Cloning and Expression of Chicken Mature IL-18 Gene in E.coli

Objective To amplify the cDNA encoding chicken mature IL 18 protein from the mRNA of chicken splenocytes and express in E.coli. Methods Extract mRNA from the chicken splenocytes stimulated with phytohemagglutinin (PHA) and lipopolysaccharide (LPS), then amplify the cDNA encoding chicken mature IL 18 protein and sequence. Insert the cDNA into vector pET 28b and transform to E.coli BL21(DE3) plys S for expression. Identify the expressed product by SDS PAGE. Results The cloned cDNA fragment, consisting of 507 nucleotides encoding 169 amino acids, covered the whole chicken mature IL 18 gene. A recombinant protein with a relative molecular weight of 19000 was expressed in E.coli. Conclusion Chicken mature IL 18 gene was successfully cloned and expressed in vitro at first in China.