Animal Nutrition Institute, Sichuan Agricultural University, Xinkang Road 46#, Ya'an, Sichuan Province 625014, People's Republic of China.
Br J Nutr. 2012 Sep 28;108(6):1069-76. doi: 10.1017/S0007114511006350. Epub 2012 Jan 3.
The present study evaluated whether dietary arginine (Arg) supplementation could attenuate immune challenge induced by Salmonella enterica serovar Choleraesuis C500 (S.C500) through the Toll-like receptor (TLR) 4-myeloid differentiation factor 88 (Myd88) signalling pathway in weaned piglets. A total of thirty-six weaned pigs were randomly allocated into six groups with six replicates per group. Pigs were subjected to three dietary treatments (namely two groups per treatment) in the first week (0-7 d) and fed with diets containing 0, 0·5 and 1·0 % l-Arg, respectively. On day 8, pigs were injected intramuscularly either with S.C500 or sterile saline. Serum samples were collected at day 8 (before injection), and at 1, 3 and 10 d post-injection, pigs were killed for evaluation of tissue gene expression following the last blood collection. Piglets fed the diets with 0·5 or 1·0 % Arg supplementation had a higher concentration of serum Arg (P < 0·05). S.C500-challenged piglets had higher (P < 0·05) serum antibody levels during the days 9-18. Weight gain and feed intake were decreased remarkably (P < 0·01) after the injection of S.C500, and 0·5 or 1·0 % Arg supplementation tended to alleviate the inhibition. The S.C500 challenge significantly enhanced (P < 0·05) serum C-reactive protein (CRP), interferon-γ and IL-12 concentrations, but Arg supplementation attenuated (P < 0·05) the increase in CRP level. The mRNA expression of TLR4, TLR5, Myd88, p65 NF-κB and TNF-α was up-regulated (P < 0·05) by the S.C500 challenge in different tissues, but was down-regulated (P < 0·05) by Arg supplementation. In conclusion, Arg supplementation could inhibit the excessive activation of the TLR4-Myd88 signalling pathway and thus attenuated the negative effects caused by the immune challenge of S.C500.
本研究评估了在断奶仔猪中，通过 Toll 样受体（TLR）4-髓样分化因子 88（Myd88）信号通路，饮食补充精氨酸（Arg）是否可以减轻沙门氏菌血清型霍乱 C500（S.C500）引起的免疫挑战。总共 36 头断奶仔猪被随机分配到 6 个组，每个组有 6 个重复。在第一周（0-7 d），猪接受了三种饮食处理（每组两种），分别用 0、0.5 和 1.0% l-Arg 喂养。在第 8 天，猪肌肉内注射 S.C500 或无菌生理盐水。在第 8 天（注射前）以及注射后 1、3 和 10 d 采集血清样品，在最后一次采血后评估组织基因表达。饲喂 0.5 或 1.0%Arg 补充剂的猪血清 Arg 浓度较高（P<0.05）。S.C500 攻毒猪在第 9-18 天血清抗体水平升高（P<0.05）。S.C500 注射后，猪的体重增加和采食量显著下降（P<0.01），0.5 或 1.0%Arg 补充剂有缓解抑制的趋势。S.C500 攻毒显著增加（P<0.05）血清 C 反应蛋白（CRP）、干扰素-γ和 IL-12 浓度，但 Arg 补充剂降低（P<0.05）了 CRP 水平的升高。TLR4、TLR5、Myd88、p65 NF-κB 和 TNF-α 的 mRNA 表达在不同组织中因 S.C500 攻毒而上调（P<0.05），但 Arg 补充剂下调（P<0.05）。综上所述，Arg 补充剂可抑制 TLR4-Myd88 信号通路的过度激活，从而减轻 S.C500 免疫挑战造成的负面影响。
