Sequencing and Analysis of Porcine IL-18 Gene

[Objective]The study aimed to lay a foundation for the development of new type antiviral agents and vaccine adjuvants so as to control the severe porcine infectious diseases effectively.[Method]According to the porcine interleukin-18 gene(IL-18) published in GenBank,a pair of specific primers was designed for amplifying the porcine IL-18 gene from the spleen lymphocytes of Henan three-way cross-breeding pigs by RT-PCR.Subsequently,the gene was cloned,sequenced and analyzed.[Result] The porcine IL-18 gene was 579 bp,encoding an inactive precursor protein with 192 amino acids.The precursor protein had no typical hydrophobic signal peptide and contained an unusual leader sequence composed of 35 amino acids that was cleaved for biological activity by Interleukin-1β converting enzyme(ICE).After comparing the IL-18 gene obtained in this experiment with other known porcine IL-18 genes,it showed that the nucleotide sequence homology was over 96% and the deduced amino acid homology was more than 98%.[Conclusion] The eukaryotic expression recombinant vector for porcine IL-18 gene was constructed successfully,which could instantaneously express products with biological activity.