Abstract:

To detect avian beta-defensin 6 (AvBD6) quantitatively, a sandwich ELISA method was established and applied to detect the  concentration of AvBD6 in serum. The results showed that the optimal dilution of capture antibody (mouse anti\|B cell linear epitopes of AvBD6 polyclonal antibody), detecting antibody (rabbit anti\|N\|terminal of AvBD6 polyclonal antibody) and horseradish peroxidase (HRP)\|conjugated goat anti\|rabbit IgG was 2 500, 2 000 and 10 000, respectively. The standard curve regression equation was y=12 024x-2 583, (R2=0.984 2) in the linear detection range from 20 to 320 ng/mL. The serum AvBD6 concentration of control group was slightly higher than that of ACTH group(P>0.05) after 1 day of ACTH (25 IU/kg BW) injection, but the AvBD6 concentration of the control group was slightly lower than that of ACTH group(P>0.05) after 5 d of ACTH injection; and the effect was not significant. The serum AvBD6 concentration of infected group after 24 h of Escherichia coli exposure or 3 h and 24 h of salmonella exposure were significantly higher than that of the control group (P<0.05). Our results indicated that AvBD6 involved in the resistance to system infection of Escherichia coli and salmonella.

Key words: AvBD6, sandwich ELISA, ACTH, Escherichia coli, Salmonella

摘要：

为定量检测禽β-防御素6（avian beta\|defensin 6，AvBD6），建立了AvBD6的双抗体夹心ELISA法，并应用于鸡血清中AvBD6浓度的检测。研究结果显示，包被抗体（鼠抗AvBD6 B细胞线性表位的多克隆抗体）、检测抗体（兔抗AvBD6氮端的多克隆抗体）和辣根过氧化酶(HRP)标记羊抗兔IgG的最佳工作稀释倍数分别为2 500、2 000和10 000，AvBD6在20~320 ng/mL的线性范围内，标准曲线回归方程为：y=12 024x-2 583，（R2=0.984 2）。对不同状态下鸡血清AvBD6浓度检测结果显示：ACTH（25 IU/kgBW）注射1 d后，对照组AvBD6浓度高于ACTH组；连续注射ACTH 5 d，对照组AvBD6浓度低于ACTH组，但二者间差异均不显著(P>0.05)。大肠杆菌感染后24 h和沙门氏菌感染后3 h、24 h，感染组AvBD6浓度均显著地高于对照组（P<0.05），表明AvBD6参与对大肠杆菌和沙门氏菌系统感染的抵抗。

关键词: AvBD6, 夹心ELISA, ACTH, 大肠杆菌, 沙门氏菌