In a recent study, UNMC researchers discovered new viral mutants, or molecular signatures of “rebound viruses” that may have led to viral escape in antiretroviral drug and CRISPR-treated HIV-1-infected animals.
In the study from the lab of Prasanta Dash, PhD, published in Communications Biology, the research team sought to understand why a combination of long-acting, slow-effective release antiretroviral therapy and CRISPR-Cas9 failed to permanently remove HIV DNA from cells harboring the virus.
Over the past four years, Dr. Dash and Chen Zhang, PhD, identified molecular signatures that led to viral rebound in a highly cited paper, the first report of HIV-1 elimination from infected animals, in which Dr. Dash was the first author.
Exploring the genetic makeup of the rebound viruses, Drs. Dash and Chen tested the stored frozen samples of the previous study and used both conventional Sanger sequencing and highly sensitive next-generation sequencing (NGS) to target a specific region of the HIV genome, where the ART and CRISPR therapy was designed.
During the work, the team found several novel drug-resistant variants.
“We also looked for times when the new mutations were introduced, and found these were generated either during or after the antiretroviral drug was administered,” Dr. Dash said.
The follow-up question will identify the virus-containing body compartments.
“We found the unique mutations are linked to the antiretroviral drugs or to the dual therapy rather than the solo CRISPR therapy,” Dr. Dash said.
The absence of CRISPR-associated mutations, Dr. Dash said, highlights future opportunities for improved viral guide RNA targeting of cells that contain latent HIV-1, which may be achieved by improved therapeutic delivery.
The study’s findings underscore the importance of monitoring how the virus can change during various therapies over time, Dr. Dash said.
“The future of HIV elimination likely depends on a multi-modal regimen that includes several options: long-acting antiretroviral drugs, biologicals, vaccines, and gene and cell therapies,” said Paul Domanico, PhD, of the Clinton Health Access Initiative. “Identifying unique viral mutations/signatures associated with long-acting antiretroviral drugs and CRISPR-Cas9, as shown by Dr. Dash and team, is of great interest to the entire HIV community.”