Chapman H P, White M H, Rahman R, Gilden R V
J Virol. 1975 Jan;17(1):51-9. doi: 10.1128/JVI.17.1.51-59.1976.
The major internal protein, p30, of rat type C virus (RaLV) was purified and utilized to establish intra- and interspecies radioimmunoassays. Three rat viruses were compared in homologous and heterologous intraspecies assays with no evidence of type specificity. The only heterologous viruses to give inhibition in these species assays were the feline (FeLV) and hamster (HaLV) type C viruses; these reactions were incomplete and required high virus concentrations. An interspecies assay using a goat antiserum prepared after sequentially immunizing with FeLV, RD 114, and woolly monkey virus p30's and labeled RaLV p30 was inhibited by all mammalian type C viruses, although preferentially by RaLV, FeLV, and HaLV. Thus, as in a previously reported assay developed with HaLV p30, rat, hamster, and cat p30's seem more closely related to each other than to mouse type C virus p30. High levels of specific antigen were found in all cell lines producing rat virus, whereas embryonic tissues from several rat strains and cell lines considered virus-free based on other tests were negative for p30. Rats bearing tumors containing Moloney murine sarcoma virus (RaLV) did not contain free circulating antibody to RaLV p30. Fifty-one human tumor extracts (including two tumor cell lines) were tested for activity in the RaLV species and 47 in the interspecies assays after Sephadex gel filtration and pooling of material in the 15,000- to 40,000-molecular-weight range. At a sensitivity level of 7 ng/ml (0.7 ng/assay) in the interspecies assay, all human tissues, with one exception, were negative. The one positive result is considered nonspecific based on proteolysis of the labeled antigen. Input tissue protein of the purified tumor extracts averaged 1.9 mg/ml with a range of less than 0.025 to 22 mg/ml. Tissues from NIH Swiss mice processed in the same manner were positive in the interspecies assay but negative in the intraspecies RaLV assay.
大鼠C型病毒（RaLV）的主要内部蛋白p30被纯化，并用于建立种内和种间放射免疫测定法。在同源和异源种内测定中比较了三种大鼠病毒，没有发现型特异性的证据。在这些种内测定中唯一能产生抑制作用的异源病毒是猫（FeLV）和仓鼠（HaLV）C型病毒；这些反应不完全，需要高病毒浓度。使用依次用FeLV、RD 114和绒毛猴病毒p30免疫后制备的山羊抗血清和标记的RaLV p30进行的种间测定，受到所有哺乳动物C型病毒的抑制，尽管RaLV、FeLV和HaLV优先抑制。因此，正如先前用HaLV p30开发的测定法一样，大鼠、仓鼠和猫的p30彼此之间的关系似乎比与小鼠C型病毒p30的关系更密切。在所有产生大鼠病毒的细胞系中都发现了高水平的特异性抗原，而来自几个大鼠品系的胚胎组织和根据其他测试被认为无病毒的细胞系p30呈阴性。携带含有莫洛尼鼠肉瘤病毒（RaLV）肿瘤的大鼠不含针对RaLV p30的游离循环抗体。对51份人类肿瘤提取物（包括两个肿瘤细胞系）进行了RaLV种内测定活性测试，对47份进行了种间测定活性测试，这些提取物经过Sephadex凝胶过滤，并收集了分子量在15000至40000范围内的物质。在种间测定中灵敏度水平为7 ng/ml（0.7 ng/测定）时，除一个例外，所有人类组织均为阴性。基于标记抗原的蛋白水解作用，这一阳性结果被认为是非特异性的。纯化肿瘤提取物的输入组织蛋白平均为1.9 mg/ml，范围为小于0.025至22 mg/ml。以相同方式处理的NIH瑞士小鼠的组织在种间测定中呈阳性，但在种内RaLV测定中呈阴性。
