HDAC1介导的组蛋白修饰对KSHV复制速率的调控机制研究

Kaposi's sarcoma-associated herpesvirus (KSHV) has been documented as the major contributor to primary effusion lymphoma (PEL) and Multicentric Castleman's Disease (MCD), which are B-cell lymphomas and mainly occurs in the immuosuppressed population such as AIDS patients and seniors. Persistent replication of KSHV plays a critical role in the development of KSHV-associated B-cell lymphomas because most B cells in PEL and MCD are latently infected by KSHV. In this proposed project, we will characterize the KSHV replication on its genome with histone acetylation using ChIP-seq and Single Molecule Analysis of Replicated DNA (SMARD) technology. Our aims are: 1) characterizing the KSHV replication controlled by HDAC1-mediated histone acetylation on KSHV genome during latency in B cells and confirming the mechanism of viral replication rate controlled by histone acetylation; 2) Comparing the patterns of histone acetylation and viral replication across KSHV genome in the T and B cells from primary infection of human PBMCs and elucidating the critical role of KSHV replication rate in inducing B-cell immortalization; 3) Establishing the relationship of the HDAC1 inhibitors and KSHV replication rate in infected B-cell lymphomas and primary B cells, and developing B-cell evaluation system for HDAC1 inhibitors, further providing the possibilities for developing HDAC inhibitors (HDACi) for the combination therapy of KSHV associated B-cell lymphomas.

卡波氏肉瘤相关疱疹病毒（KSHV）是原发渗出性淋巴瘤（PEL）和多中心卡斯特曼病(MCD)等B细胞淋巴瘤的主要病原体，多发于免疫力低下的人群。持续复制是KSHV在B细胞中建立潜伏态并永生化B细胞的必要条件。本项目拟利用ChIP-seq和单分子复制DNA分析技术（SMARD）对KSHV基因组上高度组蛋白乙酰化区域的复制状态进行可视化及定量分析，达到以下目的：1）阐明HDAC1通过组蛋白乙酰化修饰控制KSHV复制的单分子特征，验证乙酰化修饰对KSHV复制速率的控制；2）分析原发感染的T和B细胞中KSHV基因组上组蛋白乙酰化修饰和单分子复制的特征，阐明其差异性，并解释该病毒复制能力对其诱导B细胞永生化的重要性；3）量化HDAC1抑制剂与KSHV在感染B细胞中复制速率的对应关系，探索建立一个评估HDAC1抑制剂系统，为研发协同治疗KSHV相关淋巴瘤的组蛋白去乙酰化酶抑制剂（HDACi）奠定基础。

原发性淋巴瘤（primary effusion lymphoma，PEL）是由卡波西肉瘤疱疹相关病毒（Kaposi’s Sarcoma-Associated Herpesvirus，KSHV）引起的B细胞淋巴瘤，多发于免疫力低下的人群。目前，关于PEL的致瘤机制尚不清楚。相关研究已表明细胞转录共激活因子p300能够调节宿主与病毒之间的相互作用，从而控制病毒复制过程。在此项目的支持下，本人带领课题组探索了p300在KSHV感染的BCBL1细胞中的功能。首先构建了稳定敲除p300的B淋巴细胞系，然后通过RNAseq检测了病毒和细胞因子的基因表达，最后分析了细胞内的KSHV基因组拷贝数和病毒粒子的产量以及B淋巴瘤细胞的增殖情况。结果发现p300对抑制BCBL1中的KSHV病毒复制及控制细胞的增殖起着重要作用，并鉴定相关控制B淋巴瘤的关键细胞因子ATF3。这为进一步开发治疗原发性淋巴瘤的药物奠定理论基础。