How HTLV-I Tax and HBZ control telomerase activity to induce adult T-cell leukemia

项目摘要/摘要 人类T细胞白血病病毒I型(HTLV-I)是一种感染和转化人类CD4的肿瘤逆转录病毒 T细胞的体外和体内实验。HTLV-I是成人T细胞白血病/淋巴瘤(ATLL)的病原体。 侵袭性且总是致命的血液病。该病毒通过性接触传播， 通过母乳喂养污染了血液和母婴，全世界有2000-3000万人感染。 HTLV-I介导的T细胞转化源于病毒诱导的多步骤致癌过程 慢性T细胞增殖，导致遗传缺陷积聚和细胞生长失控。现在还不是 完全了解HTLV-I是如何产生ATL的，但该病毒阻断了细胞凋亡网络，并使 感染细胞的增殖能力。HTLV-I在体外感染并永生化原代人类T细胞，并在 几个月后，这些细胞在没有白细胞介素2的情况下获得生长的能力，称为 转型。我们先前证明了病毒致癌基因Tax可以重新激活端粒酶。 表达，这是HTLV-I转化细胞在体外和体内长期增殖所必需的事件。这 应用程序将研究与解除调节的端粒酶活性相关的分子事件及其在 HTLV-I转换过程。因为端粒酶重新激活是人类 致癌，这项研究的结果将在病毒致癌之外具有广泛的应用。

PROJECT SUMMARY/ABSTRACT The human T-cell leukemia virus type I (HTLV-I) is an onco-retrovirus that infects and transforms human CD4 T cells in vitro and in vivo. HTLV-I is the etiological agent of adult T-cell leukemia/lymphoma (ATLL), an aggressive and invariably fatal hematological disease. The virus is transmitted through sexual contact, contaminated blood and mother-to-child by breastfeeding, and is present in 20-30 million people worldwide. HTLV-I-mediated T-cell transformation arises from a multi-step oncogenic process in which the virus induces chronic T-cell proliferation, resulting in accumulation of genetic defects and deregulated cell growth. It is not yet fully understood how HTLV-I engenders ATLL, but the virus blocks the apoptotic network and expends the proliferative capacity of infected cells. HTLV-I infects and immortalizes primary human T cells in vitro and, after several months, these cells acquire the ability to grow in the absence of interleukin-2, referred to as transformation. We previously demonstrated that the viral oncogenic Tax can reactivate telomerase expression, an event required for long-term proliferation of HTLV-I-transformed cells in vitro and in vivo. This application will investigate the molecular events associated with deregulated telomerase activity and its role in the HTLV-I transformation process. Since telomerase reactivation represents one of the central steps in human carcinogenesis, results from this study will have broad application beyond viral oncogenesis.