The present invention encompasses a novel S. aureus bioconjugate vaccine. More generally, the invention is directed to Gram-positive and other bioconjugate vaccines containing a protein carrier, at least one polysaccharide such as a capsular Gram-positive polysaccharide, and, optionally, an adjuvant or pharmaceutically acceptable carrier. The instant invention also includes methods of producing Gram-positive and other bioconjugate vaccines. An N-glycosylated protein is also provided that contains one or more polysaccharides such as Gram-positive polysaccharides. The invention is additionally directed to engineered prokaryotic organisms comprising nucleotide sequences encoding a glycosyltransferase of a first prokaryotic organism and a glycosyltransferase of a second prokaryotic organism. The invention further includes plasmids and prokaryotic cells transformed with plasmids encoding polysaccharides and enzymes which produce an N-glycosylated protein and/or bioconjugate vaccine. Further, the invention is directed to methods of inducing an immune response in a mammal comprising administering said bioconjugate vaccines.

The present invention encompasses a novel S. aureus bioconjugate vaccine. More generally, the invention is directed to Gram-positive and other bioconjugate vaccines containing a protein carrier, at least one polysaccharide such as a capsular Gram-positive polysaccharide, and, optionally, an adjuvant or pharmaceutically acceptable carrier. The instant invention also includes methods of producing Gram-positive and other bioconjugate vaccines. An N-glycosylated protein is also provided that contains one or more polysaccharides such as Gram-positive polysaccharides. The invention is additionally directed to engineered prokaryotic organisms comprising nucleotide sequences encoding a glycosyltransferase of a first prokaryotic organism and a glycosyltransferase of a second prokaryotic organism. The invention further includes plasmids and prokaryotic cells transformed with plasmids encoding polysaccharides and enzymes which produce an N-glycosylated protein and/or bioconjugate vaccine. Further, the invention is directed to methods of inducing an immune response in a mammal comprising administering said bioconjugate vaccines.

Disclosed herein are systems and methods for producing recombinant proteins utilizing mutant E. coli strains containing expression vectors carrying nucleic acids encoding the proteins, and secretory signal sequences to direct the secretion of the proteins to the culture medium. Host cells transformed with the expression vectors are also provided.

The present invention is directed generally to host cells with artificial endosymbionts, wherein the artificial endosymbiont and the host cell communicate with each other to alter a phenotype of the host cell. In some embodiments, the communication comprises the secretion of a polypeptide from the artificial endosymbiont into the host cell. The secreted polypeptide can be a selectable marker, a reporter protein, a transcription factor, a signal pathway protein, a receptor, a growth factor, a cytokine, an effector molecule or other factors that can produce a phenotype in the host cell.

The present invention relates to recombinant N-glycosylated proteins, comprising one or more introduced N-glycosylated optimized amino acid sequence(s), nucleic acids encoding these proteins as well as corresponding vectors and host cells. In addition, the present invention is directed to the use of said proteins, nucleic acids, vectors and host cells for preparing medicaments. Furthermore, the present invention provides methods for producing said proteins.

An expression system and process for the production of Diphtheria toxin polypeptides or mutated forms thereof, such as the toxoid CRM197 polypeptide, in genetically-modified E. coli with high yield is described. The system and process is based on the uncoupling of biomass growth from recombinant protein induction, i.e. using an inducer of protein production that cannot be used as a carbon source for growth by the bacteria. The use of specific components and conditions that improve protein yields are also described.

Certain embodiments are directed to an attenuated bacterial platform for autotransporter-mediated display of antigens. In certain aspects the display is surface display or periplasmic display. In other aspects the antigen is a microbial antigen. The microbial antigen can be a bacterial or viral antigen. The antigen can be antigen derived from a biothreat.

Provided is an E. coli cell for the production of a Diphtheria toxin polypeptide or mutated form thereof, such as the toxoid CRM197 polypeptide. The E. coli's endogenous gene encoding leucine/isoleucine/valine transporter subunit (LivK) is disrupted, deleted, or engineered to encode an affinity tag fused to the LivK and/or the E. coli's endogenous gene encoding maltose transporter subunit (MalE) is disrupted, deleted, or engineered to encode an affinity tag fused to the MalE to facilitate purification of the Diphtheria toxin polypeptide or mutated form thereof from the E. coli.

A recombinant protein comprising a functional polypeptide and, linked to the N-terminus of said functional polypeptide, an N-terminal spacer having a length such that the number of amino acid residues between a signal peptide cleaving site and an N-terminus proximal structural unit of said functional polypeptide is 14-24.