Researchers at Cardiff University in Wales discovered a different kind of T-cell receptor (TCR)—one that recognizes and kills most human cancer cells while ignoring healthy ones.
The early-stage findings, published this week in the journal Nature Immunology, have not yet been tested in patients. But the team said they have “enormous potential.”
T-cells are a type of lymphocyte (white blood cell) that develop in the thymus gland (hence the name). Born from stem cells in bone marrow, they help protect the body from infection.
But T-cells can’t always differentiate between destructive and nourishing cells, allowing some cancerous cells to fall through the cracks.
Scientists are working to improve this system through various immunotherapies, including CAR-T—a specialized treatment that targets only a few types of cancer and has not been successful for solid tumors.
New TCR on the Block
Conventional T-cells scan other cells looking for anomalies; the system recognizes small parts of cellular proteins bound to surface-level molecules called human leukocyte antigen (HLA).
Annoyingly, HLA varies between individuals, preventing scientists from creating a single T-cell-based treatment to target most cancers.
Enter Cardiff’s unique TCR—able to recognize a range of cancers via the single HLA-like molecule MR1.
Show and Tell
Early experiments show the new, as-yet-unnamed TCR can kill lung, skin, blood, colon, breast, bone, prostate, ovarian, kidney, and cervical cancer cells. A germ of all trades, if you will.
Lead study author Andrew Sewell, an expert in T-cells from Cardiff University, said it is “highly unusual” to find a TCR with such broad cancer specificity, raising the prospect of “universal” therapy.
“Current TCR-based therapies can only be used in a minority of patients with a minority of cancers,” he explained. “We hope this new TCR may provide us with a different route to target and destroy a wide range of cancers in all individuals.”
When injected into cancerous mice bearing a human immune system, the MR1-spotting T-cells showed “encouraging” cancer-clearing results.
The team also showed that modified T-cells of melanoma patients destroyed not only their cancer cells but those of other patients’ in the lab, regardless of HLA type.
“Cancer-targeting via MR1-restricted T-cells is an exciting new frontier,” Sewell said. “Previously nobody believed this could be possible.”