CRISPR Eliminates HIV In Live Animals (genengnews.com)

Researchers from the Lewis Katz School of Medicine at Temple University and the University of Pittsburgh show that HIV-1 infections can be eliminated from the genomes of living animals. Findings from the study have been published in the journal Molecular Therapy. Genetic Engineering and Biotechnology News reports: This is the first study to demonstrate that HIV-1 replication can be completely shut down and the virus eliminated from infected cells in animals with a powerful gene-editing technology known as CRISPR/Cas9. The new work builds on a previous proof-of-concept study that the team published in 2016, in which they used transgenic rat and mouse models with HIV-1 DNA incorporated into the genome of every tissue of the animals' bodies. They demonstrated that their strategy could delete the targeted fragments of HIV-1 from the genome in most tissues in the experimental animals. In this new study, the LKSOM team genetically inactivated HIV-1 in transgenic mice, reducing the RNA expression of viral genes by roughly 60% to 95% -- confirming their earlier findings. They then tested their system in mice acutely infected with EcoHIV, the mouse equivalent of human HIV-1. In the third animal model, a latent HIV-1 infection was recapitulated in humanized mice engrafted with human immune cells, including T cells, followed by HIV-1 infection. "These animals carry latent HIV in the genomes of human T cells, where the virus can escape detection," Dr. Hu explained. Amazingly, after a single treatment with CRISPR/Cas9, viral fragments were successfully excised from latently infected human cells embedded in mouse tissues and organs.

Comments

Subtypes of HIV

[Gravis Zero]

HIV-1 is the most common and pathogenic strain of the virus.
HIV-2 has not been widely recognized outside of Africa.

HIV-2 has been found to be less pathogenic than HIV-1. The mechanism of HIV-2 is not clearly defined, nor the difference from HIV-1, however the transmission rate is much lower in HIV-2 than HIV-1.

source

Efficient delivery of CRISPR remains THE challenge

[coldandcalculating]

While it's important the continue testing the limits of CRISPR technology in preclinical studies like this, the truth is that viral vector based delivery isn't quite up to the challenge (yet!) of a total genomic clearance of HIV in all infected cells. From the news and views comment on the article:

several issues remain to be addressed prior to clinical trials. While an AAV serotype with broad tropism is ideal for proof-of-concept studies, replication competent HIV is rare (present only in one of every 10,000 to 1,000,000 CD4+ T cells), and thus identifying delivery vectors with high specificity to the HIV reservoir remains a significant hurdle. There is currently no known viral or non-viral agent that is capable of efficiently and selectively delivering and expressing transgenes in these cells. An ideal delivery candidate should possess the ability to carry a relatively large cargo to relevant reservoir cells and facilitate pharmacologically significant enzymatic activity. It should also exhibit little to no toxicity irrespective of the duration of its presence in vivo, whether transient or long term.

(emphasis mine)

Still, this is a very encouraging development toward a possible HIV cure.

Re: Do you want a zombie apocalypse?

[Anonymous Coward]

HIV is a much bigger problem in 3rd world countries. And, contrary to your "belief", it is primarily a heterosexual disease outside the US.