title: B cells are crucial for determinant spreading of T cell autoimmunity among beta cell antigens in diabetes-prone nonobese diabetic mice.
abstract: The determinant spreading of T cell autoimmunity plays an important role in the pathogenesis of type 1 diabetes and in the protective mechanism of Ag-based immunotherapy in NOD mice. However, little is known about the role of APCs, particularly B cells, in the spreading of T cell autoimmunity. We studied determinant spreading in NOD/scid or Igmu(-/-) NOD mice reconstituted with NOD T and/or B cells and found that mice with mature B cells (TB NOD/scid and BMB Igmu(-/-) NOD), but not mice that lacked mature B cells (T NOD/scid and BM Igmu(-/-) NOD), spontaneously developed Th1 autoimmunity, which spread sequentially among different beta cell Ags. Immunization of T NOD/scid and BM Igmu(-/-) NOD mice with a beta cell Ag could prime Ag-specific Th1 or Th2 responses, but those T cell responses did not spread to other beta cell Ags. In contrast, immunization of TB NOD/scid and BMB Igmu(-/-) NOD mice with a beta cell Ag in IFA induced Th2 responses, which spread to other beta cell Ags. Furthermore, we found that while macrophages and dendritic cells could evoke memory and effector T cell responses in vitro, B cells significantly enhanced the detection of spontaneously primed and induced Th1 responses to beta cell Ags. Our data suggest that B cells, but not other APCs, mediate the spreading of T cell responses during the type 1 diabetes process and following Ag-based immunotherapy. Conceivably, the modulation of the capacity of B cells to present Ag may provide new interventions for enhancing Ag-based immunotherapy and controlling autoimmune diseases.
authors.affiliation: Department of Molecular and Medical Pharmacology, University of California, Los Angeles, 90095, USA. jtian@mednet.ucla.edu
authors.forename: Jide
authors.initials: J
authors.lastname: Tian
authors.forename: Dan
authors.initials: D
authors.lastname: Zekzer
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Lu
authors.forename: Hoa
authors.initials: H
authors.lastname: Dang
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Kaufman
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000276:immunology*; D015551:Autoimmunity / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology; D003920:Diabetes Mellitus / Q000276:immunology*; D007114:Immunization; D007156:Immunologic Memory; D007515:Islets of Langerhans / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D051379:Mice; D016688:Mice, Inbred NOD; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D001324:Autoantigens