血管内皮细胞和巨噬细胞等表面的受体识别正常或修饰性低密度脂蛋白（LDL），诱发下游信号传导并导致细胞向泡沫细胞转化，是动脉粥样硬化形成的起始和关键。目前已知的相关受体多达十几种，其中多种受体可识别正常或修饰性LDL。然而，现实中某种LDL只被某种细胞的某一种主要受体识别；同时，一个细胞周围可能同时存在多种LDL，然而，某种细胞只识别其中的某一种。因此，可以推测，不同种类LDL与各种受体之间存在相互作用力上的强弱差异和识别竞争。本课题主要采用原子力显微镜等技术来探测正常或修饰性LDL与各种受体、LDL与其抗体、受体与其抗体等之间的相互作用力的大小，并从几个层次进行比较研究（1.不同种类细胞之间；2.不同种类LDL之间；3.不同种类受体之间；4.LDL-受体与LDL或受体-抗体之间），以期验证那个推测，为深入理解动脉粥样硬化形成机理提供重要信息，并为寻找拮抗这些识别的药物提供理论依据。

Recognization of native or modified low-density lipoproteins (LDLs) by the corresponding receptors on vascular endothelial cells and macrophages, which induces the downstream signal transduction and the formation of foam cells, is the beginning and milestone of atherosgenesis. Currently, almost twenty members of the receptor family have been discovered, many of which are able to interact with different types of low-density lipoprotein. Generally, a cell bearing multiple types of receptors is potentially surrounded by several types of low-density lipoprotein in our vessel wall. The fact is, interestingly however, only a major type of receptor on the cell selectvely recognizes a specific type of low-density lipoprotein. Therefore, we hypothesize that the distinction in strength of lipoprotein-receptor interaction among various types of low-density lipoproteins or among various types of receptors is the major determinant for a specific type of receptor to recognize a specific type of low-density lipoprotein. Mainly by using atomic force microscopy (AFM), this project will detect the interactions of native or modified LDLs with different types of receptors or their corresponding antibodies and the interactions between receptors and anti-receptor antibodies in order to test the hypothesis. We hope that this study will provide important information for promoting the understanding of atherogenesis and for finding efficient drugs mainly antagonizing the lipoprotein-receptor interactions.