Stimulation of the human immunodeficiency virus type 1 enhancer by the human T-cell leukemia virus type I tax gene product involves the action of inducible cellular proteins

J Virol. 1989 Apr;63(4):1578-86. doi: 10.1128/JVI.63.4.1578-1586.1989.


The human immunodeficiency virus type 1 (HIV-1) preferentially infects CD4+ T lymphocytes and may exist as a latent provirus within these cells for extended periods. The transition to a productive retroviral infection results in T-cell death and clinically may lead to the acquired immune deficiency syndrome. Accelerated production of infectious HIV-1 virions appears to be closely linked to a heightened state of T-cell activation. The transactivator (Tax) protein of the type I human T-cell leukemia virus (HTLV-I) can produce such an activated T-cell phenotype and augments activity of the HIV-1 long terminal repeat. One Tax-responsive region within the HIV-1 long terminal repeat has been mapped to a locus composed of two 10-base-pair direct repeats sharing homology with the binding site for the eucaryotic transcription factor NF-kappaB (GGGACTTTCC). Tax-expressing Jurkat T cells contain one or more inducible cellular proteins that specifically associate with the HIV-1 enhancer at these binding sites. Microscale DNA affinity precipitation assays identified a Tax-inducible 86-kilodalton protein, HIVEN86A, as one of these HIV-1 enhancer-binding factors. The interaction of HIVEN86A, and presumably other cellular proteins, with the HIV-1 enhancer appears functionally important as oligonucleotides corresponding to this enhancer were sufficient to impart Tax inducibility to an unresponsive heterologous promoter. These findings suggest that the Tax-inducible cellular protein HIVEN86A plays an important role in the transcriptional activation of the HIV-1 enhancer. These specific protein-DNA interactions may also be important for the transition of HIV-1 from a latent to a productive mode of infection. Furthermore, these findings highlight an intriguing biological interplay between HTLV-1 and HIV-1 through a cellular transcriptional pathway that is normally involved in T-cell activation and growth.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Line
  • DNA Mutational Analysis
  • Enhancer Elements, Genetic*
  • Gene Expression Regulation
  • HIV / genetics*
  • HTLV-I Antigens / physiology*
  • Human T-lymphotropic virus 1 / genetics*
  • Humans
  • Molecular Weight
  • Promoter Regions, Genetic
  • Retroviridae Proteins / physiology*
  • Trans-Activators
  • Transcription Factors / physiology*


  • HTLV-I Antigens
  • Retroviridae Proteins
  • Trans-Activators
  • Transcription Factors