Selective survival of peripheral blood lymphocytes in children with HIV-1 following delivery of an anti-HIV gene to bone marrow CD34+ cells

Childrens Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, CA 90027, USA.
Molecular Therapy (Impact Factor: 6.23). 08/2005; 12(1):77-86. DOI: 10.1016/j.ymthe.2005.02.024
Source: PubMed


Two HIV-1-infected children on antiretroviral therapy were enrolled into a clinical study of retroviral-mediated transfer of a gene that inhibits replication of HIV-1, targeting bone marrow CD34+ hematopoietic stem/progenitor cells. Two retroviral vectors were used, one encoding a "humanized" dominant-negative REV protein (huM10) that is a potent inhibitor of HIV-1 replication and one encoding a nontranslated marker gene (FX) to serve as an internal control for the level of gene marking. Peripheral blood mononuclear cells (PBMC) containing the huM10 gene or FX gene were detected by quantitative PCR at frequencies of approximately 1/10,000 in both subjects for the first 1-3 months following re-infusion of the gene-transduced bone marrow, but then were at or below the limits of detection (<1/1,000,000) at most times over 2 years. In one patient, a reappearance of PBMC containing the huM10 gene, but not the FX gene, occurred concomitant with a rise in the HIV-1 viral load during a period of nonadherence to the antiretroviral regimen. Unique clones of gene-marked PBMC were detected by LAM-PCR during the time of elevated HIV-1 levels. These findings indicate that there was a selective survival advantage for PBMC containing the huM10 gene during the time of increased HIV-1 load.

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Available from: Elzbieta Monika Smogorzewska, May 17, 2015
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    • "Several groups have performed clinical trials in which autologous peripheral blood T-cells or HSPCs were genetically modified to introduce anti-HIV moieties that are RNA or protein in nature.5 These trials have proven the safety and potential efficacy of a cell-based approach to immunotherapy for HIV-1 with observations of selective T-cell survival and reduced viral loads following infusion of gene-modified T-cells.6,7,8 Based on these results and our prior work in stem cell transplantation for HIV/AIDS-related lymphomas,9 we rationalized that transplantation of autologous HSPC that were genetically altered to prevent expression of CCR5 would result in an HIV-resistant immune system for patients without an allogeneic donor. "
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    ABSTRACT: The HIV-1 coreceptor CCR5 is a validated target for HIV/AIDS therapy. The apparent elimination of HIV-1 in a patient treated with an allogeneic stem cell transplant homozygous for a naturally occurring CCR5 deletion mutation (CCR5(Δ32/Δ32)) supports the concept that a single dose of HIV-resistant hematopoietic stem cells can provide disease protection. Given the low frequency of naturally occurring CCR5(Δ32/Δ32) donors, we reasoned that engineered autologous CD34(+) hematopoietic stem/progenitor cells (HSPCs) could be used for AIDS therapy. We evaluated disruption of CCR5 gene expression in HSPCs isolated from granulocyte colony-stimulating factor (CSF)-mobilized adult blood using a recombinant adenoviral vector encoding a CCR5-specific pair of zinc finger nucleases (CCR5-ZFN). Our results demonstrate that CCR5-ZFN RNA and protein expression from the adenoviral vector is enhanced by pretreatment of HSPC with protein kinase C (PKC) activators resulting in >25% CCR5 gene disruption and that activation of the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway is responsible for this activity. Importantly, using an optimized dose of PKC activator and adenoviral vector we could generate CCR5-modified HSPCs which engraft in a humanized mouse model (albeit at a reduced level) and support multilineage differentiation in vitro and in vivo. Together, these data establish the basis for improved approaches exploiting adenoviral vector delivery in the modification of HSPCs.Molecular Therapy (2013); doi:10.1038/mt.2013.65.
    Full-text · Article · Apr 2013 · Molecular Therapy
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    • "Most clinical trials were phase I studies aimed at evaluating the safety and feasibility of anti-HIV gene transduced autologus hematopoietic stem/progenitor cell transplantation in patients. In early trials, transdominant RevM10 (Kang et al., 2002; Podsakoff et al., 2005), RRE decoy (Kohn et al., 1999), or an anti HIV ribozymeribozyme (Amado et al., 2004) were introduced into patient's CD34+ cells with Molony murine leukemia virus based gammaretroviral vectors. In summary, all of these phase I clinical studies demonstrated safety and feasibility of the procedures. "
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    ABSTRACT: Human stem cell-based therapeutic intervention strategies for treating HIV infection have recently undergone a renaissance as a major focus of investigation. Unlike most conventional antiviral therapies, genetically engineered hematopoietic stem cells possess the capacity for prolonged self-renewal that would continuously produce protected immune cells to fight against HIV. A successful strategy therefore has the potential to stably control and ultimately eradicate HIV from patients by a single or minimal treatment. Recent progress in the development of new technologies and clinical trials sets the stage for the current generation of gene therapy approaches to combat HIV infection. In this review, we will discuss two major approaches that are currently underway in the development of stem cell-based gene therapy to target HIV: one that focuses on the protection of cells from productive infection with HIV, and the other that focuses on targeting immune cells to directly combat HIV infection.
    Full-text · Article · Mar 2011 · Virology
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    • "For adoptive T cell transfer studies of genetic inhibitors of HIV-1 infection, although in vitro transduction efficiencies resulting in more than 1 vector copy per cell have been obtained [14], after infusion into patients, the frequency of vector-containing CD4+ T cells in vivo has generally been in the range of 0.01% to 1% [14]–[18]. For trials of hematopoietic stem cell gene therapy for AIDS, levels of gene marking in CD4+ T cells in vivo after transduction with gammaretroviral vectors have been disappointingly low, typically 0.01% or less [19], [20]. At these low levels of gene marking, inhibition of HIV-1 replication in the small fraction of cells containing an inhibitory gene is unlikely to have a significant impact on either viral replication or immune reconstitution. "
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