Chances of eliminating HIV infection rise with new dual gene editing approach

“The idea to couple HIV-1 DNA cleavage with CCR5 inactivation using gene-editing technology is based on observations of reported cures in human HIV patients,” said Kamel Khalili, PhD, Laura H Professor Carnell and director of the Department. of Microbiology, Immunology and Inflammation, Director of the Center for Neurovirology and Gene Editing, and Director of the Comprehensive Center for NeuroAIDS at the Lewis Katz School of Medicine. “In the few cases of human HIV cures, patients underwent bone marrow transplantation for leukemia, and the donor cells that were used carried inactivating CCR5 mutations.”

Dr. Khalili and Howard E. Gendelman, MD, Professor and Chair of the UNMC Department of Pharmacology and Experiential Neuroscience, were the principal investigators of the new study. The two researchers have been long-time collaborators and have strategically combined their research strengths to find a cure for HIV.

“We are true partners and what we have achieved here is truly spectacular,” said Dr. Gendelman. “Dr. Khalili’s team generated the essential gene-editing constructs, and then we applied those constructs in our LASER-ART mouse model in Nebraska, figuring out when to administer gene-editing therapy and performing analyzes to maximize HIV cleavage.” -1, CCR5 inactivation and suppression of viral growth”.

In previous work, Drs. Khalili and Gendelman and their respective teams showed that HIV can be eliminated from the genomes of HIV-infected humanized live mice, leading to a cure in some animals. For that research, Dr. Khalili and co-investigator Rafal Kaminski, PhD, Assistant Professor in the Center for Neurovirology and Gene Editing at Katz School of Medicine, combined their expertise in CRISPR gene editing technology to targeting HIV-1 with a therapeutic approach known as long-acting slow-release and effective antiretroviral therapy (LASER) that was co-developed by Dr. Gendelman and Benson Edagwa, PhD, Assistant Professor of Pharmacology at UNMC. LASER ART keeps HIV replication at low levels for long periods of time, thus reducing the frequency of ART administration.

Despite being able to kill HIV in LASER-ART mice, the researchers found that HIV could eventually re-emerge from tissue reservoirs and cause rebound infection. This effect is similar to rebound infection in human patients who have been taking ART but suddenly stop treatment or experience a discontinuation. HIV integrates its DNA into the genome of host cells, it can remain dormant in tissue reservoirs for long periods of time, out of reach of antiretroviral drugs. As a consequence, when ART is stopped, HIV replication is renewed, giving rise to AIDS.

To prevent rebound infection, Dr. Khalili and his colleagues began work on next-generation CRISPR technology for HIV cleavage, developing a new dual system aimed at permanently removing HIV from the animal model. “From the success stories of human HIV patients who underwent bone marrow transplantation for leukemia and were cured of HIV, we hypothesized that loss of the virus receptor, CCR5, is important in permanently eliminating HIV infection,” he explained. They developed a simple and more practical procedure for CCR5 inactivation that includes an IV inoculation of the CRISPR gene-editing molecule.

Experiments in humanized LASER-ART mice carried out by Dr. Gendelman’s team showed that the constructs developed in Temple, when administered together, resulted in viral suppression, restoration of human T cells, and elimination of the replication of HIV-1 in 58 percent of those infected. animals The findings support the idea that CCR5 has a key role in facilitating HIV infection.

Temple’s team also plans to test the dual gene-editing strategy in non-human primates soon. To do so, Dr. Khalili will collaborate with Tricia H. Burdo, PhD, professor and vice chair of the Department of Microbiology, Immunology, and Inflammation at Katz School of Medicine, a recognized expert in the use of nonhuman primate models. for studying HIV-1, who also co-authored the new study. Dr. Burdo and her team are interested in understanding the role of CCR5 in SIV-infected primates. Previously, her lab played a key role in research that demonstrated the efficacy and safety of CRISPR-based technology in removing HIV DNA from primate cells.

The new dual CRISPR gene-editing strategy holds exceptional promise for the treatment of HIV in humans. “It’s a simple and relatively inexpensive approach,” Dr. Khalili noted. “The type of bone marrow transplant that has produced cures in humans is reserved for patients who also have leukemia. It requires multiple rounds of radiation and is not applicable in resource-limited regions where HIV infection tends to be more common.”

“Curing HIV is the big picture,” added Dr. Gendelman. “Through our ongoing collaboration, Temple and UNMC have conducted significant research that could ultimately affect the lives of many people.”

In addition to Rafal Kaminski, other researchers who contributed to the study include Prasanta K. Dash, Hang Su, Brady Sillman, Chen Zhang, Sruthi Sravanam, Emiko Waight, Lili Guo, Saumi Mathews, R. Lee Mosley, Larisa Y. Poluektova, Santhi Gorantla and Benson Edagwa, Department of Pharmacology and Experimental Neuroscience, UNMC; and Chen Chen, Pietro Mancuso, Shuren Liao, Hong Liu, Rahsan Sariyer, Maurizio Caocci, and Shohreh Amini, Department of Microbiology, Immunology, and Inflammation, Center for Neurovirology and Gene Editing, Lewis Katz School of Medicine, Temple University.

The research was supported by the National Institutes of Health, including grants T32NS105594, 5R01MH121402, 1R01Al158160, R01DA054535, 1041 R01NS126089, R01 AI145542, R01NS36126, R01MH115860, 1R3 3DA04101 8, 1042 and 2R01NS034239 (UNMC), and T32MH079785, P30MH092177 and UM1AI164568 (Lewis Katz School of Medicine).