Construction of human interleukin-26 lentivirus expression plasmid and gene knockout plasmid and their activity verification in HEK293T cells / 中国生物制品学杂志

@#Objective To construct a lentivirus-based expression plasmid and gene knockout plasmid of human interleukin(IL)-26 so as to lay a foundation of studying the function of IL-26 gene in cell signaling pathway and autophagy.Methods IL-26 gene sequence was amplified from human peripheral blood mononuclear cells by RT-PCR and cloned into pCDH-CMVMCS-EF1-copGFP eukaryotic expression vector to construct overexpression plasmid;Four knockout targets,Exon1sgRNA1,Exon1sgRNA2,Exon3sgRNA1 and Exon3sgRNA2,were designed based on the exon sequence of IL-26,and constructed into lentiCRISPRv2 vector by CRISPR/Cas9 technology to construct gene knockout plasmid. The overexpression plasmid and gene knockout plasmid were transiently transfected into HEK293T cells respectively,and the expression of IL-26 was verified by RT-qPCR and Western blot. In addition,amino acid sequence analysis,structure prediction and subcellular localization observation of IL-26 were performed.Results The results of restriction digestion,sequencing and bioinformatics analysis showed that IL-26 was 516 bp in length,encoding 171 amino acids. The IL-26 mRNA level and protein level of HEK293T cells transfected with IL-26 overexpression plasmid increased by 656. 789 times and 1. 978 times respectively with significant differences as compared with the normal control group(t = 17. 976 and 7. 859,P < 0. 000 1 and < 0. 001,respectively). With the transfection of 4 knockout targets Exon1sgRNA1,Exon1sgRNA2,Exon3sgRNA1 and Exon3sg-RNA2 into HEK293T cells,the expression of IL-26 decreased by 0. 930,0. 980,0. 523 3 and 0. 316 9 times,respectively,among which Exon3sgRNA2 significantly down-regulated the expression of IL-26(t = 7. 440,P < 0. 001). IL-26protein showed signal peptide structure and certain transmembrane function in the first 22 amino acids,which existed in cytoplasm.Conclusion IL-26overexpression and gene knockout plasmids were successfully constructed,which laid a foundation of the follow-up study of the function of IL-26.

Gene Knocking Out of Hyaluronidase in Streptococcus zoopidemics / 中国生物工程杂志

To construct knockout vectors containing ampicillin resistant gene and partial sequence of hyaluronidase gene(Hyl)so that Hyl can be knock out by transforming the plasmid into Streptococcus zoopidemics mutans.First,partial sequence of Hyl(Hyl-1)was cloned into the vector of pMD19-T by using DNA of Streptococcus zoopidemics as template,and then a knockout vector pMD19T-SA was constructed,in which Hyl-1 gene was disrupted by inserting ampicillin resistant gene(Amp)from reverse PCR.As expected,the vector was proved to be consisted of Hyl-1-Amp-Hyl-1-pMD19-T.Thereafter,DNA fragment of Hyl-1-Amp-Hyl-1 was subcloned into pBR322 vector,the resulting construct was then checked by PCR and restriction analysis for the proper configuration of the knockout vector pBR322-SA.Both of the knockout vectors were used to transform Streptococcus zoopidemics and one recombinant was obtained in result.From results of PCR and Hyl activity assay,it was indicated that in the recombinant the Hyl gene was disrupted completely.