title: Indefinite survival of neonatal porcine islet xenografts by simultaneous targeting of LFA-1 and CD154 or CD45RB.
abstract: A variety of transient therapies directed against molecules involved in T-cell activation and function result in long-term islet allograft survival. However, there are relatively few examples of durable islet xenograft survival using similar short-term approaches, especially regarding highly phylogenetically disparate xenograft donors. Previous studies demonstrate that combined anti-lymphocyte function-associated antigen-1 (LFA-1) plus anti-CD154 therapy results in a robust form of islet allograft tolerance not observed with either individual monotherapy. Thus, the aim of this study was to determine whether the perturbation of anti-LFA-1, either alone or in combination with targeting CD154 or CD45RB, would promote neonatal porcine islet (NPI) xenograft survival in mice. NPI xenografts are rapidly rejected in wild-type C57BL/6 mice but reproducibly mature and restore durable euglycemia in diabetic, immune-deficient C57BL/6 rag-1(-/-) recipients. A short course of individual anti-LFA-1, anti-CD154, or anti-CD45RB therapy resulted in long-term (>100 days) survival in a moderate proportion of C57BL/6 recipients. However, simultaneous treatment with anti-LFA-1 plus either anti-CD154 or anti-CD45RB therapy could achieve indefinite xenograft function in the majority of recipient animals. Importantly, prolongation of islet xenograft survival using combined anti-LFA-1/anti-CD154 therapy was associated with little mononuclear cell infiltration and greatly reduced anti-porcine antibody levels. Taken together, results indicate that therapies simultaneously targeting differing pathways impacting T-cell function can show marked efficacy for inducing long-term xenograft survival and produce a prolonged state of host hyporeactivity in vivo.
authors.affiliation: Surgical-Medical Research Institute, University of Alberta, Edmonton, Canada.
authors.forename: Gina R
authors.initials: GR
authors.lastname: Rayat
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Gill
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000906:Antibodies / Q000494:pharmacology; D023201:CD40 Ligand / Q000276:immunology*; D003921:Diabetes Mellitus, Experimental / Q000276:immunology / Q000473:pathology / Q000601:surgery*; D006084:Graft Rejection / Q000517:prevention & control; D006085:Graft Survival / Q000276:immunology*; D016381:Islets of Langerhans Transplantation / Q000276:immunology*; D017493:Leukocyte Common Antigens / Q000276:immunology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D020123:Sirolimus / Q000494:pharmacology; D013552:Swine; D014183:Transplantation, Heterologous
chemical_list: D000906:Antibodies; D016169:Lymphocyte Function-Associated Antigen-1; D023201:CD40 Ligand; D017493:Leukocyte Common Antigens; D020123:Sirolimus