Effect of Lipopolysaccharide and Muramyl Dipeptide on Apoptosis of Bovine Mammary Gland Lymphocytes
Effect of Lipopolysaccharide and Muramyl Dipeptide on Apoptosis of Bovine Mammary Gland Lymphocytes
复制标题
脂多糖和胞壁酰二肽对牛乳腺淋巴细胞凋亡的影响
DOI：
10.3390/ani10060990
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发表时间：
2020-06-01
期刊：
影响因子：
3
通讯作者：
Zouharova, Monika
中科院分区：
文献类型：
--
作者：
Slama, Petr;Kabourkova, Eliska;Zouharova, Monika
奶牛乳腺炎是一个全球性的问题，给奶农造成了巨大的经济损失。炎症是由许多种细菌通过乳头管进入乳房引起的。这些细菌通常通过乳房内注射抗生素来消除，同时它们也被奶牛的免疫细胞消除。其中一种免疫细胞是淋巴细胞，负责特异性免疫。如果可行，它们能够履行其正常职能。本研究旨在探讨奶牛乳腺炎症过程中淋巴细胞的死亡。我们分析了在革兰氏阴性菌的内毒素和革兰氏阳性菌的细胞壁的天然内容物的脂多糖和胞壁酰二肽的刺激下乳腺淋巴细胞的凋亡。我们发现，它们在炎症的早期阶段诱导淋巴细胞凋亡，这可能与淋巴细胞上CD44受体的表达有关。该受体在许多生理过程中是重要的，包括细胞凋亡。为了更好地了解乳腺中的免疫反应和开发无抗生素的免疫治疗，炎症过程，包括免疫细胞的细胞死亡，需要进一步的整体研究。本研究旨在探讨大肠杆菌胞壁酰二肽（MDP）脂多糖（LPS）刺激淋巴细胞是否可调节淋巴细胞凋亡。通过在乳房内诱导炎症后24、48、72和168 h灌洗乳腺获得细胞群。LPS或MDP处理后48 h凋亡淋巴细胞比例达到高峰。相同细胞群的CD44表达分析显示，LPS或MDP诱导炎症后24和48小时，CD44阳性淋巴细胞的百分比较高。结果表明，在用LPS或MDP实验感染牛乳腺期间，在炎症反应的初始阶段诱导淋巴细胞凋亡，并且在炎症开始时CD44也过表达。这些数据表明淋巴细胞凋亡与CD44受体的表达有关。
Simple Summary Inflammation of the mammary gland in dairy cattle is a global problem and causes huge financial loss to dairy farmers. Inflammation is caused by many species of bacteria penetrating through the teat canals into the udder. Those bacteria are usually eliminated by treatment with intramammary injection of antibiotics, while they are also eliminated by the immune cells of the cow. One of the immune cells are lymphocytes which are responsible for specific immunity. When viable, they are able to carry out their normal functions. The present study focused on the investigation of cell death of lymphocytes during bovine mammary gland inflammation. We analyzed apoptosis in mammary gland lymphocytes under the stimulation of lipopolysaccharides and muramyl dipeptide as the endotoxin of Gram-negative bacteria and the natural content of the cell wall of Gram-positive bacteria. We found that they induce lymphocyte apoptosis in the early phase of inflammation, which can be associated with the expression of CD44 receptors on lymphocytes. This receptor is important in many physiological processes, including apoptosis of cells. For a better understanding of immune responses in mammary glands and for developing of immunotherapy without antibiotics, the process of inflammation, including cell death of immune cells necessitates further holistic studies. The aim of this study was to evaluate whether apoptosis of lymphocytes is modulated by stimulation by lipopolysaccharide (LPS) ofEscherichia colior muramyl dipeptide (MDP). Cell populations were obtained by lavaging of the mammary glands 24, 48, 72, and 168 h following intramammary induced inflammation. The portion of apoptotic lymphocytes peaked at 48 h after treatment with LPS or MDP. The analysis of CD44 expression of the same cell populations showed a higher percentage of CD44-positive lymphocytes 24- and 48-h following induction of inflammation by LPS or MDP. The results demonstrate that during both experimental infection of bovine mammary glands with LPS or MDP, apoptosis of lymphocytes was induced in the initial phase of the inflammatory response and CD44 was also overexpressed at the beginning of inflammation. These data suggest a connection of lymphocyte apoptosis with the expression of CD44 receptors.