PDIA3 knockdown in dendritic cells regulates IL-4 dependent mast cell degranulation

Background: A previous study found that expression of protein disulfide isomerase A3 (PDIA3) in dendritic cells (DCs) is a potential mediator of exaggerated intestinal mucosal immunity response in a rodent model of irritable bowel syndrome (IBS). Aim: The aim of this study was to explore the roles of PDIA3 in the interaction between DCs and mast cells (MCs) in the context of IBS. Methods: This study investigated the effects of shRNA-mediated knockdown of PDIA3 expression in a dendritic cell line and spleen lymphocyte co-cultures. Resultant co-culture supernatants were used to challenge MC. PDIA3 expression was assessed using q-PCR and Western blotting. Expression of surface markers was analyzed by flow cytometry. CD4(+) and CD8(+) T-cell proliferation were examined using Cell Trace CFSE kits. Cytokine production was determined by ELISA testing. MC viability was ascertained using CCK-8 production. MC degranulation was determined by ELISA and transmission electron microscope (TEM). Results: Knockdown of PDIA3 expression in a dendritic cell line decreased the production of interleukin-4 in subsequently performed co-cultures of a dendritic cell line with spleen lymphocytes. Challenge with such lysates provoked a decrease in the viability and functionality of MC. Conclusion: Co-culture experiments of dendritic cell lines and spleen lymphocytes revealed the roles of PDIA3 expression, as determined by IL-4 production and co-culture supernatant-provoked MC activation. These observations confirm that PDIA3 has a role in the interaction between DCs and MC activation. However, results simultaneously argue for further research concerning the usefulness of PDIA3 as a potential therapeutic target in IBS.