Thormar H, Mehta P D, Brown H R
J Exp Med. 1978 Sep 1;148(3):674-91. doi: 10.1084/jem.148.3.674.
The neurovirulence of two wild type (wt) and seven Subacute Sclerosing Panencephalitis (SSPE) measles virus strains was tested in young adult ferrets by intracerebral (IC) inoculation of infected Vero cell suspensions. Wt strains Edmonston and Woodfolk and SSPE strains Mantooth, Halle, and LEC-S did not produce a detectable encephalitis in the ferrets, but caused a significant formation of serum antibodies against measles virus. SSPE strains LEC, IP-3, Biken, and D.R., on the other hand, were all neurovirulent in ferrets, particularly strain D.R. which caused an acute encephalitis in all inoculated animals. Strain Biken was of particular interest since it caused a subacute encephalitis in four of seven ferrets. The subacute encephalitis was characterized by a long incubation time, persistence of virus in the brain for at least 8 mo, widespread inflammatory lesions, and production of measles virus specific IgG in the brain. A study of the biological properties of the various measles virus strains showed that wt strains Edmonston and Woodfolk and SSPE strains Mantooth, Halle, and LEC-S produced free virus particles in significant titers both in Vero and ferret brain (FB) cultures. Cytopathic effect (CPE) with cell-fusion was marked in Vero cultures, whereas only minimal CPE and no cell-fusion were observed in the FB cultures. SSPE strains LEC, IP-3, Biken, and D.R., on the other hand, were mostly cell-associated in Vero and FB cultures, although atypical cell-free particles were produced by strains Biken and IP-3. All four strains showed cell-fusing activity in FB cultures, particularly strain D.R., which was the only strain that spread more actively by fusion in FB than in Vero cultures. The results are discussed in relation to the neurovirulence of the various measles virus strains in adult ferrets. Pronounced cell-fusing activity in FB cells and cell-association with minimal or no production of cell-free virus seem to be essential to establish a brain infection in the animals.
通过向成年幼雪貂脑内接种感染的Vero细胞悬液，对两株野生型（wt）和七株亚急性硬化性全脑炎（SSPE）麻疹病毒株的神经毒力进行了检测。野生型毒株埃德蒙斯顿和伍德福克以及SSPE毒株曼图思、哈勒和LEC - S在雪貂中未引发可检测到的脑炎，但导致了针对麻疹病毒的血清抗体显著形成。另一方面，SSPE毒株LEC、IP - 3、比肯和D.R.在雪貂中均具有神经毒力，尤其是毒株D.R.，它在所有接种动物中引发了急性脑炎。毒株比肯特别引人关注，因为它在七只雪貂中的四只引发了亚急性脑炎。亚急性脑炎的特征是潜伏期长、病毒在脑中持续存在至少8个月、广泛的炎性病变以及脑中产生麻疹病毒特异性IgG。对各种麻疹病毒株生物学特性的研究表明，野生型毒株埃德蒙斯顿和伍德福克以及SSPE毒株曼图思、哈勒和LEC - S在Vero细胞和雪貂脑（FB）培养物中均产生了高滴度的游离病毒颗粒。在Vero细胞培养物中，伴有细胞融合的细胞病变效应（CPE）明显，而在FB培养物中仅观察到极小的CPE且无细胞融合。另一方面，SSPE毒株LEC、IP - 3、比肯和D.R.在Vero细胞和FB培养物中大多与细胞相关，尽管比肯和IP - 3毒株产生了非典型的游离颗粒。所有四株毒株在FB培养物中均显示出细胞融合活性，尤其是毒株D.R.，它是唯一在FB培养物中通过融合比在Vero细胞培养物中更活跃传播的毒株。结合各种麻疹病毒株在成年雪貂中的神经毒力对结果进行了讨论。FB细胞中明显的细胞融合活性以及与细胞的关联且极少或不产生游离病毒似乎是在动物中建立脑部感染的关键。
