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和高影响力的贡献 在艾滋病和癌症中。我们将专注于实验室中的一些正在进行的项目： 1.人类HERV-K（HML-2）多态性。HML-2是目前最活跃的内源性逆转录病毒 组在人类中，有90或前病毒，其中11个，所有非传染性，已知是多态性的， 人口为了测试活跃成员是否可能以低频率出现，但仍然未被发现，我们 已经开发了生物信息学和实验室工具来识别和描述罕见的，因此是最近的 和潜在的传染性--在大型序列数据库中的前病毒，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，在人群中很少见，其中一种似乎在- 机智我们将确定其编码感染性病毒的潜力以及在癌症中的可能作用。 2. HML-2表达与癌症为了检测HML-2前病毒在肿瘤发展中的作用，我们 开发了测序、生物信息学和其他工具，以研究它们在癌细胞系中的表达，并确定 我知道90种前病毒中的哪些被表达以及通过什么机制表达：即，无论是前， 正常细胞和癌细胞之间的表达是由于顺式（例如，DNA甲基化，染色质结构）或反式 (e.g.,转录因子模式）的影响。我们将确定这种上调是否会导致再整合- 新的HML-2前病毒，以及它是否对肿瘤的发展和生长有积极的影响。 3. HML-2表达与HIV感染HIV-1感染患者HML-2表达水平升高， 锡永PBMC中。我们正在开发与2相同的方法来测试这种细胞和前病毒的特异性。 在这些个体中的表达以及它是否在恶性肿瘤的发展中起任何作用。 4. HML-2受体特异性的演变。HML-2已经与灵长类动物共同进化了超过2000万年 多年来，可能受到类似于ALV的进化力量的影响。我们制定了一个策略来识别- 基于用HML-2 Env蛋白假型化的病毒感染表达- 从允许细胞中构建cDNA文库。然后，我们将利用灵长类动物基因组中的“化石记录”来研究 这种相互作用的共同进化。 5.逆转录病毒-APOBEC相互作用。免疫缺陷患者中人异种移植物的MLV感染的预防 小鼠是一个重要的问题，这是由于目前对开发“个性化免疫”小鼠以生长人类免疫细胞的兴趣。 用于治疗目的的人体组织。我们的策略是使受体小鼠在全球范围内表达一种限制性的 因子（人APOBEC 3g），其将防止移植的人肿瘤细胞系的生产性感染。我们 还致力于了解MLV对人和鼠APOBEC蛋白的不同敏感性。

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.