Prevention of rejection of murine islet allografts by pretreatment with anti-dendritic cell antibody.

Abstract

Previously, it has been demonstrated that islets of Langerhans treated with donor-specific anti-Ia serum and complement survive when transplanted across the major histocompatibility complex of the mouse. Here, using immunofluorescence, 2 morphologically distinct populations of Ia-positive cells scattered within the Ia-negative islet tissue are demonstrated. A large irregularly shaped Ia-positive subset of cells was identified as dendritic cells by using the 33D1 antibody specific for a mouse dendritic cell antigen. The other small, round Ia-positive subset was 33D1 negative. Islets pretreated with anti-dendritic cell antibody and complement prior to transplantation survived in their histoincompatible recipients for > 200 days. Rejection of stable islet allografts promptly occurred when transplant recipients were challenged with 1 .times. 105 donor dendritic cells 60 days after transplantation. An important in vivo role for donor dendritic cells in the stimulation of allograft rejection was demonstrated.