Diabetes, Vol 49, Issue 10 1666-1670, Copyright © 2000 by American Diabetes Association
Anti-CD154 (CD40L) prevents recurrence of diabetes in islet isografts in the DR-BB rat
KL Kover, Z Geng, DM Hess, CD Benjamin and WV Moore
Section of Pediatric Endocrinology, Children's Mercy Hospital, University of Missouri-Kansas City, 64108, USA.
Islet transplantation for the treatment of autoimmune diabetes is more
difficult because of the additional barrier presented by the autoimmunity.
We tested the ability of hamster anti-rat CD154 to prevent recurrence of
diabetes in renal subcapsular islet isografts in DR-BB (RT1uu) rats with
established autoimmune diabetes. Experimental animals with established
diabetes received intravenous injections of 15 mg/kg anti-CD154 on a
specified schedule starting 2 days before renal subcapsular transplantation
of an islet isograft. Control animals received either saline or hamster
IgG. Plasma glucose levels >250 mg/dl over 3 days were used to indicate
the recurrence of diabetes. Rats that received saline (n = 5) or control
antibody (n = 3) had a recurrence of diabetes 6-11 days after
transplantation. Histological examination of islet isografts from these
rats showed complete destruction of the insulin-producing portion of the
isograft with residual cells positive for glucagon. Recipient rats that
received anti-CD154 at the 15-mg/kg dosage (n = 6) did not have a
recurrence of diabetes for 308-461 days after transplantation. Islet
isografts removed from the rats showed low levels of insulin
immunoreactivity, high levels of insulin mRNA, and focal infiltration with
lymphocytes but no evidence of islet destruction. Mean peak antibody
concentration was 266 microg/ml and returned to undetectable levels by
67-88 days after transplantation. Rats that received anti-CD154 starting at
4-7 days after transplantation had a recurrence of diabetes within 11 days
of the isotransplantation. Therefore, anti-CD154 as the sole
immunomodulator prevented the recurrence of diabetes in islet isografts in
rats with established autoimmune diabetes. This suggests that CD40/CD154
blockade is effective in preventing the insulitis or the effector phase of
autoimmune diabetes.