Building CAR T cells inside the body: cancer research takes a new turn
CAR T-cell therapy is one of the most promising weapons against cancer, but producing it is slow, expensive and fiendishly complex. Researchers have now developed a CRISPR-based method that reprograms immune cells directly inside the body, and the results in mice are striking.
In the conventional approach, T cells are taken from a patient's blood, genetically modified in the laboratory to recognise a specific cancer protein, and then infused back into the body. That process takes weeks, costs tens of thousands of euros, and does not work equally well for everyone. On top of that, the cells can age and lose their effectiveness while being handled outside the body.
The new study, published via Lifespan.io, bypasses that step entirely. Using a CRISPR-based system delivered directly into the body, the researchers reprogrammed the mice's own T cells on the spot, turning them into CAR T cells in vivo. In experiments across three different cancer types, including a solid tumour, traditionally the weak point of CAR T therapy, the in vivo generated cells cleared tumours more effectively than some of their conventionally produced counterparts.
Solid tumours: the hard nut to crack
Blood cancers such as leukaemia respond relatively well to CAR T therapy. Solid tumours, breast cancer, lung cancer, brain tumours, are a different story. They create a microenvironment that actively suppresses and excludes immune cells. The fact that the in vivo method shows results precisely there makes it scientifically significant. Whether that effect holds up beyond the mouse model remains the big unknown.
The research also touches on broader questions about ageing and immunology. As people get older, the quality of their T cells declines; they become less responsive and less resilient. That makes CAR T therapy particularly problematic in older cancer patients: the very cells you need are the ones that work least well. A method that reprograms T cells in their natural environment, rather than manipulating them outside the body, could sidestep that problem, at least in part.
From mouse to human: the gap remains wide
The caveats are as large as the promise. Mouse immunology differs fundamentally from human immunology, and CRISPR systems delivered in vivo raise questions about precision, safety and unintended edits elsewhere in the genome. Clinical trials have not yet begun. The path from a laboratory result to an approved therapy takes more than a decade on average, and most promising cancer treatments never make it to the finish line.
What this study does do is lower a technical barrier that was long considered nearly insurmountable: the idea that you can carry out complex immunotherapy directly inside the body, without a manufacturing facility and without weeks of waiting. That concept alone opens up new directions for research.