Severe Combined Immunodeficient(SCID) Mice As Animal Models for Human Echinococcosis

本研究首先比较了两株严重联合免疫缺陷小鼠C.B-17/Icr-scid和NOD/Shi-scid对泡球蚴的敏感性。于感染后9周和12周，对两株菌腹腔下发育的后囊蚴进行称重和比较。NOD/Shi-scid在两周内均比C.B-17/Icr-scid表现出更高程度的增重。结果表明，scid基因的表达与巨噬细胞功能和补体活性的下降共同影响NOD/Shi-scid小鼠后绦虫的发育和生长。感染后1、2、3周，NOD/Shi-scid小鼠和对照NOD/Shi-+/+小鼠的后绦虫重量和形态均无明显差异。NOD/Shi-+/+小鼠在这些时间段内未发现rEm-18抗体。认为这是一个尚未产生抗体的潜伏期。感染后6周，NOD/Shi-scid小鼠迅速发生多囊化和原头节形成。NOD/Shi-scid小鼠对寄生虫的生长发育具有明显的耐受性。作者认为NOD/Shi-scid小鼠可作为人体包虫病的动物模型，并对NOD/Shi-scid小鼠与NOD/Shi-+/+小鼠之间的多囊蚴形成和原头节形成进行了定量研究。感染后6周，NOD/Shi-scid小鼠多囊化指数和原头节形成指数突然增加。而NOD/Shi-+/+小鼠，尽管寄生虫和炎症性墨角藻扩散，但多囊泡指数降低，而囊泡数量不变。NOD/Shi-scid小鼠的原头节指数也比NOD/Shi-+/+小鼠增加。因此，建立寄生虫生长发育指数的方法，可作为评价宿主敏感性、药物疗效、判断感染点的参考。

At first, two strains of sever combined immune-deficiency mice, C.B-17/Icr-scid and NOD/Shi-scid were compared with the sensitivity to Echinococcus multilocularis metacestode. At post infection 9 and 12weeks, the developed metacestode of two strains infra peritoneal cavities were weighed and compared. NOD/Shi-scid showed more high degree weight than C.B-17/Icr-scid at both points of weeks. It was suggested that scid-gene, declines of macrophage function and compliment activity were influenced together.So, development and growth of metacestode in NOD/Shi-scid were observed in detail. At post infection 1,2,3 weeks, between NOD/Shi-scid and control NOD/Shi-+/+ mice, there were no defferences both weight and morphologies of metacestodes. NOD/Shi-+/+ mice were not revealed for rEm-18 antibody in these periods. It was considered that so-called prepatent period which antibody was not yet producted in host immune system. After post infection 6 weeks, in NOD/Shi-scid mice, multivesiculation and formation of protoscolex were rapidly proceeded. NOD/Shi-scid mice showed striking torelance for the parasite development and growth. It was suggested that NOD/Shi-scid mouse would be a model for human echinococcosis.And moreover, it was attempted of quantification of multivesiculation and protoscolex formation of the parasite between NOD/Shi-scid and NOD/Shi-+/+ mice. After post infection 6 weeks, in NOD/Shi-scid mice, index of multivesiculation and protoscolex formation suddenly increased. While in NOD/Shi-+/+ mice, in spite of spread of parasite and inflamated fucus, index of multivesicelation was decreased for not changed number of vesicular. Index of protoscolex also increased more in NOD/Shi-scid mice than in NOD/Shi-+/+ mice. It was expected that index methods of these parasite development or growth was usefullness in evaluation of host sensitivity and drug efficacy, estimate of infectious point.