Department of Animal Sciences, The Ohio State University, Wooster, OH 44691, United States of America.
Poult Sci. 2019 Feb 1;98(2):722-733. doi: 10.3382/ps/pey460.
During the course of multi-stage incubation, small locational differences in incubation temperature within a machine are not uncommon and so the goal of this study was to study the immune response of ducklings exposed to thermal manipulation during incubation. Commercial Pekin duck eggs (n = 200) were distributed among four treatment: SS-Control (37.5°C from embryonic day [ED] 1 to 25); SS-LPS (37.5°C from ED1 to 25 + LPS at D0 [hatch]); HH-LPS (38°C from ED1 to 25+ LPS at D0); SH-LPS (37.5°C from ED1 to 10 and 38°C from ED 11 to 25 + LPS at D0). At D0, ducklings received a lipopolysaccharide (LPS) injection. At D1 and D5, the HH-LPS treatment significantly reduced body weight (P ≤ 0.05). At D1 and D3 post-LPS injection, the SH-LPS and HH-LPS treatments significantly reduced splenic and bursal heat shock protein 70 (HSP70), mRNA abundance, and macrophage nitric oxide production compared with the SS-LPS treatment (P ≤ 0.05). At D1, the HH-LPS and SH-LPS treatments had increased splenic IL-10 mRNA and lower MHC I mRNA compared with the SS-LPS treatment (P ≤ 0.05). At D1, the HH-LPS treatment increased splenic IL-6 mRNA and bursal IFNγ mRNA transcription while the SH-LPS treatment reduced splenic IL-6 mRNA compared with the SS-LPS treatment (P ≤ 0.05). The HH-LPS treatment reduced thymocyte proliferation efficiency, while at D1, D3, and D5, the SH-LPS treatment increased thymocyte proliferation efficiency compared with the SS-LPS treatment (P ≤ 0.05). Ducklings in the HH-LPS treatment had a higher splenic CD8+/CD4+ ratio compared to the SS-LPS treatment at D3 post-LPS injection (P ≤ 0.05). In summary, the HH-LPS treatment compromised immunocompetence via decreased NO production and thymocyte proliferation efficiency, while the SH-LPS treatment increased body weight and thymocyte proliferation and reduced IL-6 mRNA abundance. This suggests that an embryonic temperature stress during the latter half of incubation may prime the immune system which may be beneficial during secondary post-hatch inflammatory challenges.
在多阶段孵化过程中，机器内孵育温度的小位置差异并不罕见，因此本研究的目的是研究在孵育过程中暴露于热处理的雏鸭的免疫反应。商业北京鸭蛋（n = 200）分布在四个处理组中：SS-Control（从胚胎日 [ED] 1 至 25 孵育温度为 37.5°C）；SS-LPS（从 ED1 至 25 孵育温度为 37.5°C，孵育第 0 天 [孵化] 给予 LPS）；HH-LPS（从 ED1 至 25 孵育温度为 38°C，孵育第 0 天给予 LPS）；SH-LPS（从 ED1 至 10 孵育温度为 37.5°C，从 ED11 至 25 孵育温度为 38°C，孵育第 0 天给予 LPS）。孵育第 0 天，雏鸭接受脂多糖（LPS）注射。孵育第 1 天和第 5 天，HH-LPS 处理组显著降低体重（P ≤ 0.05）。与 SS-LPS 处理相比，孵育第 1 天和第 3 天，SH-LPS 和 HH-LPS 处理组显著降低了脾脏和法氏囊热休克蛋白 70（HSP70）、mRNA 丰度和巨噬细胞一氧化氮的产生（P ≤ 0.05）。孵育第 1 天，与 SS-LPS 处理相比，HH-LPS 和 SH-LPS 处理组的脾脏 IL-10 mRNA 增加，MHC I mRNA 减少（P ≤ 0.05）。孵育第 1 天，HH-LPS 处理组增加了脾脏 IL-6 mRNA 和法氏囊 IFNγ mRNA 的转录，而 SH-LPS 处理组降低了脾脏 IL-6 mRNA 的转录，与 SS-LPS 处理相比（P ≤ 0.05）。HH-LPS 处理降低了胸腺细胞增殖效率，而 SH-LPS 处理在孵育第 1 天、第 3 天和第 5 天增加了胸腺细胞增殖效率，与 SS-LPS 处理相比（P ≤ 0.05）。与 SS-LPS 处理相比，孵育第 3 天 LPS 注射后，HH-LPS 处理组的脾脏 CD8+/CD4+比值更高（P ≤ 0.05）。总之，HH-LPS 处理通过降低 NO 产生和胸腺细胞增殖效率来损害免疫能力，而 SH-LPS 处理则增加了体重和胸腺细胞增殖，并降低了 IL-6 mRNA 丰度。这表明在孵化后期胚胎期温度应激可能会启动免疫系统，这可能在二次孵化后炎症挑战期间是有益的。
