[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.