DISTRIBUTION OF GAMMA-DELTA-T-CELLS IN THE BRONCHIAL TREE OF SMOKERS AND NONSMOKERS

Aims-To assess the distribution of gammadeltaT-cells in the human bronchial tree; and to compare quantitatively the differences between gammadeltaT-cell numbers in different parts of the airway wall in smokers and non-smokers. Methods-Full thickness bronchial wall sections were taken from 10 whole lung specimens from both smokers and non-smokers. Serial cryostat sections stained with the monoclonal antibodies CD3 and TCRdelta-1 were examined with the aid of interactive image analysis to assess gammadeltaT-cell numbers both in absolute terms and as a proportion of total T lymphocyte numbers. Results-In all cases gammadeltaT-cells were demonstrable throughout the airway wall. Although in absolute terms they tend to occur predominantly in the bronchial epithelium, this seems to reflect higher numbers of T lymphocytes in the epithelium in general compared with the submucosa. No genuine epitheliotropism is evident. Comparison by smoking status shows a significant increase in gammadeltaT-cell numbers in the bronchial glands of smokers compared with non-smokers. Conclusions-gammadeltaT-cells form an integral though variable component of the immunocompetent cell population of the human airway in both smokers and non-smokers. Although epitheliotropism does not exist in the bronchial tree, gammadeltaT-cells seem to form a significant part of the bronchial gland inflammation associated with smoking.