title: The immunoprotective effect of Sertoli cells coencapsulated with islet xenografts is not dependent upon Fas ligand expression.
abstract: Coencapsulation with Sertoli-enriched testicular cell fractions prolongs islet graft survival time compared with islet encapsulation alone in a highly discordant tilapia (fish)-to-mouse xenotransplantation model. Here we investigate whether Fas ligand (Fas-L) expression by testicular Sertoli cells is responsible for this additional protective effect. Sertoli-enriched testicular cell fractions (7 x 10(6) cells) harvested from either Fas-L-defective (group I) or Fas-L-positive (group II) mice were coencapsulated in alginate gel spheres with fish islets and then transplanted into streptozotocin-diabetic Balb/c recipients. Group III mice received encapsulated islets without coencapsulated Sertoli cells. After transplantation, blood glucose levels were monitored three times per week. Mean graft survival times for the three groups were: group I = 35.6 +/- 10.2 days (n = 9), group II = 31.3 +/- 9.4 days (n = 7), and group III = 23.3 +/- 2.2 days (n = 6) (ANOVA, p = 0.043). Coencapsulation, regardless of the Fas-L status of the Sertoli cell donors, modestly prolonged graft survival. There was no significant difference between Fas-L-deficient and Fas-L-positive donors. Our results suggest that Fas/Fas-L interaction is not responsible for the additional protection afforded to encapsulated discordant islet xenografts by coencapsulation with Sertoli cells.
authors.affiliation: Department of Pathology, IWK Health Centre and Dalhousie University Faculty of Medicine, Halifax, Nova Scotia, Canada B3H 1V7.
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.forename: Ayman
authors.initials: A
authors.lastname: Al-Jazaeri
authors.forename: James R
authors.initials: JR
authors.lastname: Wright
mesh_terms: D000464:Alginates; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000601:surgery; D053222:Fas Ligand Protein; D020723:Glucuronic Acid; D006085:Graft Survival / Q000276:immunology; D006603:Hexuronic Acids; D016381:Islets of Langerhans Transplantation / Q000379:methods*; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D012708:Sertoli Cells / Q000276:immunology* / Q000378:metabolism / Q000637:transplantation*; D014183:Transplantation, Heterologous
chemical_list: D000464:Alginates; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D006603:Hexuronic Acids; D008562:Membrane Glycoproteins; D020723:Glucuronic Acid