These cells slow an immune response. Derailing them could help fight tumors
Drugs that release brakes on the immune system have helped thousands of people with cancers that were previously untreatable. Yet these therapies, known as checkpoint blockers (SN: 10/1/18), fail in many patients and work poorly for some cancers. That’s because the body’s defense system can stall in more than one way. Checkpoint blockers traditionally target a particular set of brakes: protein interactions that disarm the body’s T cells, allowing cancer to grow unchecked. But an additional brake may be at work as well — an immune cell population called myeloid-derived suppressor cells, or MDSCs. These cells reach unusually high levels in people with cancer. Now, experiments in mice suggest that immune checkpoint therapies could get a boost if paired with other drugs targeting MDSCs. Researchers reported their initial findings at the annual meeting of the American Association for Cancer Research, held virtually in late June. MDSCs are a mix of immature cells from...