Interleukin-35 regulates the differentiation of regulatory T cells through the JAK-STAT pathway and influences glutamine metabolism in ARDS

The aim of this study was to elucidate the effect of IL-35 on T cell differentiation and its mechanism. We evaluated the therapeutic effect of IL-35 on acute respiratory distress syndrome (ARDS) using clinical samples and mouse cecum ligation and puncture (CLP) model. The effects of IL-35 on Regulatory T cells (Treg) were verified by flow cytometry, immunohistochemistry (IHC) and qRT-PCR. Liquid chromatography-mass spectrometry (LC-MS) was used to detect the effects of IL-35 on changes in glutamin metabolites and TCA circulation. Western blot was used to detect changes in forkhead box protein 3 (Foxp3), key Enzymes and STAT phosphorylation subgroup proteins in the presence of cerdulatinib. Finally, A549 cells were treated with EL-4 cell supernatant to explore the effect of cerdulatinib on the therapeutic effect of IL-35 injury. Inflammatory factors decreased and Foxp3 increased in response to IL-35. In addition, Foxp3 was upregulated in a glutamine-deficient environment, and notably, glutamine-related metabolism and TCA cycle-related substances were altered with the involvement of IL-35. IL-35 upregulated phosphorylation of STAT isoforms, and cerdulatinib reversed it. Finally, the effects of IL-35 on Foxp3, key Enzymes and glutamine metabolite changes were all reversed by cerdulatinib. Our study shows that IL-35 reduces lung inflammation and promotes Treg differentiation. IL-35 affects the glutamine metabolism and the TCA cycle. In addition, we demonstrated that the relevant functions of IL-35 may be mediated by STAT isoform phosphorylation.

IL-35; Treg.