Single Antibody Dose Maintains Four-Year HIV-Like Virus Remission in Infant Monkeys
A single dose of an experimental antibody targeting CCR5 and CD3 proteins, combined with early antiretroviral therapy, prevented simian immunodeficiency virus (SIV) from returning in some infant monkeys for up to four years. Published in Nature Microbiology, the study by UC Davis researchers suggests this approach can significantly reduce viral reservoirs, though it has not yet been tested in humans.
Key points
- UC Davis researchers Jesse Deere and Dennis Hartigan-O'Connor tested an antibody binding CCR5 and CD3 to direct T cells against cells that could harbor SIV.
- In a study of 20 infected infant rhesus macaques, the CCR5/CD3 antibody group showed prolonged remission, with one animal remaining virus-free for four years.
- Animals receiving only antiretroviral drugs saw the virus return within a week of stopping treatment, highlighting the antibody's potential impact on viral reservoirs.
- Further tests on animals in sustained remission found no viral genetic material or infectious virus in lymph nodes, supporting substantial reservoir reduction.
- The study notes that while the approach worked in infants treated soon after infection, its efficacy in adults or those with longstanding infections remains unknown.
Background
This research builds on earlier findings that rare cases of lasting HIV remission occurred after stem-cell transplants performed for cancer treatment, underscoring the importance of reducing viral reservoirs. It also follows recent breakthroughs in immunotherapy, such as experimental CAR-T therapies achieving durable remission in pediatric cancer patients, which highlight the potential of harnessing the immune system to eliminate persistent infections or tumors.
Why it matters
This study offers a potential pathway toward an HIV cure by targeting the latent viral reservoir that antiretroviral drugs cannot clear. If effective in humans, a single-dose antibody therapy could provide a long-term solution without the need for lifelong medication, though safety and efficacy in adult populations must still be established.
What to watch
Researchers must now determine if the CCR5/CD3 antibody approach is effective and safe in humans, particularly in adults and individuals with longstanding infections. Further studies are needed to assess the long-term impact on immune defenses against other infections and to confirm whether the virus is completely cleared or merely suppressed.
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