不同特性IgG促进PRRSV在PAM细胞中的增值作用

The role of the different characteristics of IgG in the promoting infection of PRRSV in PAM Cells

本试验通过研究IgG对猪繁殖与呼吸综合征(PRRSV)增殖情况的影响,来探讨抗PRRSV特异性和PRRS非特异性抗体在PRRSV-ADE中的作用。分别将抗PRRS特异性IgG(2.64g/L)和非特异性IgG(2.63g/L)作倍比稀释,与等体积含200TCID50/100μL的PRRSV Hn-1/06株病毒液混合,制备成一系列的感染性免疫复合物(PRRSVIgG)和阴性抗体-病毒混合液(PRRSV+IgG),接种PAM细胞;同时将纯化的猪阴性IgG(2.63g/L)和兔抗猪IgG(2.64g/L l)等体积混合制备免疫复合物(IC),分别与等体积含200TCID50/100μL的PRRSV Hn-1/06株病毒液混合,制备成免疫复合物-病毒混合液(PRRSV+IC),接种PAM细胞。接种24h后,用实时荧光定量PCR方法检测PRRSV的mRNA水平。同样的方法,分别将2倍稀释的PRRSV-IgG,PRRSV+IgG和4倍稀释的PRRSV+IC接种PAM细胞,用实时荧光定量PCR方法分别检测感染12、24、36和48h后不同时间段内PRRSV的mRNA水平。结果显示,一定质量浓度的PRRS特异性亚中和水平抗体和非特异性抗体,在感染48h内均能极显著促进PRRSV在PAM细胞中增殖;而适当剂量的免疫复合物,在感染48h内也均能促进PRRSV在PAM细胞中增殖。结果表明,一定质量浓度的PRRS特异性亚中和水平抗体和非特异性抗体均能促进PRRSV在PAM细胞中增殖,但是不同特性的抗体对PRRSV的增殖能力存在着差异。

This study aimed to discuss the role of specific and non-specific antibody in antibody-dependent enhancement of porcine reproductive and respiratory syndrome(PRRS)infection by studying the effect of IgG on the proliferation of PRRSV.Anti-specific antibodies against PRRSV(2.64g/L)and non-specific IgG(2.63g/L)were diluted by a series dilution method,and then an equal volume of PRRSV Hn-1/06 virus with a titer of 200TCID50/100μL was added to each dilution,and a series of infectious immune complex(PRRSV-IgG)and negetive antibody-virus mixture(PRRSV+IgG)were prepared for inoculating PAM cells;at the same time,we mixed purified swine negative IgG(2.63g/L)with rabbit anti-swine IgG(2.64g/L)by equal volume to make immune complex(IC),and an equal volume of PRRSV Hn-1/06virus with a titer of 200TCID50/100μL prepared immune complex-the virus mixture(PRRSV+IC)for inoculating PAM cells.after cultured for 24h,we detected the level of mRNA by real-time fluorescent quantitative PCR.In the same method,we inoculated PAM cells with 2times diluted PRRSV-IgG,PRRSV+IgG,and 4times diluted PRRSV+IC,then detected the mRNA level of of PRRSV after infecting12,24,36 and 48h with the real-time fluorescent quantitative PCR.The results indicated that a certain concentration of PRRS specifically sub-neutralizing level antibody and nonspecific antibody all could significantly promote the proliferation of PRRSV in PAM cells during the period of infecting48h,while the suitable dose of immune complex also can promote the proliferation of PRRSV in PAM cells during the period of infecting 48h.The results indicated that a certain concentration of PRRS specifically sub-neutralizing level antibody and nonspecific antibody all could promote the proliferation of PRRSV in PAM cells,but different characteristic of antibody had some differences in the ability of proliferation of PRRSV.