Regulation of immune system in newly hatched chicks by control of cytokine production

本研究旨在通过营养调控雏鸡孵化后第1周细胞因子的产生，提高雏鸡的免疫功能，尤其是脾脏T细胞功能。在孵化后的第一周，增殖反应和脾脏淋巴细胞mRNA表达估计的白细胞介素2的产生较低，但干扰素γ没有。营养缺乏不仅在孵化后第一周显著降低T细胞功能，而且在生长后期也显著降低T细胞功能。残留的蛋黄可能有助于维持功能。蛋黄中的DHA是增强T细胞功能的必需营养素，但不足以完全增强T细胞功能。其他脂溶性物质是必需的。共轭亚油酸和木糖醇是增强免疫力的新型营养物质，雏鸡单次口服木糖醇可改善雏鸡的生长和T细胞功能。流式细胞术分析表明，膳食DHA和共轭亚油酸可能影响胸腺T细胞的分化。目前尚未发现由2-T细胞产生的雏鸡白细胞介素4与哺乳动物高度同源。建立了实时PCR检测诱导NOS、Cox-2和ppar - γ mRNA的方法。结果表明，在雏鸡孵化后的最初几周内，通过营养调控来调节细胞因子的产生，从而增强免疫功能，尤其是脾脏T细胞功能，这可能与DHA、共轭亚油酸和木糖醇等营养物质对细胞因子产生的影响有关，本研究建立的方法有助于了解新孵化雏鸡的T细胞功能。

This research was conducted to enhance immunity especially splenic T cells function through the regulation of cytokine production during first weeks afler hatch of chicks by nutritional manipulation. Proliferative response and interleukin 2 production estimated by mRNA expression in splenic lymphocytes was low during first weeks after the hatch, but interferon-gamma was not. Nutrients deficiency markedly lowered the T cell functions in not only during first week after the hatch but also in the later of growth stage. Residual egg yolk may contribute to maintain the functions. DHA in egg yolk was an essential nutrient to enhance T cell function, but it was not enough to completely enhance the function. The other fat soluble substance(s) would be required. Conjugated linoleic acid and xylitol are novel nutrients to enhance immunity, and a single oral administration of xylitol with newly hatched chicks improved latter growth and T cell functions. Flow cytometry analysis showed suggested that dietary DHA and conjugated linoleic acid may be affect T cell differentiation in thymus. Highly homologous chicks' interleukin 4 to mammals, produced by type 2-T cell has not been identified at the present research. The method for determination of inducible NOS, Cox-2 and PPAR-gamma mRNA by real time PCR has been developed. The result suggests that an enhancement of immunity especially splenic T cells function through the regulation of cytokine production during first weeks after hatch of chicks by nutritional manipulation is available to due change in cytokine production by nutrients such as DHA, conjugated linoleic acid and xylitol, and the method developed in this research is useful to understand the T cell functions in newly hatched chicks.