[Characterization of expression of adhesion molecules on eosinophils in bronchial asthma]

It is well known that inflammatory processes play an important role in allergic reactions such as bronchial asthma (BA). Eosinophils are considered to the main players in such allergic inflammation. Moreover, adhesion molecules have recently been found to play an important role in the inflammatory processes in allergic and immune reactions. Thus, in this study, the characteristics of the adhesion molecules expression on human eosinophils obtained from BA patients were examined. High intensity expressions of adhesion molecules (CR3, LFA-1 alpha, LFA-1 beta) on eosinophils obtained from the patients were observed. Furthermore, ICAM-1, which is the ligand for LFA-1 molecules, was also expressed on eosinophils from BA patients. To extend our understanding of this high intensity expression of adhesion molecules (CR3, LFA-1 alpha, LFA-1 beta, ICAM-1) on such eosinophils, we examined whether chemotactic agents might be involved in adhesion molecule expression using an eosinophilic cell line named EoL-3. These characteristics of adhesion molecules on eosinophils were induced by the chemotactic agent, platelet factor 4 (PF4). Taken together, we could conclude that chemotactic agents might be involved in the high intensity expressions of adhesion molecules on eosinophils from BA patients. Moreover, to investigate the mechanisms of the induction of adhesion molecules on EoL-3 cells by PF4, sICAM-1 levels in the supernatants of EoL-3 with PF4 and without PF4 were examined. In our results, the presence or absence of PF4 made no difference in sICAM-1 levels, suggesting that the shedding of ICAM-1 has little relation to the induction of adhesion molecules.