title: Alloreactivity but failure to reject human islet transplants by humanized Balb/c/Rag2gc mice.
abstract: A human islet transplant can cure patients with type 1 diabetes. A drawback of islet transplantation is the life-long immunosuppressive medication, often associated with severe side effects. Moreover, in spite of the immunosuppressive therapy, islets are lost in the majority of transplanted patients over time. An improved small animal model for studies on human islet allograft rejection mechanisms and the development of new measures for its prevention is clearly warranted. Here, we evaluated the potential of Balb/cRag2(-/-)gammac(-/-) mice carrying a human-like immune system (so-called humanized mice) as a tool for studies on the rejection of transplanted human islets. Human T cells from Balb/cRag2(-/-)gammac(-/-) mice, which as neonates had been transplanted with CD34(+) human cord blood haematopoietic stem cells (HIS mice), proliferated in response to allogeneic human dendritic cells, but failed to reject a human islet allograft transplanted to the renal subcapsular space as assessed by immunohistochemistry and analysis of human serum C-peptide levels. Histological analysis revealed that few if any T cells had migrated to the grafted tissue. These observations question the usefulness of the HIS mouse model for studies on human islet allograft rejection mechanisms and highlight the need for further improvements.
authors.affiliation: Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Jacobson
authors.forename: F
authors.initials: F
authors.lastname: Heuts
authors.forename: J
authors.initials: J
authors.lastname: Juarez
authors.forename: M
authors.initials: M
authors.lastname: Hultcrantz
authors.forename: O
authors.initials: O
authors.lastname: Korsgren
authors.forename: M
authors.initials: M
authors.lastname: Svensson
authors.forename: M
authors.initials: M
authors.lastname: Rottenberg
authors.forename: M
authors.initials: M
authors.lastname: Flodström-Tullberg
mesh_terms: D000818:Animals; D002469:Cell Separation; D004268:DNA-Binding Proteins / Q000235:genetics; D003922:Diabetes Mellitus, Type 1 / Q000601:surgery; D004195:Disease Models, Animal; D005312:Fetal Blood; D005434:Flow Cytometry; D006084:Graft Rejection / Q000276:immunology*; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006801:Humans; D007150:Immunohistochemistry; D016381:Islets of Langerhans Transplantation / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D013601:T-Lymphocytes / Q000276:immunology; D014184:Transplantation, Homologous
chemical_list: D004268:DNA-Binding Proteins; C499308:Rag2 protein, mouse