DNA vaccines co-expressing containing Hsp70 and GP5 /M protein of porcine reproductive and respiratory syndrome virus (PRRSV) display enhanced immunogenicity

Construction of Eukaryotic recombinant expression Vector pCI-ORF5-ORF6/pCI-ORF5-ORF6B-Hsp70 Containing Hsp70 and PRRSV GP5/M (encoded by ORF5 and ORF6 genes), and to study its immune effect. After identified by enzyme analysis and nucleotide sequencing test, the repression vector plasmid was transfected into COS-7 cells. The transient expression protein was detected by indirect immunofluorescence assay (IFA) and Western-blotting. The immunogenicities of this DNA vaccine constructs were firstly investigated in a mouse model. IFN-gamma IFN I gamma-4 of cytokine and the spleen T-lymphocyte subgroup quantity (CD4+ /CD8+) were detected. The result shows that the recombinant plasmid pCI-ORF5-ORF6-Hsp70 could induce higher response of cellular immune responses and specific hummune responses in mouse, providing the clinical basic data and theoretical basis for success of the DNA vaccine development.