Generation and characterization of antibody against porcine interleukin-18

The gene-encoding mature porcine interleukin-18 (pIL-18) was amplified by PCR and cloned into a prokaryotic expression vector pET-30a(+). The resulting recombinant plasmid pET-30a-pIL-18 was transformed into Escherichia coli. Expression of recombinant pIL-18 protein was induced by 1 mM isopropyl β-D-thiogalactoside at 37°C. The purified recombinant protein was used to generate a hyperimmune antiserum in a rabbit. The anti-pIL-18 serum was evaluated for its specificity and titer through indirect enzyme-linked immunosorbent assay. The specific reactivity of the anti-pIL-18 antibody was further confirmed by Western blot and immunofluorescence assays. Moreover, the pIL-18 was able to stimulate the proliferation of pig peripheral blood mononuclear cells in vitro, indicating it may have certain biological activity.