Fusion of genes encoding Escherichia coli heat-stable enterotoxin and outer membrane protein OmpC

Abstract

The OmpC outer membrane protein of Escherichia coli was used as a carrier molecule for the nonimmunogenic heat-stable enterotoxin STa. Two fragments of different lengths of the gene encoding STa were fused in vitro to the 3' terminus of the truncated ompC gene. The resulting OmpC-STa hybrid proteins could be detected by L-[35S]cysteine labeling, and they were processed and thus exported. All synthesized hybrid protein remained cell bound and was found by fractionation mainly in the periplasm. Immunoblot analysis showed that the hybrid proteins reacted in vitro both with anti-OmpC and anti-STa antibodies, and immunization of rabbits evoked an antibody response to either of these proteins.

Expression of an Escherichia coli antigenic fusion protein comprising the heat labile toxin B subunit and the heat stable toxin, and its assembly as a functional oligomer in transplastomic tobacco plants

“…In order to develop vaccines that protect against ETEC strains producing either enterotoxin, some genetic fusions between ST and several carrier proteins have been produced (Pereira et al, 2001). Specifically, either LT or CT subunits have been used as ST carrier proteins for the purpose of inducing protective immunity against ST (Aitken and Hirst, 1993;Clements, 1990;Saarilahti et al, 1989;Sanchez et al, 1998;Zheng et al, 2005). Cardenas and Clements (1993) reported on the construction of a non-toxic LTB-ST fusion peptide by joining the 5¢ terminus of a synthetic gene coding for ST to the 3¢ terminus of the LTB gene.…”

“…, 2001). Specifically, either LT or CT subunits have been used as ST carrier proteins for the purpose of inducing protective immunity against ST (Aitken and Hirst, 1993; Clements, 1990; Saarilahti et al. , 1989; Sanchez et al.…”

Some infectious causes of diarrhea in young farm animals.

“…STa is produced by K99, F41, and 987P ETEC strains. Because of its low molecular weight, STa is nonimmunogenic, although it has been shown to behave as a hapten (307) when coupled to a carrier protein.…”

Chicken egg yolk immunoglobulin (IgY) developed against fusion protein LTB-STa-STb neutralizes the toxicity ofEscherichia coliheat-stable enterotoxins

“…However, current vaccination programmes only contain intact ETEC cells, fimbrial antigens or LT, but not ST because of its poor immunogenicity and toxicity. To enhance the immunogenicity of STs and make useful toxoids, numerous studies have constructed bivalent STa-carrier or STb-carrier fusions that vary in their immunogenicity and residual toxicity (Sanchez et al 1988;Saarilahti et al 1989;Clements 1990;Lawrence et al 1990;Lowenadler et al 1991;Cardenas and Clements 1993;Dubreuil et al 1996;Rosales-Mendoza et al 2009;Zhang et al 2010).…”