Effect of Different Concentrations of Lipopolysaccharide on Expression of NF-κB and LAP in Mammary Epithelial Cells of Dairy Cow

The paper was to study the effects of different concentrations of lipopelysaccharide （LPS） on expression of nuclear factor Kappa B （NF-κB） and lingual antimicrobial peptide （LAP） gene in mammary epithelial ceils of dairy cow. The mammary epithelial ceils of dairy cow were stimulated by different concentrations （50, 100,200,400 and 800 ng/mL） of LPS. The total RNA of cells was extracted after stimulation for 2, 4, 8, 16, 24, 48 and 72 h, respectively, and the mRNA expression levels of NF-κB P65 and LAP were evaluated by real-time quantitative PCR. The results showed that the expression of NF-κB P65 and LAP mRNA treated with 400 ng/mL LPS for 72 h were the highest compared to the control group （ P 〈0.01 ）. The result confirmed that the expression activity of NF-κB was enhanced in inflammatory effects of inammary epithelial cells induced by LPS, which regulated the expression of defense gene LAP, with certain dose and time effects.

PEDV贴壁种毒优化及其在悬浮细胞中的适应性培养

为了给猪流行性腹泻病毒(PEDV)XJ-DB2株在悬浮驯化阶段提供稳定的贴壁种毒,验证优化后贴壁种毒在ST悬浮细胞上的感染增殖效果,试验选取3种不同来源的贴壁型Vero细胞,进行连续染毒传代后筛选出传代稳定、病毒效价高的种毒,并测定在ST悬浮细胞上进行驯化传3代后的病毒效价。结果表明:PEDV XJ-DB2株在Zj-Vero细胞上连续驯化21代,病毒效价为1×10^(7.5) TCID_(50)/mL,驯化后的毒株在ST悬浮细胞上连续3代悬浮驯化后,病毒效价为3.16×10^(6) TCID_(50)/mL。说明最适应PEDV XJ-DB2株增殖的贴壁细胞为Zj-Vero细胞,经Zj-Vero细胞驯化后的毒株可以在ST悬浮细胞上增殖培养。