Provided herein are genetically engineered Vibrio cholerae bacterial strains, compositions including the bacterial strains, and methods of using the same for the prevention of Vibrio cholerae infection in a subject.

The invention relates to methods for treating human amyloid disease by administration of modified Aβ peptide immunogens.

The present invention relates to a plasmid-based CTX phage replication system and Vibrio cholerae strain that can be infected by CTX phage and can be used for cholera toxin production. More particularly, the present invention provides a Vibrio cholera variant strain, which expresses a toxT protein in which tyrosine at position 139 is substituted by phenylalanine through the point mutation of a toxT gene using a plasmid-based CTX phage replication system, and is used as a receptor strain which can improve CTX phage infection efficiency and allows a plurality of CTX prophages to simultaneously infect the strain and to be inserted into the chromosome thereof, which the consequent provision of the effect of increasing the production yield of a cholera toxin.

The present invention provides novel, recombinant Gram-negative bacteria. In particular, the invention provides recombinant Gram-negative bacteria (e.g., E. coli) lacking genes involved in lipopolysaccharide (LPS, endotoxin) biosynthesis (e.g., lacking genes required for core oligosaccharide biosynthesis) and also provides recombinant Gram-negative bacteria lacking genes involved in LPS biosynthesis that contain one or more exogenous KDO transferases and/or one or more exogenous heptosyltransferases (e.g., from one or more types and/or strains of bacteria). The invention further provides methods of generating and utilizing (e.g., as or in an immunogenic composition (e.g., as or in an adjuvant and/or vaccine)) the recombinant Gram-negative bacteria therapeutic, preventative, and/or research applications.

The present invention relates to a novel process of production of purified recombinant cholera toxin B (rCTB) which provides protection against diarrhea caused by various bacteria such as Vibrio cholerae and Enterotoxigenic Escherichia coli (ETEC). More particularly, the present invention relates to a process of production of rCTB with significantly higher yield and higher purity. The present invention also relates to a vaccine formulation having synergistic protection against Vibrio cholerae and cross protection against ETEC.

Described is a method for the generation of a live vaccine containing stable bacteria carrying at least three attenuating mutations and a vaccine containing bacteria obtained by said method.

Described is a method for the generation of a live vaccine containing stable bacteria carrying at least three attenuating mutations and a vaccine containing bacteria obtained by said method.

Isolated polypeptides are provided that comprise a cholera toxin B subunit variant having one or more modifications to increase the expression of the polypeptide in a plant cell. Nucleic acids sequences, vectors, and plant cells for expressing the cholera toxin B subunit variant polypeptides are also provided. Further provided are methods for producing the cholera toxin B subunit variant polypeptides that include the steps of transforming a plant cell with a nucleic acid encoding the cholera toxin B subunit variant polypeptides; expressing the variant polypeptides; and purifying the polypeptides. Still further provided are methods of isolating the variant polypeptides that include the steps of obtaining a plant cell expressing the cholera toxin B subunit variant polypeptides; extracting the cholera toxin B subunit variant polypeptides from the plant cell; and purifying the cholera toxin B subunit variant polypeptides. Methods of eliciting an immune response are also provided.