Mesothelial Cell-Derived Antigen-Presenting Cancer-Associated Fibroblasts Induce Expansion of Regulatory T Cells in Pancreatic Cancer

Antigen-presenting cancer-associated fibroblasts (apCAFs) directly ligated and induced naive CD4+ T cells into regulatory T cells (Tregs) in an antigen-specific manner. Treatment with an antibody targeting the mesothelial cell marker mesothelin effectively inhibited mesothelial cell to apCAF transition and Treg formation induced by apCAFs.