gga-miR6616和gga-miR6675抑制H9N2亚型禽流感病毒在鸡树突状细胞中复制的分子机制初探

Dendritic cells, the only bridge communicated the innate and acquired immunity, have the most important antigen presenting ability and played an irreplaceable role in recognizing and clearing virus. Whilst, microRNAs influence the development of dendritic cells and their ability to present antigens as well as the replication of many virus. Our previous research found that gga-miR6616 and gga-miR6675 can significantly inhibit the replication of H9N2 subtype avian influenza virus in chicken dendritic cells. Here, we propose to study the molecular mechanisms of how gga-miR6616 and gga-miR6675 inhibit the replication of avian influenza virus in chicken dendritic cells. We will first detect the nuclear entrance situation of H9N2 viral RNP on chicken dendritic cells and check how gga-miR6616 and gga-miR6675 expression or inhibition would greatly influence the virus nuclear entrance. We will then focus on the molecular mechanisms of how such host microRNAs (gga-miR6616 and gga-miR6675 ) target and interact with the nuclear location sequence of viral RNP (PB2, PB1, PA and NP) or the pro-nuclear protein importin a/b to block the nuclear entrance of H9N2 avian influenza virus, which further inhibited the virus replication. At last, we will investigate how the host microRNAs (gga-miR6616 and gga-miR6675 ) activate the innate immunity of chicken dendritic cells to inhibit the replication of avian influenza virus. Altogether, our innovative research will shed new light on the roles and mechanisms of gga-miR6616 and gga-miR6675 in inhibiting avian influenza virus replication in chicken dendritic cells. And our results will suggest new strategies to combat avian influenza virus.

树突状细胞是体内功能最强大的专职抗原递呈细胞，在病毒的识别和递呈方面起着至关重要的作用。MicroRNA是细胞内广泛表达的非编码小RNA，可以调控树突状细胞对多种病毒的识别和递呈。本项目拟阐明鸡源microRNA调控阻断H9N2禽流感病毒在鸡树突状细胞上复制的分子机制。本项目首先检测四个病毒核糖核蛋白复合体（vRNP）蛋白的入核转运情况；其次研究gga-miR6616和gga-miR6675靶向结合禽流感病毒vRNP蛋白的核定位信号区，阻断vRNP蛋白入核进而抑制病毒复制的分子机制；再次我们探索gga-miR6616和gga-miR6675激活鸡树突状细胞天然免疫抑制禽流感病毒复制的分子机制。综上，本研究力争阐明gga-miR6616和gga-miR6675调控阻断H9N2亚型禽流感病毒在鸡树突状细胞中复制的分子机制，为合理的应用microRNA预防禽流感病毒提供理论依据。

禽流感是由A 型流感病毒引起的禽类烈性传染病，其频繁爆发给我国乃至世界上许多国家的养禽业造成了极大的经济损失。禽流感病毒主要通过呼吸道进行传播，同时具有高突变率和重组率，易导致病毒毒力的增强和跨种传播的风险。因此禽流感病毒的防控一直受到各国关科学家们的高度重视。 树突状细胞是体内功能最强大的专职抗原递呈细胞，在病毒的识别和递呈方面起着至关重要的作用。禽流感病毒致病性主要取决于宿主树突状细胞能否高效的识别、递呈和启动免疫应答。MicroRNA是细胞内广泛表达的非编码小RNA，近年来研究发现其可以调控树突状细胞对多种病毒的识别和递呈。因此本项目拟阐明鸡源microRNA调控阻断禽流感病毒在鸡树突状细胞上复制的分子机制。本项目首先筛选到4个禽流感病毒诱导宿主高表达的鸡源microRNA；在此基础上研究发现（1）gga-miR6616和gga-miR6675靶向结合禽流感病毒vRNP蛋白的核定位信号区，阻断vRNP蛋白入核进而抑制病毒复制；（2）gga-miR1635和gga-miR1644可以激活鸡树突状细胞天然免疫抑制禽流感病毒复制。综上，本研究初步揭示了鸡源microRNA抑制禽流感病毒在鸡树突状细胞中复制的分子机制，为合理的应用鸡源microRNA预防禽流感病毒提供理论依据。项目完成课题预期计划，发表SCI论文3篇（本基金号标注），最高影响因子大于7。其中一篇论文发表于医学一区杂志Oncogene（5年影响因子7.3），获得国际同行高度认可；申请相关专利1项；主持人就本项目研究成果参加高水平学术会议2次；培养2名硕士研究生。本项目揭示了鸡源microRNA调控抑制禽流感病毒复制的分子机制，为合理的应用鸡源microRNA预防禽流感病毒提供理论依据。