Production of Polyclonal Antibody against Interleukin-33 and Assessment of Its Distribution in Murine Liver and Lung

Interleukin (IL)-33 is the latest member of IL-1 cytokine family. In this study, the cloning, expression, purification, and polyclonal antibody preparation of mouse IL-33 were described. The coding region of IL-33 mature protein was cloned into the prokaryotic expression vector pET-44. The recombinant protein, IL-33 containing a hexahistidine tag in the C-terminal, was expressed in Escherichia coli. The expressed soluble protein was purified by immobilized metal-ion affinity chromatography using Ni(2+)-nitrilotriacetic acid agarose. The rabbits were immunized with the purified recombinant protein. The obtained antiserum was precipitated by saturated ammonium sulfate and then purified by Protein A affinity chromatography. The sensitivity and specificity of the antibodies were evaluated by enzyme-linked immunosorbent assay and immunohistochemistry. The high titer (1 : 32000) polyclonal antibodies with high specificity were obtained by immunizing rabbits with the purified recombinant protein. Significant expression of IL-33 was seen in mouse liver and lung tissues determined with the anti-IL-33. The production of the polyclonal antibody against IL-33 provides a good tool for studying the biofunctions of IL-33.