Publications & Reports

Evidence that an anthracycline-anti-CD8 immunoconjugate, idarubicin-anti-Ly-2.1, prolongs heart allograft survival in mice.

Mottram PL, Pietersz GA, Smyth MJ, Purcell LJ, Clunie GJ, McKenzie IF
Department of Surgery, University of Melbourne, Royal Melbourne Hospital, Parkville, Australia.


To examine the potential use of immunoconjugates of drugs and antibodies as immunosuppressive agents, mice were treated with a short course (4 days) of T-cell-specific anti-Ly-2.1 monoclonal antibody, or MAB conjugated to an anthracycline, idarubicin (IDA). The anti-Ly-2.1 MAB had no significant effect on the survival of BALB/c (Ly-2.2) heart allografts in CBA (Ly-2.1) mice, but was a potent immunosuppressive agent when coupled to IDA, with most grafts surviving for > 100 days following treatment with doses ranging from 10 to 120 micrograms IDA, covalently coupled to 1-8 mg MAB. IDA-MAB treated mice with long-surviving heart grafts showed donor-specific tolerance. They did not reject donor-type skin grafts (these survived for > 50 days), but rejected third-party skin in 10-14 days. Heart allografts in these mice survived for > 100 days. Allografts placed 30 days after treatment were rejected, showing a recovery of peripheral T cell function at this time. Newly derived thymic T cells were, however, not required for this recovery since adult thymectomized, IDA-MAB treated animals also recovered T cell function and rejected heart allografts. FACScan analysis of T cells from mice treated with 80 micrograms IDA-4 mg MAB, which had received a heart allograft, showed 95% T cell depletion in the spleen compared with ungrafted, IDA-MAB treated animals, and untreated controls with or without allografts. Splenic T cell depletion was however not significant in CBA mice immunosuppressed with the lower dose of 10 micrograms IDA-MAB. Thus rapid depletion of splenic T cells was not required for immunosuppression induced by IDA-MAB conjugates. However, the minor subpopulation of Ly-2+, which was activated by alloantigen while carrying IDA-MAB, may be depleted during the T cell response to the allograft, resulting in a state of alloantigen-specific tolerance in mice with long-surviving heart allografts.


  • Journal: Transplantation
  • Published: 01/03/1993
  • Volume: 55
  • Issue: 3
  • Pagination: 484-490