Weber Annika, Weber Allen T, McDonald Thomas L, Larson Marilynn A
Department of Pathology and Microbiology, University of Nebraska Medical Center, 4028 Wittson Hall, 986495 Nebraska Medical Center, Omaha, NE 68198-6495, USA.
Vet Immunol Immunopathol. 2006 Jan 15;109(1-2):79-83. doi: 10.1016/j.vetimm.2005.07.023. Epub 2005 Aug 31.
Mastitis is one of the most costly diseases of agriculturally important animals and is a common problem for lactating cows. Current methods used to detect clinical and especially subclinical mastitis are either inadequate or problematic. Pathogens such as the gram-positive bacterium Staphylococcus aureus or the gram-negative bacterium Escherichia coli typically cause mastitis. E. coli induces clinical mastitis, whereas, S. aureus causes a subclinical, chronic infection of the mammary gland. In this study we report the differential expression and secretion of mammary-derived serum amyloid A3 (SAA3) by bovine mammary epithelial cells following stimulation with the S. aureus cell wall component, lipotechoic acid (LTA). Two-dimensional immunoblot analyses confirmed that bovine SAA3 is the predominant SAA isoform produced by LTA stimulated mammary epithelial cells. Our previous study showed that bovine SAA3 is also differentially expressed in response to the gram-negative bacterial endotoxin lipopolysaccharide. Collectively, these data indicate that the local production of SAA3 by mammary epithelial cells in response to either gram-positive or gram-negative bacterial components may provide a sensitive indicator for early detection and treatment of mastitis in vivo, minimizing chronic cases of infection, the spread of mastitis to other animals, and economic losses.
乳腺炎是农业重要动物中代价最高的疾病之一，也是泌乳奶牛的常见问题。目前用于检测临床乳腺炎尤其是亚临床乳腺炎的方法要么不充分，要么存在问题。革兰氏阳性菌金黄色葡萄球菌或革兰氏阴性菌大肠杆菌等病原体通常会引发乳腺炎。大肠杆菌引发临床乳腺炎，而金黄色葡萄球菌则导致乳腺的亚临床慢性感染。在本研究中，我们报告了在用金黄色葡萄球菌细胞壁成分脂磷壁酸（LTA）刺激后，牛乳腺上皮细胞中乳腺来源的血清淀粉样蛋白A3（SAA3）的差异表达和分泌情况。二维免疫印迹分析证实，牛SAA3是LTA刺激的乳腺上皮细胞产生的主要SAA亚型。我们之前的研究表明，牛SAA3在对革兰氏阴性菌内毒素脂多糖的反应中也存在差异表达。总体而言，这些数据表明，乳腺上皮细胞对革兰氏阳性或革兰氏阴性细菌成分的反应中局部产生的SAA3可能为体内乳腺炎的早期检测和治疗提供一个敏感指标，从而将慢性感染病例、乳腺炎向其他动物的传播以及经济损失降至最低。
