Human Pancreatic Islet Isolation: Part II: Purification and Culture of Human Islets
Summary
Achieving high quality and appropriate quantity of human islets is one of the prominent prerequisites for successful islet transplantation. In this video, we describe step by step the procedures for human pancreatic islet isolation (part II: purification and culture of human islets) using a modified automated method.
Abstract
Management of Type 1 diabetes is burdensome, both to the individual and society, costing over 100 billion dollars annually. Despite the widespread use of glucose monitoring and new insulin formulations, many individuals still develop devastating secondary complications. Pancreatic islet transplantation can restore near normal glucose control in diabetic patients 1, without the risk of serious hypoglycemic episodes that are associated with intensive insulin therapy. Providing sufficient islet mass is important for successful islet transplantation. However, donor characteristics, organ procurement and preservation affect the isolation outcome 2. At University of Illinois at Chicago (UIC) we developed a successful isolation protocol with an improved purification gradient 3. The program started in January 2004 and more than 300 isolations were performed up to November 2008. The pancreata were sent in cold preservation solutions (UW, University of Wisconsin or HTK, Histidine-Tryptophan Ketoglutarate) 4-7 to the Cell Isolation Laboratory at UIC for islet isolation. Pancreatic islets were isolated using the UIC method, which is a modified version of the method originally described by Ricordi et al 8. As described in Part I: Digestion and Collection of Pancreatic Tissue, human pancreas was trimmed, cannulated, perfused, and digested. After collection and at least 30 minutes of incubation in UW solution, the tissue was loaded in the cell separator (COBE 2991, Cobe, Lakewood, CO) for purification 3. Following purification, islet yield (expressed as islet equivalents, IEQ), tissue volume, and purity was determined according to standard methods 9. Isolated islets were cultured in CMRL-1066 media (Mediatech, Herndon, VA), supplemented with 1.5% human albumin, 0.1% insulin-transferrin-selenium (ITS), 1 ml of Ciprofloxacin, 5 ml o f 1M HEPES, and 14.5 ml of 7.5% Sodium Bicarbonate in T175 flasks at 37°C overnight culture before islets were transplanted or used for research.
Protocol
1. Purification of islets To start the islet purification procedure, load the COBE bag, clamp all tubes except the green tube, and set the speed to 1,500 and the super out to 0. In the hood set up the pump and gradient beakers and connect the collection tubing to the green tube. Now the loading of the ficoll 1.100 can begin: push “spin” then add 110 ml of Ficoll 1.100 to the front beaker, and start the pump in order to load the COBE bag. As the Ficoll is loaded, press super out, …
Discussion
In spite of significant advancements in techniques of human islet isolation, islet yield remain highly variable and unpredictable. Purification of digested pancreatic tissue is crucial to recover a sufficient isle mass after successful enzymatic digestion for transplantation. The UIC purification method is recommended because a superior recovery of highly pure human islets was demonstrated by using this method. Moreover, up to 50 ml of digested tissue can be loaded in a single Cobe run for purification, thus minimizing t…
Acknowledgements
Supported by founding from the University of Illinois at Chicago as well as Islet Cell Resource Center NIH grant (RFA-RR 05-003), the Christopher Foundation, the Efroymson Foundation, and the Tellabs Foundation.
Materials
| Material Name | Type | Company | Catalogue Number | Comment |
|---|---|---|---|---|
| Centrifuge | equipment | Beckman Coulter | 424803 | |
| Cobe 2991 Cell Processor | equipment | Gambro. BCT | 2556 | islet purification |
| MZ6 Inverted Microscopy TLBD4.1 | equipment | Leica Diagnostic Instrument Co | 4103 | |
| Cell Culture Dish with 2 mm Grid | equipment | Nunc Brand Products | 174926 | islet counting |
| Digital Sight DS L1 | equipment | Nikon | 217267 | |
| COBE bag | disposable equipment | O.R. Solution | 66707003 | |
| T175 culture flask | disposable equipment | Sarstedt | 83.1812.500 | |
| University of Wisconcin (UW) solution | reagent | DURAMED | 1000-46-06 | |
| Hank’s Buffered Salt Solution (HBSS) | reagent | Mediatech Inc | 99-597-CM | |
| Ficoll 1.100 | reagent | Bichrom AG | L6155 | |
| M199 media (wash solution) | reagent | Mediatech Inc | 99-784-CM | |
| Final wash/Culture Medium | reagent | Mediatech Inc | 99-785-CV | |
| Dithizone | reagent | Sigma | D5130 |
References
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- Nano, R. Islet isolation for allotransplantation: variables associated with successful islet yield and graft function. Diabetologia. 48, 906-912 (2005).
- Barbaro, B. Improved human pancreatic islet purification with the refined UIC-UB density gradient. Transplantation. 84, 1200-1203 (2007).
- Lakey, J. R., Rajotte, R. V., Warnock, G. L., Kneteman, N. M. Human pancreas preservation prior to islet isolation. Cold ischemic tolerance. Transplantation. 59, 689-694 (1995).
- Fridell, J. A. Comparison of histidine-tryptophan-ketoglutarate solution and University of Wisconsin solution for organ preservation in clinical pancreas transplantation. Transplantation. 77, 1304-1306 (2004).
- Potdar, S. Initial experience using histidine-tryptophan-ketoglutarate solution in clinical pancreas transplantation. Clin Transplant. 18, 661-665 (2004).
- Salehi, P. Human islet isolation outcomes from pancreata preserved with Histidine-Tryptophan Ketoglutarate versus University of Wisconsin solution. Transplantation. 82, 983-985 (2006).
- Ricordi, C., Lacy, P. E., Scharp, D. W. Automated islet isolation from human pancreas. Diabetes. 38 Suppl 1, 140-142 (1989).
- Ricordi, C. Islet isolation assessment in man and large animals. Acta Diabetol Lat. 27, 185-195 (1990).
Tags
Human Pancreatic Islet IsolationPurificationCultureType 1 DiabetesGlucose ControlInsulin TherapyIslet TransplantationDonor CharacteristicsOrgan ProcurementPreservationIsolation OutcomeUIC (University Of Illinois At Chicago)Isolation ProtocolPurification GradientCold Preservation Solutions (UWHTK)Cell Isolation LaboratoryUIC MethodRicordi Et Al Method
Cite This Article
Qi, M., Barbaro, B., Wang, S., Wang, Y., Hansen, M., Oberholzer, J. Human Pancreatic Islet Isolation: Part II: Purification and Culture of Human Islets. J. Vis. Exp. (27), e1343, doi:10.3791/1343 (2009).