Halliday A M, Routledge C M, Smith S K, Matthews J B, Smith W D
Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland, UK.
Parasite Immunol. 2007 Aug;29(8):425-34. doi: 10.1111/j.1365-3024.2007.00959.x.
Groups of yearling sheep, which had been trickle infected with Teladorsagia circumcincta for 8 weeks and then drenched, were challenged with 50 000 T. circumcincta larvae together with groups of worm-free controls. Fewer parasites and a greater proportion of early fourth stage larvae were recovered from previously infected sheep compared to controls. Worm loss and arrested development were evident by 5 days after challenge whereas growth retardation of developing worms was observed by day 10. In the previously infected sheep a secondary IgA response was observed in the efferent gastric lymph from 5 days post-infection. Western blot analysis showed the lymph IgA to be predominantly dimeric and nonsecretory in nature and that the somatic antigens recognized were predominantly in the 100-250 kDa range. The concentration of IgA in lymph was always higher than in blood and in the previously infected sheep increased fivefold 8 days post-challenge in contrast to blood where IgA levels were unchanged. The timing of the response suggested that it occurred too late to have been the cause of worm loss or arrested development, though it may have retarded the growth of developing parasites.
将一岁绵羊分成几组，这些绵羊已被环形泰勒虫持续感染8周，然后进行灌药，之后与未感染蠕虫的对照组一起，用50000条环形泰勒虫幼虫进行攻虫试验。与对照组相比，从先前感染的绵羊体内回收的寄生虫较少，早期第四期幼虫的比例更高。攻虫后5天，蠕虫损失和发育停滞明显，而在第10天观察到发育中蠕虫的生长迟缓。在先前感染的绵羊中，感染后5天在胃输出淋巴中观察到继发性IgA反应。蛋白质印迹分析表明，淋巴IgA主要为二聚体且本质上是非分泌性的，所识别的体抗原主要在100 - 250 kDa范围内。淋巴中IgA的浓度始终高于血液中的浓度，在先前感染的绵羊中，攻虫后8天IgA浓度增加了五倍，而血液中IgA水平未变。反应的时间表明，它发生得太晚，不可能是蠕虫损失或发育停滞的原因，尽管它可能阻碍了发育中寄生虫的生长。
