Brewer A W, Osburn B I
Department of Veterinary Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, USA.
Arch Virol. 1998;143(1):145-55. doi: 10.1007/s007050050274.
Neurotropism of bluetongue virus (BLU) has been demonstrated in the developing brain of fetal ruminants and neonatal mouse models. Two strains of BLU serotype 11, UC8 and UC2, differentiated by their electrophoretic characteristics and abilities to cause brain lesions in bovine fetuses and neonatal mice were investigated to determine differences in tissue distribution in new born mice following subcutaneous inoculation. Tissue analysis by reverse transcriptase-polymerase chain reaction (RT-PCR) showed selective distribution of both BLU strains to the brain and spleen as early as 3 h post-inoculation (PI) but viral RNA was not detected in the blood or other tissues for the duration of the 15 day experiment. UC2 persisted within the brain and spleen until 9 h PI without development of CNS lesions. In contrast, UC8 persisted within the spleen for 24 h and in the brain through the end of the experiment. UC8 infected mice developed necrotizing lesions throughout the cerebrum and cerebellum that were most severe on PI days 11 and 13. Immunohistochemical staining for BLU identified infected cells within the brains of UC8 inoculated mice before inflammatory lesions were present and gave supportive evidence of the ability of UC2 to infect brain cells. Our results show that both UC8 and UC2 selectively target the brain and spleen in neonatal mice early after inoculation and suggest that the differences in neurovirulence between these strains are due to differences in replicative efficacy within host target cells.
蓝舌病病毒（BLU）的嗜神经性已在反刍动物胎儿和新生小鼠模型的发育中的大脑中得到证实。研究了两种11型蓝舌病病毒毒株UC8和UC2，它们通过电泳特征以及在牛胎儿和新生小鼠中引起脑损伤的能力来区分，以确定皮下接种后新生小鼠组织分布的差异。通过逆转录聚合酶链反应（RT-PCR）进行的组织分析表明，早在接种后3小时（PI），两种蓝舌病病毒毒株就选择性地分布于大脑和脾脏，但在为期15天的实验期间，在血液或其他组织中未检测到病毒RNA。UC2在大脑和脾脏中持续存在至接种后9小时，未出现中枢神经系统病变。相比之下，UC8在脾脏中持续存在24小时，并在整个实验结束时一直存在于大脑中。感染UC8的小鼠在整个大脑和小脑中出现坏死性病变，在接种后第11天和第13天最为严重。对蓝舌病病毒的免疫组织化学染色在炎症病变出现之前就鉴定出接种UC8的小鼠大脑中的感染细胞，并为UC2感染脑细胞的能力提供了支持性证据。我们的结果表明，UC8和UC2在接种后早期都选择性地靶向新生小鼠的大脑和脾脏，并表明这些毒株之间神经毒力的差异是由于宿主靶细胞内复制效率的差异所致。
