Chapter 1: Introduction and Literature Review Chapter 2: Low dose exposure and immunogenicity of transgenic maize expressing the Escherichia coli heat-labile toxin B subunit Chapter 3: Immunogenicity of daily and intermittent oral administration of transgenic maize expressing the Escherichia coli heat-labile toxin B subunit Chapter 4: Discussion Acknowledgements iii

Rabies remains an important worldwide public health threat, so safe, effective, and affordable vaccines are still being sought. Virus-like particle-based vaccines targeting various viral pathogens have been successfully produced, licensed, and commercialized. Here, we designed and constructed two chimeric rabies virus-like particles (cRVLPs) containing rabies virus (RABV) glycoprotein (G), matr...

An LT-B-ST (LT-B/ST) fusion peptide was constructed by genetically joining the 5' terminus of a synthetic gene coding for the heat-stable enterotoxin (ST) of Escherichia coli to the 3' terminus of the gene coding for the binding subunit of the heat-labile enterotoxin (LT-B) of E. coli. An eight-amino-acid, proline-containing linker was included between the LT-B and ST moieties. An aroA mutant o...

The Elek test was modified for detection of the heat-labile enterotoxin of enterotoxigenic Escherichia coli. A total of 164 strains of E. coli were tested by the modified Elek test, and the results correlated well with those of the Chinese hamster ovary cell assay and passive immune hemolysis. It is concluded that the modified Elek test is a simple and reproducible assay method for identificati...

Enterotoxigenic Escherichia coli is a major cause of acute diarrheal illness worldwide and is responsible for high infant and child mortality rates in developing nations. Two types of enterotoxins, one heat labile and the other heat stable, are known to cause diarrhea. The expression of soluble heat-labile toxin is subject to catabolite (glucose) activation, and three binding sites for cAMP rec...

125I-labelled heat-labile toxin (from Escherichia coli) and 125I-labelled cholera toxin bound to immobilized ganglioside GM1 and Balb/c 3T3 cell membranes with identical specificities, i.e. each toxin inhibited binding of the other. Binding of both toxins to Balb/c 3T3 cell membranes was saturable, with 50% of maximal binding occurring at 0.3 nM for cholera toxin and 1.1 nM for heat-labile toxi...

One hundred strains of Escherichia coli were tested for the production of the heat-labile enterotoxin by the Y1 adrenal cell test and a commercially available reversed passive latex agglutination test. The strains were grown in Casamino Acids-yeast extract broth, and filtered culture supernatants were tested for the presence of heat-labile enterotoxin. There was perfect correlation between the ...

Protein A-containing staphylococci coated with specific antiserum were tested for heat-labile enterotoxin of Escherichia coli. The immunological cross-reactivity of E. coli heat-labile enterotoxin with Vibrio cholerae toxin (choleragen) was the basis for sensitizing stabilized suspensions of the Cowan I strain of Staphylococcus aureus with anticholeragen. Unconcentrated culture supernatant flui...