T-cell repertoire in the blood and lungs of atopic asthmatics before and after ragweed challenge

VV Yurovsky*, EJM Weersink, SS Meltzer, WC Moore, DS Postma, ER Bleecker, B White

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

19 Citations (Scopus)

Abstract

T cells play a pivotal role in initiating and orchestrating allergic responses in asthma. The goal of this work was to learn whether ragweed challenge in the lungs alters the T-cell repertoire expressed in the blood and lungs of atopic asthmatics. Analyses of cell numbers, differentials, and T-cell subsets in bronchoalveolar lavage (BAL) fluids showed that ragweed challenge was associated with preferential recruitment of CD4+ T cells into the lungs. A reverse transcriptase-polymerase chain reaction (RT-PCR) was used to amplify T-cell receptor (TCR) gene transcripts from unfractionated, CD4(+) and CD8(+) T cells in blood and BAL fluids. As judged by RT-PCR, the usage of TCR Vol and VP gene families in BAL fluids was similar to that in blood. Ragweed challenge did not change the levels of expression of these V gene families, The clonality of T cells was estimated by analyzing the diversity of TCR V-(D)-J junctional region nucleotide lengths associated with each Vol and VP gene family, using sequencing gel electrophoresis. Most V gene families in blood and BAL fluids were associated with multiple junctional region lengths before and after ragweed challenge, indicating polyclonal expression. Some V gene families were expressed in an oligoclonal manner in unfractionated, CD4(+), and CD8(+) T cells in BAL fluids before ragweed challenge, as indicated by a few predominant junctional region lengths. The majority of these V gene families became polyclonal after challenge, compatible with polyclonal T-cell influx during inflammation immediately after ragweed challenge, However, some V gene families became oligoclonal or developed a new oligoclonal pattern of junctional region lengths in BAL T cells after ragweed challenge. Surprisingly, this occurred in both CD4(+) and CD8(+) T cells. In one of these instances. DNA sequencing of V beta 21 junctional regions in CD8(+) T cells confirmed a change from polyclonal to oligoclonal expression after ragweed challenge. These findings show that ragweed challenge is associated with polyclonal influx and oligoclonal activation of both CD4(+) and CD8(+) T cells in the lungs.

Original languageEnglish
Pages (from-to)370-383
Number of pages14
JournalAmerican Journal of Respiratory Cell and Molecular Biology
Volume18
Issue number3
Publication statusPublished - Mar-1998

Keywords

  • RECEPTOR ALPHA-CHAIN
  • BRONCHOALVEOLAR LAVAGE
  • BETA-CHAIN
  • MAST-CELLS
  • INDUCED RECRUITMENT
  • INVIVO DISTRIBUTION
  • PERIPHERAL-BLOOD
  • LYMPHOCYTES-T
  • ALLERGEN
  • GENES

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