Department of Animal Sciences, The Ohio State University, Wooster, OH, 44691, USA; Department of Poultry Sciences, University of Georgia, Athens, GA, 30602, USA.
Department of Animal Sciences, The Ohio State University, Wooster, OH, 44691, USA.
Dev Comp Immunol. 2019 Dec;101:103436. doi: 10.1016/j.dci.2019.103436. Epub 2019 Jul 5.
The effect of embryonic thermal manipulation on the post-hatch immune response to a lipopolysaccharide (LPS) challenge was studied in Pekin ducklings and turkey poults. Commercial duck and turkey eggs were distributed among four treatments: 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 ED16 and ED24, the egg shell temperature of the duck and turkey eggs in the HH and SH treatments were higher (P ≤ 0.01) than the SS treatment. Ducklings and poults in the HH treatment had the lowest yolk free body weight at hatch (P ≤ 0.05). At 24, 48, and 72 h post-LPS injection, ducklings and poults in the HH-LPS treatment had significantly reduced BW compared with the SS-Con treatments (P ≤ 0.05). Ducklings and poults in the SH-LPS and HH-LPS treatments had increased plasma heat shock protein 70 (HSP70) and lower splenic HSP70 mRNA amounts than the SS-LPS treatments at 24, and 48 h post-challenge (P ≤ 0.05). At 48 and 72 h, macrophage nitric oxide (NO) production in ducklings and poults in the SH-LPS and HH-LPS treatments was lower than in the SS-LPS treatments (P ≤ 0.05). Ducklings and poults in the SH-LPS treatment had increased thymocyte proliferation compared to the SS-LPS treatment at 24, 48 and 72 h (P ≤ 0.05). At 24 h, ducklings in the SH-LPS treatment had increased splenic IL-10 and reduced IFNγ and IL-6 mRNA abundance. However, both ducklings and poults in the HH-LPS treatment had increased IFNγ, and IL-10 mRNA abundance compared to the SS-LPS treatment (P ≤ 0.05). At 48 h, SH-LPS ducklings and poults had lower splenic IL-10 mRNA abundance (P ≤ 0.05) while the HH-LPS treatment resulted in comparable splenic IL-10 mRNA compared to the SS-LPS treatment (P ≥ 0.05). Ducklings and poults in the SH-LPS treatment had increased thymic and splenic CD8/CD4 ratios at 24 h versus the SS-LPS treatment (P ≤ 0.05). In conclusion, embryonic thermal manipulation from ED11-25 increased extracellular HSP70 release, thymocyte proliferation and IL-10 but decreased splenic HSP70 and IFNγ mRNA amounts at 24 h post-LPS injection. This suggests that mild heat stress during the later stages of incubation could potentially prime the embryonic immune system thereby enhances the immune response as earlier than 24 h to eliminate the inflammatory response without affecting the growth performance by increase the extracellular release of HSP70 in both ducklings and poults. Continuous exposure to the small increase in temperature from ED 1-25 (HH) caused an imbalance between pro (IFNγ)- and anti-inflammatory cytokines(IL-10) which affects hatchling responses to an inflammatory challenge and increased mortality. The amount of extracellular HSP70 could potentially play an important role in modulating the immune response against inflammatory challenges.
胚胎热操作对脂多糖（LPS）挑战后雏鸭和火鸡雏鸡的孵化后免疫反应的影响进行了研究。商业鸭蛋和火鸡蛋分配到四个处理组中：SS-对照（从胚胎日 [ED] 1 到 25 为 37.5°C）；SS-LPS（从 ED1 到 25 为 37.5°C+D0 时的 LPS）；HH-LPS（从 ED1 到 25 为 38°C+D0 时的 LPS）；SH-LPS（从 ED1 到 10 为 37.5°C，从 ED11 到 25 为 38°C+D0 时的 LPS）。在 ED16 和 ED24，鸭和火鸡蛋在 HH 和 SH 处理中的蛋壳温度高于 SS 处理（P≤0.01）。HH 处理的雏鸭和火鸡在孵化时蛋黄游离体重最低（P≤0.05）。在 LPS 注射后 24、48 和 72 小时，与 SS-Con 处理相比，HH-LPS 处理的雏鸭和火鸡的 BW 明显降低（P≤0.05）。与 SS-LPS 处理相比，在 LPS 注射后 24 和 48 小时，SH-LPS 和 HH-LPS 处理的雏鸭和火鸡的血浆热休克蛋白 70（HSP70）升高，脾 HSP70 mRNA 减少（P≤0.05）。在 48 和 72 小时时，SH-LPS 和 HH-LPS 处理的雏鸭和火鸡的巨噬细胞一氧化氮（NO）产生低于 SS-LPS 处理（P≤0.05）。与 SS-LPS 处理相比，在 24、48 和 72 小时时，SH-LPS 处理的雏鸭的胸腺细胞增殖增加（P≤0.05）。在 24 小时时，SH-LPS 处理的雏鸭的脾 IL-10 增加，IFNγ 和 IL-6 mRNA 丰度降低。然而，与 SS-LPS 处理相比，HH-LPS 处理的雏鸭和火鸡的 IFNγ 和 IL-10 mRNA 丰度增加（P≤0.05）。在 48 小时时，SH-LPS 处理的雏鸭的脾 IL-10 mRNA 丰度降低（P≤0.05），而 HH-LPS 处理导致脾 IL-10 mRNA 与 SS-LPS 处理相当（P≥0.05）。与 SS-LPS 处理相比，SH-LPS 处理的雏鸭在 24 小时时胸腺和脾 CD8/CD4 比值增加（P≤0.05）。总之，从 ED11-25 进行胚胎热操作增加了 LPS 注射后 24 小时的细胞外 HSP70 释放、胸腺细胞增殖和 IL-10，但降低了脾 HSP70 和 IFNγ mRNA 量。这表明在孵化后期轻度热应激可以潜在地启动胚胎免疫系统，从而增强免疫反应，比 24 小时更早地消除炎症反应，而不会通过增加 HSP70 在雏鸭和火鸡中的细胞外释放来影响生长性能。从 ED1-25 持续暴露于小的温度升高（HH）会导致促炎（IFNγ）和抗炎细胞因子（IL-10）之间的失衡，这会影响孵化后的对炎症挑战的反应，并增加死亡率。细胞外 HSP70 的量可能在调节对炎症挑战的免疫反应中发挥重要作用。
