Taming autoimmune thyroiditis: cellular immunomodulation through MSCs, Tregs, and tolDCs.

Autoimmune thyroiditis (AIT), typified by Hashimoto's thyroiditis, represents a prototypical organ-specific autoimmune disorder marked by lymphocytic infiltration, autoantibody production, and progressive thyroid dysfunction. Conventional hormone replacement alleviates hypothyroidism but fails to correct the underlying immune dysregulation. Preclinical models of experimental autoimmune thyroiditis (EAT) consistently demonstrate that these cell-based approaches mitigate inflammatory responses, correct Th17/Treg imbalance, and prevent follicular destruction. Moreover, emerging data on extracellular vesicle-mediated mechanisms and antigen-specific dendritic targeting further underscore the potential for durable immunological reprogramming. This review summarizes recent advances in tolerogenic cellular therapies aimed at restoring immune homeostasis in AIT. Mesenchymal stem cells (MSCs), regulatory T cells (Tregs), and tolerogenic dendritic cells (tolDCs) exert multifaceted immunomodulatory effects via cytokine secretion, metabolic reprogramming, and induction of antigen-specific tolerance, offering a promising immunotherapeutic strategy to modify AIT progression, moving beyond symptomatic relief toward long-term immune tolerance.