A novel lectin-dependent activation pathway of complement

一种新的凝集素依赖性补体激活途径

基本信息

批准号：
07044285
负责人：
FUJITA Teizo
金额：
$ 1.28万
依托单位：
Fukushima Medical College
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1995
资助国家：
日本
起止时间：
1995 至无数据
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07044285/
关键词：
complement lectin pathway MBP MASP C1

项目摘要

Serum mannose-binding protein (MBP) is a C-type lectin capable of activating the complement system (the lectin pathway). A novel serine protease designated MASP (MBP-associated-serine protease) is involved in the activation by MBP,exerting C4-and C2-activating capacity when bound to MBP on its ligands.1.We investigated reconstitution of recombinant MBPs and MASP for exhibiting complement activation. Wild type recombinant MBP (MBP_G) was found to be able to be associated with MASP,resulting in complement activation, whereas recombinant mutated MBP (MBP_D) in which glycine (G) is substituted with asparatic acid (D) in the fifth collagen repeat and responsible for the complement-dependent opsonic defect is unable to activate complement when incubated with MASP.These results indicate that lack of complement-activating capacity of MBP_D might be due to inability of association with MASP (Biochem.J., 1995).2.To clarify the mechanisms by which C1r/C1s is substitute for MASP in the activation of the lectin pathway, we measured the affinity constant of C1r/C1s or C1q and MBP using a Biacore apparatus. The results indicate that affinity constants of the four possible mixtures are very similar. Since only MBP-MASP and C1q-C1r/C1s complexes were present in serum, the other factors would influence the interaction of MBP and C1r/C1s.3.To evaluate the role of the MASP in various diseases, we established sandwich ELISA using several monoclonal antibodies. The mean value of normal human is about 6mug/ml. Estimation of MASP in various diseases is currently under investigation.

血清甘露糖结合蛋白（MBP）是能够激活补体系统（凝集素途径）的C型凝集素。一种新型的丝氨酸蛋白酶指定的MASP（MBP相关链蛋白酶）参与MBP的激活，当与MBP绑定到MBP的配体上时施加C4和C2激活能力。补体激活。发现野生型重组MBP（MBP_G）能够与MASP相关联，导致补体激活，而重组突变的MBP（MBP_D），其中甘氨酸（g）在第五次胶原重复和第五次胶原重复和高素质的重复酸（D）中代替与MASP一起孵育时，负责补体依赖性Opsonic缺陷无法激活补体。这些结果表明，MBP_D的补体激活能力的缺乏可能是由于与MASP无关（Biochem.j。，1995年）.2。为了阐明在凝集素途径激活中C1R/C1s代替MASP的机制，我们使用Biacore设备测量了C1R/C1S或C1Q和MBP的亲和力常数。结果表明，这四种可能的混合物的亲和力常数非常相似。由于血清中仅存在MBP-MASP和C1Q-C1R/C1S络合物，因此其他因素将影响MBP和C1R/C1S.3.3.为了评估MASP在各种疾病中的作用，我们使用几个夹心ELISA建立单克隆抗体。正常人的平均值约为6mug/ml。目前正在研究各种疾病中MASP的估计。