淋巴结是传播朊病毒的关键

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发表在最新在线版刊物BMC Veterinary Research上的文章表示，淋巴结是传播少量朊病毒到神经系统的关键所在，这是羊搔痒症和人类克雅氏症的病原。

  尽管局域性的淋巴结对于神经系统感染大量的朊病毒并没有明显作用，但我们不能排除其它可能：淋巴结和朊病毒在身体内向其它非神经组织传播有关。

  以上研究由德国柏林的Robert-Koch研究所的Michael Beekes小组负责进行，这为揭开朊病毒是如何从感染区域转移到大脑和脊髓的机制带来了帮助，在中枢神经系统这些病原会造成不可逆转的致命损伤。

  Christine Kratzel和同事研究了淋巴系统在羊搔痒症转移到大鼠神经中的作用－淋巴系统是淋巴结组成的网络，这是我们身体的防御系统的一部分。小组发现在发生大量或中量朊病毒感染后6天内摘除感染处附近的淋巴结，动物依然会患病。而在感染前4周摘除，则高剂量病原致病而低剂量不会（在研究的整个314天时间内）。结果显示在发生低剂量病原感染时，淋巴系统对于朊病毒向中枢神经系统的转移很重要。

  小组同时发现在移除淋巴结而且伤口未愈合时，朊病毒感染会持续加速。以上发现非常重要，因为科学家对于淋巴系统和炎症反应在朊病毒感染在身体内的传播过程中的作用了解很少。而清楚了解病原传播的过程中各个因素能帮助科学家和医生发明新的预防和治疗朊病毒疾病的方法。（教育部科技发展中心）

　原文链接：http://www.physorg.com/news109905897.html

原始出处:

Relevance of the regional lymph node in scrapie pathogenesis after peripheral infection of hamsters

Christine Kratzel , Dominique Kruger and Michael Beekes

BMC Veterinary Research 2007, 3:22doi:10.1186/1746-6148-3-22

Published:25 September 2007

Abstract (provisional)

Background
The exact role of the lymphoreticular system in the spread of peripheral prion infections to the central nervous system still needs further elucidation. Against this background, the influence of the regional lymph node (Ln. popliteus) on the pathogenesis of scrapie was monitored in a hamster model of prion infection via the footpad.

Methods
Surgical lymphadenectomy was carried out at different time points after infection, or prior to inoculation, in order to elucidate the impact of the lymph node on lethal neuroinvasion.

Results
The Ln. popliteus did not show an influence on pathogenesis when a high dose of infectivity was administered. However, it was found to modulate the interval of time until the development of terminal scrapie in a subset of animals lymphadenectomized after low-dose infection. In additon, lymphadenectomy performed four weeks before inoculation prevented cerebral PrPTSE deposition and development of disease during the period of observation (314 days) in the majority of hamsters challenged with a very low dose of scrapie agent.

Conclusions
Our findings suggest the regional lymph node as a potentially facilitating or even essential factor for invasion of the brain after peripheral challenge with low doses of infectious scrapie agent. The invasive in vivo approach pursued in this study may be applied also to other animal species for further elucidating the involvement of lymphoid tissue in the pathogenesis of experimental and natural TSEs.