高致病性猪繁殖与呼吸综合征病毒非结构蛋白NSP1对猪体免疫抑制作用

Suppression of immune responses in pigs by highly pathogenic porcine reproductive and respiratory syndrome virus NSP1

为了研究高致病性PRRSV NSP1蛋白的免疫作用,本研究将高致病性PRRSV NSP1重组腺病毒(rAd-NSP1)接种体外培养的猪肺泡细胞(PAM),用实时荧光定量PCR和ELISA方法分别检测IFN-γ和IL-10水平,结果为rAd-NSP1接种PAM细胞72h后可显著降低细胞上清中IFN-γ的水平,而IL-10的含量显著提高。将rAd-NSP1接种无PRRSV感染的30日龄商品仔猪,分别检测其外周血液淋巴细胞增殖作用和IFN-γ与IL-10的水平,结果显示,NSP1可显著减低淋巴细胞增殖和IFN-γ的表达,同时诱导产生较强的IL-10反应。采用无PRRSV感染的30日龄商品仔猪免疫猪瘟疫苗后1周接种rAd-NSP1,结果猪瘟抗体的水平明显低于wtAd组(P<0.05),证明高致病性PRRSV NSP1蛋白具有免疫抑制作用。

In order to know the immunity of the NSP1 of highly pathogenic PRRSV, the immune re- sponses of recombinant adenoviruses expressing NSP1 of PRRSV （rAd-NSP1） was investigated in porcine alveolar macrophages （PAMs） and pigs. The results showed that the level of interferon-γ in PAMs infected with rAd-NSP1 were significantly lower than those of infected with wild type adenovirus （wtAd） at 72 h post-infection. The levels of interleukin （IL）-10 in PAMS infected with rAd-NSP1 were significantly higher than those of in PAMs infected with wtAd. Pigs inoculated with rAd-NSP1 produced significantly lower levels of lymphocyte proliferation and IFN-γrespon- ses,but higher levels of 11710 compared to those immunized with wtAd or medium alone. Moreo- ver,the antibody reslaonse to classic swine fever virus （CSFV） vaccine was significantly impaired by inoculation of NSP1 followed by CSFV vaccination in pigs. It indicated that NSP1 of PRRSV could inhibit the immunity in pigs.