左氏无绿藻对奶牛乳腺上皮细胞先天性免疫应答的影响

Prototheca zopfii is an important bovine mastitis pathogen, which could result in severe mammary infection. However, the innate immune response in bovine mastitis associated with P. zopfii was not clear. Therefore, the aim of this study is to investigate invitro innate immune responses implicated by P. zopfii.Bovine mammary epithelial cells (bMECs) were infected with5.0 x104 cells/ml P. zopfii genotype-II independently and the mRNA expression of TLR-2, TLR-4, TNF-α, IL-1β, IL-8, NOD-1, NOD-2 and β-defensin-5 were determined by real-time polymerase chain reaction (RT-PCR) over a time course of 1, 3, 6, 12 and 24h. The detection of the NF-κB p65 protein in nucleus and cytoplasm of infected bMEC over the same time course were evaluated. Results showed that P.zopfii genotypes-II hasability to up-regulate the expression of TLR-2, TLR-4, TNF-α, IL-1β, IL-8, NOD-1, NOD-2 and β-defensin-5 more strongly than the control group. Western blotresults showed that when bMECs were challenged byP.zopfii genotype-II, the expression of NF-κB p65 protein in the nucleus was up-regulated while in cytoplasm it appeared to be repressed, which indicated that bMECs partlyregulate the innate immune responses and inflammationby the NF-κB signaling pathway whilst being infected by P. zopfii genotype-II. It was concluded that genotype-II causes inflammation of bovine mammary tissue.