## New Study Finds Viral Mutants May Hamper HIV Elimination
Researchers at the University of Nebraska Medical Center (UNMC) have identified novel viral mutations that may contribute to viral escape following treatment with antiretroviral drugs and CRISPR-Cas9 gene editing in HIV-1 infected animals. The findings, recently published in *Communications Biology*, shed light on why a combination of long-acting antiretroviral therapy and CRISPR-Cas9 did not achieve permanent HIV DNA removal.The study, led by Prasanta dash, PhD, builds upon previous work from Dr. Dash and Chen Zhang, PhD, who first reported HIV-1 elimination from infected animals four years ago. This earlier research, in which Dr. Dash was the first author, prompted inquiry into the mechanisms behind potential viral rebound.
To understand the emergence of rebound viruses, the team analyzed stored frozen samples from the previous study. Utilizing both conventional Sanger sequencing and highly sensitive next-generation sequencing (NGS),they focused on a specific region of the HIV genome targeted by the antiretroviral therapy and CRISPR-Cas9.
This analysis revealed several new 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,” explained Dr. Dash. The team plans to further investigate which body compartments harbor these viruses.
Importantly, the researchers found that these unique mutations were linked to the antiretroviral drugs or the combined therapy, rather than the CRISPR-Cas9 treatment itself. “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 mutations directly associated with CRISPR-Cas9 suggests opportunities to improve the targeting of viral guide RNA to cells containing latent HIV-1, potentially thru enhanced therapeutic delivery. Dr. Dash emphasized the importance of ongoing viral monitoring during treatment. “The study’s findings underscore the importance of monitoring how the virus can change during various therapies over time,” he said.
Paul Domanico, PhD, of the Clinton Health Access Initiative, highlighted the broader implications of the research. “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,” he stated. “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.”
