Gene engineering using CRISPR/Cas9 mutagenesis to eliminate latent HIV-1

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DESCRIPTION (provided by applicant): Highly active antiretroviral therapy (HAART) has substantially decreased the morbidity and mortality of HIV-1 infection. However, these drugs require daily, life-long administration. Development of resistant strains of HIV-1 and adherence difficulties with daily drug administration are still a problem. Even when the drugs effectively suppress HIV-1, the virus persists in a post-integration latent state which rapidly emerges once drug treatment is interrupted. Therefore, there is an urgent need for additional approaches directed to new therapeutic targets and targeting latent reservoirs. A relatively recent approach is to gene modify cells such that they are resistant to HIV-1 infection. The approach most advanced in preclinical and clinical studies is knockdown of the HIV-1 co-receptor, CCR5. Other targets for gene modification, such as the HIV-1 genome itself, have been considered, but efficient delivery is the limiting factor. Anti-HIV efficacy requires both efficient delivery into ells and, once delivered, efficient activity for gene-modification. Efficient gene-modification activity has been achieved by a number of systems including zinc-finger nucleases (ZNFs), transcription activator-like effector nucleases (TALENs) and homing endonucleases. These powerful genome editing nucleases have been used to create various mutations including substitutions, deletions and insertions in genomic DNA and for gene- modified transgenic animals. However, the design of nucleases directed to specific genomic sites is relatively difficult and time consuming. Recently, another genome editing method was identified in bacteria and archaea. The advantage of this system over previous genome modifying activities is simplicity- a guide RNA (gRNA) with homology to the target and a nuclease, Cas9, are all that is required to cleave specific target sequences. This CRISPR/Cas9 system has been adapted for genome-modification of mammalian cells including generation of mice bearing mutations in multiple genes with high efficiency. Recently the CRISPR/Cas system has been used to knockout latent HIV-1 provirus. Despite the efficient in vitro activity, all of the above methods ae limited for therapy by inefficient delivery to HIV-1 reservoir cells. The overall hypothesis to be tested in this proposal is that a nanotechnology platform whereby single macromolecules are encapsulated into a thin polymer shell can be used to effectively deliver CRISPR/Cas9 components into target cells and mutagenize the HIV-1 provirus such that replication is aborted.