Optimization of the Coating of Pancreatic Islets with T Regulatory Cells in the Novel Immunoprotective Approach
Department of Surgery, University of Chicago, Chicago, IL
Department of Chemical and Biological Engineering, College of Engineering, Koc University, Istanbul, Turkey
Department of Medicine, University of Chicago, Chicago, IL
Meeting: 2013 American Transplant Congress
Abstract number: A694
Aim. T regulatory cells (Tregs) possess immunosuppressive properties and can serve as an effective therapy in transplantation. Recently, we have shown that Tregs can be attached to the surface of human pancreatic islets using Biotin-Polyethylene- (biotin-PEG-) glycol-N-hydroxylsuccinimide (NHS) molecule providing local immunoprotection. Further optimization of the method can improve coating parameters and the efficiency of this novel immunoprotective approach, which may prolong graft survival. In this study, we compared two molecules to coat pancreatic islets with Tregs in order to increase number of Tregs attached to islets surface without compromising islets viability and function. Methods. Cell surface of human Tregs and pancreatic islets was modified using our previous approach- biotin-PEG- NHS or new molecule instead- succinimidyl valeric acid ester (SVA) (1mg/ml and 0.6 mg/ml was used for Tregs and islets, respectively). Then, islets were incubated for 15 minutes in 37oC with 1mg/ml of streptavidin as islet/Tregs bridging molecule. Subsequently 150 islets were combined with 50×106 Tregs and incubated overnight for binding. To compare coating effectiveness between using NHS or SVA group, Tregs were stained with CellTracker™ CM-DiL dye and visualized using the Olympus FV1000 Laser Scanning Confocal Microscope. The number of Tregs attached to islets and islet surface area were counted on Imaris software. The effect of coating on islets functionality was determined using Glucose-Stimulated Insulin Response (GSIR) assay. Results. Coating procedure with biotin-PEG-SVA in comparison to biotin-PEG-NHS allowed attaching 40% more Tregs per 1 Μm2 of islets surface. While viability was comparable, function of the islets after coating using biotin-PEG-SVA molecule was better preserved than with NHS molecule. GSIR was 62% higher for islets coated with biotin-PEG-SVA than biotin-PEG-NHS, and as high as in unmodified islet controls. Conclusion. Coating of islets with Tregs using biotin-PEG-SVA improves effectiveness of coating with better preservation of the islet function comparing to biotin-PEG- NHS. Improvement in the method of coating pancreatic islets with Tregs if significant in vivo, could further facilitate the effectiveness of this novel immunoprotective approach and translation into clinical settings.
To cite this abstract in AMA style:
Golab K, Kizilel S, Bal T, Hara M, Zielinski M, Wang X, Grzanka J, Wang L, Cochet O, Tibudan M, Witkowski P. Optimization of the Coating of Pancreatic Islets with T Regulatory Cells in the Novel Immunoprotective Approach [abstract]. Am J Transplant. 2013; 13 (suppl 5). https://atcmeetingabstracts.com/abstract/optimization-of-the-coating-of-pancreatic-islets-with-t-regulatory-cells-in-the-novel-immunoprotective-approach/. Accessed November 22, 2024.« Back to 2013 American Transplant Congress