IL-35 and IL-35-Induced Regulatory T Cells Inhibited Type II Innate Lymphoid Cells Response Through GATA3/RORα Pathway in Allergic Rhinitis

Abstract

Background: IL-35 and IL-35 induced IL-35-producing regulatory T cells (iTr35) have been reported to inhibit Th2 response in allergic rhinitis (AR). However, the effect of IL-35 and iTr35 on type II innate lymphoid cells (ILC2) in AR is not well characterized. Objective: We aimed to explore the effect of IL-35 and iTr35 on type II innate lymphoid cells (ILC2) in AR. Methods: Twenty-five AR patients and 20 healthy controls were recruited. The proteint expression of IL-35, the proportion of ILC2, IL-4+ILC2, IL-5+ILC2, IL-13+ILC2 and IL-35+CD4+CD25+ cells were detected by enzyme-linked immunosorbnent assay (ELISA) and flow cytometry. The expression and regulation of IL-35 receptor in ILC2 were analyzed by real-time PCR. The effect of IL-35 on ILC2 differentiation and cytokine production were analyzed by real-time PCR and ELISA. The iTr35 were cocultured with ILC2 in Transwell or non-Transwell system to explore the regulation of the iTr35 on ILC2 differentiation and function using RT-PCR and ELISA. AR mice models were also established to confirm the role of IL-35 in the regulation of ILC2 in vivo. Results: AR patients had decreased IL-35 expression and iTr35 proportion and increased proportion of ILC2 and type II cytokines compared with controls (P<0.05). The recombinant IL-35 inhibited ILC2 differentiation and type II cytokine production through GATA3/RORα pathway by regulation of IL-12Rβ2 and gp130. IL-35 promoted the inducible costimulatory molecule (ICOS) expression by iTr35 and ICOS ligand (ICOSL) expression by ILC2. iTr35 inhibited the function of ILC2s through ICOS:ICOS ligand. IL-35 treated AR mice presented as inhibited ILC2 inflammation compared with control mice. Conclusions: IL-35 inhibited ILC2 responses directly or through mutual contaction between iTr35 and ILC2 in AR, suggesting that IL-35 may be used as potential treatment target in AR. Funding: This study was supported by grants from the National Natural Science Grant of China (No.81600785, No. 81700892, No.81970861), the Pearl River S&T Nova Program of Guangzhou (No.201710010085), Key Clinical Speciality of Guangzhou Women and Children’s Medical Center, Grant of Institute of Pediatrics of Guangzhou Women and Children’s Medical Center (YIP-2016-022, Pre-NSFC-2018-005). Declaration of Interest: The authors declare that they have no relevant conflicts of interest. Ethical Approval: This study protocols were approved by local ethical committee boards and written informed consent was obtained. All animal care and experimental protocols were approved by local ethics committee boards.