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ARTICLE INFO

Article Type

Original Research

Authors

Khalesi R. ^{(1 )}
Nazarian Sh. ^{(* )}
Ehsaei Z. ^{(1 )}
Mansouri M. ^{(1 )}
Amani J. ^{(2 )}
Salimian J. ^{(1 )}
Moazzeni S. M. ⁽³⁾

^{(* )} Department of Biological Sciences, Faculty of Basic Sciences, Imam Hossein University, Tehran, Iran
^{(1 )} Department of Biological Sciences, Faculty of Basic Sciences, Imam Hossein University, Tehran, Iran
^{(2 )} Applied Biotechnology Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
⁽³⁾ Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran

Correspondence

Article History

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ABSTRACT

Aims It has been estimated that gastroenteritis is caused by bacteria in 30-70% of cases. Enterotoxigenic Escherichia coli or ETEC is one of the most common agents causing diarrhea. Protective immunity may be induced against this disease. Designing and producing a vaccine against this disease is one of the purposes of World Health Organization. Vaccine candidate molecules have to induce protective immunity against a broad spectrum of ETEC bacteria. Most ETEC strains can produce labile toxin; therefore labile toxin may be a proper candidate for being used as a vaccine molecule. The aim of this study was to optimize Heat-labile Toxin B Subunit expression in order to investigate its immunological properties.
Materials & Methods Optimizing of 3 parameters (IPTG concentration, time and temperature of promoter induction) was performed. Recombinant protein was purified with Ni-NTA column. Purified Heat-labile Toxin B Subunit was injected to mice subcutaneously in 4 sessions. Blood samples were taken during the interval between the injections and after last injection. Then, ELISA was performed.
Results The optimum expression occurred at 1mM IPTG concentration, after 3 hours and at 37ºC. Recombinant protein was highly purified (>95%) with Ni-NTA column. Also, ELISA showed high titer of antibody production in mice.
Conclusion Expressed Heat-labile Toxin B Subunit is an immunogenic protein and can be one of the important components in vaccine development against ETEC.

Keywords: Enterotoxigenic Escherichia coli, Heat-Labile Toxin B Subunit, Expression, Recombinant Vaccine, Antibody,