摘要
【目的】监测当前湖南省猪圆环病毒2型(Porcine circovirus type 2,PCV2)流行毒株及其衣壳蛋白(capsid protein,Cap)变异情况,并预测Cap蛋白细胞毒性T淋巴细胞(cytotoxic T lymphocyte,CTL)表位,为新型PCV2疫苗研制和病毒净化提供参考依据。【方法】本研究对2019-2021年于湖南省6个地区收集的17份PCV2阳性组织样品进行PCV2全基因组序列扩增及测序分析,绘制系统进化树,利用生物信息学方法分析Cap蛋白氨基酸变异情况,并预测CTL表位。【结果】系统进化树显示,获得的17株PCV2全基因组序列中,1株PCV2a、7株PCV2b和9株PCV2d。Cap蛋白氨基酸序列比对分析发现,共有16个氨基酸残基突变位点位于病毒Cap蛋白表面,且有11个突变位点参与构象型表位的形成。此外,共预测出9个PCV2 Cap蛋白潜在的CTL表位,其中4个表位(16-24、28-36、136-144和179-187位氨基酸)在GenBank的1610株PCV2不同基因型毒株中高度保守。通过TCR-pMHC复合物3D结构对4个保守性表位进一步分析,结果显示,这4个肽段均能与MHCⅠ分子和TCR形成稳定的TCR-pMHC复合物。【结论】本研究结果表明,PCV2b和PCV2d为当前湖南省主要流行的基因型,且表现出高度变异;预测的CTL表位可作为候选抗原表位。
【Objective】This study was aimed to monitor the current Porcine circovirus type 2(PCV2)strains circulating in Hunan province and its capsid protein(Cap)variation,predict the cytotoxic T lymphocyte(CTL)epitopes,and provide some insights for the development of PCV2 novel vaccines and virus clearance.【Method】In this study,PCV2 complete genome amplification,sequencing and phylogenetic analysis were performed on 17 PCV2 positive tissue samples collected from 6 regions in Hunan province from 2019 to 2021,and bioinformatic methods were used to analyze the amino acid variation of Cap and its CTL epitopes were predicted.【Result】The phylogenetic tree showed that 1 strain of PCV2a,7 strains of PCV2b and 9 strains of PCV2d were obtained from the 17 PCV2 genome sequences.Multiple sequence alignments of Cap protein revealed that there were 16 mutated amino acid residues located on the capsid surface,and 11 residues were involved in the formation of conformational epitopes.Furthermore,among the predicted 9 potential CTL epitopes,epitopes 16-24,28-36,136-144 and 179-187 amino acids were highly conserved in 1610 PCV2 genotypes from GenBank.The four conserved epitopes were further analyzed by the 3D structure of the TCR-pMHC complex,the results showed that all the four peptides could form stable TCR-pMHC complexes with MHCⅠmolecule and TCR.【Conclusion】This study showed that PCV2b and PCV2d became the predominant genotypes in Hunan province with highly variability.These predicted CTL epitopes could be used as candidate epitopes.
作者
周文锋
张英婕
白一涵
张露华
麦金辉
王乃东
杨毅
湛洋
王东亮
ZHOU Wenfeng;ZHANG Yingjie;BAI Yihan;ZHANG Luhua;MAI Jinhui;WANG Naidong;YANG Yi;ZHAN Yang;WANG Dongliang(College of Veterinary Medicine,Hunan Agricultural University,Changsha 410128,China;Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines,Changsha 410128,China)
出处
《中国畜牧兽医》
CAS
CSCD
北大核心
2023年第2期656-665,共10页
China Animal Husbandry & Veterinary Medicine
基金
国家自然科学基金项目(32172844)
湖南省技术攻关“揭榜挂帅”项目(2021NK1030)
湖南省自然科学基金项目(2022JJ40183)
长沙市自然科学基金项目(kq2202231)。
