title: Restricted T-cell antigen receptor repertoire in bronchoalveolar T cells from normal humans.
abstract: The repertoire of variable alpha (AV) and beta (BV) TCR genes was compared in the peripheral blood and BAL fluid of five healthy individuals. Rearranged TCR transcripts were amplified by a reverse transcription-polymerase chain reaction, using oligonucleotide primers specific for 22 AV and 24 BV gene families. Nearly all AV and BV gene families were expressed in BAL T cells at levels similar to those in blood T cells. The diversity of AV and BV gene repertoire was examined further, testing the distribution of nucleotide lengths of TCR junctional regions. Most V gene families had a normal distribution of junctional region lengths in both blood and BAL T cells. Some gene families, particularly AV21 and BV9 in BAL samples, had a skewed banding pattern, with fewer bands or predominance of several bands. The limited diversity in TCR junctional region lengths was more prominent in CD8+ T cells from BAL fluids than from blood. CD4+ T cells also contributed to the limited diversity in BAL T cells. The oligoclonal expansion of bronchoalveolar CD8+ T cells was confirmed by sequence analysis of AV21-constant alpha (AC) and BV9-BC junctional regions in the blood and BAL cells. The levels of V gene expression and the diversity of junctional region lengths were very similar in T cells obtained from three separate lobes of one donor. In general, skewed patterns of TCR junctional region lengths were not consistent over time two donors, over periods of 3 and 17 months. Together, these data show that the T-cell repertoire is diverse within the lungs of normal humans, except for an oligoclonal predominance of a few V gene families in both CD4+ and CD8+ T cells. The T-cell repertoire in the lungs changes over time, which may reflect environmental exposures.
authors.affiliation: Department of Medicine, University of Maryland School of Medicine, Baltimore 21201, USA.
authors.forename: V V
authors.initials: VV
authors.lastname: Yurovsky
authors.forename: E R
authors.initials: ER
authors.lastname: Bleecker
authors.forename: B
authors.initials: B
authors.lastname: White
mesh_terms: D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D001772:Blood Cell Count; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology*; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D005810:Multigene Family / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics* / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D016693:Receptors, Antigen, T-Cell, alpha-beta