Patient-adapted, specific activation of HIV-1 by customized TAL effectors (TALEs), a proof of principle study

- A new technical alternative is presented to purge HIV expression.
- Engineered TALE effector proteins target specific regions of the HIV promoter.
- TALEs activate transcription and viral outgrowth in PBMCs of different patients.
- TALEs may be useful tools in future strategies aimed at removing HIV-1 reservoirs.

The major obstacle to cure infections with human immunodeficiency virus (HIV-1) is integrated proviral genomes, which are not eliminated by antiretroviral therapies (ART). Treatment approaches with latency-reversing agents (LRAs) aim at inducing provirus expression to tag latently-infected cells for clearance through viral cytopathic effects or cytotoxic T cell (CTL) responses. However, the currently tested LRAs reveal evident drawbacks as gene expression is globally induced and viral outgrowth is insecure. Here, we present transcription activator-like effector (TALE) proteins as potent tools to activate HIV-1 specifically. The large variety of circulating HIV-1 strains and, accordingly, integrated proviruses was addressed by the programmable DNA-specificity of TALEs. Using customized engineered TALEs, a substantial transcription activation and viral outgrowth was achieved with cells obtained from different HIV-1 patients. Our data suggest that TALEs may be useful tools in future strategies aimed at removing HIV-1 reservoirs.