Scientists discovered a new way that cancer hides from the body’s defense system. The hidden part is a protein called SLAMF6 that lives on immune cells and stops them from attacking tumors.
A Hidden Brake on the Immune System
Most immune‑checkpoint proteins need a tumor cell to tell them to turn off the attack. SLAMF6 works differently. It can turn itself on right on the T‑cell surface.
When SLAMF6 is active, it sends three signals:
- It makes T‑cells weaker against cancer.
- It reduces the number of strong, long‑lasting T‑cells.
- It speeds up “exhaustion,” a state where T‑cells stop working well.
Current cancer immunotherapies, such as PD‑1 or PD‑L1 blockers, only remove signals that come from the tumor. Many patients still do not respond or become resistant.
New Antibodies That Unlock T‑Cells
To stop SLAMF6, the research team created special monoclonal antibodies. These antibodies block the protein from binding to itself, so the brake stays off.
Lab tests in mice showed promising results:
- Human T‑cells became more active.
- More durable immune cells were produced.
- Fewer exhausted T‑cells were seen.
- Mice showed strong tumor‑killing responses.
The new antibodies worked better than any previous method that tried to target SLAMF6.
What This Could Mean for Patients
The scientists think these antibodies could start a new class of cancer immunotherapies. They might help people who no longer benefit from PD‑1 or PD‑L1 drugs.
Future plans include early‑stage clinical trials to test safety and effectiveness in patients with solid tumors and blood cancers.
"Finding this hidden brake and making antibodies that turn it off opens a new chapter in cancer treatment," said a senior researcher at the Montreal Clinical Research Institute.