|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

* Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA; and
Universita di Milano-Bicocca, Milan, Italy
1Correspondence: Beth Israel Deaconess Medical Center, Harvard Medical School, 99 Brookline Ave., Boston, MA 02215, USA. E-mail: hwang3{at}bidmc.harvard.edu
Carbon monoxide (CO) exposure of an islet donor frequently leads to islet allograft long-term survival and tolerance in recipients. We show here that CO confers its protective effects at least in part by suppressing Toll-like receptor 4 (TLR4) up-regulation in pancreatic ß cells. TLR4 is normally up-regulated in islets during the isolation procedure; donor treatment with CO suppresses TLR4 expression in isolated islets as well as in transplanted grafts. TLR4 up-regulation allows initiation of inflammation, which leads to islet allograft rejection; islet grafts from TLR4-deficient mice survive indefinitely in BALB/c recipients and show significantly less inflammation at various days after transplantation compared with grafts from a control donor. Isolated islets preinfected with a TLR4 dominant negative virus before transplantation demonstrated prolonged survival in recipients. Despite the salutary effects of TLR4 suppression, HO-1 expression is still needed in the recipient for islet survival: TLR4-deficient islets were rejected promptly after being transplanted into recipients in which HO-1 activity was blocked. In addition, incubation of an insulinoma cell line, ßTC3, with an anti-TLR4 antibody protects those cells from cytokine-induced apoptosis. Our data suggest that TLR4 induction in ß cells is involved in ß cell death and graft rejection after transplantation. CO exposure protects islets from rejection by blocking TLR4 up-regulation.—Goldberg, A., Parolini, M., Chin, B. Y., Czismadia, E., Otterbein, L. E., Bach, F. H., Wang, H. Toll-like receptor 4 suppression leads to islet allograft survival.
Key Words: islet transplantation carbon monoxide inflammation type 1 diabetes
This article has been cited by other articles:
![]() |
F. Moore, M. L. Colli, M. Cnop, M. I. Esteve, A. K. Cardozo, D. A. Cunha, M. Bugliani, P. Marchetti, and D. L. Eizirik PTPN2, a Candidate Gene for Type 1 Diabetes, Modulates Interferon-{gamma}-Induced Pancreatic {beta}-Cell Apoptosis Diabetes, June 1, 2009; 58(6): 1283 - 1291. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |