Medical Express A protein already targeted by FDA-approved cancer drugs may also help the body fight influenza, according to new research from The Jackson Laboratory (JAX). Published in Cell Reports, the study found that Programmed Death-Ligand 1 (PD-L1), a protein best known for helping tumors evade immune attack, instead helped immunocompromised mice clear flu-infected lung cells and survive infection. The findings challenge long-standing assumptions about PD-L1’s role in the immune system. While cancer therapies work by blocking PD-L1 to boost immune attack on tumors, the new research suggests that enhancing PD-L1 signaling may help the body control severe respiratory viral infections, especially in people with T cell immunodeficiencies such as those with HIV or immunosuppression after chemotherapy.
“This discovery suggests that a pathway targeted in cancer could also be useful in infectious disease, but in the opposite way. Cancer therapies block PD-L1, whereas in flu, enhancing it may strengthen host defense,” said Silke Paust, a JAX professor and immunologist who directed the research.