CpG-DNA对金黄色葡萄球菌诱导的大鼠实验性乳腺炎的作用  

Effect of CpG-DNA on mastitis induced by Staphylococcus aureus infection in rat models

作　　者：朱于敏[1] 陈伟华[1] 邹思湘[1] 

机构地区：[1]南京农业大学农业部动物生理生化重点开放实验室,江苏南京210095

出　　处：《中国兽医学报》2007年第2期240-244,共5页Chinese Journal of Veterinary Science

基　　金：国家自然科学基金资助项目(30371049)

摘　　要：72只泌乳期SD雌性大鼠随机均分成对照组和试验组(n=36),对照组于产后0h左后腿胫骨前肌内注射0.01mol/L、pH7.2 PBS100μL/只;试验组肌注CpG-DNA 200μg/只。产后72h经乳头管灌注2×1012CFU/mL金黄色葡萄球菌各100μL/侧到第4对乳腺(两侧)内。分别于灌注前0h,灌注后8、16、24、48和72h(n=6)颈静脉放血处死。结果显示,乳腺组织细菌数在灌注后24h上升至最高,CpG-DNA能显著降低8、16和72h的细菌数。IL-2在不同时间点有显著下降,对照和试验组乳腺组织IL-2分别在16和24h下降至最低。TNF-α在24h达最高,CpG-DNA能显著提高0、24和72h乳腺组织TNF-α水平。CpG-DNA能显著提高血清感染后各时间点及乳腺组织0和16h MPO水平。乳腺组织NAGase和白蛋白在24h上升至最高,血清中24h下降至最低。CpG-DNA能显著降低48和72h乳腺组织NAGase活力,并极显著降低8和72h乳腺白蛋白浓度。上述结果显示,CpG-DNA可促进细胞因子的产生,减少乳腺组织细菌数量,减轻炎症介质对细胞和血-乳屏障完整性的损伤,提示CpG-DNA对金黄色葡萄球菌感染诱发的大鼠乳腺炎有一定的保护作用。Seventy-two lactating SD rats were randomly divided into control and treatment group.The 100 μL of sterile 0.01 mol/L,pH7.2 PBS(control),CpG-DNA 200 μg/rat(treatment group) were injected intramuscularly into tibialis anterior of the left leg at 72 h after parturition respectively.Then 100 μL/rat of bacterial suspension containing 2×1012 CFU/mL(both group) of Staphylococcus aureus were inoculated into the fourth(two sides) mammary gland via the teat duct at 72 h after parturition respectively.Before and after 8 h,16 h,24 h,48 h and 72 h(n=6) of inoculation,all the rats were euthanatized and the mammary glands and serum were harvested.Significant decreases in IL-2 were observed at different time points in both groups.Maximal decreases of IL-2 were observed in control at 16 h postinfection and in treatment group at 24 h.CpG-DNA induced significant elevated IL-2 before infection compared with control.Significant increases of TNF-α in mammary gland were observed at different time points in both groups.Maximal amounts of TNF-α was observed at 24 h postinfection.CpG-DNA elicited significant elevated TNF-α in mammary gland before infection,at 24 h and 72 h postinfection.CpG-DNA induced significant increase of MPO in serum at all time points postinfection and in mammary gland before infection and at 16 h postinfection.Bacteria counts in mammary gland peaked at 24 h postinfection and CpG-DNA induced significant decrease of viable bacteria at 8 h,16 h and 72 h postinfection.There were maximal increase of NAGase and albumin in mammary gland at 24 h postinfection and maximal decrease in serum at 24 h postinfection.CpG-DNA could significantly reduce activity of NAGase in mammary gland at 48 h and 72 h postinfection and concentration of albumin in mammary gland at 8 h and 72 h postinfection.The results showed that CpG-DNA stimulated the secretion of cytokines,decreased the bacteria counts in mammary gland and attenuate the destroy of inflammation-mediator to blood-milk barrier.It is considered that to some extent CpG-DNA

关 键 词：CPG-DNA 乳腺炎 大鼠 金黄色葡萄球菌 

分 类 号：S857.26[农业科学—临床兽医学] S852.611[农业科学—兽医学]