AAT-Engineered MSCs Reprogram Immunity in Early T1D: Preclinical Mouse Data Signals Shift from Symptom Management to Root-Cause Intervention

The MUSC team's 2026 Molecular Therapy study (DOI: 10.1016/j.ymthe.2026.03.032) demonstrates that AAT-secreting MSCs reverse new-onset hyperglycemia in NOD mice by expanding Tregs while driving CD8+ T-cell exhaustion, an effect persisting after rapid cell clearance. This is a preclinical animal model study, not an RCT, with unspecified sample sizes and no reported conflicts of interest. The work advances prior MSC trials (e.g., an observational 2022 phase I/II study in Diabetologia, n=24 adults, showing modest C-peptide preservation) by adding an anti-inflammatory payload that counters the cytokine storm overwhelming native MSCs. It also aligns with teplizumab data (NEJM 2023 RCT, n=76, delaying stage 3 T1D by ~2 years via partial Treg bias) but offers a cellular delivery vehicle for sustained factor secretion. Coverage missed scalability hurdles—GMP-grade AAT-MSC manufacturing variability—and durability beyond 8-week mouse endpoints. Broader pattern: single-dose immune reset could complement beta-cell replacement (Vertex VX-880, ongoing phase I/II), yet human translation demands phase I safety trials focused on infusion reactions and off-target immunosuppression.