Background and Objectives: The toxin co-regulated pilus A (TcpA) has been described as a criti- cal pathogenicity factor of Vibrio cholerae. TcpA is a candidate for making subunit vaccine against chol- era. The aim of this study was to produce a candidate vaccine by expressing recombinant TcpA in E. coli.
Materials and Methods: In this study, the toxin co-regulated pilus A gene from EL-Tor, V. cholerae subspecies, was am- plified by PCR and sub-cloned into prokaryotic expression vector pGEX4T1. E. coli BL21 (DE3) was transformed with pGEX4T1- TcpA and gene expression was induced by IPTG and purified by GST resin. The integrity of the product was confirmed by Western blot analysis using a standard rabbit anti-V. cholerae antibody. Sera reactivity of infected individuals was further analyzed against the recombinant TcpA protein.
Results: The concentration of purified recombinant protein was calculated to be 8 mg/L of initial culture. The in- tegrity of product was confirmed by Western blot analysis using a standard rabbit anti V. cholerae antibody. Sera re- activity of infected individual was further analyzed against the recombinant TcpA protein. The obtained data in- dicated that recombinant TcpA protein from V. cholerae was recognized by patient serum and animal sera.
Conclusion: These results show that the recombinant TcpA is antigenic and could be used in a carrier host as an oral vaccine against cholera.