UCSF team engineers CAR-T cells inside the living body using CRISPR two-particle system
Researchers at UC San Francisco have bypassed ex-vivo cell manufacturing by delivering CRISPR machinery directly into circulating T cells, inserting cancer-targeting DNA at a defined genomic site.
Scientists at the University of California, San Francisco have published a method for generating chimeric antigen receptor T (CAR-T) cells without removing cells from the patient. The approach uses a two-particle delivery system: one particle carries CRISPR gene-editing tools and a second carries a DNA template encoding a cancer-targeting receptor. Together, the particles direct targeted insertion of the new DNA into a defined locus within circulating T cells in vivo.
Current approved CAR-T therapies require leukapheresis to harvest a patient's T cells, followed by ex-vivo viral transduction and expansion before reinfusion — a process that can take several weeks and costs hundreds of thousands of pounds per treatment course. The UCSF method, if it translates to clinical settings, could substantially simplify manufacturing logistics and potentially reduce cost, though the researchers note that preclinical to clinical translation will require further safety and efficacy evaluation.
The work adds to a growing body of research exploring in-vivo cell engineering as an alternative to ex-vivo manufacture. It is conceptually related to earlier lipid-nanoparticle approaches for transient T-cell modification, but the UCSF team's two-particle design and site-specific integration distinguish it from previous work. The study was described in reporting by ScienceDaily; the primary journal publication details had not been confirmed at time of writing.
Plain-language version
For patients, families, and general readers. Educational only — not medical advice.
CAR-T therapy is a type of cancer treatment in which a patient's own immune cells — called T cells — are taken out of the body, modified in a laboratory to recognise cancer, and then put back in. This process is complex and expensive. Researchers at UC San Francisco have been working on a way to skip the step of removing the cells at all. Instead, they used tiny particles to deliver gene-editing tools directly into T cells while they are still inside the body, reprogramming them to fight cancer. The approach has only been tested in early laboratory and animal studies so far, and it would need to pass many more tests before it could be used in patients. Researchers say the method could eventually make this type of treatment simpler and more accessible, but those steps are still some way off.
This is an educational summary, not medical advice. If anything here raises questions for you, please speak with your GP or a clinical professional.
Sources
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Primary source ScienceDaily · 2026-10-07Scientists reprogram immune cells inside the body to fight cancer