[Construction of a recombinant eukaryotic expression vector containing HSV 2gD and its immune responses].

AIM: To construct and express pcDNA3.1-IL-18-HSV P6 recombinant DNA vaccine, and to observe the immune responses of pcDNA3.1-IL-18-HSV P6 genetic vaccine. METHODS: Genes of P6 and IL-18 were cloned into the eukaryotic expression vector pcDNA3.1(-) respectively, and confirmed by enzyme digestion and sequence analysis, the recombinant plasmid pcDNA3.1-IL-18-HSVP6 was transformed into CHO cells. The expressed protein was characterized by indirect immunofluorescence and Western blotting. The recombinant plasmid pcDNA3.1-IL-18-HSVP6 was used to inoculate BALB/c mice by intramuscular injection for three times, once a week. One week after the last vaccination, the levels of specific IgG antibody, IFN-γ and IL-18 were detected by ELISA; One month after the last vaccination, spleen cells of vaccinated mice were separated and proliferation of spleen lymphocytes were detected by MTT assay. RESULTS: Recombinant pcDNA3.1-IL-18-HSV P6 plasmid was confirmed by enzyme digestion and DNA sequencing. After inoculated by pcDNA3.1-IL-18-HSV P6 vaccine, the mice could produce higher level of splenocytes proliferation and secrected higher level of IFN-γ, IL-18 and specific antibody. CONCLUSION: DNA vaccine of pcDNA3.1-IL-18-HSV P6 has been successfully constructed, and it can effectively induce humoral and cellular immune responses, which provided a basis for constructing new type of DNA vaccine.

[Cloning and expression of human interleukin-32 and studies on its bioactivity].

AIM: To clone human interleukin-32(hIL-32) gene and express it in E.coli efficiently. METHODS: The gene of hIL-32 was amplified by RT-PCR from human peripheral blood mononuclear cells (PBMC) which stimulated with Con A for 60 h. The PCR product was inserted into the pMD18-T vector. The hIL-32 cDNA confirmed by sequencing was inserted into expression vector pET-30a(+) and expressed in E.coli BL21(DE3) strain. The hIL-32 protein expression was induced by IPTG and assayed by SDS-PAGE and coomassie blue stain. The recombination protein was identified by Western blot and its biological activity was analyzed. RESULTS: DNA sequencing confirmed that the cloned cDNA was identical to the published sequence of hIL-32 that the nucleotide sequence of this gene was 567 bp. The recombinant plasmid pET30a-hIL32 was transformed into E.coli BL21(DE3) strain for expression. An expected 28 kDa protein of hIL-32 was found mainly in the induced host strains by SDS-PAGE and coomassie blue stain. The 28 kDa protein was recognized by anti-IL-32 antibody in western blot. The purified recombination protein could induce the producing of IL-6 in the human PBMC. CONCLUSION: We have successfully cloned the gene and expressed the protein of hIL-32 and the expressed protein has specific bioactivity.