Cloning and Expression of Porcine Interleukin-18 Mature Protein Gene in Escherichia coli

Porcine interleukin 18 mature protein gene was amplified from porcine spleen cells stimulated with phytohemagglutinin(PHA) and lipopolysaccharide(LPS). PCR product was cloned into the T vector pUCm T for sequencing. The result showed the nucleotide sequence of this gene was 474 bp. Then, this pIL 18 mature protein gene was subcloned into the prokaryotic expressing plasmid vector pET 28a and transformed into host E.coli strain BL21(DE3) for expression. The expression of pIL 18 mature protein gene was identified by SDS PAGE and Western blotting. The results revealed it had a molecular weight of 19 000, and could be specifically recognized by the mouse monoantibody to human IL 18.