While the treatment is yet to be tested in humans, initial experiments in mice and human tissues in the lab suggest these new CAR-NK cells are well tolerated and effective at fighting cancer<\/a> \u2013 a promising start for these next-gen upgrades.<\/p>\n Related: Cancer Vaccine Blocks Multiple Tumors in Mice For 250 Days<\/a><\/strong><\/p>\n Natural killer cells are produced in the body as a first-line defense against cancers or tissues infected with viruses<\/a>. They don’t need priming, reacting to suspect cells that don’t seem to belong. By engineering chimeric antigen receptors onto NK cells taken from a patient’s own blood, the tiny killers can better target specific proteins known to identify cancerous cells.<\/p>\n The process of engineering enough CAR-NK cells to return to a patient takes several weeks, prompting scientists to consider using blood from healthy donors instead. While it means an army of CAR-NK cells can be ready to go at all times, the process increases the risk of immune system rejection<\/a>.<\/p>\n Identifying specific immune cells that could potentially attack the treatment, researchers have made precise molecular changes that alter CAR-NK’s surface proteins, effectively hiding the transplanted cells.<\/p>\n These modifications, together with carefully engineered boosts to the cancer-fighting capabilities<\/a> of the cells, can be included on a single DNA piece called a construct, simplifying the process.<\/p>\n “This enables us to do one-step engineering of CAR-NK cells that can avoid rejection by host T cells and other immune cells,” says<\/a> biologist Jianzhu Chen, from MIT.<\/p>\n “And, they kill cancer<\/a> cells better and they’re safer.”<\/p>\n In mouse experiments, the differences between the tweaked CAR-NK cells and the standard versions were stark. The enhanced versions lasted at least three weeks, whereas the standard CAR-NK and NK cells were rejected by the immune systems of the mice, leaving the cancer to grow.<\/p>\n There was another benefit of the upgraded CAR-NK cells: a reduced likelihood of cytokine release syndrome<\/a> \u2013 a potentially fatal side effect where the immune system triggers severe inflammation.<\/p>\n The study team thinks their approach may also improve CAR-T cell therapies<\/a>, which use ‘T’ immune cells instead of natural killer cells. These therapies work well in some patients, but not in others.<\/p>\n One of the key next steps here will be clinical trials<\/a>, so the researchers can see if these positive effects are seen in people as well. If those trials go well, there’s plenty of potential for these allogeneic therapies<\/a> (using immune cell fighters from healthy donors).<\/p>\n “We believe our approach could also be applied to other allogeneic cell-based products and can aid the design of ‘off-the-shelf’ allogeneic therapies,” write<\/a> the researchers in their published paper.<\/p>\n![\"Tumor](\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2025\/10\/MiceTumors.jpg\")
The engineered cells had a noticeable impact on tumors in mice (shown by the bright blotches). (Liu et al., Nat. Commun., 2025)<\/p>\n![\"Win](\"https:\/\/www.europesays.com\/ie\/wp-content\/uploads\/2025\/10\/Mid-Article-Promo-Astro-642x272.jpg\")
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