Fischinger P J, Nomura S, Blevins C S, Bolognesi D P
J Gen Virol. 1975 Oct;29(1):51-62. doi: 10.1099/0022-1317-29-1-51.
Mouse and cat cells were each examined for the mode of restriction of endogenous xenotropic oncornavirus. Murine xenotropic helper virus (MuX) and its pseudo-type of Moloney murine sarcoma virus (MSV(MuX)) were grown in cat cells to high titre. MuX alone did not replicate in any mouse cell tested including normal or transformed outbred Swis 3T3 cells or SC-I cells, but did grow in a variety of other mammalian cells. MSV(MuX) was not able to achieve that intracellular state from which it could be rescued by mouse leukaemia virus (MuLV) in any mouse cell tested with the exception of SC-I cells. Detection of MSV(MuX) foci with appropriate helper virus was as sensitive in SC-I cells as in the cells of several other species. Sequential passage of MSV(MuX) virus complex in SC=I cells resulted in a loss of infectious sarcoma and helper viruses, but transformed, MSV rescuable cells were retained. If cat embryo cells were infected with either the feline endogenous xenotropic virus (FeX) or its MSV pseudotype (MSV(FeX), two analogous states of restriction were observed. FeX alone did not replicate in cat cells as measured by release of progeny virus or by FeX group-specific antigen induction. Cat cells could be susceptible or insusceptible to the entry of MSV(FeX) as measured by MSV rescue with appropriate ecotropic feline leukaemia virus. The sensitivity of detection of MSV(FeX) foci in some cat cells in the presence of feline ecotropic virus was comparable to that exhibited by cells of other mammalian species. A single strain of cat cells underwent a change in its restrictive capacity for MSV(FeX) on prolonged passage. Late passage cat cells became very insusceptible to MSV(FeX) but not to other pseudotypes of MSV. Infectious FeX or its group-specific antigens were not detected in the insusceptible cells. The major glycoprotein of FeX did appear as a surface antigen of the insusceptibel cells. It is apparent that two levels of cellular restriction can be distinguished in each of two mammalian cell systems by the susceptibility to penetration of MSV coated with endogenous xenotropic oncornavirus.
对小鼠和猫细胞进行了检查，以研究内源性嗜异性肿瘤病毒的限制模式。鼠嗜异性辅助病毒（MuX）及其莫洛尼氏鼠肉瘤病毒假型（MSV(MuX)）在猫细胞中生长至高滴度。单独的MuX在任何测试的小鼠细胞中均不复制，包括正常或转化的远交系Swis 3T3细胞或SC-I细胞，但能在多种其他哺乳动物细胞中生长。MSV(MuX)在除SC-I细胞外的任何测试小鼠细胞中都无法达到能被小鼠白血病病毒（MuLV）拯救的细胞内状态。在用适当的辅助病毒检测MSV(MuX)病灶时，SC-I细胞与其他几个物种的细胞一样敏感。MSV(MuX)病毒复合物在SC-I细胞中连续传代导致感染性肉瘤病毒和辅助病毒丧失，但保留了可被MSV拯救的转化细胞。如果猫胚胎细胞感染了猫内源性嗜异性病毒（FeX）或其MSV假型（MSV(FeX)），则会观察到两种类似的限制状态。通过子代病毒释放或FeX组特异性抗原诱导来衡量，单独的FeX在猫细胞中不复制。用适当的亲嗜性猫白血病病毒进行MSV拯救来衡量，猫细胞对MSV(FeX)的进入可能敏感或不敏感。在存在亲嗜性猫病毒的情况下，某些猫细胞中MSV(FeX)病灶的检测灵敏度与其他哺乳动物物种的细胞相当。单一猫细胞系在长期传代后其对MSV(FeX)的限制能力发生了变化。传代后期的猫细胞对MSV(FeX)变得非常不敏感，但对MSV的其他假型不敏感。在不敏感细胞中未检测到感染性FeX或其组特异性抗原。FeX的主要糖蛋白确实作为不敏感细胞的表面抗原出现。显然，通过对内源性嗜异性肿瘤病毒包膜的MSV穿透的敏感性，可以在两个哺乳动物细胞系统中的每一个中区分出两个水平的细胞限制。
