Immune development and performance characteristics of Romney sheep selected for either resistance or resilience to gastrointestinal nematodes.
Immune development and performance characteristics of Romney sheep selected for either resistance or resilience to gastrointestinal nematodes.
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罗姆尼羊的免疫发育和性能特征选择对胃肠道线虫具有抵抗力或恢复力。
DOI：
10.1016/j.vetpar.2017.12.013
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发表时间：
2018
影响因子：
2.6
通讯作者：
T. McNeilly
中科院分区：
文献类型：
--
作者：
A. Greer;J. McKenzie;R. McAnulty;J. Huntley;T. McNeilly
研究了罗姆尼绵羊对寄生虫感染的抗性和恢复力的免疫学和生产性能特征。在平均78 日龄时，来自抗性（RT）选系的双胞胎羔羊和来自弹性（RL）选系的羔羊感染肠道线虫色毛圆线虫100 天(I)，而它们的双胞胎仍然作为未感染的对照(C)。与RL相比，RT动物的循环CD4+ t细胞水平较低（P = 0.003），但这些细胞在感染反应中被激活（CD4+CD25+）的比例更高（P = 0.007）。不同系之间对线虫感染的体液免疫反应的差异随着高水平的ofT而变化。彩色虫特异性免疫球蛋白（Ig） E在RT-I中高于RL-I (P = 0.002)，但IgG （P = 0.926）和IgA （P = 0.321）反应水平相近。免疫反应的时间差异也存在于不同系之间，RT-I动物表现出更早的FEC峰值和更快速的降低，以及更早的inT峰值。colubriformisspecific IgA。此外，与RT-C和RL-C相比，感染导致第56天采食量减少22% (P = 0.001)，RT-I和RL-I的总采食量分别减少15%和9%。RL动物的累积活重增加最大（P = 0.026），相对于RT-C和RL- c， RT-I和RL- i分别减少5.8 kg和4.9 kg。总的来说，这些选择系似乎在免疫特性上存在差异，这些特性既依赖于寄生虫感染，又独立于寄生虫感染。此外，未感染动物的生长差异加上相似的感染成本表明，与rl - 1相比，rt - 1的活重增加较低可能是由于品系之间生长潜力的固有差异，而不是选择具有抗性的动物的感染成本更高。
Immunological and performance characteristics were explored in Romney sheep from lines selected for either resistance or resilience to parasite infection. At a mean 78 days-of-age, twin lambs from a line selected for resistance (RT) and lambs from a line selected for resilience (RL) were infected with the intestinal nematodeTrichostrongylus colubriformisfor 100 days (I) while their twin remained as an uninfected control (C). Compared with RL, RT animals had lower levels of circulating CD4+T-cells (P = 0.003) but a greater proportion of these were activated (CD4+CD25+) in response to infection (P = 0.007). Differences between the lines in humoral immune responses to nematode infection varied with higher levels ofT. colubriformisspecific immunoglobulin (Ig) E in RT-I than RL-I (P = 0.002) but similar levels of both IgG (P = 0.926) and IgA (P = 0.321) responses. Temporal differences in the immune response also existed between the lines with RT-I animals displaying an earlier peak and more rapid reduction in FEC and an earlier peak inT. colubriformisspecific IgA. In addition, compared with their RT-C and RL-C counterparts, infection caused a 22% reduction in feed intake from day 56 (P = 0.001) with total feed intake reduced by 15% and 9% for RT-I and RL-I, respectively. Cumulative liveweight gain was greatest for RL animals (P = 0.026) and relative to RT-C and RL-C was reduced by 5.8 kg and 4.9 kg for RT-I and RL-I, respectively. Overall, the selection lines appear to have differences in immunological characteristics that are both dependent on, and independent of parasite infection. Further, the difference in growth in the uninfected animals coupled with the similar cost of infection suggests the lower liveweight gain of RT-I compared with RL-I may be due to inherent differences between the lines in their growth potential, rather than a greater cost of infection in animals selected for resistance.