The Development and Testing of Retroviral Vectors Expressing Trans -Dominant Mutants of HIV-1 Proteins to Confer Anti-HIV-1 Resistance

Abstract

Trans-dominant mutants of human immunodeficiency virus type 1 (HIV-1) Tat and Rev are attractive candidates for use in gene therapy in the treatment of HIV-1 infections because both are essential for viral replication. Retroviral vectors were constructed to allow either Tat-inducible or Tat- and Rev-inducible expression of trans-dominant mutants of Tat and Rev. These vectors were used to infect a human CD4⁺ lymphocyte-derived cell line, MT₄. To determine the efficacy of various Tat and Rev mutants in inhibiting HIV-1 multiplication, MT₄ cells containing mutant-expressing constructs were infected with HIV-1, and the amount of HIV-1 released in the culture medium was measured for up to 30 days. A high level of resistance was observed in cells expressing the double tat/rev mutant in a Tat-inducible manner.

Overview summary

The various anti-HIV-1 genes that have thus far been proposed for use in retroviral vector-mediated gene transfer are generally in the form of either an RNA molecule (antisense RNA, ribozymes, and sense RNA which serve as RNA decoys of HIV-1 regulatory protein binding sites) or a protein (soluble CD4, interferon-α, diphtheria toxin A, and HSV-tk in the presence of a nucleoside analog). Therefore, it is evident with the many options available that a number of stages within the HIV-1 life cycle may be disrupted by the use of retroviral vector-mediated transfer of anti-HIV-1 genes. In this paper, we report that trans-dominant mutants of Tat and Rev when produced in a Tat-inducible manner can also be considered for anti-HIV-1 gene therapy.