内毒素结合蛋白样分子p48体内外生物学活性的初步研究  

In vitro and in vivo biological function of p48—a new type of lipopolysaccharide binding protein

作　　者：葛晓冬[1] 杨艳丽 段光杰[1] 陈锐[1] 潘峰[3] 朱江[1] 刘友生[1] 

机构地区：[1]第三军医大学西南医院病理学研究所,重庆400038 [2]解放军兰州军区总院病理科,兰州730030 [3]第三军医大学基础医学部中心实验室,重庆400038

出　　处：《第三军医大学学报》2008年第2期142-145,共4页Journal of Third Military Medical University

基　　金：国家自然科学基金(30400426)~~

摘　　要：目的以LBP为对照,对比研究p48的体内、外生物学功能。方法采用生物传感器、流式细胞分析技术研究p48与LPS及Lipid A的结合力。通过体外培养人单核细胞(U937)和小鼠体内TNF-α的分泌实验,研究p48的生物学功能。采用ELISA方法初步探索p48与LBP是否具有一定相似的空间结构。结果p48能促进LPS与PBMC结合,其活性为LBP的81%。p48能与LPS及Lipid A结合,其亲和常数(KD)分别为1.59×10-6、1.48×10-6mol/L。体内外实验中p48均能促进TNF-α的分泌,其生物学活性约为LBP的77%。高浓度抗NH-LBP Fab抗体能与p48特异性结合,p48部分空间结构与LBP可能有一定的相似性。结论p48具有与LBP相近似的生物学功能,在机体炎症反应中也发挥较重要的作用。Objective To study the biological function of p48 by comparing with that of lipopolysaccharide binding protein （LBP）. Methods The ability of p48 to bind lipopolysaccharide （LPS） or lipid A was determined by the experiment of Biosensor and flow cytometry. The biological function of p48 was identified by meas- uring the secretion of tumor necrosis factor alpha （TNF-α） in human monocyte （ U937 ） or mice. Using the monoclonal antibody （mAb） Fab to NH-LBP, the spatial structure of p48 was assessed by ELISA to determine whether its structure is similar to that of LBP. Results p48 could accelerate the binding of LPS with peripheral blood mononuclear cells （PBMC）, whose ability is about 81% of LBP. p48 could bind LPS or lipid A directly, with the affinity constant of 1.59 ×10^-6mol/L or 1.48×10^-6mol/L respectively. The secretion rate of TNF-α was enhanced by p48, whose effect is about 77% of LBP in vivo or in vitro. That the mAb Fab could bind p48 at high concentration indicated some similar spatial structure between p48 and LBP. Conclusion p48, similar to LBP in biological function, plays an important role in innate immunity and inflammatory reaction.

关 键 词：内毒素结合蛋白样分子p48 生物传感器 流式细胞分析技术 TNF-α分泌实验 

分 类 号：R341[医药卫生—基础医学] R392-33