Bunting Michaela, Challice Bethan, Gibson Amanda, van Winden Steven
Pathobiology and Population Sciences, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield AL9 7TA, UK.
London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
Animals (Basel). 2021 Sep 19;11(9):2739. doi: 10.3390/ani11092739.
This study investigated the association of copper levels and monocyte plasticity between M1 (CD14 CD16) and M2 (CD14 CD16) phenotypes. Five samples of female bovine PBMCs were incubated in 0, 4, 8 and 16 μM copper and stimulated (PPD-A, TLR- 2 ligand (PamCSK), or media alone) before they were washed and stained for cell surface expression analysis by flow cytometry. M1 function was measured through nitric oxide production using a Griess assay. Flow cytometry analysis showed a significant reduction in viability with increased copper ( < 0.001). Increasing copper had a significant impact on CD14 expression ( = 0.026) and in cows older than 4 years copper levels positively affected CD14 expression ( = 0.001), whereas in animals of four years or younger, Cu did not affect the CD14 expression ( = 0.701 and 0.939, respectively). CD14 expression affected both CD16 expression and NO production. For CD16 expression, there was a further significant negative effect of copper levels in cows older than 4 years, NO was not affected by varying copper levels. In our small sample, monocytes in the presence of a higher copper environment showed a stronger M1 support for better cellular immunity which might contain intracellular infections more effectively. To test this, a randomised clinical trial will be required to determine whether copper supplementation could prevent progression to Johne's disease in MAP infected cows.
本研究调查了铜水平与单核细胞在M1（CD14⁺CD16⁻）和M2（CD14⁺CD16⁺）表型之间可塑性的关联。将五份雌性牛外周血单核细胞样本分别置于0、4、8和16 μM的铜环境中孵育，并进行刺激（纯化蛋白衍生物A、Toll样受体2配体（PamCSK）或仅用培养基），之后进行洗涤并染色，通过流式细胞术分析细胞表面表达。使用格里斯试剂通过检测一氧化氮生成来测定M1功能。流式细胞术分析显示，随着铜浓度升高，细胞活力显著降低（P < 0.001）。铜浓度增加对CD14表达有显著影响（P = 0.026），在4岁以上的奶牛中，铜水平对CD14表达有正向影响（P = 0.001），而在4岁及以下的动物中，铜对CD14表达无影响（P分别为0.701和0.939）。CD14表达同时影响CD16表达和一氧化氮生成。对于CD16表达而言，在4岁以上的奶牛中，铜水平有进一步的显著负向影响，一氧化氮生成不受铜水平变化的影响。在我们的小样本中，处于较高铜环境中的单核细胞对M1的支持更强，可能更有效地抑制细胞内感染，从而增强细胞免疫。为验证这一点，需要进行一项随机临床试验，以确定补充铜是否可以预防感染副结核分枝杆菌的奶牛发展为约内氏病。
