Targeted shock-and-kill HIV-1 gene therapy approach combining CRISPR activation, suicide gene tBid and retargeted adenovirus delivery.

Infections with the human immunodeficiency virus type 1 (HIV-1) are incurable due the long-lasting, latent viral reservoir. The shock-and-kill cure approach aims to activate latent proviruses in HIV-1 infected cells and subsequently kill these cells with strategies such as therapeutic vaccines or immune enhancement. Here, we combined the dCas9-VPR CRISPR activation (CRISPRa) system with gRNA-V, the truncated Bid (tBid)-based suicide gene strategy and CD3-retargeted adenovirus (Ad) delivery vectors, in an all-in-one targeted shock-and-kill gene therapy approach to achieve specific elimination of latently HIV-1 infected cells. Simultaneous transduction of latently HIV-1 infected J-Lat 10.6 cells with a CD3-retargeted Ad-CRISPRa-V and Ad-tBid led to a 57.7 ± 17.0% reduction of productively HIV-1 infected cells and 2.4-fold ± 0.25 increase in cell death. The effective activation of latent HIV-1 provirus by Ad-CRISPRa-V was similar to the activation control TNF-α. The strictly HIV-1 dependent and non-leaky killing by tBid could be demonstrated. Furthermore, the high transduction efficiencies of up to 70.8 ± 0.4% by the CD3-retargeting technology in HIV-1 latently infected cell lines was the basis of successful shock-and-kill. This novel targeted shock-and-kill all-in-one gene therapy approach has the potential to safely and effectively eliminate HIV-1 infected cells in a highly HIV-1 and T cell specific manner.