The human T cell leukemia virus type 1 (HTVL-1), first reported in 1980 by Robert Gallo’s group, is the etiologic agent of both cancer and inflammatory diseases. Despite approximately 40 years of investigation, the prognosis for afflicted patients remains poor with no effective treatments. The virus persists in the infected host by evading the host immune response and inducing proliferation of infected CD4+ T-cells. Here, we will review the role that viral orf-I protein products play in altering intracellular signaling, protein expression and cell–cell communication in order to escape immune recognition and promote T-cell proliferation. We will also review studies of orf-I mutations found in infected patients and their potential impact on viral load, transmission and persistence. Finally, we will compare the orf-I gene in HTLV-1 subtypes as well as related STLV-1.

中文翻译：

---

HTLV-1 orf-I 编码蛋白在病毒传播和持久性中的作用

人类 T 细胞白血病病毒 1 型 (HTVL-1) 于 1980 年由 Robert Gallo 小组首次报道，是癌症和炎症性疾病的病原体。尽管进行了大约 40 年的研究，受累患者的预后仍然很差，没有有效的治疗方法。该病毒通过逃避宿主免疫反应并诱导受感染的 CD4+ T 细胞增殖而在受感染的宿主中持续存在。在这里，我们将回顾病毒 orf-I 蛋白产物在改变细胞内信号、蛋白表达和细胞间通讯以逃避免疫识别和促进 T 细胞增殖方面的作用。我们还将审查在受感染患者中发现的 orf-I 突变及其对病毒载量、传播和持久性的潜在影响的研究。最后，