An exhausted phenotype of T _H 2 cells is primed by allergen exposure, but not reinforced by allergen‐specific immunotherapy

Background Studies show that proallergic TH2 cells decrease after successful allergen-specific immunotherapy (AIT). It is likely iatrogenic administration of allergens drives these to exhaustion due chronic T-cell receptor stimulation. This study aimed investigate the T in connection with allergen exposure during AIT mice and two independent patient cohorts. Methods OVA-sensitized C57BL/6J were challenged treated OVA, development local systemic was analyzed. In patients, expression exhaustion-associated surface markers on evaluated using flow cytometry a cross-sectional grass pollen allergy cohort without AIT. The treatment effect further studied PBMC collected from prospective long-term cohort. Results CTLA-4 PD-1 significantly upregulated upon OVA aerosol OVA-allergic compared non-allergic mice. decreased AIT, particular lung cells. Similarly, enhanced patients allergic rhinitis an even stronger those concomitant asthma. Using unbiased Louvain clustering analysis, we discovered late-differentiated population expressing both up-dosing but persisted long term maintenance phase. Conclusions shows promotes dynamic change frequencies exhausted exhibits differential pattern versus phases