新的天然免疫保护分子——PLUNC家族蛋白

PLUNC Family: Novel Class of Innate Immune Protective Molecules in Upper Airway

在呼吸道上皮与消化道上皮的表面 ,覆盖有一层由免疫保护分子所组成的蛋白质混合物 ,在上皮组织与外界各种信号之间 ,它们起着信号传递中介与信号执行分子的作用 .我们新克隆的NASG基因为这一混合物添加了新的成员 ,对其结构与功能分析表明 :它属于腭、肺及鼻咽上皮克隆 (PLUNC)家族中SPLUNC1的全新转录本 .目前发现人类PLUNC家族至少有 8个以上成员 ,分布在人类 2 0号染色体大约 30 0kb的狭窄区域 ,它们具有杀菌 \渗透增强蛋白结构域 ,在进化上高度保守 ,每个成员分别在呼吸道上皮的不同部位特异性表达 ,具有潜在的结合细菌脂多糖的功能 ,能对外来物理及化学刺激做出反应 ,以分泌蛋白的形式进入鼻咽分泌物或唾液中 ,部分家族成员可能具有抗微生物、清除有害化学物质、抗肿瘤等多重功效 .以上说明 ,PLUNC家族可能是上呼吸道的一种新的天然免疫保护分子 。

Epithelial surfaces of the upper alimentary tract and upper respiratory tract are swarming with protein compounds that protect itself from many kinds of damages. These compounds are consisted of innate immune molecules. From the structure and functional predication, the new member is added, plunc family, to the compounds. They are located at a narrow area less than 300 kb of human chromosome 20, including at least eight members. All the members of the family have the BPI domain and a signal peptide at the N-terminal. The sequences are highly conserved in human, mouse and rat, each expressed at the different sites of the airway epithelial, tongue, von Ebner gland and parotid gland. Some of them can be detected in the nasal lavage fluid. They may function to protect epithelial surfaces from pathogenic micro-organism and harmful gases, the wrong expression will lead to host tissues destruction and tumorigenesis.