Dendritic Cells as Immunometabolic Regulatory Nodes in Diabetes: Molecular Mechanisms and Therapeutic Reprogramming

Diabetes mellitus comprises a group of heterogeneous metabolic disorders characterized by persistent hyperglycemia, progressive β-cell dysfunction, and multi-organ complications. Although type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) have distinct pathogenic origins, both involve immune dysregulation, tissue stress, release of danger signals, and chronic inflammation. Dendritic cells (DCs), as antigen-presenting cells, integrate innate immune sensing, antigen presentation, cytokine production, T-cell regulation, and peripheral immune tolerance, placing them at a critical interface between autoimmunity and metabolic inflammation. In T1DM, DCs contribute to β-cell autoantigen presentation, tolerance breakdown, autoreactive T-cell activation, and insulitis amplification. In T2DM, DCs may contribute to adipose tissue inflammation, hepatic immunometabolic crosstalk, β-cell stress, vascular inflammation, and immune remodeling associated with diabetes-related complications. Here, we review the disease-specific roles of DC subsets in T1DM and T2DM and discuss shared molecular mechanisms, including pattern-recognition receptor signaling, metabolic reprogramming, inflammasome activation, cytokine networks, and the shift from immune tolerance to inflammation. We also evaluate therapeutic DC reprogramming strategies and their potential implications for targeted immunometabolic intervention in diabetes.