Intracellular Immunization Against HIV-1 Infection of Human T Lymphocytes: Utility of Anti-Rev Single-Chain Variable Fragments

Abstract

Genetic therapy offers a potentially promising approach with which to combat human immunodeficiency virus type 1 (HIV-1) infections. Several modalities, using protein- and RNA-based systems, have recently been shown to inhibit HIV-1 replication. A single-chain variable fragment (SFv), constructed from the cDNA of a monoclonal antibody to the HTV-1 regulatory protein Rev, has been demonstrated to potently inhibit HIV-1 replication, when expressed intracellularly in an epithelial cell-line (HeLa-CD4). Murine retroviral shuttle vectors, which express the anti-Rev SFv moiety, have now been constructed. HIV-1 infection was dramatically inhibited in human T-lymphocytic cell-lines, CEM and Sup-Tl, transduced with these anti-Rev SFv-expressing vectors. This resistance to high levels of HIV-1 expression was demonstrated in both mixed populations and clones of these cells. Of further potential clinical significance, HIV-1 infection was also potently inhibited in human peripheral blood mononuclear cells (PBMC), transduced with retroviral vectors expressing the anti-Rev SFv molecule. These data suggest that intracellular expression of anti-Rev SFvs, or related approaches, may be utilized as genetic therapy, or intracellular immunization, for HIV-1 infections in vivo.

Overview summary

An anti-Rev single-chain variable fragment (SFv) moiety can be efficiently expressed, using murine retroviral vectors, in human T lymphocytic cell lines as well as in primary human blood mononuclear cells (PBMC). Both mixed cellular populations and cell clones, transduced with the anti-Rev SFv, demonstrated significant resistance to productive human immunodeficiency virus type 1 (HIV-1) replication. Thus, intracellular immunization may be approachable, using ex vivo transduction of human cells with anti-Rev SFvs, in HIV-1-infected individuals.