细胞内吞是动物病毒的常见入胞方式，需要多种蛋白质分子参与并引起不同的信号转导通路将病毒转运入细胞内的过程。未成熟的树突状细胞（DCs）具有极强的内吞能力以及多种内吞途径，其中巨胞饮作用在DCs捕获糖基化抗原时高度活跃并通过抗原提呈作用调节免疫应答功能。研究表明，痘苗病毒和人类免疫缺陷病毒可以通过巨胞饮内吞感染DCs并干扰免疫应答，而新城疫病毒（NDV）在禽类DCs上未见报道。前期实验发现，NDV感染DCs可能以巨胞饮方式入胞，但是具体入胞机制尚不清楚。本项目将对NDV利用内吞途径感染DCs入胞过程以及病毒粒子经DCs抗原提呈激活免疫应答反应进行研究，内容主要包括：（1）研究NDV感染DCs后肌动蛋白发生重排作用的调控机制；（2）研究NDV入胞后抗原提呈途径以及激活特异性免疫应答的作用机制。

Viruses often enter the cells by endocytosis. This process requires a variety of protein kinases involved in signal transduction which causes membrane ruffling or invagination facilitate virus engulfed into the cell. Immature dendritic cells (DCs) possess strong endocytosis ability and a variety of endocytosis pathways in which macropinocytosis is highly active when DCs capture glycosylated antigens and regulate immunity response by antigen presentation system. Studies have shown that vaccinia virus and human immunodeficiency virus can infect DCs through macropinocytosis and interfere with immune responses, whereas Newcastle disease virus (NDV) has not been reported in poultry DCs. Previous studies have found that NDV infection may be DCs to macropinocytosis way into the cell, but the specific mechanisms of endocytosis is not clear. In this project, we will study the process of NDV entry and specific immune response of virus particles induced by DCs antigen presentation, including (1) study on the mechanism of actin rearrangement in NDV infected DCs; (2) study on the DCs antigen presentation pathway and the immune responses specific to NDV.