Institute of Animal Science, Physiology and Hygiene Group, University of Bonn, Germany.
Vet Microbiol. 2010 Jul 14;143(2-4):293-8. doi: 10.1016/j.vetmic.2009.11.035. Epub 2009 Dec 5.
Human psoriasin (S100A7) has been described as a member of the family of S100 calcium-binding proteins and is over-expressed in patients suffering from psoriasis. The bovine homolog was first identified as a cow-derived respiratory allergen. Human psoriasin as well as its bovine homolog exhibit antibacterial activity especially against Escherichia coli. During E. coli mastitis, the host defence status is a cardinal factor influencing systemic disease severity, and E. coli mastitis is a common problem in dairy cattle. We therefore examined by immunoblotting and immunohistochemistry whether and in which location the bovine protein is expressed in the mammary gland and whether this expression is inducible by E. coli infection. Additionally, milk samples from the cows were investigated. To obtain an antiserum, rabbits were immunised with recombinant bovine psoriasin. Six German Holstein cows in their first lactation were used; four of them were intramammarily infected with an E. coli strain isolated from udder secretions of cows with clinical mastitis, two cows served as healthy control animals. After 24h, cows were slaughtered and samples were collected from three different locations of the quarters. Psoriasin expression was limited to the teat cistern of the E. coli-infected cows, but was absent in the teat cistern of the non-infected cows and in the parenchyma of both groups, whereas the expression on udder skin was demonstrated in both infected and non-infected cows. Psoriasin thus appears to be a part of the local host defence mechanisms in the udder and seems to be inducible by infection with E. coli.
人源角蛋白 17（S100A7）被描述为 S100 钙结合蛋白家族的成员，在患有银屑病的患者中过度表达。牛源同系物最初被鉴定为牛源呼吸过敏原。人源角蛋白 17及其牛源同系物均具有抗菌活性，特别是对大肠杆菌。在大肠杆菌乳腺炎中，宿主防御状态是影响全身疾病严重程度的关键因素，而大肠杆菌乳腺炎是奶牛的常见问题。因此，我们通过免疫印迹和免疫组织化学检查了牛蛋白在乳腺中的表达情况及其是否可以被大肠杆菌感染诱导。此外，还对奶牛的奶样进行了研究。为了获得抗血清，用重组牛源角蛋白 17 免疫兔子。使用 6 头处于泌乳期的德国荷斯坦奶牛；其中 4 头经乳腺内感染从患有临床乳腺炎的奶牛乳汁中分离的大肠杆菌菌株，2 头奶牛作为健康对照动物。24 小时后，奶牛被屠宰，从四个象限的三个不同部位采集样本。角蛋白 17 的表达仅限于大肠杆菌感染奶牛的乳池，但在未感染奶牛的乳池和两组的实质中均不存在，而在两组奶牛的乳房皮肤上均有表达。因此，角蛋白 17 似乎是乳腺局部宿主防御机制的一部分，似乎可以被大肠杆菌感染诱导。
