Weill Cornell Medicine researchers have discovered that PD-1—a molecule best known for putting the brakes on immune cells—also plays a critical role in helping T cells become long-term immune defenders in the skin. Early during infection, PD-1 acts like a steering wheel, guiding T cells to become protective resident memory T cells (TRM) that stay in place. These cells remember invading germs or cancer and quickly mount a response if that enemy reappears.
The preclinical findings, published July 29 in Nature Immunology, may impact how clinicians approach cancer treatments called immune checkpoint inhibitors. These drugs bind to PD-1 on the surface of T cells, releasing the brakes and unleashing the immune system to attack cancer cells.
Though immune checkpoint inhibitors are successful in treating melanoma, an aggressive skin cancer, about 40% of patients develop inflammatory rashes and itching in the skin or reactions in other epithelial tissues that cover internal and external surfaces of the body.