The role of macrophage-derived proteinase in Teller's virus-induced demyelination

塞勒病毒(TV)分为两个亚组。GDVII亚群毒株在小鼠脊髓引起急性脊髓灰质炎，而DA亚群毒株尽管在血清和CSF中存在高滴度的抗TV抗体，但仍可引起持续性脱髓鞘疾病。我们提出了位于VP1 3‘端的胰酶敏感中和表位，它可能对DA毒株的持久性和脱髓鞘起重要作用。目前的研究表明，GDVII株的中和表位也随着胰酶的切割而被破坏，病毒可以逃脱抗体的监测。副总统！然而，直接从中枢组织分离的GDVII毒株是完整的，尽管有报道从感染的CNS组织中分离到DA病毒VP1。此外，我们比较了急性GDVII感染与DA感染早期和晚期的CNS组织中单个核细胞的表型，并对病毒滴度、抗体滴度、淋巴细胞增殖反应进行了比较研究。结果表明，宿主免疫应答的差异可能是TV两个亚群生物活性不同的原因之一，而病毒复制的有效性也可能是影响TV生物学活性的另一个因素。

Theller's virus (TV) is divided into two subgroups. GDVII subgroups strains cause acute polioencephalomyelitis in the spinal cords of mice, whereas DA subgroup strains cause a persistent demyelinating disease in spite of the presence of high antibody titers against TV in the sera and CSF.We have proposed a trypsin-sensitive neutralizing epitope which locates at the 3' end of VP1 might be important for the persistence of DA strain and the demyelination. The present study revealed that the neutralizing epitope of GDVII strain is also disrupted along with trypsin cleavage and that the virus could be escaped from antibody surveillance. VP! of GDVII virous directly isolated from the CNS tissues is, however, intact although VP1 of DA virus from the infected CNS tissues is reported to be cleaved.In addition, we compared the phenotype of mononuclear cell infiltrates in the CNS tissue in acute GDVII infection with that in the early and the late stages of DA infection in conjunction with comparative studies of virus titers, antibody titers, lymphoproliferative responses. The results suggest that the difference in the host immune responses could contribute to the different biological activities between two subgroups of TV although the efficacy of virus replication could be abother factor as well.