摘要
Background:In Type 1 diabetes,the insulin-producingβ-cells within the pancreatic islets of Langerhans are destroyed.We showed previously that immunotherapy with Bacillus Calmette-Guerin(BCG)or complete Freund’s adjuvant(CFA)of non-obese diabetic(NOD)mice can prevent disease process and pancreaticβ-cell loss.This was associated with increased islet Regenerating(Reg)genes expression,and elevated IL-22-producing Th17 T-cells in the pancreas.Results:We hypothesized that IL-22 was responsible for the increased Reg gene expression in the pancreas.We therefore quantified the Reg1,Reg2,and Reg3δ(INGAP)mRNA expression in isolated pre-diabetic NOD islets treated with IL-22.We measured IL-22,and IL-22 receptor(R)-αmRNA expression in the pancreas and spleen of pre-diabetic and diabetic NOD mice.Our results showed:1)Reg1 and Reg2 mRNA abundance to be significantly increased in IL-22-treated islets in vitro;2)IL-22 mRNA expression in the pre-diabetic mouse pancreas increased with time following CFA treatment;3)a reduced expression of IL-22Rαfollowing CFA treatment;4)a down-regulation in Reg1 and Reg2 mRNA expression in the pancreas of pre-diabetic mice injected with an IL-22 neutralizing antibody;and 5)an increased isletβ-cell DNA synthesis in vitro in the presence of IL-22.Conclusions:We conclude that IL-22 may contribute to the regeneration ofβ-cells by up-regulating Regenerating Reg1 and Reg2 genes in the islets.
基金
We thank Ms.Brenda Strutt and Jessica Hill for technical help and Dr.Margery Ma from Pfizer,Cambridge,MA for anti-IL-22 antibody.We also thank Dr.Kathleen Hill,Dr.Alexander Timoshenko and Morgan Kleiber for assistance in experimental design and interpretation of the data.This work was supported by grants from the Canadian Institutes of Health Research(CIHR).
