重组腺病毒载体表达的α干扰素对猪繁殖与呼吸综合征病毒复制的抑制作用

Inhibition of porcine reproductive and respiratory syndrome virus replication induced by recombinant adenovirus expression interferon-α

目的:研究猪繁殖与呼吸综合征病毒(PRRSV)新的防治方法。方法:利用表达猪α干扰素的重组腺病毒(rAd-IFNα),通过病毒滴度、间接免疫荧光试验和实时定量RT-PCR检测,在Marc-145细胞上观察其对高致病性PRRSV SY0608株的复制抑制作用。结果:将rAd-IFNα接种细胞后24 h,再感染PRRSV,可以有效阻止PRRSV造成的细胞病变,PRRSV滴度和mRNA水平明显降低;该抑制作用随rAd-IFNα接种剂量的增加而增强,但随病毒培养时间延长而逐渐减弱。此外,将PRRSV感染细胞后24 h,再接种rAd-IFNα,仍可以有效降低PRRSV滴度和mRNA水平,并且rAd-IFNα对PRRSV传统毒株S1株同样具有明显的抑制作用。结论:rAd-IFNα可以有效抑制PRRSV在Marc-145细胞上复制,为PRRSV的防治提供了理论依据。

Objective： To study a new strategy of prophylaxis and therapy for controlling Porcine reproductive and respiratory syn- drome virus （PRRSV） infection. Methods： In this study, the inhibition of a highly pathogenic strain （SY0608） of PRRSV induced by recombinant adenovirus expression IFN-α （rAd-IFNα） was evaluated by virus titer test, indirect immunofluoresence assay （IFA） and real- time RT-PCR detection in Marc-145 cells. Results： The cytopathogenic effect induced by PRRSV was prevented thoroughly in the cells inoculated with rAd-IFNα 24h before PRRSV infection; the virus titers and viral RNA level were decreased significantly. The inhibition effect appeared to be dose-dependent on rAd-IFNα but tapered with the culturing time. In addition, PRRSV titers and mRNA level in cells inoculated with rAd-IFNα, at 24h after PRRSV infection, were also suppressed. Furthermore, rAd-IFNα could significantly suppress the replication of PRRSV S 1 strain in our study. Conclusion： rAd-IFNα could inhibit the replication of PRRSV in Marc-145 cells, which provided a good academic strategy of prophylaxis and therapy for controlling PRRSV infection.