The role of eisonphil chemotactic cytokine in parasitic infections

ECF-L是几丁质酶家族蛋白中的嗜酸性趋化细胞因子。在本研究中，我们确定了嗜酸性趋化细胞因子ECF-L在血吸虫感染小鼠中的作用。在肝脏嗜酸性肉芽肿病灶周围可见嗜酸性粒细胞系髓外造血灶。髓外造血病灶多见未成熟嗜酸性粒细胞环状核，而嗜酸性肉芽肿病灶多见成熟嗜酸性粒细胞多形态核，说明嗜酸性粒细胞是通过趋化因子募集而来。为了阐明ECF-L在寄生虫感染中的作用，我们对日本血吸虫病和中孔血吸虫病的肉芽肿病变形成进行了时间过程研究。结果表明，日本血吸虫感染小鼠肉芽肿病变培养上清的嗜酸性粒细胞趋化活性在感染后6周和15周达到峰值，感染后6周达到峰值，感染后15周达到峰值。日本血吸虫感染后6周，肝内卵周围可见大量炎性嗜酸性粒细胞聚集。相比之下，在感染米孔假丝酵母菌后9-12周，观察到肉芽肿形成较慢，有许多液泡。感染后15周，肉芽肿病灶上大部分空泡消失。因此，无论是日本血吸虫病还是中孔血吸虫病，ECF-L的产生都与肉芽肿病变特征的变化密切相关。此外，将嗜酸性粒细胞与几丁质酶A预先孵育可导致ECF对ECF- l或合成ECF- l肽的活性增加。这些事实表明，ECF-L不仅是化学引诱剂，而且是嗜酸性粒细胞的刺激剂，以增强白细胞的功能。少

ECF-L is the eosinophil chemotactic cytokine that belong to the chitinase family proteins. In the present study, we identified the role of eosinophil chemotactic cytokine ECF-L in Schistosoma or Mesocestoides-infected mouse. Extra-medulla hemopoietic focii of eosinophilic linage were observed around eosinophilic granulomatous lesions in the liver upon infection with those tissue-dwelling parasites. Immature eosinophils with donut-type ring nuclei were generally observed in those extra-medulla hemopoietic foci, whereas mature eosinophil with polymorphic nuclei were generally observed in the eosinophilic granulomatous lesions, indicating that those eosinophils were recruited there by chemotactic factors.In order to clarify the role of ECF-L in parasitic infections, we employed the time-course study of the granulomatous lesion formation in schistosomiasis japonicum and schistosomiasis mekongi. When eosinophil chemotactic activity of the culture supernatants of the granulomatous lesions fr … More om S. japonicum or S. mekongi-infected mice, the peak of the eosinophil chemotactic activity was observed at 6 week and at 15 wk post-infection, in S. japonicum infection and in S. mekongi infection, respectively. In S. japonicum infection, intense accumulation of inflammatory eosinophils were observed around the deposited eggs in the liver at 6 wk post-infection. In contrast, slower granuloma formation with many vacuoles were observed at 9-12 weeks after S. mekongi infection. At 15 weeks after infection, most of the vacuoles were disappeared from the granulomatous lesions. Thus, the production of ECF-L was closely related with the change of the feature of granulomatous lesions both in schistosomiasis japonicum and schistosomiasis mekongi. Furthermore, pre-incubation of eosinophils with chitinase A resulted in the increase of ECF activity to ECF-L or synthetic ECF-L peptides. These facts indicates that ECF-L acts not only chemoattractants but also the stimulator of eosinophils for the enhancement of leukotactic functions. Less