IL-9 as a naturally orthogonal cytokine with optimal JAK/STAT signaling for engineered T cell therapyJiang, Limsuwannarot, Kulhanek
et albioRxiv (2025)
Abstract: Arming T cells with a synthetically orthogonal IL-9 receptor (o9R) permits facile engraftment and potent anti-tumor functions. We considered whether the paucity of natural IL-9R expression could be exploited for T cell immunotherapy given that, in mice, high doses of IL-9 were well-tolerated without discernible immune modulation. Compared to o9R, T cells engineered with IL-9R exhibit superior tissue infiltration, stemness, and anti-tumor activity. These qualities are consistent with a stronger JAK/STAT signal, which in addition to STAT1/3/5, unexpectedly includes STAT4 (canonically associated with IL-12 but not common γ-chain cytokines). IL-9R T cells are exquisitely sensitive to perturbations of proximal signaling, including structure-guided attenuation, amplification, and rebalancing of JAK/STAT signals. Biased IL-9R mutants uncover STAT1 as a rheostat between proliferative stem-like and terminally differentiated effector states. In summary, we identify native IL-9/IL-9R as a natural cytokine-receptor pair with near-orthogonal qualities and an optimal JAK/STAT signaling profile for engineered T cell therapy.
IL-9 sensitizes human TH2 cells to proinflammatory IL-18 signals in atopic dermatitisSchärli, Luther, Di Domizio
et alJ Allergy Clin Immunol (2025) 155 (2), 491-504.e9
Abstract: TH2 cells crucially contribute to the pathogenesis of atopic dermatitis (AD) by secreting high levels of IL-13 and IL-22. Yet the upstream regulators that activate TH2 cells in AD skin remain unclear. IL-18 is a putative upstream regulator of TH2 cells because it is implicated in AD pathogenesis and has the capacity to activate T cells.We sought to decipher the role of IL-18 in TH2 responses in blood and skin of AD patients.Peripheral blood mononuclear cells and skin biopsy samples from AD patients and healthy donors were used. Functional assays were performed ex vivo using stimulation or blocking experiments. Analysis was performed by flow cytometry, bead-based multiplex assays, RT-qPCR, RNA-Seq, Western blot, and spatial sequencing.IL-18Rα+ TH2 cells were enriched in blood and lesional skin of AD patients. Of all the cytokines for which TH2 cells express the receptor, only IL-9 was able to induce IL-18R via an IL-9R-JAK1/JAK3-STAT1 signaling pathway. Functionally, stimulation of circulating TH2 cells with IL-18 induced secretion of IL-13 and IL-22, an effect that was enhanced by costimulation with IL-9. Mechanistically, IL-18 induced TH2 cytokines via activation of IRAK4, NF-κB, and AP-1 signaling in TH2 cells, and neutralization of IL-18 inhibited these cytokines in cultured explants of AD skin lesions. Finally, IL-18 protein levels correlated positively with disease severity in lesional AD skin.Our data identify a novel IL-9/IL-18 axis that contributes to TH2 responses in AD. Our findings suggest that both IL-9 and IL-18 could represent upstream targets for future treatment of AD.Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.
Functional diversity and regulation of IL-9-producing T cells in cancer immunotherapyKalim, Jing, Guo
et alCancer Lett (2024) 606, 217306
Abstract: IL-9-producing T cells (T9) regulate immunological responses that affect various cellular biological processes, though their precise function remains fully understood. Previous studies have linked T9 cells to conditions such as allergic disorders, parasitic infection clearance, and various types of cancers. While the functional heterogeneity of IL-9 and T9 cells in cancer development has been documented, these cells present promising therapeutic opportunities for treating solid tumors. This review highlights the roles of IL-9 and T9 cells in cancer progression and treatment responses, focusing on potential discrepancies in IL-9/IL-9R signaling between murine tumors and cancer patients. Additionally, we discuss the regulation of tumor-specific Th9/Tc9 cell differentiation, the therapeutic potential of these cells, and current strategies to enhance their anti-tumor activities.Copyright © 2024. Published by Elsevier B.V.
Interleukin-9 promotes EMT-mediated PM2.5-induced pulmonary fibrosis by activating the STAT3 pathwayLi, Zhong, Li
et alArch Toxicol (2024) 98 (12), 4047-4058
Abstract: This study investigated the impact of PM2.5 on promoting EMT in PM2.5-induced pulmonary fibrosis (PF) development and explored molecular mechanisms of the IL-9/STAT3/Snail/TWIST1 signaling pathway in PF owing to PM2.5. Four groups of male SD rats were formed: control (0 mg/kg.bw), low (1 mg/kg.bw), medium (5 mg/kg.bw), and high-dose (25 mg/kg.bw) PM2.5 groups. Experimental rats were subjected to PM2.5 exposure via intratracheal instillation, given once weekly for 16 weeks. 24 h after the final exposure, blood, BALF, and lung tissues were collected. Pulmonary epithelial cells underwent cultivation and exposure to varying PM2.5 concentrations with/without inhibitors for 24 h, after which total protein was extracted for relevant protein assays. The findings demonstrated that PM2.5 damaged lung tissue to different degrees and led to PF in rats. Rats subjected to PM2.5 exposure exhibited elevated concentrations of IL-9 protein in both serum and BALF, and elevated levels of IL-9 and its receptor, IL-9R, in lung tissues, compared to control counterparts. Furthermore, PM2.5-exposed groups demonstrated significantly augmented protein levels of p-STAT3, Snail, TWIST1, Vimentin, COL-I, and α-SMA, while displaying notably diminished levels of E-Cadherin compared to control group. The same findings were observed in PM2.5-treated cells. In BEAS-2B cells co-treated with Stattic (STAT3 inhibitor) and PM2.5, the opposite results occurred. Similar results were obtained for cells co-treated with IL-9-neutralizing antibody and PM2.5. Our findings suggest PM2.5 mediates PF development by promoting IL-9 expression, leading to STAT3 phosphorylation and upregulation of Snail and TWIST1 expression, triggering EMT occurrence and progression in lung epithelial cells.© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.