Specific Transduction of HIV-Susceptible Cells for CCR5 Knockdown and Resistance to HIV Infection: A Novel Method for Targeted Gene Therapy and Intracellular Immunization

Abstract

Summary HIV-1 gene therapy offers a promising alternative to small molecule antiretroviral treatments and current vaccination strategies by transferring, into HIV-1–susceptible cells, the genetic ability to resist infection. The need for novel and innovative strategies to prevent and treat HIV-1 infection is critical due to devastating effects of the virus in developing countries, high cost, toxicity, generation of escape mutants from antiretroviral therapies, and the failure of past and current vaccination efforts. As a first step toward achieving this goal, an HIV-1–susceptible cell-specific targeting vector was evaluated to selectively transfer, into CCR5-positive target cells, an anti-HIV CCR5 shRNA gene for subsequent knockdown of CCR5 expression and protection from HIV-1 infection. Using a ZZ domain/monoclonal antibody–conjugated Sindbis virus glycoprotein pseudotyped lentiviral vector, here we demonstrate the utility of this strategy for HIV-1 gene therapy by specifically targeting HIV-1–susceptible cells and engineering these cells to resist HIV-1 infection. CCR5-positive human cells were successfully and specifically targeted in vitro and in vivo for transduction by a lentiviral vector expressing a highly potent CCR5 shRNA which conferred resistance to HIV-1 infection. Here we report the initial evaluation of this targeting vector for HIV-1 gene therapy in a preexposure prophylactic setting.

Seamless modification of wild-type induced pluripotent stem cells to the natural CCR5Δ32 mutation confers resistance to HIV infection

“…Using iPSC-derived CCR5 −/− stem cells for an autologous transplant has advantages over using primary CD4+ T cells. First, generation of iPSCs only (6,10) and the parental line (P). The closest gene name is used to indicate the amplification presented on top of the lines.…”

“…+ hematopoietic stem progenitor cells (HSPCs) or CD4 + T cells using shRNA or by gene disruption using zinc finger nucleases (ZFNs) (5)(6)(7)(8)(9)(10)(11). These reagents are delivered into CD34 + or T cells using lentiviral or adenoviral vectors.…”

Targeted DNA Mutagenesis for the Cure of Chronic Viral Infections

“…One novel approach to the problem of HIV latency is the use of gene editing to render T cells resistant to HIV. Initial experiments in mice have used a variety of approaches to downregulate CCR5, an entry receptor for HIV-1 strains (5,47,86,91,99,166). Cells deficient for CCR5 expression would theoretically expand and become enriched due to the selective advantage conferred by resistance to HIV infection.…”

Novel Cell and Gene Therapies for HIV

“…Transduction of such vectors into human CD34 þ HSC allowed HIV resistance to be conferred on both macrophages derived in vitro from the transduced cells (Liang et al 2010) as well as T-cell progeny that differentiated in vivo in a bone marrow/liver/thymus (BLT) mouse model (Shimizu et al 2010). A targeted strategy to deliver lentiviral vectors expressing an anti-CCR5 shRNA specifically to CCR5 þ cells in vivo was also shown using a PBMC transplanted mouse (Anderson et al 2009) and in nonhuman primates after stem cell transplants .…”