Broad tropic zinc finger protein guided transcriptional activation of HIV

Human Immunodeficiency Virus type 1 (HIV-1) is a lentivirus that causes a persistent viral infection and results in the demise of immune regulatory cells. Clearance of HIV-1 infection by the immune system is inefficient, and integration of proviral DNA into the genome of host cells provides a means for evasion and long-term persistence. A therapeutic compound that specifically targets and sustainably activates a latent HIV provirus could be transformative and is an overarching goal for the “shock and kill” approach to a functional cure for HIV. Substantial progress has been made towards the development of recombinant proteins that can target specific genomic loci for gene activation, repression or inactivation by directed mutations. However, most of these modalities are too large, or too complex, for efficient therapeutic application. We describe here the development and testing of a novel recombinant zinc finger protein transactivator, ZFPb-362-VPR, which specifically and potently enhances proviral HIV transcription both in established latency models and across different viral clades. Additionally, ZFP-362-VPR activated HIV reporter gene expression in a well-established primary human CD4+ T-cell latency model and was specific in targeting the HIV LTR as determined from off-target transcriptome analyses. This study provides clear proof of concept for the application of a novel, and therapeutically relevant, protein transactivator to purge cellular reservoirs of HIV-1. To determine the extent to which ZFP-362-VPR and dCas9-VPR+sgF2-362 disrupted RNA expression, we compared pMo-HEK cells transfected with either construct to those transfected with a pcDNA3.1 control, each in quadruplicate.