CCL4 Protects From Type 1 Diabetes by Altering Islet β-Cell–Targeted Inflammatory Responses

Abstract

We previously reported that interleukin (IL)-4 treatment of nonobese diabetic (NOD) mice elevates intrapancreatic CCL4 expression and protects from type 1 diabetes. Here, we show that antibody neutralization of CCL4 abrogates the ability of T-cells from IL-4 -treated NOD mice to transfer protection against type 1 diabetes. Intradermal delivery of CCL4 via a plasmid vector stabilized by incorporation of the Epstein-Barr virus EBNA1/oriP episomal maintenance replicon (pHERO8100-CCL4) to NOD mice beginning at later stages of disease progression protects against type 1 diabetes. This protection was associated with a Th2-like response in the spleen and pancreas; decreased recruitment of activated CD8؉ T-cells to islets, accompanied by diminished CCR5 expression on CD8 ؉ T-cells; and regulatory T-cell activity in the draining pancreatic lymph nodes. Thus, inflammatory responses that target islet ␤-cells are suppressed by CCL4, which implicates the use of CCL4 therapeutically to prevent type 1 diabetes. Diabetes 56: 809 -817, 2007 D evelopment of type 1 diabetes depends upon the selective recruitment of pathogenic leukocytes to pancreatic islets by chemokines and their receptors (1-5). Previously, we demonstrated in nonobese diabetic (NOD) mice that treatment with interleukin (IL)-4 elevates intrapancreatic CCL4 levels that correlate with decreased intraislet CCR5 expression and protection from type 1 diabetes (4). Increased intrapancreatic CCL4 expression is associated with enhanced recruitment of insulin B-chain reactive regulatory CD4ϩ T-cells to the pancreas and prevention of destructive insulitis upon oral insulin administration (6), and protection from type 1 diabetes by a neutralizing anti-IL-16 monoclonal antibody depends on CCL4 activity. These results suggest that enhanced CCL4 expression in secondary lymphoid organs and the pancreas blocks the development of type 1 diabetes.In this study, we tested whether CCL4 protects against type 1 diabetes using a gene transfer approach. A plasmid vector stabilized by the Epstein-Barr virus EBNA1/oriP episomal maintenance replicon was utilized to sustain CCL4 expression in vivo. We demonstrate that intradermal gene transfer of CCL4 prevents type 1 diabetes and that antibody-mediated CCL4 blockade reverses the ability of T-cells from IL-4 -treated NOD mice to transfer protection against type 1 diabetes. This is the first demonstration that IL-4 -mediated protection against type 1 diabetes relies upon CCL4 activity in vivo and that CCL4 inhibits progression to type 1 diabetes. RESEARCH DESIGN AND METHODSNOD/Del, NOD.Scid (from Dr. Len Schultz; The Jackson Laboratories, Bar Harbor, ME) and NOD8.3 TCR transgenic mice were bred in a specific pathogen-free barrier facility at the Robarts Research Institute (7,8). Mice were maintained in a specific pathogen-free facility at the University of Western Ontario according to institutional guidelines. IL-4 treatment, cell transfer, and CCL4 neutralization. One hundred nanograms (1,000 units) of recombinant mIL-4 (Immunex, Seattle, WA...

Relation of circulating concentrations of chemokine receptor CCR5 ligands to C-peptide, proinsulin and HbA1c and disease progression in type 1 diabetes

“…Due to the considerable overlap of measurements at the different time points these cytokine measurements do not qualify as diagnostic markers on an individual basis. However, they may offer insights on the role of chemokines in type 1 diabetes and our findings such as associations with remission or metabolic parameters are in line with observations made in animal experiments in vivo [4,23,24].…”

“…CCL4 that is related to Th2 was negatively associated with proinsulin. This finding supports the suggestion of a protective role of CCL4 to β-cell during diabetes progression [23,24]. The missing association of CCL4 with remission that was defined by metabolic control and insulin requirement might be explained by the reason that remission is caused by different factors than just β-cell function [31,32].…”

“…Whether elevated CCL3 concentrations in remitters reflect an enforced leukocyte attraction due to the presence of more insulin producing β-cells remains speculative. Interestingly, we could not observe a statistical significant elevation of the Th2 related CCL4 in remitters that has been described to prevent diabetes in NOD mice [24].…”

Molecular mechanisms of death ligand‐mediated immune modulation: A gene therapy model to prolong islet survival in type 1 diabetes

“…Adenovirus vectors expressing TGF-b also protected pancreatic islets from autoimmune destruction [Suarez-Pinzon et al, 2002]. Lastly, intra-pancreatic CCL4 expression effectively suppressed inflammatory response targeting beta cells [Meagher et al, 2007]. Collectively, these studies suggest that improving islet graft survival is achievable in the experimental gene therapy animal models.…”

Genetic vaccination for re-establishing T-cell tolerance in type 1 diabetes

“…injection of pDNA encoding CCL4 or CXCL10 to young NOD mice results in the induction of neutralizing antibodies specific for the respective chemokines. 63,64 Consequently, T cell trafficking to the islets is blocked and the development of diabetes prevented. This approach, however, is limited by the lack of specificity for the autoimmune response.…”