🧬 Scientists Find the "Off Switch" That Exhausts CAR T Cells — and Show How to Flip It
CAR T-cell therapy is one of the most powerful tools in modern oncology: take a patient's own immune cells, genetically reprogram them to hunt cancer, and put them back. It works wonders against some blood cancers. But against solid tumors — the majority of cancer cases — CAR T cells burn out too fast. Now, an international team has pinpointed exactly why.
Researchers at Columbia University and University Hospital Tübingen, led by CAR T pioneer Prof. Michel Sadelain and Prof. Judith Feucht, screened roughly 400 transcription factors — proteins that act as master switches for gene activity inside cells. One protein stood out dramatically: NFIL3. It turned out to be a primary driver of T-cell exhaustion, the process that gradually strips engineered immune cells of their cancer-killing power.
Using CRISPR/Cas9 gene editing, the team snipped out the gene responsible for NFIL3. The result? The edited CAR T cells stayed active significantly longer, multiplied more efficiently, and maintained a sustained anti-tumor assault. In mouse models, NFIL3-disabled cells delivered stronger tumor control and extended survival compared to standard CAR T cells.
Key findings:
— NFIL3 was identified as the dominant transcription factor driving CAR T-cell exhaustion out of ~400 candidates screened
— CRISPR deletion of NFIL3 kept CAR T cells functional and proliferating for much longer periods
— NFIL3-knockout CAR T cells showed superior tumor control across multiple animal models, including solid tumors
— The approach targets the biology of exhaustion itself rather than the tumor type, potentially helping across many cancers
"Switching off NFIL3 could be a decisive step toward significantly improving the long-term potency of CAR T cells," said Prof. Feucht. "We expect this to open up new possibilities in the treatment of cancer patients."
Why it matters: CAR T therapy has been a revolution in blood cancers but has largely failed against solid tumors — breast, lung, pancreatic, brain — because the engineered cells simply don't last. This discovery offers a concrete, druggable target to make CAR T durable enough for the cancers that kill the most people. It's not a new therapy — it's a way to make the existing one finally work where it's needed most.
📄 Original paper (Cancer Discovery): https://doi.org/10.1158/2159-8290.CD-25-1524
📖 Readable summary: https://www.sciencedaily.com/releases/2026/06/260602021641.htm
#CARTcell #CancerResearch #CRISPR #Immunotherapy #Oncology
CAR T-cell therapy is one of the most powerful tools in modern oncology: take a patient's own immune cells, genetically reprogram them to hunt cancer, and put them back. It works wonders against some blood cancers. But against solid tumors — the majority of cancer cases — CAR T cells burn out too fast. Now, an international team has pinpointed exactly why.
Researchers at Columbia University and University Hospital Tübingen, led by CAR T pioneer Prof. Michel Sadelain and Prof. Judith Feucht, screened roughly 400 transcription factors — proteins that act as master switches for gene activity inside cells. One protein stood out dramatically: NFIL3. It turned out to be a primary driver of T-cell exhaustion, the process that gradually strips engineered immune cells of their cancer-killing power.
Using CRISPR/Cas9 gene editing, the team snipped out the gene responsible for NFIL3. The result? The edited CAR T cells stayed active significantly longer, multiplied more efficiently, and maintained a sustained anti-tumor assault. In mouse models, NFIL3-disabled cells delivered stronger tumor control and extended survival compared to standard CAR T cells.
Key findings:
— NFIL3 was identified as the dominant transcription factor driving CAR T-cell exhaustion out of ~400 candidates screened
— CRISPR deletion of NFIL3 kept CAR T cells functional and proliferating for much longer periods
— NFIL3-knockout CAR T cells showed superior tumor control across multiple animal models, including solid tumors
— The approach targets the biology of exhaustion itself rather than the tumor type, potentially helping across many cancers
"Switching off NFIL3 could be a decisive step toward significantly improving the long-term potency of CAR T cells," said Prof. Feucht. "We expect this to open up new possibilities in the treatment of cancer patients."
Why it matters: CAR T therapy has been a revolution in blood cancers but has largely failed against solid tumors — breast, lung, pancreatic, brain — because the engineered cells simply don't last. This discovery offers a concrete, druggable target to make CAR T durable enough for the cancers that kill the most people. It's not a new therapy — it's a way to make the existing one finally work where it's needed most.
📄 Original paper (Cancer Discovery): https://doi.org/10.1158/2159-8290.CD-25-1524
📖 Readable summary: https://www.sciencedaily.com/releases/2026/06/260602021641.htm
#CARTcell #CancerResearch #CRISPR #Immunotherapy #Oncology
ScienceDaily
A single protein may be holding back CAR T cancer therapy
A newly identified protein may be one of the biggest obstacles holding CAR T-cell therapy back. Researchers found that NFIL3 causes these engineered immune cells to become exhausted and lose their cancer-fighting power over time. When NFIL3 was disabled,…
1🔥27👍22⚡9👀5