Anti-HIV designer T cells progressively eradicate a latently infected cell line by sequentially inducing HIV reactivation then killing the newly gp120-positive cells

Abstract

The current antiretroviral therapy (ART) can effectively reduce plasma HIV loads to undetectable levels, but cannot eliminate latently infected resting memory CD4 T cells that persist for the lifetime of infected patients. Therefore, designing new therapeutic approaches to eliminate these latently infected cells or the cells that produce HIV upon reactivation from latency is a priority in the ART era in order to progress to a cure of HIV. Here, we show that “designer” T cells expressing chimeric antigen receptor (CAR), CD4-CD28-CD3ζ, can target and kill HIV Env-expressing cells. Further, they secrete effector cytokines upon contact with HIV Env+ target cells that can reactivate latent HIV in a cell line model, thereby exposing those cells to recognition and killing by anti-HIV CAR+ T cells. Taken to the limit, this process could form the basis for an eventual functional or sterilizing cure for HIV in patients.

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

“…We found that the newly designed CAR-T cells, here referred to as VC-CAR-T cells, were able to induce T cell-mediated cytolysis after coculture with gp120-expressing cells and wild-type HIV-1-infected CD4 ϩ T cells. We also found that VC-CAR-T cells display superior potency compared to the CD4-CAR described previously (26,27,(31)(32)(33)(34)(35)(36). Importantly, we have also confirmed that they can effectively kill the reactivated HIV-1-infected CD4 ϩ T lymphocytes isolated from HIV-1-infected patients.…”

“…Therefore, we chose to use VRC01-28BBZ-3-expressing T cells, here referred to as VC-CAR-T cells, for subsequent experiments. Previous studies have reported that CD4-based CAR-T cells, referred to here as CD4-CAR-T cells, display direct cytotoxic activity against HIV-1 Env-expressing target cells (26,27,(31)(32)(33)(34)(35)(36). To compare the efficiency of CD4-CAR and VC-CAR, we generated the former by replacing the VC-CAR scFv with the human CD4 extracellular domain and transduced this construct into CD8 ϩ T lymphocytes (Fig.…”

“…It is concerning that the specific interaction between the scFv and HIV-1 gp120 might result in CAR-T cells being susceptible to HIV-1 infection (31,32,50). To examine this possibility, unmodified CD8…”

“…Previous reports have described the generation of HIV-1-specific CAR-T cells by connection of an extracellular antigenbinding domain to intracellular T cell activation domains (e.g., CD3 and CD28). The former can be a single-chain variable fragment (scFv) (26)(27)(28)(29)(30) or a natural molecule, such as CD4 (26,27,(31)(32)(33)(34)(35)(36), capable of directly inducing the death of cells expressing the viral envelope glycoprotein (Env). However, it remains to be determined whether these CAR-T cells can be used to kill the reactivated HIV-1 latently infected cells from the infected individuals receiving suppressive cART.…”

Latent HIV reservoirs exhibit inherent resistance to elimination by CD8+ T cells

“…The kick-and-kill paradigm gained traction when it was demonstrated that latency reversal (kick) alone, with the LRA vorinostat, was insufficient to cause the death of infected cells in a postactivation in vitro latency model, whereas the addition of expanded HIV-specific CD8 + T cells resulted in infected cell elimination (5). Others have since reported similar results using additional in vitro latency models, combined with natural or engineered CD8 + T cells, or NK cells as effectors (9)(10)(11)(12)(13)(14). These results have motivated the translation of the kick-and-kill approach into clinical trials that, thus far, have failed to achieve reductions in infectious viral reservoirs (15)(16)(17).…”