病毒细胞侵入的相关研究有助于阐明其致病机制及辅助药物设计，现已证明轮状病毒（Rotavirus, RV）利用多种黏附受体分子及多种内吞途径来完成侵入，早期相互作用与侵入途径之间无相关性且无共性，故RV早期细胞侵入特性无助于药物设计。本项目以细胞侵入晚期阶段为节点，利用两株特性相反的A群RV代表株：UK（黏附过程依赖网格蛋白，在晚期内体处侵入胞浆）和RRV株（黏附过程不依赖网格蛋白，在成熟内体处侵入胞浆），通过基因重配方法制备VP4或VP7单基因替换的重配病毒，在Caco-2细胞上，利用免疫荧光、激光共聚焦和Q-PCR等方法，从病毒（VP4、VP7）和细胞（网格蛋白、动力蛋白）两个方面研究病毒粒子在内体囊泡内运输和侵入机制，并分析细胞类型与RV侵入途径之间的相关性，旨在发现RV细胞侵入晚期过程中的关键驱动力及共同点，预期结果对揭示病毒的细胞嗜性和侵入机制及治疗性药物的创制具有重要意义。

Understanding how rotaviruses penetrate the target cells will help get light on rotavirus tropism, pathological mechanism and develop efficious therapeutic reagents. It was demonstrated that rotaviruses enable to employ mutiples of cellular receptors and pathways to complete the adhesion and internalization, however, no correlation between the early interaction with receptors and rotavirus penetration was found, resulting in failure to find the target, which interaction between the rotaviruses and cell receptor is crucial for the penetration during early stage to design the theraputic medicine. Therefore, we try to elucidate the role of rotavirus outer protein VP4 and VP7, as well as celluar protein clathrin and dynamin on rotavirus penetration, transportation in cytoplasma and infection during late stage by the preparation of reassortant rotavirus strains between UK(characterized by SA-independent, integrin-independent, clathrin-dependent during adhesion and penetrates into cytoplasm at late endosome) and RRV (characterized by SA-dependent, integrin-dependent, clathrin-independent during adhesion and penetrates into cytoplasm at mature endosome) strains, which the VP4 or VP7 gene is replaced, irrespectively and by utlization of Caco-2 cells, which were demonstrated to be advantageous over MA104 cells when the mechanisms of cell entry were studied by means of immunofluorescence assay, laser confocal microscopy and quantitive real-time PCR. Besides, we also aim to confirm the effect of sensitive cell types on rotavirus internalization and infection. This study will help understand how rotaviruses employ multiple mechanisms to penetrate cells and help design therapeutic medicine.