In vivo selection of CD4(+) T cells transduced with a gamma-retroviral vector expressing a single-chain intrabody targeting HIV-1 tat

Hum Gene Ther. 2012 Sep;23(9):917-31. doi: 10.1089/hum.2011.184.


We evaluated the potential of an anti-human immunodeficiency virus (HIV) Tat intrabody (intracellular antibody) to promote the survival of CD4(+) cells after chimeric simian immunodeficiency virus (SIV)/HIV (SHIV) infection in rhesus macaques. Following optimization of stimulation and transduction conditions, purified CD4(+) T cells were transduced with GaLV-pseudotyped retroviral vectors expressing either an anti-HIV-1 Tat or a control single-chain intrabody. Ex vivo intrabody-gene marking was highly efficient, averaging four copies per CD4(+) cell. Upon reinfusion of engineered autologous CD4(+) cells into two macaques, high levels of gene marking (peak of 0.6% and 6.8% of peripheral blood mononuclear cells (PBMCs) and 0.3% or 2.2% of the lymph node cells) were detected in vivo. One week post cell infusion, animals were challenged with SHIV 89.6p and the ability of the anti-HIV Tat intrabody to promote cell survival was evaluated. The frequency of genetically modified CD4(+) T cells progressively decreased, concurrent with loss of CD4(+) cells and elevated viral loads in both animals. However, CD4(+) T cells expressing the therapeutic anti-Tat intrabody exhibited a relative survival advantage over an 8- and 21-week period compared with CD4(+) cells expressing a control intrabody. In one animal, this survival benefit of anti-Tat transduced cells was associated with a reduction in viral load. Overall, these results indicate that a retrovirus-mediated anti-Tat intrabody provided significant levels of gene marking in PBMCs and peripheral tissues and increased relative survival of transduced cells in vivo.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD4-Positive T-Lymphocytes / immunology
  • CD4-Positive T-Lymphocytes / metabolism*
  • Cell Survival
  • Gammaretrovirus*
  • Gene Expression
  • HIV Antibodies / biosynthesis*
  • HIV Antibodies / genetics
  • HIV-1*
  • Humans
  • Lymphocyte Transfusion
  • Macaca mulatta
  • Single-Chain Antibodies / biosynthesis*
  • Single-Chain Antibodies / genetics
  • Time Factors
  • Transduction, Genetic*
  • tat Gene Products, Human Immunodeficiency Virus / antagonists & inhibitors*
  • tat Gene Products, Human Immunodeficiency Virus / genetics
  • tat Gene Products, Human Immunodeficiency Virus / immunology


  • HIV Antibodies
  • Single-Chain Antibodies
  • tat Gene Products, Human Immunodeficiency Virus