Issues

Elyada and colleagues profiled human pancreatic ductal adenocarcinoma tumors and adjacent normal tissue along with mouse pancreatic tumors and discovered a previously unknown class of cancer-associated fibroblasts (CAF) they named antigen-presenting CAFs (apCAF). These CAFs are unique in their expression of MHC class II–related genes, which implies they may interact with CD4⁺ T cells; supporting this idea, apCAFs activated CD4⁺ T cells ex vivo in an antigen-dependent fashion. Also unlike other CAFs, apCAFs upregulate MYC targets and antigen presentation, antigen processing, fatty-acid metabolism, and MTORC1 signaling pathways. Hinting that apCAFs may contribute to immune suppression in PDAC, they do not produce costimulatory molecules needed for induction of T-cell proliferation For details, please see the article by Elyada and colleagues on page 1102.