細胞動態測定装置(EZ-TAXIScan)による好酸球遊走能測定の基礎的検討  [in Japanese] EOSINOPHIL CHEMOTAXIS ASSAY USING NOVEL DEVICE EZ-TAXISCAN  [in Japanese]

【背景・目的】好酸球の活性化の調節はアレルギー疾患病態・治療応用を考える上で重要な意味を持つ.我々は新しく開発された細胞動態測定装置を用いて好酸球遊走能について基礎的な検討を行った.【方法】ヒト分離好酸球の各種走化性因子に対する遊走とその速度をEZ-TAXIScanを用いて測定し,Boyden chamber法でも経時的な遊走動態の検討を行った.【結果】EZ-TAXIScanでは,PAF,prostaglandin D_2 (PGD_2)に対しては早い速度の遊走反応が数分後から観察されたが,eotaxin,RANTESに対しては60分ほど遅延して反応がみられた.一方,Boyden chamber法ではいずれの走化性因子に対しても20〜60分をピークとした遊走が観察された.【結語】EZ-TAXIScanは好酸球遊走の検討においても有用であるが,走化性因子によっては従来の方法と比較して遊走動態に相違が認められ,評価に際して注意を要すると考えられた.

Background: Eosinophils are major effector cells in the pathogenesis of allergic inflammation such as bronchial asthma, and eosinophil migration to sites of inflammation is an important step. To date, several approaches have been developed to study eosinophil chemotaxis. Among them, the Boyden chamber method has been widely used, although this system requires a relatively large number of cells, and it usually provides no longitudinal information. In this study, we investigated real-time eosinophil chemotaxis using EZ-TAXIScan, a novel horizontal microchannel device. Methods: Eosinophils were isolated from subjects with mild eosinophilia by modified CD16-negative selection. Eosinophil chemotaxis and migration speed induced by various chemoattractants including eotaxin, RANTES, PAF, and prostaglandin (PGD_2) were measured by EZ-TAXIScan. We also determined the time course of chemotaxis using Boyden chambers. Result: By using EZ-TAXIScan, rapid (a few minutes after stimulation) and fast (20-30μm/min) eosinophil chemotactic responses were observed by stimulation with PAF or PGD_2, although eosinophils stimulated with eotaxin or RANTES showed relatively late (60 minutes after stimulation) and slow (15μm/min) responses. In contrast, using a Boyden Chamber, the chemotactic responses we tested showed a similar time course peaking at 20〜60min. Conclusion: The availability of EZ-TAXIScan for investigation of eosinophil chemotaxis was confirmed. However, it should be noted that EZ-TAXIScan showed a different response to certain chemoattractants compared with the conventional method.