Retrovirus Evolution and Cancer

这份申请寻求对我的研究项目的持续支持，该项目由NCI资助了近40年， 对逆转录病毒的生物学和进化及其作用的许多创新性和高影响力的贡献 在艾滋病和癌症方面。我们将重点关注实验室中正在进行的一些项目： 1.人类HERV-K(HML-2)基因多态性。HML-2是最新活跃的内源性逆转录病毒 在人类中，有90个或前病毒，其中11个都是非传染性的，已知在 人口。为了测试活跃成员是否可能以低频率出现，但仍未被检测到，我们 已经开发了生物信息学和实验室工具来识别和表征稀有-因此最近 以及潜在的感染性前病毒，存在于大型序列数据库中，比如来自“1000个基因组”的那些 项目。我们发现了一些新的前病毒，在人群中很罕见，其中一种似乎在- 机智。我们将确定它编码传染性病毒的潜力以及在癌症中的可能作用。 2.HML-2表达与肿瘤的关系。为了测试HML-2前体在肿瘤发展中的作用，我们有 开发了测序、生物信息学和其他工具来研究它们在癌细胞系中的表达，并阻止- 我的90个前驱动力中的哪些是被表达的，是通过什么机制来表达的：即，前两者之间的差异是否 正常细胞和癌细胞之间的抑制是由于顺式(例如DNA甲基化、染色质结构)或反式 (例如，转录因子模式)效应。我们将确定这种上调是否会导致重新整合- 新的HML-2病毒的释放，以及它是否对肿瘤的发展和生长有积极的作用。 3.HML-2表达与HIV感染HIV-1感染患者HML-2表达水平升高- PBMC中的Sion。我们正在开发与2中相同的方法来测试该病毒的细胞和前病毒特异性 在这些个体中的表达，以及它在恶性肿瘤的发展中是否起到任何作用。 4.HML-2受体特异性的演变。HML-2与灵长类动物的共同进化已超过2000万 多年来，很可能受到类似ALV的进化力量的影响。我们已经制定了一项战略来确定- 根据HML-2包膜蛋白假型病毒感染细胞表达的能力来确定其宿主受体- 从允许细胞中获得一个cdna文库。然后我们将使用灵长类基因组中的“化石记录”来研究 这种相互作用的共同进化。 5.逆转录病毒与APOBEC的相互作用。免疫缺陷人移植瘤MLV感染的预防 小鼠是一个重要的问题，因为目前有兴趣开发“个性化免疫”小鼠来生长人类。 用于治疗目的的人体组织。我们的策略是让受体老鼠在全球范围内表达一项限制 将防止对移植的人类肿瘤细胞系进行生产性感染的因子(人APOBEC3G)。我们是 还致力于了解MLV对人和小鼠APOBEC蛋白的差异敏感性。

This application seeks continued support for my research program, funded by the NCI for almost 40 years, with numerous innovative and high-impact contributions to the biology and evolution of retroviruses and their roles in AIDS and cancer. We will focus on a number of ongoing projects in the laboratory: 1. HERV-K (HML-2) Polymorphism in humans. HML-2 is the most recently active endogenous retrovirus group in humans, with 90 or proviruses, of which 11, all noninfectious, were known to be polymorphic in the population. To test whether active members may be present at low frequency, but remain undetected, we have developed bioinformatic and laboratory tools to identify and characterize rare - and therefore more recent and potentially infectious - proviruses in large sequence databases like those from the the “1000 genomes” project. We have identified a number of new proviruses, rare in the population, one of which appears to be in- tact. We will determine its potential to encode infectious virus and possible role in cancer. 2. HML-2 Expression and cancer. To test for a role of HML-2 proviruses in tumor development, we have developed sequencing, bioinformatic and other tools to study their expression in cancer cell lines and deter- mine which of the 90 proviruses are expressed and by what mechanism: i.e., whether the differences in ex- pression between normal and cancer cells are due to cis (e.g., DNA methylation, chromatin structure) or trans (e.g., transcription factor patterns) effects. We will determine whether this upregulation might lead to reintegra- tion of new HML-2 proviruses, and whether it has a positive effect on tumor development and growth. 3. HML-2 expression and HIV infection. HIV-1 infected patients exhibit elevated levels of HML-2 expres- sion in PBMCs. We are developing the same approaches as in 2 to test the cell and provirus specificity of this expression in these individuals and whether it plays any role in the development of malignancy. 4. Evolution of HML-2 receptor specificity. HML-2 has been coevolving with primates for over 20 million years and has likely been subject to evolutionary forces similar to ALV. We have developed a strategy to iden- tify its host receptor based on the ability of viruses pseudotyped with HML-2 Env protein to infect cells express- ing a cDNA library from permissive cells. We will then use the “fossil record” in primate genomes to study the coevolution of this interaction. 5. Retrovirus-APOBEC interaction. Prevention of MLV infection of human xenografts in immunodeficient mice is an issue of importance due the current interest in developing “personalized immune” mice to grow hu- man tissues for therapeutic purposes. Our strategy is to make the recipient mice globally express a restriction factor (human APOBEC3g) that will prevent productive infection of the grafted human tumor cell line. We are also working to understand the differential sensitivity of MLV to human and murine APOBEC proteins.