Title

Idd loci synergize to prolong islet allograft survival induced by costimulation blockade in NOD mice.

Document Type

Article

Publication Date

2009

Keywords

Antibodies-Monoclonal, CD40-Ligand, Cytotoxicity-Immunologic, Diabetes-Mellitus-Type-1, Flow-Cytometry, Graft-Survival, Islets-of-Langerhans, Islets-of-Langerhans-Transplantation, Killer-Cells-Natural, Mice-Congenic, Mice-Inbred-C3H, Mice-Inbred-NOD, Transplantation-Homologous

JAX Source

Diabetes 2009 Jan; 58(1):165-73.

Abstract

OBJECTIVE: NOD mice model human type 1 diabetes and are used to investigate tolerance induction protocols for islet transplantation in a setting of autoimmunity. However, costimulation blockade-based tolerance protocols have failed in prolonging islet allograft survival in NOD mice. RESEARCH DESIGN AND METHODS: To investigate the underlying mechanisms, we studied the ability of costimulation blockade to prolong islet allograft survival in congenic NOD mice bearing insulin-dependent diabetes (Idd) loci that reduce the frequency of diabetes. RESULTS: The frequency of diabetes is reduced in NOD.B6 Idd3 mice and is virtually absent in NOD.B6/B10 Idd3 Idd5 mice. Islet allograft survival in NOD.B6 Idd3 mice treated with costimulation blockade is prolonged compared with NOD mice, and in NOD.B6/B10 Idd3 Idd5, mice islet allograft survival is similar to that achieved in C57BL/6 mice. Conversely, some Idd loci were not beneficial for the induction of transplantation tolerance. Alloreactive CD8 T-cell depletion in (NOD x CBA)F1 mice treated with costimulation blockade was impaired compared with similarly treated (C57BL/6.H2(g7) x CBA)F1 mice. Injection of exogenous interleukin (IL)-2 into NOD mice treated with costimulation prolonged islet allograft survival. NOD.B6 Idd3 mice treated with costimulation blockade deleted alloreactive CD8 T-cells and exhibited prolonged islet allograft survival. CONCLUSIONS: Il2 is the Idd3 diabetes susceptibility gene and can influence the outcome of T-cell deletion and islet allograft survival in mice treated with costimulation blockade. These data suggest that Idd loci can facilitate induction of transplantation tolerance by costimulation blockade and that IL-2/Idd3 is a critical component in this process.