Molecular biological study of the latent viral infection and its reactivation of the human sensory ganglia in the temporal bone.

病毒感染，尤其是潜伏疱疹病毒的重新激活被认为是特发性周围性面神经麻痹(贝尔麻痹)、突发性感音神经性耳聋、前庭神经炎和Ramsey-Hunt综合征的可能原因。然而，到目前为止，HSV-1和VZV潜伏在膝状神经节、螺旋神经节和前庭神经节的感觉神经元中以及重新激活的途径尚不清楚。到目前为止，尽管我们在三叉神经节和膝状神经节中可以明显检测到潜伏期相关转录本(LAT)，但只有一个前庭神经节的LAT呈阳性，而螺旋神经节呈阴性。我们推测这些神经节之间感染拷贝数的差异可能会影响这些结果。为了阐明这个问题，在这个项目中，我们用分子生物学技术进一步研究了这些神经节。计算每个神经节之间的LAT相对量。三叉神经节和膝状神经节的HSV-1 DNA或LAT拷贝数是前庭神经节的10-100倍。计算出LAT在三叉神经节和膝状神经节的阳性杂交数占总神经节的百分比分别为1.2%和6.2%。前庭神经节阳性率低于0.1%，螺旋神经节未见阳性结果。提示HSV-1在不同感觉神经节的趋化性可能不同，但不同感觉神经节之间LAT阳性感染数的差异仍然是核的。

Viral infection, in particular, by reactivation of latent herpes virus has been considered to be a possible explanation for the pathogenesis of idiopathic peripheral facial nerve palsy (Bell's palsy), sudden sensorineural hearing loss, vestibular neuronitis and Ramsey-Hunt syndrome. As of yet, however, latent HSV-1 and VZV in the sensory neurons of the geniculate, spiral or vestibular ganglia and the way for reactivation has been sitll unknown.Up to now, although we could obviously detect latency-associated transcript (LAT) in trigeminal and geniculte ganglia, only one vestibular ganglia showed positive for LAT and negative in spiral ganglia. We postulated that the difference of infected copy number between these ganglia might influence these results. To elucidate this problem, in this project, we further examined these ganglia using molecular biological technique. A relative amount of LAT between each ganglia were calculated. HSV-1 DNA or copy number of LAT in trigeminal and geniculate ganglia were 10-100 times as many as taht of vbestibular ganglia. The percentage of positive hybridization number for LAT out of total ganglia calculated was 1.2% in trigeminal ganglion and 6.2% in geniculate ganglion. On the other hand, the positive rate in vestibular ganglion was under 0.1% and spiral ganglia showed no positive findings. Our results suggest the neurotropism of HSV-1 may different in each sensory ganglia, but the difference of positive infectid number for LAT between each sensory ganglia remains still nuclear.