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Evidence for an antigen‐release induced cellular immune response against alginate‐polylysine encapsulated islets
Author(s) -
Zekorn Tobias D.C.,
Endl Ulrich,
Horcher Andrea,
Siebers Ulrike,
Bretzel Reinhard G.,
Federlin Konrad
Publication year - 1995
Publication title -
xenotransplantation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.052
H-Index - 61
eISSN - 1399-3089
pISSN - 0908-665X
DOI - 10.1111/j.1399-3089.1995.tb00076.x
Subject(s) - islet , in vitro , immune system , transplantation , polylysine , chemistry , pancreatic islets , immunology , andrology , biology , microbiology and biotechnology , medicine , endocrinology , biochemistry , insulin
For almost 15 years microencapsulated islets have been successfully transplanted in different animal models. Besides long‐lasting success, a certain rate of graft failures also has been reported. This study evaluated the cellular immune response toward alginate‐polylysine microencapsulated islets (mc‐islets) in vitro by means of mixed‐lymphocyte‐islet‐culture. Method: Islets were isolated from LEWIS‐rats and lymphocytes from the spleens of NMRl‐mice. After overnight culture and prior to encapsulation the islets were gamma‐irradiated with 22.5 Gy. 50 mc‐islets, 50 nonencapsulated islets, and 50 empty me were co‐cultured for 72 h with 1 × 10 6 in 1 ml medium in 24‐well plates. Thymidine incorporation during the last 24 hr served as a measure for lymphoid activation. Result: Non‐encapsulated islets were potent stimulators of lymphoid proliferation. This could be reduced by 55% when the islets were entrapped in microcapsules. Empty microcapsules induced a minor lymphoid activation (18% of mc‐islets) only. Conclusion: Despite encapsulation islets could be recognised by lymphocytes in vitro. This may explain at least partially graft failure rates after transplantation of encapsulated islets.