SD大鼠天然抗日本血吸虫感染免疫特性的初步研究

为探讨SD大鼠天然抗日本血吸虫（Schistosoma japonicum,Sj)感染的免疫学特性，用间接ELISA检测正常大鼠血清（NRS）与感染大鼠血清（IRS）中抗成虫可溶性抗原（AWA）及抗可溶性虫卵抗原（SEA）的特异性抗体，并用酶联免疫印迹技术分析NRS、IRS对AWA的识别；将NRS经尾静脉被动转移至昆明小鼠，攻击感染后第45d解剖冲虫，计算减虫率与减卵率。结果显示NRS与IRS中抗AWA、抗SEA特异性IgG抗体水平均高于正常昆明小鼠血清中相应的抗体水平。AWA中有两个抗原分子可被NRS特异性识别，分子量为272kDa与236kDa；IRS则识别AWA中分子量为272kDa、236kDa和80kDa的特异性条带。用NRS被动转移后，与对照组相比，实验组小鼠的减虫率与减卵率分别为19.10%及46．42％。故大鼠血清中存在天然抗Sj感染的抗体，对Sj攻击感染及生殖发育具有一定的拮抗作用。

Preliminary Study on the Immunological Characteristics of Natural Resistance in Rat to Infection with Schistosoma japonicum

In order to explore the immunological characteristics of natural resistance to Schistosoma japonicum (Sj) infection in rat, the levels of antibodies that react to adult worm antigens (AWA) and soluble egg antigens (SEA) of Sj were assayed in normal rat's sera (NRS) and infected rat's sera (IRS) by indirect ELISA, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) and enzyme linked immunoblotting (ELIB) methods were used to recognize AWA by NRS and IRS. Passive transfer of NRS to Kunming mice was performed to observe the acquired protection. The results showed that the levels of IgG to AWA and SEA in NRS and IRS were significantly higher than the corresponding levels observed in the uninfected mice. NRS could specifically react to two molecules of 272 kDa and 236 kDa in AWA, and IRS specifically recognized three molecules of 272 kDa, 236 kDa and 80 kDa in AWA. Compared with the control group, the reduction rates of worm burden and LEPG in test group were 19.10% and 46.42%, respectively. So natural antibodies to Sj exist in rat, which may play an important role in the resistance to Sj infection.