the receptor for the alternatively spliced domain of fibronectin on peripheral blood lymphocytes. HTLV-I-related alterations in cell surface adhesion molecules may contribute to the abnormal proliferation of T cells in adult T cell leukemia (ATL) or to the abnormal localization of activated or infected T cells to the central nervous system of patients with tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM).

MeSH terms

  • Cell Adhesion
  • Cell Line, Transformed
  • Fibronectins
  • Human T-lymphotropic virus 1 / growth & development*
  • Humans
  • Integrin alpha4beta1
  • Integrins / biosynthesis*
  • Laminin
  • Lymphocytes / microbiology*
  • Paraparesis, Tropical Spastic / etiology
  • Receptors, Fibronectin
  • Receptors, Very Late Antigen / biosynthesis*
  • Retroviridae Proteins, Oncogenic / biosynthesis


  • Fibronectins
  • Integrin alpha4beta1
  • Integrins
  • Laminin
  • Receptors, Fibronectin
  • Receptors, Very Late Antigen
  • Retroviridae Proteins, Oncogenic
  • p24 protein, Human T-lymphotropic virus 1