Clarke B J, Axelrad A A, Housman D
J Natl Cancer Inst. 1976 Oct;57(4):853-9. doi: 10.1093/jnci/57.4.853.
We developed a cell line (IS) that continuously produced both Friend spleen focus-forming virus (SFFV) and XC plaque-forming virus in vitro. The line was derived from the enlarged spleen of an inbred SIM mouse previously infected with a polycythemic strain of Friend leukemia virus in vivo. Friend SFFV titers of 10(4) spleen focus-forming units/ml of culture medium were maintained for more than 200 cell generations. The virus from IS cells induced the splenomegaly and high hematocrit typical of Friend virus-induced erythroid disease in SIM mice. Cells of the IS line were adherent and phagocytic and had a low saturation density. They produced no tumors after being injected sc into normal syngeneic hosts and no spleen colonies after being injected iv into supralethally irradiated hosts. IS cells did not have the character of erythroid cells: They did not contain detectable heme as measured by benzidine-peroxide reagent, did not contain globin mRNA in detectable amounts, and did not produce erythroid colonies in plasma culture in the absence or presence of erythropoietin. According to these criteria, growth in the presence of dimethyl sulfoxide did not stimulate erythroid differentiation of IS cells. We concluded that Friend SFFV can infect nonerythroid spleen cells but that replication of the virus was not obligatorily coupled to expression of genes associated with the erythroid phenotype.
我们培育了一种细胞系（IS），该细胞系在体外能持续产生弗氏脾脏病灶形成病毒（SFFV）和XC空斑形成病毒。该细胞系源自一只近交系SIM小鼠肿大的脾脏，这只小鼠先前在体内感染了多血症株的弗氏白血病病毒。在超过200个细胞代中，培养基中弗氏SFFV的滴度维持在10⁴脾脏病灶形成单位/毫升。来自IS细胞的病毒在SIM小鼠中诱发了典型的弗氏病毒诱导的红细胞疾病的脾肿大和高血细胞比容。IS细胞系的细胞具有贴壁和吞噬特性，且饱和密度较低。将其皮下注射到同基因正常宿主中不会产生肿瘤，静脉注射到经超致死剂量照射的宿主中也不会形成脾脏集落。IS细胞不具备红细胞的特征：用联苯胺 - 过氧化物试剂检测时，它们不含可检测到的血红素，不含可检测量的珠蛋白mRNA，并且在有无促红细胞生成素的血浆培养中都不会产生红细胞集落。根据这些标准，在二甲基亚砜存在下的生长并未刺激IS细胞的红细胞分化。我们得出结论，弗氏SFFV可感染非红细胞脾脏细胞，但病毒的复制并非必然与红细胞表型相关基因的表达相耦合。
