Pancreatic Stellate Cells Do Not Exhibit Features of Antigen-Presenting Cells

Objectives: Major histocompatibility complex (MHC) class II molecules are expressed on professional antigen-presenting cells (APCs), and pancreatic stellate cells (PSCs) have endocytic and phagocytic functions and play a role in the immune responses of the pancreas. The aim of the present study was to investigate whether PSCs exhibit features of APCs. Methods: Rat and human PSCs were cultured with interferon-gamma (IFN-gamma) or an exogenous antigen, ovalbumin (OVA), and they were analyzed for expression of MHC II molecules by flow cytometry and reverse transcription-polymerase chain reaction. Results: The cells simulated with IFN-gamma expressed very little or no MHC class II molecules or human leukocyte antigen (HLA)-DR at the transcriptional level. Stimulation with IFN-gamma failed to induce expression of MHC class II molecules and HLA-DR molecules according to the results of flow cytometry. Dual-color flow cytometric analysis showed that approximately 95% of the PSCs took up OVA; however, none of the cells that took up OVA expressed MHC class II molecules or HLA-DR molecules. Conclusions: Pancreatic stellate cells do not seem to be responsible for the MHC class II-dependent pathway of antigen presentation, suggesting that PSCs do not play a role in adaptive immunity as APCs.