Department of Animal Sciences and Industry, Kansas State University, Manhattan, KS, United States.
Balchem Corporation, New Hampton, NY, United States.
Front Immunol. 2018 Oct 25;9:2448. doi: 10.3389/fimmu.2018.02448. eCollection 2018.
Dietary choline can impact systemic immunity, but it remains unclear whether this is primarily via direct impacts on immune cells or secondary effects of altered metabolic function. To determine whether increased choline concentrations (3.2, 8.2, 13.2 μM) in cell culture alter the function of bovine innate and adaptive immune cells, we isolated cells from dairy cows in early and mid-lactation as models of immuno-compromised and competent cells, respectively. Phagocytic and killing capacity of isolated neutrophils were linearly diminished with increasing doses of choline. In contrast, lymphocyte proliferation was linearly enhanced with increasing doses of choline. Furthermore, increasing doses of choline increased the mRNA abundance of genes involved in the synthesis of choline products (betaine, phosphatidylcholine, and acetylcholine) as well as muscarinic and nicotinic acetylcholine receptors in a quadratic and linear fashion for neutrophils and monocytes, respectively. Phagocytic and killing capacity of neutrophils and proliferation of lymphocytes were not affected by stage of lactation or its interaction with choline or LPS. In neutrophils from early lactation cows, choline linearly increased the mRNA abundance of muscarinic and nicotinic cholinergic receptors, whereas choline-supplemented monocytes from mid-lactation cows linearly increased the mRNA abundance of several genes coding for choline metabolism enzymes. These data demonstrate that choline regulates the inflammatory response of immune cells and suggest that the mechanism may involve one or more of its metabolic products.
膳食胆碱可以影响全身免疫，但目前尚不清楚这主要是通过直接影响免疫细胞还是改变代谢功能的继发效应。为了确定细胞培养物中胆碱浓度（3.2、8.2、13.2μM）的增加是否改变牛先天和适应性免疫细胞的功能，我们分别以免疫功能受损和功能正常的细胞为模型，从泌乳早期和中期奶牛中分离出细胞。分离的中性粒细胞的吞噬和杀伤能力随胆碱剂量的增加呈线性下降。相比之下，淋巴细胞的增殖随胆碱剂量的增加呈线性增加。此外，随着胆碱剂量的增加，参与胆碱产物（甜菜碱、磷脂酰胆碱和乙酰胆碱）合成的基因以及中性粒细胞和单核细胞中烟碱型和毒蕈碱型乙酰胆碱受体的 mRNA 丰度呈二次和线性增加。中性粒细胞的吞噬和杀伤能力以及淋巴细胞的增殖不受泌乳阶段或其与胆碱或 LPS 的相互作用的影响。在泌乳早期奶牛的中性粒细胞中，胆碱线性增加了烟碱型和毒蕈碱型胆碱能受体的 mRNA 丰度，而补充胆碱的泌乳中期奶牛的单核细胞则线性增加了编码胆碱代谢酶的几个基因的 mRNA 丰度。这些数据表明胆碱调节免疫细胞的炎症反应，并表明该机制可能涉及其一种或多种代谢产物。
