a Animal Nutrition Institute , Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, Sichuan Agricultural University , Ya'an , People's Republic of China.
Arch Anim Nutr. 2014;68(1):1-15. doi: 10.1080/1745039X.2013.869988. Epub 2014 Jan 15.
The present study was conducted to determine whether dietary threonine supplementation can improve immunity of weaned pigs challenged by swine Pseudorabies live vaccine (SPLV). Thirty crossbred piglets weaned at 21 days of age were randomly assigned to three groups receiving diets containing true ileal digestible threonine (TIDT) at 0.74, 0.89 and 1.11% for 14 days. On day 8, all pigs were injected intramuscularly with SPLV or sterile 0.9% NaCl solution. SPLV injection enhanced serum IgA, IgM, IgG, IFN-γ, IL-1β, TNF-α and IL-10 concentrations (p < 0.05) and stimulated the relative mRNA abundance of Toll-like receptors (TLR3, TLR7 or TLR9) in different tissues (p < 0.05). Under no challenge, increasing dietary TIDT levels enhanced serum IgG (p < 0.05), IgM (p = 0.07) and IFN-γ (p < 0.05) concentration, tended to decrease serum IL-1β, TNF-α and IL-10 concentration, and regulated relative mRNA abundance of TLR3, TLR7 or TLR9 in different tissues (p < 0.05). However, there was a synergistic role for increasing the serum IL-10 concentration between dietary TIDT levels and SPLV injection (p < 0.05). Under SPLV challenge, increasing dietary TIDT levels attenuated the increase of the serum IFN-γ concentration, and the increase of the relative mRNA abundance of TLR3, TLR7 and TLR9 in the different tissues (p < 0.05). These results suggest that an appropriate dietary threonine supplementation could improve the immune status of weaned pigs injected with SPLV by down-regulating the expression of TLR3, TLR7 and TLR9 in tissues, and thus regulating T-helper cytokine secretion.
本研究旨在确定饲粮添加苏氨酸能否改善猪伪狂犬病活疫苗（PRV）攻毒断奶仔猪的免疫功能。30 头 21 日龄断奶杂交仔猪随机分为 3 组，每组 10 个重复，每个重复 1 头仔猪。试验仔猪分别饲喂含真可消化苏氨酸（TIDT）0.74%、0.89%和 1.11%的试验饲粮 14 d。第 8 天，所有仔猪肌肉注射 PRV 或无菌 0.9%NaCl 溶液。PRV 攻毒显著提高了血清 IgA、IgM、IgG、IFN-γ、IL-1β、TNF-α和 IL-10 浓度（p<0.05），并刺激了不同组织 Toll 样受体（TLR3、TLR7 或 TLR9）相对 mRNA 丰度（p<0.05）。在无攻毒情况下，饲粮 TIDT 水平的提高显著提高了血清 IgG（p<0.05）、IgM（p=0.07）和 IFN-γ（p<0.05）浓度，血清中 IL-1β、TNF-α和 IL-10 浓度有降低的趋势，调节了不同组织 TLR3、TLR7 或 TLR9 相对 mRNA 丰度（p<0.05）。然而，饲粮 TIDT 水平与 PRV 注射之间存在协同作用，提高了血清 IL-10 浓度（p<0.05）。在 PRV 攻毒的情况下，饲粮 TIDT 水平的增加减弱了血清 IFN-γ浓度的增加，以及不同组织中 TLR3、TLR7 和 TLR9 相对 mRNA 丰度的增加（p<0.05）。这些结果表明，饲粮添加适量苏氨酸通过下调组织中 TLR3、TLR7 和 TLR9 的表达，调节 T 辅助细胞因子的分泌，从而改善注射 PRV 的断奶仔猪的免疫状态。
