BIOLOGICAL AND PHYSICAL PROPERTIES OF FRIEND VIRUS

这个项目的总体目标是确定有缺陷的朋友 脾病灶形成病毒(SFFV)携带的遗传信息能够 作为一种造血自我更新基因，当被导入 小鼠骨髓细胞多能造血干细胞(CFU-S)。 重大具体目标； SFFV结构。构建一种可传播的逆转录病毒，包括 分子克隆的Friend SFFV和一种改良的小鼠二氢叶酸 还原酶(DHFR)序列。单个突变型DHFR序列的存在 作为显性作用的可选择基因。 持久性，如果工程设计的有缺陷的SFFV。鼠骨悬浮液 富含CFU-S的骨髓细胞将暴露于传染性SFFV-DHFR 确定这种经过改造的有缺陷病毒的宿主范围是否包括 造血细胞。经过病毒治疗的骨髓将被注射到 组织相容的致死成年受者。这些老鼠将会是 监控潜在的SFFV持久性。 SFFV和干细胞自我更新。使用捐赠者的骨髓 主要是SFFV CFU-S，以探索SFFV诱导的宿主变化 造血和干细胞更新。SFFV骨髓细胞将被取回 从潜伏感染的小鼠身上连续移植以确定它们的 自我更新和保护或拯救受致命性辐射的接受者的能力 从完全的造血衰竭和死亡。通过以下方式确保重新人口 以SFFV CFU-S为主，我们将用一种药物治疗重组小鼠 甲氨蝶呤(MTX)方案。 鉴定一个SFFV自我更新基因。要确定封套(环境)是否 编码gp52sfv的序列是诱导延伸的所必需的 CFU-S自强不息。一些定义明确的SFFV插入-删除 突变体将与dhfr重组，伪型将与助手重组，并使用 感染CFU-S。将使用SFFV确认潜在持久性 有代表性的探针，而SFFV干细胞将被监测 通过连续移植获得致死照射后的自我更新能力 同基因成年小鼠。 载体转移的自我更新最终可能会被利用起来 宿主是否患有获得性或先天性 造血系、红系和淋巴系缺陷。

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.