title: The role of autoimmunity in islet allograft destruction: major histocompatibility complex class II matching is necessary for autoimmune destruction of allogeneic islet transplants after T-cell costimulatory blockade.
abstract: Although it has often been assumed that transplanted allogeneic islets can be destroyed by recurrent autoimmunity in recipients with type 1 diabetes, definitive evidence is lacking and the settings in which this may occur have not been defined. To address these issues, we compared the survival of islet transplants (subject to tissue-specific autoimmunity) with cardiac transplants (not subject to tissue-specific autoimmunity) from various major histocompatibility complex (MHC)-matched and -mismatched donors transplanted into autoimmune NOD recipients. We found that when recipients were treated with combined B7 and CD154 T-cell costimulatory blockade, hearts survived best with better MHC matching, whereas islets survived worst when the donor and recipient shared MHC class II antigens. In the absence of full or MHC class II matching, there was no difference in the survival of islet and cardiac allografts. We also found that the tendency of NOD mice to resist tolerance induction by costimulation blockade is mediated by both CD4+ and CD8+ T-cells, not directly linked to the presence of autoimmunity, and conferred by non-MHC background genes. These findings have clinical importance because they suggest that under some circumstances, avoiding MHC class II sharing may provide better islet allograft survival in recipients with autoimmune diabetes, since mismatched allogeneic islets may be resistant to recurrent autoimmunity. Our results may have implications for the design of future clinical trials in islet transplantation.
authors.affiliation: Laboratory of Immunogenetics and Transplantation, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Leila
authors.initials: L
authors.lastname: Makhlouf
authors.forename: Koji
authors.initials: K
authors.lastname: Kishimoto
authors.forename: Rex N
authors.initials: RN
authors.lastname: Smith
authors.forename: Reza
authors.initials: R
authors.lastname: Abdi
authors.forename: Maria
authors.initials: M
authors.lastname: Koulmanda
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Winn
authors.forename: Hugh
authors.initials: H
authors.lastname: Auchincloss
authors.forename: Mohamed H
authors.initials: MH
authors.lastname: Sayegh
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000276:immunology* / Q000473:pathology; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology / Q000601:surgery*; D004195:Disease Models, Animal; D005260:Female; D005934:Glucagon / Q000032:analysis; D006085:Graft Survival / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006650:Histocompatibility Testing; D007328:Insulin / Q000032:analysis; D016381:Islets of Langerhans Transplantation / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D008815:Mice, Inbred Strains; D013045:Species Specificity; D013601:T-Lymphocytes / Q000276:immunology*; D013997:Time Factors; D014184:Transplantation, Homologous / Q000276:immunology* / Q000473:pathology
chemical_list: D000949:Histocompatibility Antigens Class II; D007328:Insulin; D005934:Glucagon