Intramammary 25-hydroxyvitamin D3 treatment modulates innate immune responses to endotoxin-induced mastitis
Intramammary 25-hydroxyvitamin D3 treatment modulates innate immune responses to endotoxin-induced mastitis
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DOI：
10.3168/jds.2017-14143
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发表时间：
2018-08-01
影响因子：
3.5
通讯作者：
Nelson, Corwin D.
中科院分区：
文献类型：
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作者：
Merriman, Kathryn E.;Powell, Jessi L.;Nelson, Corwin D.
维生素D信号对病原体相关分子的应答有助于激活牛单核细胞的先天免疫反应。我们推测，奶牛乳房炎相关细菌的脂多糖(LPS)激活了乳房天然免疫细胞中的维生素D途径，增加25-羟基维生素D-3[25(OH)D-3]的可获得性将增强维生素D相关基因的表达。本实验的目的是确定乳房内注射内毒素和25(OH)D-3对乳房免疫细胞维生素D途径的激活和天然免疫反应的影响。分别用安慰剂、100 mU 25(OH)D-3、5 mU L PS或100 mW 25(OH)D-3+5 mU L PS处理5头哺乳奶牛。检测乳汁中中性粒细胞和巨噬细胞的比例以及维生素D代谢和天然免疫相关基因的表达。对激发后4~12h采集的样本数据进行分析，以了解内毒素和25(OH)D-3处理的主要影响、处理的交互作用和25(OH)D-3处理的简单影响。来自挑战时收集的样本的数据被用作协变量。在攻击后8h，乳中性粒细胞的百分比分别为对照组、25(OH)D-3、LPS和LPS+25(OH)D-3腺体乳中性粒细胞的58+/-10、82+/-11、89+/-10和63+/-10%，说明LPS和25(OH)D-3之间存在显著的相互作用。乳汁中总细胞、巨噬细胞和中性粒细胞中维生素D1a-羟基酶(CYP27B1)和维生素D受体基因的表达被内毒素处理上调。此外，25(OH)D-3和脂多糖处理上调了乳汁体细胞中维生素D24-羟基酶基因(CYP24A1)的表达。乳汁中诱导型一氧化氮合酶(INOS)、趋化因子(C-C-Motif)配体5(CCL5)、β-防御素3(DEFB3)、DEFB7和DEFB10基因表达上调。内毒素与25(OH)D-3的相互作用倾向于影响乳汁体细胞中iNOS的表达，即25(OH)D-3在无内毒素的情况下增加iNOS的表达，而在有内毒素的情况下不增加iNOS的表达。此外，25(OH)D-3下调巨噬细胞CCL5的表达。综上所述，乳房内毒素刺激激活了乳房巨噬细胞和中性粒细胞中的维生素D途径，乳房内25(OH)D-3处理改变了乳汁体细胞中中性粒细胞的百分比和免疫基因的表达。
Vitamin D signaling in response to pathogen-associated molecules contributes to activation of innate immune responses of bovine monocytes. We hypothesized that lipopolysaccharide (LPS) of bacteria associated with mastitis in dairy cows activates the vitamin D pathway in innate immune cells of the udder and that increasing availability of 25-hydroxyvitamin D-3 [25(OH) D-3] would augment expression of vitamin D-associated genes. The objective of this experiment was to determine the effects of intramammary LPS and 25(OH) D-3 treatments on activation of the vitamin D pathway and innate immune responses of mammary immune cells. Individual mammary quarters of 5 lactating cows were treated with placebo control, 100 mu g of 25(OH) D-3, 5 mu g of LPS, or a combination of 100 mu g of 25(OH) D-3 and 5 mu g of LPS. Somatic cells from milk were evaluated for percentage of neutrophil and macrophage populations and expression of genes associated with vitamin D metabolism and innate immunity. Data from samples collected from 4 to 12 h after challenge were analyzed for main effects of LPS and 25(OH) D-3 treatments, treatment interactions, and simple effects of 25(OH) D-3 treatment. Data from samples collected at the time of challenge were used as covariates. The percentages of neutrophils in milk at 8 h postchallenge were 58 +/- 10, 82 +/- 11, 89 +/- 10, and 63 +/- 10% of total cells in milk from control, 25(OH) D-3, LPS, and LPS plus 25(OH) D-3 glands, respectively, such that the interaction of LPS and 25(OH) D-3 was significant. Expression of the vitamin D 1a-hydroxylase (CYP27B1) and vitamin D receptor genes was upregulated by LPS treatment in total cells, macrophages, and neutrophils in milk. In addition, expression of the vitamin D 24-hydroxylase (CYP24A1) gene in milk somatic cells was upregulated by 25(OH) D-3 and LPS treatments. The inducible nitric oxide synthase (iNOS), chemokine (C-C-motif) ligand 5 (CCL5), beta-defensin 3 (DEFB3), DEFB7, and DEFB10 genes were upregulated by LPS treatment in total cells and neutrophils from milk. Expression of iNOS in milk somatic cells tended to be affected by the interaction between LPS and 25(OH) D-3, such that 25(OH) D-3 tended to increase iNOS in the absence of LPS but not in the presence of LPS. Furthermore, expression of CCL5 in macrophages was downregulated by 25(OH) D-3. In conclusion, intramammary endotoxin challenge activates the vitamin D pathway in mammary macrophages and neutrophils, and intramammary 25(OH) D-3 treatment alters the percentage of neutrophils and expression of immune genes in milk somatic cells.