Proteins Linked to a Protein Transduction Domain Efficiently Transduce Pancreatic Islets

Jennifer Embury, Dagmar Klein, Antonello Pileggi, Melina Ribeiro, Sundararajan Jayaraman, R. Damaris Molano, Christopher Fraker, Norma Kenyon, Camillo Ricordi, Luca Inverardi, Ricardo L. Pastori

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101 Scopus citations

Abstract

The resounding success of a new immunosuppressive regimen known as the Edmonton protocol demonstrates that islet cell transplantation is becoming a therapeutic reality for diabetes. However, under the Edmonton protocol, a single donor does not provide enough islets to attain the insulin independence of a transplant recipient. This limitation is mainly caused by islet apoptosis triggered during isolation. In this study, we describe a highly efficient system of transiently transferring anti-apoptotic proteins into pancreatic islets, thus opening an exciting new therapeutic opportunity to improve the viability of transplantable islets. We fused β-galactosidase to the 11-amino acid residues that constitute the protein transduction domain (PTD) of the HIV/TAT protein and transduced pancreatic islets ex vivo with this fusion protein in a dose-dependent manner with >80% efficiency. We observed that transduction of the anti-apoptotic proteins Bcl-XL and PEA-15 fused to TAT/PTD prevented apoptosis induced by tumor necrosis factor-a in a pancreatic β-cell line, indicating that TAT/PTD anti-apoptotic proteins retained their biological activity. Finally, we demonstrated that TAT-fusion proteins did not affect the insulin secretion capability of islets, as determined by glucose static incubation and by reversion of hyperglycemia in diabetic immunodeficient mice.

Original languageEnglish (US)
Pages (from-to)1706-1713
Number of pages8
JournalDiabetes
Volume50
Issue number8
DOIs
StatePublished - Aug 2001

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ASJC Scopus subject areas

  • Internal Medicine
  • Endocrinology, Diabetes and Metabolism

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