EPITRANSCRIPTOMIC REGULATION OF CYTOMEGALOVIRUS INFECTION

7.项目总结/摘要 mRNA的化学修饰为动态改变真核生物基因表达提供了强有力的手段 通过epitranscriptomic变化。特别地，腺苷在N6位置（m6 A）的甲基化构成了腺苷的甲基化。 最广泛的内部碱基修饰的mRNA。m6 A对mRNA的修饰影响了许多 生物过程包括发育、分化、重编程、昼夜节律、细胞周期， 疾病发病机制和包括病毒感染在内的应激反应。值得注意的是，病毒编码的mRNA 也被m6 A化学修饰，并且m6 A在人巨细胞病毒（HCMV）感染生物学中的作用是 正在浮现作为一个典型的火炬（T。弓形虫，其他，风疹病毒，HCMV，HSV）病原体，原发性HCMV 怀孕期间的感染仍然是导致出生缺陷的主要病毒原因。虽然HCMV感染导致轻度 如果有任何母体发病，并且在健康个体中主要是无症状的，则会导致危及生命的 疾病的免疫功能低下，包括实体器官或干细胞移植受体，是一种 这是发达国家新生儿先天性发病率和死亡率的重要来源。 解决HCMV先天性感染仍然是一个严重的未满足的医疗需求，因为没有HCMV疫苗， 预防怀孕期间的原发感染，目前没有预防母婴传播的治疗方法。 胎儿我们的长期目标是了解宿主和/或病毒RNA的化学修饰是如何 m6 A影响HCMV的繁殖，HCMV是一种常见的感染，仍然是导致人类免疫缺陷病毒的主要病毒原因。 先天性畸形初步结果表明，细胞m6 A甲基转移酶亚基 胃L3/14、m6 A去甲基化酶ALKBH 5和m6 A识别蛋白调节HCMV繁殖， 在未感染的细胞中对双链DNA（dsDNA）的反应。这部分是通过改变 干扰素B 1基因表达。这些发现证实了m6 A RNA修饰酶调节 细胞对HCMV和dsDNA传感的反应，其形成宿主免疫并有助于自身免疫性 疾病它进一步表明，m6 A表观转录组的变化在细胞内在的先天性免疫应答中起着重要作用。 对TORCH病原体HCMV的免疫应答。根据我们的初步结果，我们假设 HCMV复制受宿主m6 A修饰机制的差异控制。这个假设 将在三个具体目标进行测试，旨在：（i）确定主机m6 a改装机械如何 调节响应HCMV感染;（ii）确定细胞m6 A修饰酶如何调节IFNB 1 在HCMV感染的细胞中的mRNA积累;和（iii）鉴定HCMV基因表达如何受到 差异化m6 A修饰。该项目是重要的，因为它调查如何epitranscriptomic变化 影响HCMV繁殖和先天免疫。了解HCMV感染是如何通过 表转录组RNA修饰可能为治疗干预带来新的机会， 疫苗开发的新策略。

7. PROJECT SUMMARY / ABSTRACT Chemical modification of mRNA provides a powerful means to dynamically alter gene expression in eukaryotes via epitranscriptomic changes. In particular, methylation of adenosine at the N6 position (m6A) constitutes the most widespread internal base modification to mRNA. Modification of mRNA by m6A influences numerous biological processes including development, differentiation, reprogramming, circadian rhythm, cell cycle, disease pathogenesis, and stress responses including virus infection. Significantly, virus-encoded mRNAs are also chemically modified by m6A, and a role for m6A in Human Cytomegalovirus (HCMV) infection biology is emerging. As a canonical TORCH (T. gondii, other, rubella virus, HCMV, HSV) pathogen, primary HCMV infection during pregnancy remains the leading viral cause of birth defects. While HCMV infection causes mild if any maternal morbidity and is predominately asymptomatic in healthy individuals, it results in life-threatening disease among the immunocompromised, including solid-organ or stem cell transplant recipients, and is a significant source of congenital morbidity and mortality among newborn infants in the developed world. Addressing HCMV congenital infection remains a serious unmet medical need as there is no HCMV vaccine to prevent primary infection during pregnancy and no current treatment to prevent transmission from mother to fetus. Our long-term objective is to understand how the chemical modification of host and/or viral RNA by m6A impacts reproduction of HCMV, a common infection that remains the leading viral cause of congenital abnormalities. Preliminary results demonstrate that cellular m6A methyltransferase subunits METTL3/14, the m6A demethylase ALKBH5, and m6A recognition proteins regulate HCMV reproduction and responses to double strand DNA (dsDNA) in uninfected cells. This is achieved in part through changes in interferon b gene (IFNB1) expression. These findings establish that m6A RNA modification enzymes regulate cellular responses to HCMV and dsDNA sensing, which shapes host immunity and contributes to autoimmune disease. It further suggests that m6A epitranscriptomic changes play a fundamental role in cell-intrinsic innate immune responses to the TORCH pathogen HCMV. Based upon our preliminary results, we hypothesize that HCMV reproduction is differentially controlled by the host m6A modification machinery. Here, this hypothesis will be tested in three specific aims designed to: (i) identify how the host m6A modification machinery is regulated in response to HCMV infection; (ii) determine how cellular m6A modification enzymes regulate IFNB1 mRNA accumulation in HCMV-infected cells; and (iii) identify how HCMV gene expression is impacted by differential m6A modification. The project is significant because it investigates how epitranscriptomic changes impact HCMV reproduction and innate immunity. Understanding how HCMV infection is regulated by epitranscriptomic RNA modification could lead to new opportunities for therapeutic intervention and possibly new strategies for vaccine development.