Press Charles McL, Heggebø Ragna, Espenes Arild
Department of Morphology, Genetics and Aquatic Biology, Norwegian School of Veterinary Science, P.O. Box 8146 Dep., Oslo, Norway.
Adv Drug Deliv Rev. 2004 Apr 19;56(6):885-99. doi: 10.1016/j.addr.2003.09.008.
Scrapie is a transmissible spongiform encephalopathy (TSE) and its spread across the intestine of sheep is linked to the biology of intestinal Peyer's patches (PPs). Specialized epithelial cells, M cells, would appear to be the portal of entry for the scrapie agent, PrP(Sc), while lymphoid nodules of PPs become major sites of accumulation of PrP(Sc) as the infection becomes established. Furthermore, evidence suggests that the enteric nervous system supplying the PPs is important for neuroinvasion. The gut-associated lymphoid tissue (GALT) of ruminants shows morphological and functional differences to the GALT of mice and humans. Recent investigations of aging scrapie-affected sheep revealed a substantial network of nerve fibres in the lymphoid nodules of PPs, contradicting the widely held notion that lymphoid nodules are poorly innervated. Advances in the understanding of the pathogenesis of scrapie may be achieved by a deeper appreciation of the development, morphology and function of GALT in small ruminants.
羊瘙痒症是一种传染性海绵状脑病（TSE），其在绵羊肠道中的传播与肠道派伊尔氏结（PPs）的生物学特性有关。特化的上皮细胞，即M细胞，似乎是瘙痒病病原体PrP(Sc)的进入门户，而随着感染的建立，PPs的淋巴小结成为PrP(Sc)积累的主要部位。此外，有证据表明，为PPs提供神经支配的肠神经系统对神经侵袭很重要。反刍动物的肠道相关淋巴组织（GALT）在形态和功能上与小鼠和人类的GALT有所不同。最近对受瘙痒症影响的老龄绵羊的研究发现，PPs淋巴小结中有大量神经纤维网络，这与普遍认为淋巴小结神经支配不足的观点相矛盾。通过更深入地了解小型反刍动物GALT的发育、形态和功能，可能会在羊瘙痒症发病机制的理解上取得进展。
