CpG-ODN enhances mammary gland defense during mastitis induced by Escherichia coli infection in goats.
Seven healthy native goats in early lactation, weighing 30-40 kg, were used in this study. The right mammary gland of the seven does were infused with CpG-ODN at a dosage of 100 microg kg(-1) body weight on the day 5 postpartum (PP). The left glands were used as controls and infused with sterile phosphate-buffered saline (PBS). On day 8 PP, the same dosage of CpG-ODN or PBS was again infused. On day 9 PP, the mammary glands (both right and left) of the seven does were infused with 6 x 10(6) colony-forming units (CFU) Escherichia coli and, at 0, 8, 16, 24, 48 and 72 h postinfection (PI), milk samples were collected from all glands. Goats were euthanized at 72 h PI and the mammary tissue harvested. Infusion with 6 x 10(6)CFU ml(-1)E. coli induced acute mastitis. Histopathological evaluations showed that polymorphonuclear neutrophils (PMNs) were still present in alveoli at 72 h PI, but PMNs in the CpG-ODN-treated glands has disappeared. Bacteria counts in milk peaked at 16 h PI and CpG-ODN induced a significant decrease in viable bacteria from 16 h PI until the end of the experiment. This study showed that CpG-ODN promoted the expression of its specific receptor (TLR-9 mRNA) in mammary tissue, stimulated IL-6 production, reduced bacteria counts in milk, attenuated the impact of inflammation mediators on cells and significantly shortened the inflammation course. These results suggest that the CpG-ODN improved mammary gland defense and, thereby, had a beneficial effects against mastitis caused by E. coli infection in goats.
Zhu
Yu-Min
YM
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China. zym7712@yahoo.com.cn <zym7712@yahoo.com.cn>
Miao
Jin-Feng
JF
Zhang
Yuan-Shu
YS
Li
Zhen
Z
Zou
Si-Xiang
SX
Deng
Yue-E
YE
D000118:Acetylglucosaminidase / Q000032:analysis / Q000378:metabolism; D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000276:immunology / Q000662:veterinary*; D005260:Female; D005786:Gene Expression Regulation; D015511:Goat Diseases / Q000188:drug therapy / Q000276:immunology*; D006041:Goats; D015850:Interleukin-6 / Q000032:analysis; D008321:Mammary Glands, Animal / Q000166:cytology / Q000276:immunology* / Q000473:pathology; D008413:Mastitis / Q000188:drug therapy / Q000276:immunology / Q000662:veterinary*; D008892:Milk / Q000737:chemistry; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012709:Serum Albumin / Q000032:analysis; D013997:Time Factors; D051217:Toll-Like Receptor 9 / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D000276:Adjuvants, Immunologic; C408982:CPG-oligonucleotide; D015850:Interleukin-6; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D012709:Serum Albumin; D051217:Toll-Like Receptor 9; D014409:Tumor Necrosis Factor-alpha; D000118:Acetylglucosaminidase