Chimeric Antigen Receptor T Cells Guided by the Single-Chain Fv of a Broadly Neutralizing Antibody Specifically and Effectively Eradicate Virus Reactivated from Latency in CD4 ⁺ T Lymphocytes Isolated from HIV-1-Infected Individuals Receiving Suppressive Combined Antiretroviral Therapy

Abstract

Despite the advent of combined antiretroviral therapy (cART), the persistence of viral reservoirs remains a major barrier to curing human immunodeficiency virus type 1 (HIV-1) infection. Recently, the shock and kill strategy, by which such reservoirs are eradicated following reactivation of latent HIV-1 by latency-reversing agents (LRAs), has been extensively practiced. It is important to reestablish virus-specific and reliable immune surveillance to eradicate the reactivated virus-harboring cells. In this report, we attempted to reach this goal by using newly developed chimeric antigen receptor (CAR)-T cell technology. To generate anti-HIV-1 CAR-T cells, we connected the single-chain variable fragment of the broadly neutralizing HIV-1-specific antibody VRC01 to a third-generation CAR moiety as the extracellular and intracellular domains and subsequently transduced this into primary CD8 ؉ T lymphocytes. We demonstrated that the resulting VC-CAR-T cells induced T cell-mediated cytolysis of cells expressing HIV-1 Env proteins and significantly inhibited HIV-1 rebound after removal of antiviral inhibitors in a viral infectivity model in cell culture that mimics the termination of the cART in the clinic. Importantly, the VC-CAR-T cells also effectively induced the cytolysis of LRA-reactivated HIV-1-infected CD4؉ T lymphocytes isolated from infected individuals receiving suppressive cART. Our data demonstrate that the special features of genetically engineered CAR-T cells make them a particularly suitable candidate for therapeutic application in efforts to reach a functional HIV cure. IMPORTANCEThe presence of latently infected cells remains a key obstacle to the development of a functional HIV-1 cure. Reactivation of dormant viruses is possible with latency-reversing agents, but the effectiveness of these compounds and the subsequent immune response require optimization if the eradication of HIV-1-infected cells is to be achieved. Here, we describe the use of a chimeric antigen receptor, comprised of T cell activation domains and a broadly neutralizing antibody, VRC01, targeting HIV-1 to treat the infected cells. T cells expressing this construct exerted specific cytotoxic activity against wild-type HIV-1-infected cells, resulting in a dramatic reduction in viral rebound in vitro, and showed persistent effectiveness against reactivated latently infected T lymphocytes from HIV-1 patients receiving combined antiretroviral therapy. The methods used in this study constitute an improvement over existing CD4-based CAR-T technology and offer a promising approach to HIV-1 immunotherapy. HIV-1 replication can be efficiently suppressed with combined antiretroviral therapy (cART). However, treatment must be maintained throughout the lifetime of the patient, as this virus can persist in a stable latent reservoir, constituting a major barrier to the establishment of an HIV-1 cure. To date, many strategies have been proposed for the eradication of HIV-1 reservoirs (1-3). Recent efforts have focused on the reactivation of ...

Control of the HIV-1 DNA Reservoir Is AssociatedIn VivoandIn Vitrowith NKp46/NKp30 (CD335 CD337) Inducibility and Interferon Gamma Production by Transcriptionally Unique NK Cells

“…Finally, current programs and protocols for HIV eradication, including histone deacetylase inhibitor (HDACi) administration and immunotherapy, reportedly need improved immunotherapeutic strategies to clear virus in reactivated cells and to limit new virus integration (43,55,59,72,73). Selection and expansion of NK cells with high NCR and IFN-␥ inducibility may represent a useful tool to efficiently clear HIV-1 when combined within the frame of virus eradication strategies exploiting latency exit induction and immuno-/antiretroviral therapy (72)(73)(74).…”

“…Selection and expansion of NK cells with high NCR and IFN-␥ inducibility may represent a useful tool to efficiently clear HIV-1 when combined within the frame of virus eradication strategies exploiting latency exit induction and immuno-/antiretroviral therapy (72)(73)(74).…”

Combining Cell and Gene Therapy in an Effort to Eradicate HIV

“…[71][72][73][74][75][76][77][78][79][80] used measure of the viable HIV reservoir) and rectal HIV DNA (-0.5 log), and a trend toward less viral rebound, although no decrease in peripheral blood HIV DNA or rectal HIV RNA. 81 Long-term follow-up suggests that this approach was safe and results in long-lived cells with CAR DNA that persisted for more than a decade.…”

Engineering HIV-Specific Immunity with Chimeric Antigen Receptors

“…Upon assessment in a suite of assays, each of these CARs is functional; however, efficiency varies with each ligand-binding moiety, each assay used, and the virus strain being employed. Importantly, Liu et al 42 recently reported that…”

“…32,42 Some of these CARs also contain additional signaling sequences, which provide costimulatory capability upon ligand binding, to achieve a more robust activation event upon ligation with the target epitope. Upon assessment in a suite of assays, each of these CARs is functional; however, efficiency varies with each ligand-binding moiety, each assay used, and the virus strain being employed.…”