Genetic Engineering Publications - GEG Tech top picks

A new study from Tel Aviv University proposes a new and unique AIDS treatment that could be developed into a vaccine or a one-time treatment for HIV patients. The study examined the engineering of B-type white blood cells in the patient's body to secrete anti-HIV antibodies in response to the virus. The technique developed in his laboratory uses B-white blood cells that would be genetically modified inside the patient's body to secrete neutralizing antibodies against the HIV virus. The gene editing was done with a CRISPR system. The researchers are able to engineer the B cells inside the patient's body using two viral vectors from the AAV family, one encodes the desired antibody and the second encodes the CRISPR system. When CRISPR cuts the desired site in the genome of the B cells it directs the introduction of the desired gene: the gene coding for the antibody against the HIV virus. On the basis of this study, we can hope that in the next few years we will be able to produce a drug against AIDS in this way, but also against other infectious diseases, for certain types of cancer caused by a virus, such as cervical cancer. 

In this report, the scientists designed two different gRNA combinations targeting both CXCR4 and CCR5, in a single vector. The CRISPR-sgRNAs-Cas9 could successfully induce editing of CXCR4 and CCR5 genes in various cell lines and primary CD4+ T cells. Using HIV-1 challenge assays, they demonstrated that CXCR4-tropic or CCR5-tropic HIV-1 infections were significantly reduced in CXCR4- and CCR5-modified cells, and the modified cells exhibited a selective advantage over unmodified cells during HIV-1 infection. The off-target analysis showed that no non-specific editing was identified in all predicted sites. In addition, apoptosis assays indicated that simultaneous disruption of CXCR4 and CCR5 in primary CD4+ T cells by CRISPR-Cas9 had no obvious cytotoxic effects on cell viability.

Using gene editing technology, researchers at the Lewis Katz School of Medicine at Temple University have, for the first time, successfully excised a segment of HIV-1 DNA - the virus responsible for AIDS - from the genomes of living animals. The breakthrough, described online this month in the journal Gene Therapy, is a critical step in the development of a potentially curative strategy for HIV infection.

In this work, the authors used the CRISPR system to target HIV and suppresse HIV-1 replication. They demonstrated that many of these indels are indeed lethal for the virus, but that others lead to the emergence of replication competent viruses that are resistant to Cas9/sgRNA. This observation illustrates two opposite outcomes of Cas9/sgRNA action, i.e., inactivation of HIV-1 and acceleration of viral escape, thereby potentially limiting the use of Cas9/sgRNA in HIV-1 therapy.

Here, the authors show that sequential treatment with long-acting slow-effective release ART and AAV9- based delivery of CRISPR-Cas9 results in undetectable levels of virus and integrated DNA in a subset of humanized HIV-1 infected mice. This proof-of-concept study suggests that HIV-1 elimination is possible.

Novel strategies, such as CRISPR/Cas9 gRNA-based genome-editing, can permanently disrupt the HIV genome. However, HIV genome-editing may accelerate viral escape, questioning the feasibility of the approach.

Researchers in China have reported editing the genes of human embryos to try to make them resistant to HIV infection. Their paper which used CRISPR-editing tools in non-viable embryos that were destroyed after three days is only the second published claim of gene editing in human embryos.

In this work the scientists employed an RNA-guided CRISPR/Cas9 DNA editing system to precisely remove the entire HIV-1 genome spanning between 5′ and 3′ LTRs of integrated HIV-1 proviral DNA copies from latently infected human CD4+ T-cells.