Immune system restarts to fight pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDA) typically has a poor prognosis. One reason is that the immune system within these tumors is shut down, preventing immune recognition and elimination of cancer cells. A recent article in Science, however, underlines a technique that may reverse this process. University of Pennsylvania researchers used antibodies directed against a protein found on the surface of immune cells called macrophages. Activation of CD40 was shown to jumpstart the activity of macrophages, key players in the immune system. Once activated, these macrophages were observed to enter tumors and reduce their size and activity.