RORγt inhibitor SR1001 alleviates acute pancreatitis by suppressing pancreatic IL-17-producing Th17 and γδ-T cells in mice with ceruletide-induced pancreatitis.

The management of acute pancreatitis (AP) remains a challenge to clinicians worldwide for limited effective interventions. Retinoid orphan receptor gamma t (RORγt) is a therapeutic target for several diseases; however, it is unclear whether inhibiting RORγt can ameliorate AP. The relative expression of RORγt, IL-17 and IL-23 in the peripheral blood mononuclear cells of AP patients was measured by RT-PCR. An AP mouse model was induced by ceruletide, and SR1001 was injected before ceruletide administration. RORγt+ cells, T helper 17 cells (Th17), regulatory T cells (Tregs) and γδ T cells were assessed in the pancreas and spleen by flow cytometry. Higher RORγt expression in patients indicated the potential role of RORγt in AP progression. Analyses of the IL-17/IL-23 axis confirmed its role. SR1001 significantly alleviated AP histologically in the mouse model. Serum levels of amylase, IL-6, TNFalpha, IL-17 and IL-23 decreased upon SR1001 treatment. SR1001 selectively decreased the number of RORγt+, Th17, Tregs and γδ T cells in the pancreas but not the spleen. Collectively, these results showed that SR1001 exerted therapeutic effects on AP by suppressing IL-17-secreting Th17 and γδ T cells in the pancreas. Thus, SR1001 may be a promising drug for the treatment of AP in the clinic.