不同长度的聚肌胞对SPF鸡固有免疫增强作用的研究

摘要

Poly I:C (pIC) is a strong interferon inducer,and is used as an anti-viral/tumor drug in human medicine.Recent research has found distinct function of pICs with different molecular lengths on mammalian cells.It is unclear whether the length of pIC is also a key factor that influences the immune function in chicken.In this study,low (0.3 kb-1 kb) and high-molecularweight (6 kb-8 kb) pIC were employed to inject specific-pathogen-free chickens through muscular route.At 6,12,24 and 36 hrs post stimulation,EDTA-anticoagulating blood was collected and peripheral blood lymphocytes (PBLs) were separated from the blood.Real-time PCR assays were used to detect the expression dynamics of PBL cellular innate immune-related genes.The results showed that pIC of both low and high molecular weights could quickly boost chicken cellular innate immune response,resulting in the up-regulation of innate immunity-related genes including TLR3,MDA5,IFN-α,IFN-β,IFN-γ,IL-1β,IL-2,IL-6 and IL-17.The result was distinct from that of mammalian models,while similar to that of chicken cellular models (unreported data from our research).In particular,pIC of concentration (mass/body weight) as low as 10 μg/kg resulted in significant up-regulation of chicken immune-related genes with most genes reaching transcriptional peaks at 6hs post stimulating,which indicated the efficacy of pIC as chicken immunopotentiator.In conclusion,this study showed the prospection of pICs of both low and high molecular lengths as chicken immunopotentiator.%聚肌胞(poly I:C,pIC)作为强干扰素诱生剂,在人类医学上被用作抗病毒和抗肿瘤药物.已有的研究表明,聚合长度不同的pIC对哺乳动物细胞的免疫增强作用不同.为明确pIC的聚合长度是否会影响其对鸡的固有免疫增强作用,本研究将低分子量pIC (0.3 kb～1 kb)和高分子量pIC(6 kb～8 kb)分别肌肉注射1月龄的SPF鸡,各设置2个pIC浓度梯度.在pIC作用后的6h、12h、24 h和36 h,分别采集EDTA抗凝血,分离外周血淋巴细胞(PBL),通过荧光定量PCR方法检测PBL固有免疫信号通路相关基因的转录水平变化.结果表明,低和高分子量范围的pIC刺激SPF鸡后均可以迅速激活鸡体固有免疫应答,引起TLR3、MDA5、IFN-α、IFN-β、IFN-γ、IL-1β、IL-2、IL-6和IL-17等免疫相关基因转录水平的上调.该结果与哺乳动物模型的研究报道截然不同,而与本实验室以多种鸡源细胞为模型的研究结果相似.10 μg/kg(质量/体质量)的pIC即可以引起PBL固有免疫相关基因转录水平上调,而且大部分基因在pIC刺激后6h即达到转录峰值,表明pIC作为鸡用免疫增强剂的高效性.总之,本研究表明短链和长链pIC均可用作鸡免疫增强剂.