表达牛乳铁蛋白肽的重组鸡源乳酸杆菌抗IBDV感染的研究

Study on the recombinant chicken origin Lactobacillus expressing bovine lactoferrin peptides against IBDV infection

为探究表达牛乳铁蛋白肽的重组鸡源乳酸杆菌pPG-XLFEC/M11对雏鸡抵抗传染性法氏囊病病毒(IBDV)感染的作用,本研究利用IBDVCEF94株感染DF-1细胞,通过CCK-8法检测病毒感染后的细胞活性,利用qRT-PCR检测病毒载量,结果显示重组乳酸菌表达的牛乳铁蛋白肽可以抑制IBDV在DF-1细胞内的增殖;以重组乳酸菌pPG-XLFEC/M11饲喂雏鸡,利用IBDV强毒UK661株进行攻毒实验,结果显示饲喂重组菌的雏鸡相比于对照组,IBDV的感染对其组织器官的损伤较小,总免疫球蛋白IgG和SIgA含量增加,细胞因子IL-6、IL-8、TNF-琢和IFN-酌以及TLR2的mRNA转录水平均显著升高,且提高了雏鸡的存活率。本实验结果表明,重组鸡源乳酸杆菌表达的牛乳铁蛋白肽可以增强机体的免疫应答水平,对雏鸡具有一定的抗IBDV感染的作用。本研究为表达牛乳铁蛋白肽的重组鸡源乳酸杆菌在生产中的应用以及为禽类疾病的预防奠定基础。

In this study,we tried to determine whether a recombinant chicken origin Lactobacilli/pPG-XLFEC/M11 expressing bovine lactoferrin peptide has effect on protecting chicks from being infected by bursal disease virus(IBDV).The cell viability of DF-1 cells after infected by IBDV CEF94 strain was analyzed by CCK-8,and the viral load in the cells was detected by qRT-PCR.Results showed that the bovine lactoferrin peptide expressed by the recombinant Lactobacilli inhibited the proliferation of the virus in vitro.Chicks were challenged with IBDV virulent UK661 strain after feeding with the recombinant Lactobacilli.We observed that the recombinant Lactobacilli was more potent than other groups in attenuating the tissues and organs damage induced by IBDV virulent UK661 strain.Moreover,compared to the other groups,the recombinant Lactobacilli enhanced the expression levels of IgG and SIgA in serum,significantly increased the mRNA levels of IL-6,IL-8,TNF-α,IFN-γand TLR2,and increased the survival rate of chicks post the challenging.These results suggested that recombinant chicken origin Lactobacilli/pPG-XLFEC/M11 expressing bovine lactoferrin peptide has a protective effect on chick infected with IBDV.