Clonal expansion of T cells infiltrating in the airways of non-atopic asthmatics

Clin Exp Immunol. 2000 Mar;119(3):390-7. doi: 10.1046/j.1365-2249.2000.01148.x.


CD4+ T cells are thought to play an important role in airway inflammation in both atopic and non-atopic asthma. However, the mechanism by which T cells are activated in non-atopic asthma, where there is no causative antigen identified, is unknown. To elucidate this issue, we analysed T cell receptor (TCR) Vbeta gene clonotypes of T cells in the bronchoalveolar lavage fluids (BALF) of non-atopic asthmatics using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) analysis and a sequencing method. We found that the numbers of TCR Vbeta gene clonotypes of T cells in the BALF of non-atopic asthmatics were significantly increased compared with those of peripheral blood lymphocytes (PBL). We also found that there were several shared amino acid motifs in complementarity-determining region 3 (CDR3) of TCR Vbeta genes from those T cell clones in BALF of non-atopic asthmatics, whereas these shared motifs were not found in the same Vbeta family genes from PBL in the patients. Moreover, a conserved amino acid sequence was detected in two patients who shared a common HLA-DR allele. These results indicate that the infiltrating T cells in the airways of non-atopic asthmatics recognize relatively limited epitopes of antigens and are clonally expanded by antigen-driven stimulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asthma / genetics
  • Asthma / immunology*
  • Asthma / pathology*
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / pathology*
  • Cell Differentiation
  • Cell Movement / immunology*
  • Female
  • Genes, Immunoglobulin
  • Humans
  • Immunoglobulin Variable Region / genetics
  • Male
  • Middle Aged
  • Polymorphism, Genetic
  • Receptors, Antigen, T-Cell, alpha-beta / genetics
  • Receptors, Antigen, T-Cell, alpha-beta / immunology
  • Respiratory System / immunology*
  • Respiratory System / pathology*


  • Immunoglobulin Variable Region
  • Receptors, Antigen, T-Cell, alpha-beta