Increased phenotypic and functional stability of human allospecific induced Tregs is associated with Vitamin C-mediated

Introduction: While numerous preclinical models emphasize the therapeutic promise of Methods: To address this, we generated and expanded iTregs in the presence of Vitamin C, known to activate TET enzymes that demethylate critical gene regions such as FOXP3. Antigen-specific Tregs were derived from allogeneic co-cultures of monocyte-derived dendritic cells and naïve T cells. After 7 days, allo-Tregs were isolated by FACS and further expanded for 3 weeks with IL-2, TGF-β, rapamycin, with or without Vitamin C supplementation. Results: iTregs treated with Vitamin C displayed heightened FOXP3 expression and sustained high levels of suppressive markers (PD-L1, CD39, TIGIT, and CTLA-4), as well as chemokine receptors linked to allograft homing (CCR4, CCR5, and CXCR3). These cells also demonstrated enhanced allospecific suppression of CD4 Discussion: In summary, Vitamin C enhances both the phenotypic and functional stability of allospecific iTregs, even under proinflammatory conditions, correlating with increased TSDR demethylation, while preserving the transcription of key Treg genes. These results suggest that Vitamin C-treated allospecific iTregs are superior candidates for immunotherapy strategies to promote long-term tolerance in transplant recipients.