Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, UK.
Parasite Immunol. 2010 Feb;32(2):81-90. doi: 10.1111/j.1365-3024.2009.01173.x.
Groups of 5-month-old lambs which had been trickle infected with Teladorsagia circumcincta for 8 weeks then drenched, and worm-free control lambs were challenged with 50 000 T. circumcincta L3s. From 10 days later fewer parasites were recovered from the previously infected sheep, and secondary cellular and humoral responses were observed in the gastric lymph. Increases in CD4+ and CD25+ T lymphoblast traffic on day 3, followed by CD21+ and IgA+ lymphoblasts on day 5, and an increase in total and parasite specific IgA concentrations peaking on day 6 were observed in previously infected lambs. Similar peaks in lymphoblast output were not observed until days 10-12 in the control lambs. This data was highly comparable with that obtained recently from yearling sheep subjected to an identical infection-challenge regime, and contrasted with that obtained from similar experiments in the 1980s when 4(1/2)-month-old previously infected lambs were more susceptible to and had much weaker immune responses to challenge than 10-month-old sheep. The fact that 40% fewer larvae were given during the trickle infection regime in the four recent trials is offered as an explanation for this difference.
将 5 月龄绵羊分成若干组，每组 5 只，每组羊经微量感染捻转血矛线虫（Teladorsagia circumcincta）8 周后，再用虫体混悬液进行冲击感染，无虫对照组羊用 50,000 条捻转血矛线虫 L3 进行攻虫。攻虫后 10 天，从先前感染的绵羊中回收的寄生虫数量减少，胃淋巴液中观察到次级细胞和体液反应。攻虫后第 3 天，CD4+和 CD25+T 淋巴母细胞数量增加，第 5 天 CD21+和 IgA+淋巴母细胞增加，总 IgA 和寄生虫特异性 IgA 浓度在第 6 天达到峰值，先前感染的绵羊中观察到这些变化。在对照组羊中，直到攻虫后第 10-12 天，才观察到类似的淋巴母细胞输出峰值。这些数据与最近对接受相同感染-攻虫方案的一岁绵羊获得的数据高度可比，与 20 世纪 80 年代进行的类似实验结果形成对比，当时 4 个半月龄的先前感染绵羊比 10 月龄绵羊对攻虫更敏感，免疫反应也更弱。在最近的四次试验中，在微量感染方案中给予的幼虫数量减少了 40%，这一事实被认为是造成这种差异的原因。
