Barrett P N, Koschel K, Carter M, ter Meulen V
J Gen Virol. 1985 Jul;66 ( Pt 7):1411-21. doi: 10.1099/0022-1317-66-7-1411.
Maintenance of measles (SSPE-Lec) virus persistently infected C6 rat glioma cells in medium containing polyclonal measles antiserum resulted in the loss of detectable expression of all measles virus proteins. Removal of these cells from antiserum, however, led to a re-expression of virus proteins and the production of infectious virus. Cloning of antibody-modulated non-expressing cells in the presence of antiserum showed that re-expression of virus proteins was not due to an incomplete curing process following the addition of antiserum, as a large number of non-expressing cell clones developed the capacity to express measles virus antigen at different periods after removal of antiserum. Irradiation of persistently infected cells to give a non-growing culture showed that modulation was not mediated by a selection and outgrowth of a small percentage of non-expressing cells originally present in the culture. Antibody directed against C6 membrane proteins did not lead to modulation and it was also shown that only monoclonal antibodies with neutralizing activity could affect intracellular antigen expression. Immunoglobulin Fab fragments with neutralizing activity also had modulating activity. Although all modulated cell clones were more susceptible to homologous virus infection than control C6 cells, it was not possible to rescue any defective measles virus which may have been maintained in the culture.
在含有多克隆麻疹抗血清的培养基中持续培养麻疹（SSPE-Lec）病毒感染的C6大鼠胶质瘤细胞，导致所有麻疹病毒蛋白的可检测表达丧失。然而，将这些细胞从抗血清中移除后，病毒蛋白重新表达并产生有感染性的病毒。在抗血清存在的情况下对抗体调节的不表达细胞进行克隆，结果表明病毒蛋白的重新表达并非由于添加抗血清后治愈过程不完全所致，因为大量不表达细胞克隆在去除抗血清后的不同时期都获得了表达麻疹病毒抗原的能力。对持续感染的细胞进行辐照以获得不生长的培养物，结果表明调节作用不是由培养物中原本存在的一小部分不表达细胞的选择和生长介导的。针对C6膜蛋白的抗体不会导致调节作用，并且还表明只有具有中和活性的单克隆抗体才能影响细胞内抗原表达。具有中和活性的免疫球蛋白Fab片段也具有调节活性。尽管所有经调节的细胞克隆比对照C6细胞对同源病毒感染更敏感，但无法拯救培养物中可能存在的任何缺陷麻疹病毒。
