Resistance to Fas-mediated apoptosis of human T-cell lines expressing human T-lymphotropic virus type-2 (HTLV-2) Tax protein

Virology. 2001 Mar 1;281(1):43-50. doi: 10.1006/viro.2000.0765.

Abstract

The susceptibility to Fas-mediated apoptosis was evaluated in seven T-cell lines (two infected with HTLV-2, one with HTLV-1, and four HTLV-free) as well as in Jurkat cells transfected with a Tax-2 expressing vector. Fas-mediated apoptosis was significantly reduced in the HTLV-1- and HTLV-2-infected lines in comparison with the HTLV-free lines regardless of the surface expression of Fas antigen (which was no different in the infected and uninfected cells). Fas-mediated apoptosis was also significantly inhibited in Jurkat cells transfected with the Tax-2 expressing vector without any modification in Fas expression. There was significantly more antiapoptotic Bcl-x(L) mRNA and protein in the transfected than in the untransfected Jurkat T cells. In conclusion, our results suggest that HTLV-2 is capable of inhibiting Fas-mediated apoptosis by means of a mechanism involving the tax-2 gene and probably the expression of bcl-x(L) messenger and protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies / immunology
  • Antibodies / pharmacology
  • Apoptosis* / drug effects
  • Blotting, Western
  • Cells, Cultured
  • Culture Media, Conditioned / pharmacology
  • Gene Products, tax / genetics
  • Gene Products, tax / metabolism*
  • Gene Products, tax / pharmacology
  • HTLV-II Infections / pathology
  • HTLV-II Infections / virology
  • Human T-lymphotropic virus 1 / genetics
  • Human T-lymphotropic virus 1 / physiology
  • Human T-lymphotropic virus 2 / genetics
  • Human T-lymphotropic virus 2 / physiology*
  • Humans
  • In Situ Nick-End Labeling
  • Jurkat Cells
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / metabolism
  • T-Lymphocytes / pathology*
  • T-Lymphocytes / virology*
  • Transfection
  • bcl-2-Associated X Protein
  • bcl-X Protein
  • fas Receptor / analysis
  • fas Receptor / immunology
  • fas Receptor / physiology*

Substances

  • Antibodies
  • BCL2L1 protein, human
  • Culture Media, Conditioned
  • Gene Products, tax
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • RNA, Messenger
  • bcl-2-Associated X Protein
  • bcl-X Protein
  • fas Receptor