Transplantation 2002 Jul 15;74(1):35-41
Corbascio M, Mahanty H, Osterholm C, Qi Z, Pearson TC, Larsen CP, Freise CE, Ekberg H.
Department of Nephrology and Transplantation, University Hospital, Lund University, Malmo, Sweden.
Blockade of CD40 ligand (CD40L; CD154, gp39) is a potential treatment for autoimmune disease and allograft rejection. However, CD40L-/- mice are capable of mobilizing cellular immune responses to viral, parasitic, and intracellular bacterial infections as well as rejecting skin grafts with nearly the same efficiency as wild-type mice. CD40L-deficient mice (CD40L-/-) or wild-type mice treated with anti-CD40L develop chronic vasculopathy only 8 weeks after allogeneic heart transplantation. To overcome CD40L-independent immune responses, we used anti-lymphocyte function-associated antigen monoclonal antibody (LFA)-1, which has previously been shown to inhibit CD8+ immune responses.
We conducted mixed lymphocyte reactions, cytotoxicity assays, skin transplantation, and vascularized heterotopic heart transplantation in wild-type B6 and CD40L-deficient mice in the presence and absence of anti-LFA-1 to study the effects of anti-LFA-1 in the absence of CD40L signaling.
Anti-LFA-1 inhibited proliferation of naive CD40L-/- mixed leukocyte reactions and the lysis of donor targets by CD40L-/- cytotoxic T lymphocytes. Anti-LFA-1-treated CD40L-/- mice that received fully MHC-mismatched skin grafts showed significant prolongation of graft survival, with a median survival time of 55 days (mean 66 days) compared with 13 and 21 days in wild-type and CD40L-/- controls, respectively. CD40L-/- mice that received fully MHC-mismatched vascularized heart transplants treated with four doses of 200 microg of anti-LFA-1 at the time of transplantation did not develop any signs of chronic vasculopathy 150 days after transplantation.
These results indicate that anti-LFA-1 can complement CD40L inhibition in the prevention of undesirable immune responses.