按蚊血淋巴丝氨酸蛋白酶与疟原虫卵囊黑化关系研究

RELATIONSHIP BETWEEN THE SERINE PROTEASE IN THE HAEMOLYMPH OF ANOPHELES STEPHENSI AND THE MELANIZATION OF PLASMODIAL OOCYSTS

目的 探讨丝氨酸蛋白酶与疟原虫卵囊黑化的相互关系。 方法 将斯氏按蚊分为吸糖水组、吸正常小白鼠血组、吸约氏疟原虫感染血组和吸硝喹糖水组 ,挤压法收集雌斯氏按蚊血淋巴 ,Bradford法检测血淋巴蛋白浓度 ,继而对血淋巴进行SDS PAGE ,电转移后检测丝氨酸蛋白酶的表达差异。 结果 4组斯氏按蚊丝氨酸蛋白酶Western印迹均呈现两条带 ,分子质量分别约 160和 15 0ku ,与吸糖水组比较 ,吸正常小白鼠血组丝氨酸蛋白酶表达稍高 ,而感染约氏疟原虫后斯氏按蚊血淋巴丝氨酸蛋白酶表达明显增强 ,感染第 6d达高峰 ,之后表达下调 ,而硝喹诱导黑化后丝氨酸蛋白酶表达水平呈逐日下调趋势。 结论 斯氏按蚊血淋巴丝氨酸蛋白酶参与了疟原虫卵囊黑化包被反应。

Objective To explore the relationship between serine protease and Plasmodial oocysts melanization. Methods Anopheles stephensi mosquitoes were sorted out into succose solution-fed mosquitoes,normal-mouse-blood-fed mosquitoes,infected-blood-fed mosquitoes and nitroquine-adminstered mosquitoes, respectively. Hemolymph of adult female An. stephensi was collected by the expulsion method. The concentration of proteins in the hemolymph was examined with Bradford method and then was SDS-polyacrylamide gel electrophoresized. Different expressive serine protease was identified after electrotranferring by Western blotting. Results Two serine protease binds were shown within the four groups of An. stephensi mosquitoes, their molecular weight was 160 and 150 ku, respectively. Compared to the succose solution-fed mosquitoes, little enhanced expression of serine protease was observed in the normal-mouse-blood-fed mosquitoes and marked increased expression was manifested in infected-blood-fed mosquitoes. The expressive level of serine protease reached to the peak on the sixth day of infection, then the expression level decreased. Day-to-day down regulated expression could be observed after melanization by the induction of nitroquine. Conclusion Serine protease in the hemolymph of An. stephensi is involved in the melanotical encapsulation of Plasmodial oocysts.