Emergence of a broad repertoire of GAD65-specific T-cells in type 1 diabetes patients with graft dysfunction after allogeneic islet transplantation.

Daisuke Chujo, Emile Foucat, Morihito Takita, Takeshi Itoh, Koji Sugimoto, Masayuki Shimoda, Kunimasa Yagi, Masakazu Yamagishi, Yoshiko Tamura, Liping Yu, Bashoo Naziruddin, Marlon F. Levy, Hideki Ueno, Shinichi Matsumoto

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


Islet transplantation is one of the most promising therapies for type 1 diabetes (T1D). A major issue in islet transplantation is the loss of graft function at late phase. Several studies suggested the involvement of islet-specific T-cells in such islet graft dysfunction. In this study, we investigated the breadth and type of glutamic acid decarboxylase 65 (GAD65)-specific T-cells in T1D patients after allogeneic islet transplantation. Peripheral blood mononuclear cells (PBMCs) were obtained from islet-transplanted T1D patients during insulin-independent period and cultured for 7 days with pools of GAD65 overlapping peptides in the presence of IL-2. Cytokine secretion profiles of peptide-reactive T-cells were analyzed after a short-term restimulation with the same peptides by a multiplex bead-based cytokine assay and by an intracytoplasmic cytokine detection assay. Robust GAD65-specific CD4(+) and CD8(+) T-cell responses were detected in patients who eventually developed chronic graft dysfunction. Multiple GAD65 peptides were found to induce specific T-cell responses in these patients, indicating that the repertoire of GAD65-specific T-cells was broad. Furthermore, GAD65-specific CD4(+) T-cells were composed of heterogeneous populations, which differentially expressed cytokines including IFN-γ and type 2 cytokines, but not IL-10. In contrast, patients who showed only marginal GAD65-specific T-cell responses maintained substantially longer graft survival and insulin independence. In conclusion, our study suggests that the emergence of islet-specific T-cells precedes the development of chronic graft dysfunction in islet-transplanted patients. Thus, our observations support the hypothesis that these islet-specific T-cells contribute to the development of chronic islet graft dysfunction.

Original languageEnglish
Pages (from-to)2783-2795
Number of pages13
JournalUnknown Journal
Issue number12
StatePublished - 2012


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