Cell population, viability, and some key immunomodulatory molecules in different milk somatic cell samples in dairy cows
Cell population, viability, and some key immunomodulatory molecules in different milk somatic cell samples in dairy cows
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DOI：
10.1017/s0022029909004129
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发表时间：
2009-08-01
影响因子：
2.1
通讯作者：
Wellnitz, Olga
中科院分区：
文献类型：
--
作者：
Baumert, Amandine;Bruckmaier, Rupert M.;Wellnitz, Olga
牛奶中的免疫细胞在对抗入侵乳腺的病原体方面是最重要的。这项研究调查了体乳细胞的免疫能力和活力，这些细胞已经存在于牛奶和乳房中，没有感染。在新鲜取出的乳汁中研究细胞，以模拟乳房中的条件。分析了孵育、细胞制备和用来自大肠杆菌的0-5 μ g/ml脂多糖（LPS）的免疫刺激的效果。比较了高体细胞计数和低体细胞计数（SCC）乳区之间的乳细胞活力和分类计数，以及有和无LIPS刺激的池状和肺泡乳。孵育和制备的细胞造成的细胞损失，进一步增加与SCC和牛奶部分独立的时间。这些细胞的活力在孵育后3小时内保持稳定，并在孵育后6小时内下降。两种研究之间的细胞群不同，但在实验过程中没有变化。通过qPCR测量的细胞免疫和凋亡因子的mRNA表达基本上没有变化：caspase 3、Toll样受体4和GM-CSF的mRNA表达没有变化，而死亡受体Fas/APO-1（CD 95）、乳铁蛋白和溶菌酶的表达在6 h时降低。LPS处理6 h后COX-2和TNF-α mRNA表达降低。与其他体内或体外研究（细胞培养）相比，在本研究中，离体研究细胞（从乳房中取出，但保留在其自然环境中，乳汁），与病原体刺激后从血液中新鲜迁移到乳汁中的细胞相比，常驻乳汁细胞似乎更脆弱，活力更低，对刺激的反应能力更低，因此免疫能力更低。细胞活力和差异细胞计数之间的差异高和低SCC牛奶和池和肺泡奶取决于个别奶牛。总之，结果支持这样的观点，即为了最有效地防御入侵的病原体，乳腺依赖于从血液中招募新鲜的免疫细胞。
Immune cells in the milk are most important in combating pathogens that invade the mammary gland. This study investigated the immune competence and viability of somatic milk cells that are already resident in milk and udders free of infection. Cells were studied in freshly removed milk to simulate conditions in the udder. Effects of incubation, cell preparation, and immunological stimulation with 0-5 mu g/ml lipopolysaccharide (LPS) from Escherichia coli were analysed. Viability and differential counts of milk cells between high and low somatic cell count (SCC) quarters, and cisternal and alveolar milk with and without LIPS stimulation were compared. Incubation and preparation of cells caused a cell loss which further increased with time independently of SCC and milk fraction. The viability of these cells was stable until 3 h post incubation and decreased until 6 h. Cell populations differed between both investigations, but did not change during the course of the experiment. mRNA expression of immune and apoptosis factors of the cells, measured by qPCR, did not change substantially: mRNA expression of caspase 3, Toll like receptor 4, and GM-CSF did not change, whereas the expression of the death receptor Fas/APO-1 (CD95), lactoferrin and lysozyme was decreased at 6 h. Cyclooxygenase-2 and TNF-alpha mRNA expression were decreased after 6 h of LPS treatment. In comparison with other studies in vivo or in vitro (in cell culture), in this study where cells are studied ex vivo (removed from the udder but kept in their natural environment, the milk) resident milk cells seem to be more vulnerable, less viable, less able to respond to stimulation, and thus less immune competent compared with cells that have freshly migrated from blood into milk after pathogen stimulation. The cell viability and differential cell count differed between high- and low-SCC milk and between cisternal and alveolar milk depending on the individual cow. In conclusion, the results support the view that for a most effective defence against invading pathogens the mammary gland is reliant on the recruitment of fresh immune cells from the blood.