title: Changes in autoreactive T cell avidity during type 1 diabetes development.
abstract: The activation threshold for antigen-specific T cell responses is dependent on the avidity of the trimolecular interaction between TCR, antigen, and MHC. We compared CD4+ T cell avidities for the diabetes-associated autoantigen glutamic acid decarboxylase 555-567 (GAD 555) among serial samples from autoantibody-positive subjects at high risk of progression to type 1 diabetes (T1D). T cells from three at-risk subjects demonstrated significant avidity increases (p<0.05 by F test) over time. This avidity shift correlated with the outgrowth of T cells expressing TCR BV 9, 15, 17 or 20 that demonstrated higher GAD 555 tetramer-binding levels compared to cells expressing other TCR BV genes. Similar analysis of autoantibody-negative, first-degree relatives and T1D patients did not demonstrate similar changes in avidity. These data implicate the outgrowth of T cells expressing higher affinity TCR in a process of antigen-specific T cell avidity maturation during the pre-clinical stage of T1D.
authors.affiliation: Benaroya Research Institute at Virginia Mason, Seattle, WA 98101, USA. NStand@benaroyaresearch.org
authors.forename: Nathan E
authors.initials: NE
authors.lastname: Standifer
authors.forename: Emily A
authors.initials: EA
authors.lastname: Burwell
authors.forename: Vivian H
authors.initials: VH
authors.lastname: Gersuk
authors.forename: Carla J
authors.initials: CJ
authors.lastname: Greenbaum
authors.forename: Gerald T
authors.initials: GT
authors.lastname: Nepom
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D015551:Autoimmunity / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000209:etiology* / Q000276:immunology*; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology; D006801:Humans; D007328:Insulin / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D053720:Interleukin-15 Receptor alpha Subunit / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8 / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology / Q000378:metabolism; D055815:Young Adult
chemical_list: D015703:Antigens, CD; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007328:Insulin; D053720:Interleukin-15 Receptor alpha Subunit; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D007371:Interferon-gamma; D054635:Receptor-Like Protein Tyrosine Phosphatases, Class 8; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2