Development and efficacy of ex vivo expanded autologous regulatory T cells for the treatment of amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with limited therapeutic options, in which neuroinflammation critically drives disease progression. Regulatory T cells (Tregs) exert potent immunosuppressive and neuroprotective effects, offering great potential for ALS treatment. However, clinical application of Treg therapy is hampered by low peripheral cell abundance and unstable expansion quality. Here, we established and optimized a GMP-grade protocol for sorting and expanding peripheral blood-derived Tregs, and validated cryopreserved apheresis products as feasikble starting materials. Although ALS patient-derived Tregs showed reduced expansion capacity compared with healthy donor counterparts, they maintained comparable purity, stable regulatory phenotypes, and robust immunosuppressive function. Transcriptomic analysis confirmed the lineage fidelity and low pro-inflammatory characteristics of expanded Tregs. Therapeutic efficacy was verified in SOD1G93A ALS and GvHD mouse models with delayed disease progression and relieved inflammation. This study provides standardized GMP manufacturing strategies and solid preclinical evidence to support the ongoing clinical trial (NCT06671236) and facilitate Treg immunotherapy translation for ALS.