Challenges and strategies in clinical applications of CAR-T therapy for autoimmune diseases.

Chimeric antigen receptor (CAR) T-cell therapy has demonstrated substantial efficacy against various hematological malignancies. The remarkable success of CAR-T cell therapy in targeting B-cell malignancies has generated significant interest in its potential application for treating autoimmune diseases (ADs). By engineering T cells to express CARs that specifically recognize B-cell antigens, researchers aim to selectively eliminate or modulate the dysregulated autoimmune responses underlying disease pathology. Early clinical trials targeting the B-cell marker CD19 have shown promising results, including clinical remission in patients with B-cell-mediated ADs. To broaden therapeutic potential and improve the safety profile of CAR-T cell therapy in autoimmunity, innovative strategies are under investigation. These include the development of chimeric autoantibody receptors (CAARs) for the precise depletion of autoantigen-specific B cells, and the engineering of regulatory T cells (Tregs) expressing antigen-specific CARs to achieve targeted immune modulation. Critical considerations for the safe and effective translation of CAR-T therapy to ADs include optimal target cell identification, CAR construct design, toxicity management, and the capacity to induce durable immune tolerance. This review explores strategies to optimize CAR-T cell therapies for ADs, focusing on enhancing efficacy and addressing current limitations. We summarize recent advances in alternative cell sources, CAR structural modifications, genetic and metabolic interventions, clinical translation, and the integration of novel technologies, presenting approaches poised to improve the efficacy and applicability of CAR-T cell therapy in ADs.