PT  - JOURNAL ARTICLE
AU  - E Yamaguchi
AU  - A Itoh
AU  - K Furuya
AU  - N Hizawa
AU  - N Ohnuma
AU  - N Kodama
AU  - J Kojima
AU  - Y Kawakami
TI  - Reduced expression of the alphabeta T-cell antigen receptor by alveolar T-cells
AID  - 10.1034/j.1399-3003.1999.13d20.x
DP  - 1999 Apr 01
TA  - European Respiratory Journal
PG  - 814--819
VI  - 13
IP  - 4
4099  - http://erj.ersjournals.com/content/13/4/814.short
4100  - http://erj.ersjournals.com/content/13/4/814.full
SO  - Eur Respir J1999 Apr 01; 13
AB  - A previous study revealed that reduced expression (modulation) of the CD3 antigen is a common characteristic of alveolar T-cells in health and disease. As CD3 molecules are noncovalently bound to T-cell antigen receptors (TCR), it was hypothesized that modulation of TCR was also a feature of alveolar T-cells. To demonstrate this, lymphocytes from bronchoalveolar lavage fluid were stained with an anti-alphabeta TCR antibody and analysed by flow cytometry. The expression of alphabeta TCR by alveolar T-cells was evaluated by calculating mean fluorescence intensity (MFI) and was compared with alphabeta TCR expression by autologous blood T-cells. As anticipated from a previous study, modulation of TCR was observed not only in healthy volunteers but also in patients with pulmonary sarcoidosis, other pulmonary diseases, and nonpulmonary diseases. There were no significant differences in MFI of alveolar T-cells among the study groups. The degree of modulation assessed by the difference of MFI between blood and alveolar T-cells was greater for CD4+ cells than for CD8+ cells owing to the higher MFI of CD4+ blood T-cells. Coculture of alveolar macrophages with blood T-cells in vitro induced partial modulation of TCR. These results demonstrate the ubiquity of modulation of T-cell receptors on alveolar T-cells and suggest, in contrast to a previous report by other investigators that it is caused by some nonantigenic mechanism possibly inherent in the alveolar milieu. The implications of this phenomenon in in vivo immune responses of the lung need to be examined.