title: DR.lyp/lyp bone marrow maintains lymphopenia and promotes diabetes in lyp/lyp but not in +/+ recipient DR.lyp BB rats.
abstract: Lymphopenia is due to a frameshift mutation in Gimap5 on rat chromosome 4 and is linked to type 1 diabetes in the diabetes prone (DP) BB rat. The hypothesis that bone marrow derived cells confer the lymphopenia phenotype was tested by reciprocal bone marrow transplantation in 40-day-old lethally irradiated diabetes resistant (DR) congenic DR.lyp/lyp (lymphopenia and diabetes) and DR.+/+ (no lymphopenia and no diabetes) rats. In two independent series of transplants, all DR.lyp/lyp rats (n=5 and 4) receiving DR.lyp/lyp bone marrow retained lymphopenia and developed insulitis (5/5 and 4/4) as well as diabetes in some (2/5 and 3/4). Both DR.+/+ and DR.lyp/lyp rats receiving DR.+/+ bone marrow cells as well as DR.+/+ rats receiving DR.lyp/lyp bone marrow cells showed no lymphopenia or diabetes. In accordance with earlier studies in non-congenic BB rats, the DR.+/+ rats receiving DR.lyp/lyp bone marrow cells recapitulated an intermediary phenotype rather than the +/+ or lyp/lyp phenotypes. Our data demonstrate that BBDP rat lymphopenia and diabetes are transferred by bone marrow transplantation to syngeneic DR.lyp/lyp but not DR.+/+ recipients. The intermediary recapitulation of DR.lyp/lyp T cells in recipient DR.+/-/+/- rats suggests that radiation resistant +/-/+/- T cells, the Gimap5 mutation in bone marrow cells, or both may not support the development of lymphopenia.
authors.affiliation: Department of Medicine, University of Washington, Seattle, WA 98195, USA. hawkinflip@hotmail.com
authors.forename: Tyson
authors.initials: T
authors.lastname: Hawkins
authors.forename: Jessica
authors.initials: J
authors.lastname: Fuller
authors.forename: Kara
authors.initials: K
authors.lastname: Olson
authors.forename: Sara
authors.initials: S
authors.lastname: Speros
authors.forename: Ake
authors.initials: A
authors.lastname: Lernmark
mesh_terms: D000818:Animals; D016026:Bone Marrow Transplantation / Q000276:immunology* / Q000473:pathology; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D008212:Lymphocyte Depletion; D008231:Lymphopenia / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D051381:Rats; D011913:Rats, Inbred BB; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D019204:GTP-Binding Proteins; C494977:Gimap5 protein, rat