Asthma Research Today is a free monthly online journal that collates and summarizes the latest research about Asthma, including details on symptoms, diagnosis, treatment, causes, medications.

Invariant natural killer T cells in asthma and chronic obstructive pulmonary disease.

Vijayanand P, Seumois G, Pickard C, Powell RM, Angco G, Sammut D, Gadola SD, Friedmann PS, Djukanovic R

Division of Infection, Inflammation, and Repair, University of Southampton, Southampton General Hospital, Southampton, United Kingdom. vijay@soton.ac.uk

BACKGROUND: The number of type 2 helper CD4+ T cells is increased in the airways of persons with asthma. Whether the majority of these cells are class II major-histocompatibility-complex-restricted cells or are among the recently identified CD1d-restricted invariant natural killer T cells is a matter of controversy. We studied the frequency of invariant natural killer T cells in the airways of subjects with mild or moderately severe asthma to investigate the possibility of an association between the number of invariant natural killer T cells in the airway and disease severity. We also studied whether an increased number of these cells is a feature of chronic obstructive pulmonary disease (COPD). METHODS: We enumerated invariant natural killer T cells by flow cytometry with the use of CD1d tetramers loaded with alpha-galactosylceramide and antibodies specific to the invariant natural killer T-cell receptor in samples of bronchoalveolar-lavage fluid, induced sputum, and bronchial-biopsy specimens obtained from subjects with mild or moderately severe asthma, subjects with COPD, and healthy control subjects. Real-time polymerase-chain-reaction analysis was performed on bronchoalveolar-lavage cells for evidence of gene expression of the invariant natural killer T-cell receptor. RESULTS: Fewer than 2% of the T cells obtained from all subjects on airway biopsy, bronchoalveolar lavage, and sputum induction were invariant natural killer T cells, with no significant differences among the three groups of subjects. No expression of messenger RNA for the invariant natural killer T-cell-receptor domains Valpha24 and Vbeta11 was detected in bronchoalveolar-lavage cells from subjects with asthma. CONCLUSIONS: Invariant natural killer T cells are found in low numbers in the airways of subjects with asthma, subjects with COPD, and controls.

Published 5 April 2007 in N Engl J Med, 356(14): 1410-22.
Full-text of this article is available online (may require subscription).

© 2004-2008 Asthma Research Today. All Rights Reserved.