Anti-inflammatory Mechanisms of IL-38 in Chinese Patients with Allergic Rhinitis.

Background: T-helper 17 (Th17) cell response is engaged in the onset of allergic rhinitis (AR). Moreover, interleukin (IL)-38 is thought to be involved in inhibiting cytokine secretion in the Th17 pathway.

Objective: To evaluate the regulatory function of IL-38 on abnormal Th17 responses in Chinese patients with AR.

Methods: Forty-five participants, divided into an AR group (n=25) and a control group (n=20), were recruited for the study. In addition, the expression of IL-38 and Th17-related cytokines was measured as well as the Th17 cell count in participants. By implementing recombinant IL-38 (rIL-38), the intervention of human peripheral blood mononuclear cells (PBMCs) was performed. Then, flow cytometry, polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay (ELISA) were used to detect the Th17 milieu.

Results: The expression of IL-38 in the AR group notably reduced compared with that in the control, whereas Th17 cell frequency and the expression levels of its transcription factor (RORC) and cytokines (IL-17A and IL-23) increased. The differentiation and immune function of Th17 cells in PBMCs were inhibited by rIL-38.

Conclusion: Th17 responses are inhibited by IL-38 in patients with AR. Therefore, the obtained findings indicate that IL-38 is a potential therapeutic target for Chinese patients with AR.