Clinical Islet Transplantation: Where Do We Stand on? / 대한이식학회지

Islet transplantation had been suggested as a potential treatment modality for type I diabetes mellitus for the last two decades. The methods for the islet isolation and purification were developed. In 2000, the excellent clinical outcomes from the Edmonton group were reported. And various basic researches were performed for the elucidation of the mechanism of initial islet loss. Although the Edmonton protocol, which had initially raised hopes that all the technical and immunologic problems would be solved, recently revealed as a limited success within the selective cases and short-term follow-up, these inspirations led us to the subsequent clinical or basic research of islet transplantation. As a result, many clinical trials and studies have been attempted for the establishment of the optimal immune suppression regimen, the prevention from islet loss in the process of isolation, and the improvement of the intraportal engraftment. This article reviews the history and the recent progress and possible strategies for the clinical islet transplantation.

Comparative Study on Biologic and Immunologic Characteristics of the Pancreas Islet Cell between 24degrees C and 37degrees C Culture in the Rat / 대한이식학회지

PURPOSE: Islet cell transplantation, as an alternative approach to endocrine cell replacement to treat the diabetes mellitus, has received significant attention because it holds several advantages over whole gland transplantation. However cell damage from islet isolation and immunologic rejection after transplantation prevent from successful clinical application for diabetic patients. Culture of cells at low temperature has known to stabilize the cell viability, and to decrease the immunologic antigenicity. Aim of this study is to investigate the effect of culture at 24oC on cell viability, cellular function, immunogenicity and cytokine profiles in rat pancreas islet. METHODS: Pancreas islets were isolated from Lewis rat and cultured at 24oC or 37oC during 14 days. Islet recovery after culture period was counted as islet equivalent number, and islet viability was examined with fluorescent vital staining (FDA/PI). Islet function was measured with glucose stimulation test. Annexin V expression and MHC class I and II expression were measured with flow cytometric assay for apoptosis and immunogenicity respectively. Lymphocyte cell proliferation through mixed lymphocyte islet culture was examined with WST-1 proliferation assay. Cytokine profiles were analyzed with quantitative real time RT-PCR. All these parameters were measured on 1, 3, 5, 7, 14 culture days after islet isolation. RESULTS: Islet recovery was higher in islet cultured at 24oC than in islet cultured at 37oC without change of viability. Insulin secretion after glucose stimulation was more effective in 24oC culture condition. Decrease of apoptotic cell death was demonstrated in 24oC cultured islet. MHC class I and II expression on islets and lymphocyte proliferation when cocultured with islets were less prominent in 24oC cultured islet. TNF-alpha and IL-4 cytokine expression was higher in islet cultured at 24oC than in islet cultured at 37oC. IL-1beta and IL-10 cytokine expression were similar in both culture condition. CONCLUSION: This study demonstrated that cell recovery and function are increased in islet cultured at 24oC than in islet cultured at 37oC while antigenicity and proinflammatory cytokine expression are decreased. Low temperature culture can be a good approach to prevent the loss of islet mass, and to reduce the immunologic rejection of transplanted islet for successful clinical islet transplantation.