Polysaccharide Nucleic Acid of Bacillus Calmette Guerin Modulates Th1/Th2 Cytokine Gene Expression in Lipopolysaccharide-Induced Mastitis in Rats  

作　　者：MIAO Jin-feng ZHANG Yuan-shu HUANG Guo-qing MA Hai-tian ZOU Si-xiang ZHU Yu-min 

机构地区：[1]College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, P.R. China [2]Institute of Animal Science and Veterinary Medicine, Shanghai Academy of Agricultural Sciences, Shanghai 201106, P.R.China

出　　处：《Agricultural Sciences in China》2009年第8期1010-1018,共9页中国农业科学（英文版）

基　　金：sponsored by grants from the National Natural Science Foundation of China(30371049,30671533);the Scientific Research Innovation Foundation of Graduate Students of Jiangsu Province,China(CX07B-195Z)

摘　　要：The aim of this study was to evaluate, in rats, the changes in the T helper type 1（Th1）/Th2 radio in mammary glands after an intramammary infusion of lipopolysaccharide （LPS） and to characterize the moderating effects of the polysaccharide nucleic acid of Bacillus Calmette Guerin （BCG-PSN） on the mammary gland. In the control group, the levels of IL-2 and INF-7 mRNA expression increased, whereas IL-4 mRNA expression decreased after LPS challenge. As a consequence, the INF-γ/IL-4 mRNA ratio was significantly higher at 3, 6, and 9 h post-infusion （PI） compared to the control value （0 h; P〈0.01）. BCG-PSN increased mRNA expression of both INF-γ and IL-4 before infusion of LPS. LPS challenge significantly the reduced Th1/Th2 cytokine ratio due to Thl cytokine IFN-γ suppression and Th2 cytokine IL-4 upregulation compared with the control group. A significant reduction of N-acetyl-β-D-glucosaminidase （NAGase） was observed at 24 h PI in the BCG-PSN treatment group compared to the control group （P〈 0.05）. Thus, it was demonstrated that level of BCG-PSN might change the Th1/Th2 ratio mainly by enhancing the Th2 immune response. This is the first report of a Th1/Th2 change induced by coliform mastitis and characterization of the effect of BCG-PSN on mammary gland inflammation. This study makes a better understanding of the mechanisms of coliform mastitis and provides a putative novel strategy for the prevention and/or treatment of mastitis.The aim of this study was to evaluate, in rats, the changes in the T helper type 1（Th1）/Th2 radio in mammary glands after an intramammary infusion of lipopolysaccharide （LPS） and to characterize the moderating effects of the polysaccharide nucleic acid of Bacillus Calmette Guerin （BCG-PSN） on the mammary gland. In the control group, the levels of IL-2 and INF-7 mRNA expression increased, whereas IL-4 mRNA expression decreased after LPS challenge. As a consequence, the INF-γ/IL-4 mRNA ratio was significantly higher at 3, 6, and 9 h post-infusion （PI） compared to the control value （0 h; P〈0.01）. BCG-PSN increased mRNA expression of both INF-γ and IL-4 before infusion of LPS. LPS challenge significantly the reduced Th1/Th2 cytokine ratio due to Thl cytokine IFN-γ suppression and Th2 cytokine IL-4 upregulation compared with the control group. A significant reduction of N-acetyl-β-D-glucosaminidase （NAGase） was observed at 24 h PI in the BCG-PSN treatment group compared to the control group （P〈 0.05）. Thus, it was demonstrated that level of BCG-PSN might change the Th1/Th2 ratio mainly by enhancing the Th2 immune response. This is the first report of a Th1/Th2 change induced by coliform mastitis and characterization of the effect of BCG-PSN on mammary gland inflammation. This study makes a better understanding of the mechanisms of coliform mastitis and provides a putative novel strategy for the prevention and/or treatment of mastitis.

关 键 词：LIPOPOLYSACCHARIDE rat mastitis TH1/TH2 BCG-PSN 

分 类 号：S-03[农业科学]