title: A combination therapy of PEGylation and immunosuppressive agent for successful islet transplantation.
abstract: Several immunosuppressive medications are used simultaneously to protect transplanted islets. However, reports of severe side effects induced by immunosuppressive drugs have prompted attention on developing ways to reduce their toxicities. Toward attenuating the immunogenicity of islets, we studied a combination therapy of PEGylation and cyclosporin A (CsA) as a new immunoprotective strategy. This study aimed to find out whether PEGylation combined with cyclosporine and applied on islet surfaces could bring about a synergistic effect of reducing the dose of immunosuppressive medications as well as enhancing their medical effects. After islets were transplanted into the kidney of diabetic rats, different doses of CsA were administered daily. When 3 mg/kg of CsA was administered for 2 weeks, unmodified islets were completely rejected within 2 weeks, whereas the PEGylated islets survived for 32+/-14.6 days. When 1 mg/kg of CsA was further administered following the initial, 2-week CsA treatment of 3 mg/kg, the PEGylated islets in all recipients survived up to 100 days prior to nephrectomy and also rapidly responded to the fluctuation of blood glucose level. PEGylated islets were also present in large numbers in the transplantation site without causing the infiltration of immune cells. Therefore, these findings suggest that, when combined with an immunosuppressive drug, PEGylation of islets could have a dose reducing effect on the immunosuppressive medication and thus synergistically improve the survival time of islets.
authors.affiliation: College of Pharmacy, Seoul National University, San 56-1, Sillim 9-dong, Gwanak-gu, Seoul 151-742, Korea.
authors.forename: Dong Yun
authors.initials: DY
authors.lastname: Lee
authors.affiliation: Department of Life Science, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea.
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Pathology, School of Medicine, Chonnam National University, Gwangju 500-757, Korea.
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Nam
authors.affiliation: College of Pharmacy, Seoul National University, San 56-1, Sillim 9-dong, Gwanak-gu, Seoul 151-742, Korea. Electronic address: yrbyun@snu.ac.kr.
authors.forename: Youngro
authors.initials: Y
authors.lastname: Byun
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D016572:Cyclosporine / Q000008:administration & dosage* / Q000627:therapeutic use*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism; D005079:Excipients; D005951:Glucose Tolerance Test; D007166:Immunosuppressive Agents / Q000008:administration & dosage* / Q000627:therapeutic use*; D007515:Islets of Langerhans / Q000033:anatomy & histology; D016381:Islets of Langerhans Transplantation / Q000276:immunology*; D008297:Male; D009392:Nephrectomy; D011092:Polyethylene Glycols; D051381:Rats; D011916:Rats, Inbred F344; D017207:Rats, Sprague-Dawley; D013499:Surface Properties
chemical_list: D001786:Blood Glucose; D005079:Excipients; D007166:Immunosuppressive Agents; D011092:Polyethylene Glycols; D016572:Cyclosporine