Immune cells, pancreas development, regeneration and type 1 diabetes

Macrophages (MΦs), dendritic cells (DCs) and lymphocytes are involved in the pathogenesis of type 1 diabetes (T1D). However, the presence of these cells is not specific for a diabetes-prone background. MΦs are also constituents of the normal fetal, neonatal and adult pancreas. We hypothesize that MΦs, DCs and lymphocytes have a role in pancreas and islet development because immune cells (particularly MΦs) are known to participate in the morphogenesis of various organs. In addition, we hypothesize that a defective function of immune cells generates an aberrant islet morphogenesis in T1D-prone individuals or animals. In the post-weaning period (a period of islet remodelling), the same defective function of immune cells might precipitate the pro-inflammatory peri-islet microenvironment that favours islet autoimmune reactivity.