The frequency of high avidity T cells determines the hierarchy of determinant spreading.
Autoimmunity often spreads in a predefined pattern during the progression of T cell-mediated autoimmune diseases. This progression has been well described in animal models and in man, but the basis for this phenomenon is little understood. To gain insight into the factors that determine this spreading hierarchy, we characterized the binding affinity of a panel of beta cell-autoantigenic peptides to I-Ag7, as well as the precursor frequency, functional avidity, and phenotype of the T cells that recognize these peptides in type 1 diabetes-prone nonobese diabetic mice. We observed that autoimmunity gradually spreads from a beta cell determinant, which had the largest precursor pool of high avidity T cells, to beta cell determinants with progressively smaller and lower avidity T cell precursor pools. This correlation between the sequential development of spontaneous T cell autoimmunity and the frequency and avidity of autoantigen-reactive T cells suggests that the extent to which T cells were negatively selected by the self-determinants is the key factor determining the spreading hierarchy.
Tian
J
J
Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA 90095, USA.
Gregori
S
S
Adorini
L
L
Kaufman
D L
DL
D000595:Amino Acid Sequence; D000818:Animals; D001324:Autoantigens / Q000008:administration & dosage / Q000276:immunology / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000209:etiology / Q000276:immunology / Q000473:pathology; D018984:Epitopes, T-Lymphocyte / Q000276:immunology* / Q000378:metabolism; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D007279:Injections, Subcutaneous; D007515:Islets of Langerhans / Q000276:immunology / Q000473:pathology; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D051379:Mice; D016688:Mice, Inbred NOD; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000008:administration & dosage / Q000276:immunology / Q000378:metabolism; D011485:Protein Binding / Q000276:immunology; D013234:Stem Cells / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism* / Q000473:pathology
D001324:Autoantigens; D018984:Epitopes, T-Lymphocyte; D000949:Histocompatibility Antigens Class II; C407099:I-A g7 antigen; D010446:Peptide Fragments