PT - JOURNAL ARTICLE AU - Stephanie Musiol AU - Francesca Alessandrini AU - Constanze A. Jakwerth AU - Adam M. Chaker AU - Evelyn Schneider AU - Ferdinand Guerth AU - Ileana Ghiordanescu AU - Julia T. Ullmann AU - Josephine Kau AU - Mirjam Plaschke AU - Stefan Haak AU - Thorsten Buch AU - Carsten B. Schmidt-Weber AU - Ulrich M. Zissler. TI - TGF-β1 drives Th9 but not Treg cells upon allergen exposure AID - 10.1101/2021.08.18.456797 DP - 2021 Jan 01 TA - bioRxiv PG - 2021.08.18.456797 4099 - http://biorxiv.org/content/early/2021/08/19/2021.08.18.456797.short 4100 - http://biorxiv.org/content/early/2021/08/19/2021.08.18.456797.full AB - TGF-β1 is known to have a pro-inflammatory impact by inducing Th9 cells, while it also induces anti-inflammatory Treg cells (Tregs). In the context of allergic airway inflammation (AAI) its dual role can be of critical importance in influencing the outcome of the disease. Here we demonstrate that TGF-β acts in AAI by driving effector T cells into Th9 cells, while Tregs differentiate independently. Induction of experimental AAI and airway hyperreactivity in a mouse model with inducible genetic ablation of the TGFβ-receptor 2 (TGFBR2) on CD4+T cells significantly reduced the disease phenotype. Further, it blocked the induction of Th9 cell frequencies, but increased Treg cells. To translate these findings into a human clinically relevant context, Th9 and Treg cells were quantified both locally in induced sputum and systemically in blood of allergic rhinitis and asthma patients with or without allergen-specific immunotherapy (AIT). Natural allergen exposure induced local and systemic Th2, Th9 cell and reduced Tregs, while therapeutic allergen exposure by AIT suppressed Th2 and Th9 cell frequencies along with TGF-β and IL-9 secretion. Altogether, these findings support that neutralization of TGF-β represents a viable therapeutic option in allergy and asthma, not posing the risk of immune dysregulation by impacting Tregs.Competing Interest StatementDr. Chaker reports grants for clinical studies and research and other from Allergopharma, ALK Abello, AstraZeneca, Bencard / Allergen Therapeutics, ASIT Biotech, Immunotek, Lofarma, GSK, Novartis, LETI, Roche, Sanofi Genzyme and Zeller. Prof. Schmidt-Weber reports speaker fees from Bencard, personal fees from Allergopharma, during the conduct of the study.AAallergic asthmaAAIallergic airway inflammationAHRairway hyperreactivityAITallergen-specific immunotherapyARallergic rhinitisBALBronchoalveolar lavageBALFBronchoalveolar lavage fluidICIInflammatory cell infiltratei.p.intraperitonealMchmetacholinn.d.not detectableOVAovalbuminPBMCperipheral blood mononuclear cellPBSPhosphate-buffered salinemRQLQRhinoconjunctivitis Quality of Life mini QuestionnairetIgEtotal Immunoglobulin ETregsregulatory T cellsThT helper cells