title: Increased T cell reactivity to amyloid beta protein in older humans and patients with Alzheimer disease.
abstract: Alzheimer disease (AD) is characterized by the progressive deposition of the 42-residue amyloid beta protein (Abeta) in brain regions serving memory and cognition. In animal models of AD, immunization with Abeta results in the clearance of Abeta deposits from the brain. However, a trial of vaccination with synthetic human Abeta1-42 in AD resulted in the development of meningoencephalitis in some patients. We measured cellular immune responses to Abeta in middle-aged and elderly healthy subjects and in patients with AD. A significantly higher proportion of healthy elderly subjects and patients with AD had strong Abeta-reactive T cell responses than occurred in middle-aged adults. The immunodominant Abeta epitopes in humans resided in amino acids 16-33. Epitope mapping enabled the identification of MHC/T cell receptor (TCR) contact residues. The occurrence of intrinsic T cell reactivity to the self-antigen Abeta in humans has implications for the design of Abeta vaccines, may itself be linked to AD susceptibility and course, and appears to be associated with the aging process.
authors.affiliation: Center for Neurologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
authors.forename: Alon
authors.initials: A
authors.lastname: Monsonego
authors.forename: Victor
authors.initials: V
authors.lastname: Zota
authors.forename: Arnon
authors.initials: A
authors.lastname: Karni
authors.forename: Jeffery I
authors.initials: JI
authors.lastname: Krieger
authors.forename: Amit
authors.initials: A
authors.lastname: Bar-Or
authors.forename: Gal
authors.initials: G
authors.lastname: Bitan
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Budson
authors.forename: Reisa
authors.initials: R
authors.lastname: Sperling
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Selkoe
authors.forename: Howard L
authors.initials: HL
authors.lastname: Weiner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000276:immunology*; D000544:Alzheimer Disease / Q000276:immunology*; D023582:Alzheimer Vaccines / Q000276:immunology; D019943:Amino Acid Substitution; D016229:Amyloid beta-Peptides / Q000235:genetics / Q000276:immunology*; D000818:Animals; D001324:Autoantigens / Q000235:genetics; D001665:Binding Sites / Q000235:genetics; D016022:Case-Control Studies; D016207:Cytokines / Q000378:metabolism; D018604:Epitope Mapping; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology; D013601:T-Lymphocytes
chemical_list: D023582:Alzheimer Vaccines; D016229:Amyloid beta-Peptides; D001324:Autoantigens; D016207:Cytokines; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42)