BIOLOGICAL AND PHYSICAL PROPERTIES OF FRIEND VIRUS

这个项目的总体目标是确定是否有缺陷的朋友 脾病灶形成病毒（SFFV）携带遗传信息， 作为一个造血自我更新基因，当引入到 小鼠骨髓细胞的多能造血干细胞（CFU-S）。 主要具体目标; SFFV结构。 构建一种可传播的逆转录病毒， 分子克隆的Friend SFFV和改变的小鼠二氢叶酸 还原酶（dhfr）序列。 单一突变dhfr序列的存在 作为显性作用的选择基因。 如果设计缺陷SFFV，则持续存在。 鼠骨悬液 富集CFU-S的骨髓细胞将暴露于感染性SFFV-dhfr， 确定这种工程缺陷病毒的宿主范围是否包括 造血细胞 病毒处理过的骨髓将被注入 致死性辐照的组织相容性成年受体。 这些老鼠将 监测潜在的SFFV持续性。 SFFV和干细胞自我更新。 使用捐赠者的骨髓 主要是SFFV+ CFU-S，以探测SFFV诱导的宿主中的变化 造血和干细胞更新。 将回收SFFV+骨髓细胞 从潜伏感染的小鼠和连续移植，以确定其 自我更新和保护或拯救受致命辐射者的能力 造血功能衰竭和死亡 通过以下方式确保人口的重新增长 主要是SFFV+ CFU-S，我们将用药物治疗重建的小鼠， 甲氨蝶呤（Mtx）方案。 SFFV自我更新基因的鉴定。 要确定信封（env） 编码gp 52 sfv的序列是诱导延伸的 CFU-S自我更新。 一些定义明确的SFFV插入-缺失 突变体将用dhfr重组，假型用辅助基因重组， 感染CFU-S 将使用SFFV确认潜在持久性 代表性探针，而SFFV+干细胞将被监测， 通过连续移植到致死辐射的 同系成年小鼠。 自我更新的载体转移最终可能会被利用， 宿主是否患有后天性或先天性 红细胞骨髓和淋巴细胞造血缺陷。

The overall objective of this project is to determine if defective Friend spleen focus-forming virus (SFFV) carries genetic information which is able to function as a hemopoietic self-renewal gene when introduced into the pluripotent hemoietic stem cell (CFU-S) of murine bone marrow cells. Major Specific Aims; SFFV constructions. To construct a transmissible retrovirus consisting of the molecularly cloned Friend SFFV and an altered mouse dihydrofolate reductase (dhfr) sequence. The presence of a single mutant dhfr sequence serves as a dominant-acting selectable gene. Persistence if engineered defective SFFV. Suspensions of murine bone marrow cells enriched for CFU-S will be exposed to infectious SFFV-dhfr to determine if the host range of this engineered, defective virus includes hemopoietic cells. Virus-treated marrow will be injected into lethally-irradaited histocompatible adult recipients. These mice will be monitored for latent SFFV persistence. SFFV and stem cells self-renewal. Using donor marrow which are predominantly SFFV+ CFU-S, to probe for SFFV-induced alterations in host hematopoiesis and stem cell renewal. SFFV+ marrow cells will be retrieved from latently infected mice and serially transplanted to determine their ability to self-renew and protect or rescue lethally-irradiated recipients from total hemopoietic failure and death. To insure repopulation by predominantly SFFV+ CFU-S, we shall treat reconstituted mice with a drug regimen if methotrexate (Mtx). Identify of an SFFV self-renewal gene. To determine if the envelope (env) sequences which encode gp52sfv are required for the induction of extended CFU-S self renewal. A number of well-defined SFFV insertion-deletion mutants will be reconstituted with dhfr, pseudotypes with helper, and used to infect CFU-S. Latent persistence will be confirmed using an SFFV representative probe, while the SFFV+ stem cells will be monitored for self-renewal capacity via serial transplantation into lethally irradiated syngeneic adult mice. Vector transfer of self-renewal may eventually be exploited to the benefit of the host whether he/she be suffering from an aquired or congenital defect in hemopoiesis erytghromyeloid and lymphoid.