Department of Animal Science, University of Manitoba, Manitoba, Canada.
Poult Sci. 2012 Oct;91(10):2454-63. doi: 10.3382/ps.2012-02381.
We investigated the effects of dietary folic acid (FA) supplementation on immunological parameters in young laying hens under acute conditions of lipopolysaccharide (LPS) challenge. Twenty-four Shaver White laying hens at 24 wk were fed 2 diets in a completely randomized design. The diets were wheat-soybean based, with either 0 or 4 mg of supplemental FA per kilogram of diet. At 32 wk of age, 6 hens from each dietary treatment were injected intravenously with 8 mg/kg of BW of either LPS or saline. Four hours after injection, blood was collected and the hens were euthanized to obtain spleen and cecal tonsils. Heterophil:lymphocyte ratio, CD3+, CD4+, CD8+ T cells, and CD4+:CD8+ cells in the blood and spleen were not affected by dietary FA. Relative to saline-injected hens, LPS-injected hens had fewer (P < 0.05) CD3+, CD4+, CD8+, and CD4+:CD8+ cells in the blood, and no difference was found in the spleen. Total protein, albumin, and globulin were found to be higher (P < 0.05) in FA-supplemented hens compared with the control. However, total protein, albumin, and globulins decreased (P < 0.05) in the LPS-injected hens compared with the saline control. Expression of interleukin (IL)-1β in cecal tonsils decreased (P < 0.05) in FA-supplemented hens, but no dietary influence was found on the expression of other genes in both the spleen and cecal tonsils. Lipopolysaccharide upregulated (P < 0.05) expression of IL-10 and interferon (IFN)-γ in the spleen, and IL-1β, IL-10, and IFN-γ in the cecal tonsils, whereas the expression of Toll-like receptor (TLR)-4 and IL-8 was not influenced by LPS in the spleen and cecal tonsils. There was a diet × challenge interaction for total IgG, and cytokines IL-1β and IL-18 in the spleen as well as IL-18 in the cecal tonsils. In conclusion, there were few interactions of dietary FA and LPS; however, FA increased biochemical constituents, enhanced generation of total IgG, as well as exhibiting pleoitropic effects in inflammatory responses.
我们研究了在脂多糖（LPS）急性挑战下，日粮叶酸（FA）补充对年轻产蛋鸡免疫参数的影响。24 只 24 周龄的 Shavers 白产蛋鸡采用完全随机设计，饲喂 2 种日粮。日粮以小麦-豆粕为基础，分别含有 0 或 4mg/kg 日粮的补充 FA。在 32 周龄时，每个日粮处理的 6 只母鸡分别静脉注射 8mg/kg BW 的 LPS 或生理盐水。注射后 4 小时，采集血液，处死母鸡获取脾脏和盲肠扁桃体。血液中的异嗜粒细胞：淋巴细胞比值、CD3+、CD4+、CD8+T 细胞和 CD4+：CD8+细胞以及脾脏中均不受日粮 FA 的影响。与注射生理盐水的母鸡相比，注射 LPS 的母鸡血液中 CD3+、CD4+、CD8+和 CD4+：CD8+细胞较少（P＜0.05），而脾脏中则无差异。与对照组相比，添加 FA 的母鸡总蛋白、白蛋白和球蛋白含量较高（P＜0.05）。然而，与生理盐水对照组相比，注射 LPS 的母鸡总蛋白、白蛋白和球蛋白含量降低（P＜0.05）。添加 FA 可降低盲肠扁桃体中白细胞介素（IL）-1β的表达（P＜0.05），但对脾脏和盲肠扁桃体中其他基因的表达无影响。LPS 上调了脾脏中 IL-10 和干扰素（IFN）-γ（P＜0.05）的表达，以及盲肠扁桃体中 IL-1β、IL-10 和 IFN-γ的表达，但 LPS 对脾脏和盲肠扁桃体中 TLR-4 和 IL-8 的表达没有影响。在脾脏中总 IgG 以及细胞因子 IL-1β和 IL-18 和盲肠扁桃体中的 IL-18 中存在日粮与挑战的互作。总之，日粮 FA 和 LPS 之间的互作较少，但 FA 增加了生化成分，增强了总 IgG 的产生，并在炎症反应中表现出多效性。
