title: Expanded CD4+ and CD8+ T cell clones in elderly humans.
abstract: The diversity of the human TCR repertoire in aging has been studied by examining the profiles of complementarity-determining region 3 (CDR3) sizes expressed by the BV families. The TCRBV CDR3 profile, which shows size heterogeneity in young adult humans, is significantly restricted in aged humans. Clonal T cell expansions were identified using a PCR-based approach, in one or more BV families from all 14 healthy persons over the age of 65 that we studied. CD4+ T cell expansions were identified in 8 of 11 donors and CD8+ T cell expansions in 7 of 10 donors. These clonal expansions were stable during a 2-year period. Interestingly, more than half of the aged persons had clonal expansions within the BV3, -14, -16, and -23 families. Although there was no homology among the eight CDR3 sequences identified in clonal T cells from 8 aged persons, selective pressure on the expanded T cell clones was suggested by the fact that the BV families used by the T cell clones were not proportional to the number of genes in the different BV families.
authors.affiliation: Department of Medicine, Cornell University Medical College, New York, NY 10021, USA.
authors.forename: R
authors.initials: R
authors.lastname: Schwab
authors.forename: P
authors.initials: P
authors.lastname: Szabo
authors.forename: J S
authors.initials: JS
authors.lastname: Manavalan
authors.forename: M E
authors.initials: ME
authors.lastname: Weksler
authors.forename: D N
authors.initials: DN
authors.lastname: Posnett
authors.forename: C
authors.initials: C
authors.lastname: Pannetier
authors.forename: P
authors.initials: P
authors.lastname: Kourilsky
authors.forename: J
authors.initials: J
authors.lastname: Even
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000595:Amino Acid Sequence; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D017493:Leukocyte Common Antigens / Q000378:metabolism; D018655:Lymphocyte Count; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D017493:Leukocyte Common Antigens