IL-1β调控MAPK通路介导新亚群禽白血病病毒诱发脑胶质瘤研究

The isolation rate of new subgroup of avian leukosis virus in indigenous chicken breeds in our country is increasing year by year. The virus induces glioma in infected chickens, but its tumorigenesis remains unclear. Based on our previous genomic and pathogenic study of ALV isolate JS11C1, an ALV-infected-astrocyte system will be establised in the present project. The activation of astrocyte, expression of IL-1β, phosphorylation of IRAK and key protein in the MAPK pathway will be tested by Western blotting, ect, which can clarify the mechanism of ALV induced glioma mediated via MAPK pathway regulated by IL-1β. Based on the preliminary built reverse genetic operation platform, specific variable sites in the U3 sequence will be mutated using site-directed mutagenesis. The promoter and enhancer activation of LTR will be tested. The influence of mutations on proliferation of virus in astrocyte, activation of astrocyte and the IL-1β/IRAK/MAPK pathway will be tested to clarify the relationship of ALV induced glioma with the U3 sequence. The study will contribute to reveal the molecular mechanism of tumor formation caused by new subgroup of ALV. It also provides guide for study on emerging viral diseases and virus evolution.

新亚群禽白血病病毒（Avian leukosis virus, ALV）在我国地方品种鸡群中的分离比例逐年增加，能引起禽脑胶质瘤病变，目前致瘤机制尚不清楚。本课题基于前期对新亚群ALV分离株JS11C1的基因组和致病性研究，建立ALV感染星形胶质细胞模型，通过Western blotting等方法分析星形胶质细胞活化、IL-1β表达、IRAK及MAPK通路关键蛋白磷酸化水平，阐明IL-1β调控MAPK通路介导ALV致脑胶质瘤的分子机制；利用建立的反向遗传操作平台，通过定点突变技术将U3区转录激活元件中变异位点进行突变，检测LTR启动增强活性，分析其对病毒在星形胶质细胞中增殖、星型胶质细胞活化及IL-1β/IRAK/MAPK通路激活的影响，阐明U3区与ALV致脑胶质瘤特性的关系。本项目研究结果有助于揭示新亚群ALV分子致瘤机制，并对不断出现的新发病毒病和病毒进化等研究亦具有重要的指导意义。

新亚群禽白血病病毒（Avian leukosis virus, ALV）在我国地方品种鸡群中的分离比例逐年增加。本课题基于前期对新亚群ALV分离株JS11C1的研究基础，探索其致瘤机制，完成对MAPK通路在JS11C1株ALV感染宿主细胞中的激活研究，证实p38和ERK2两条通路在JS11C1株ALV感染宿主细胞中均被激活并影响病毒在宿主细胞中的复制；鉴定U3区关键转录调控元件1个，证实U3区11bp重复序列插入能增强JS11C1株病毒LTR启动子和增强子活性以及病毒的增殖，研究成果为揭示ALV分子致瘤机制提供重要的理论依据。在此基础上，本项目进一步证实U3区11bp重复序列插入引起病毒基因组与宿主HABP4蛋白发生特异性相互作用，这可能是LTR启动增强活性增强和病毒增殖加快的关键因素，本项目为后续深入分析ALV致病机制和LTR插入突变致肿瘤的分子基础提供了新的研究视角。