Antigenicity of recombinant L7/L12 in patients with brucellosis

Immune response to recombinant L7/L12, in addition to protective role, may show its importance in detection Brucellosis tests. The aim of this study was to examine antigenicity of recombinant L7/L12 from Brucella abortus by Brucellosis human sera. We amplified L7/L12 gene by polymerase chain reaction (PCR) method and sub- cloned to prokaryotic expression vector pET28a. Escherichia coli BL21-DE3-plySs was transformed with pET28a-L7/L12 and gene expression was induced by IPTG. Recombinant L7/L12 was further analyzed by Western Blot. Sera reactivity of five infected individual were further analyzed against the recombinant L7/L12 protein. The sequencing result was confirmed by Sanger method and it was the same as L7/L12 gene. Escherichia coli BL21 (DE3) pLysS was transformed with pET28a-L7/L12 and gene expression was induced by IPTG. The expressed protein was purified by affinity chromatography by Ni-NTA resin. The data also indicated that L7/L12 protein from Brucella abortus recognized by patient sera. Our data showed that recombinant L7/L12 protein can be produced by pET28a in Escherichia coli. This protein was recognized by sera in infected human as an antigen. Therefore, recombinant L7/L12 has same epitopes with natural form of this antigen. Recombinant L7/L12 also seems to be a promising antigen for protection and serologic diagnosis of Human brucellosis.