Abstract Rationale Asthma is a common chronic inflammatory airway disease. TH2-mediated asthma represents a major endotype of severe asthma, and numerous novel biologic agents, including monoclonal antibodies (mAbs), have been developed to target key factors in TH2-driven inflammation. However, mAbs do not provide sustained long-term relief, which can reduce treatment adherence and compromise therapeutic outcomes. Chimeric antigen receptor T-cell (CAR-T) therapy enables specific elimination of target cells through extracellular antigen recognition and downstream signal transduction, representing a promising strategy for long-term disease control. Given the critical contribution of IgE-activated mast cells and basophils to asthma symptoms, we developed novel IgE-CAR-T cells to deplete these populations and assessed their therapeutic potential. Methods An IgE-specific CAR was designed to bind the FCER1 receptor. An IgE CAR-Jurkat cell line was generated and co-cultured with either FCER1-positive or FCER1-negative cell lines. CAR-specific activation was assessed by measuring CD69 expression on IgE CAR-Jurkat cells using flow cytometry. To evaluate the cytotoxic effect of CAR-T cells, primary mouse CAR-T cells were constructed via retroviral transduction, and luciferase-based killing assays were performed to determine their cytotoxicity against FCER1-positive target cells. In an in vivo model, a house dust mite (HDM)-induced murine asthma model was established. The effect of IgE CAR-T treatment was assessed by flow cytometric analysis of basophil depletion, along with eosinophil infiltration in the bone marrow, lung tissue, and bronchoalveolar lavage fluid (BALF). Results In co-culture experiments, U2OS cells expressing the FCER1α specifically activated IgE CAR-Jurkat cells. In luciferase-based killing assays, IgE CAR-T cells selectively lysed FCER1α-expressing U2OS cells. In primary mouse bone marrow differentiation assays, co-culture with IgE CAR-T cells for 24 hours significantly reduced the proportions of total FCER1-positive cells, mast cells, and basophils. In the HDM-induced asthma model, IgE CAR-T treatment effectively reduced the proportion and number of basophils in both lung and bone marrow. Concurrently, a marked reduction in eosinophil expansion was observed in the lung tissue, bronchoalveolar lavage fluid (BALF), and bone marrow. Conclusion In this study, we developed novel IgE CAR-T cells that demonstrated specific cytotoxicity against FCER1-positive basophils and mast cells in both in vitro and in vivo settings. In vivo administration of IgE CAR-T cells in a murine model of HDM-induced asthma significantly reduced basophil levels and attenuated pathogenic eosinophil infiltration in the lung, BALF, and bone marrow. These findings highlight the therapeutic potential of IgE CAR-T cells for achieving long-term remission in chronic airway inflammatory diseases, including severe asthma. This abstract is funded by: National Natural Science Foundation of China (NSFC)
Sun et al. (Fri,) studied this question.