Engineered NK Cells Successfully Target HIV Viral Reservoirs in Primate Study
Researchers developed multiplex-engineered natural killer (NK) cells that successfully localized to sites of SIV (simian HIV) replication in lymph nodes and spleens of infected rhesus macaques. The cells were modified to express HIV-targeting receptors and homing factors, addressing a major barrier to HIV cure: viral persistence in B cell follicles. This represents a potential new therapeutic approach for HIV, with advantages over existing CAR T cell therapies in terms of allogeneic applicability and natural cytotoxicity.
Researchers created multiplex-engineered NK cells expressing multiple modifications—including CAR (chimeric antigen receptor), CXCR5 (follicular-homing receptor), IL-15, PD-1 knockout, and transient CCR7—to target HIV-infected cells in lymphatic tissues. In vitro studies confirmed the cells expanded to clinically relevant numbers, migrated appropriately, and secreted cytotoxic molecules. A preliminary single-animal study showed safety and localization to SIV replication sites. A larger primate study with multiple animals receiving two doses demonstrated safety, increased NK cell populations in lymphatic tissues, and critically, showed that CAR+ NK cells in lymph nodes were predominantly CCR7+, confirming the importance of combined homing mechanisms for reaching viral reservoirs in follicles. The researchers emphasize this is the first demonstration of such complex multiplex engineering in NK cells.
What's missing
The study's limitations include: testing only in non-human primates (rhesus macaques with SIV, not human HIV); lack of data on long-term persistence and durability of the engineered cells; no comparison to CAR T cell approaches in the same model; unclear efficacy in reducing viral load or achieving functional cure; and the transient nature of CCR7 expression may limit sustained homing. The authors note further optimization is needed before clinical translation.
What different sources said
- bioRxivCenter
Multiplex engineering of rhesus macaque NK cells enhances homing to sites of HIV replication in B cell follicles.
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