T cells in the lung of patients with hypersensitivity pneumonitis accumulate in a clonal manner

J Leukoc Biol. 2004 May;75(5):798-804. doi: 10.1189/jlb.0503218. Epub 2004 Feb 13.

Abstract

Hypersensitivity pneumonitis (HP) is characterized by an alveolitis sustained by CD8(+) T lymphocytes showing a limited expression of the T cell receptor (TCR). We previously demonstrated that a bias in T cell selection occurs in the lower respiratory tract of patients with HP, with a compartmentalization in the lung of CD8(+) T cells bearing (TCR)-beta variable (TCRBV) #2, 3, 5, 6, 8, and 13 gene segments. We herein characterized the clonal T cell populations present in the lung and in the blood of patients with HP. Heteroduplex analyses, cloning, and sequencing T cells bearing TCR indicate oligoclonal expansions of T cells expressing homologous or identical complementary-determining region 3. Furthermore, T cell clones isolated from the two compartments expressed similar, sometimes identical, junctional regions. Removal from antigenic exposure led to the disappearance of T cell clones. Our findings indicate that expansions of T lymphocytes bearing clonal TCRBV region gene segments take place in the lung of patients with HP during exposure. The evidence that identical T cell clones are present in the lung and the blood of the same patient suggests that the immune reaction occurring at lung level gives rise to a systemic reaction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Alveolitis, Extrinsic Allergic / etiology
  • Alveolitis, Extrinsic Allergic / immunology*
  • Alveolitis, Extrinsic Allergic / pathology
  • Amino Acid Sequence
  • Blood Cells / immunology
  • Case-Control Studies
  • Clone Cells / immunology
  • Complementarity Determining Regions / genetics
  • Female
  • Genes, T-Cell Receptor beta
  • Humans
  • Immunophenotyping
  • Lung / immunology
  • Lung / pathology
  • Lymphocyte Activation / immunology
  • Male
  • Middle Aged
  • Receptors, Antigen, T-Cell / genetics
  • T-Lymphocytes / immunology*

Substances

  • Complementarity Determining Regions
  • Receptors, Antigen, T-Cell