Provided herein are immunogenic compositions comprising a Staphylococcus aureus protein A (SpA) variant and a mutant staphylococcal leukocidin subunit polypeptide comprising a LukA polypeptide, a LukB polypeptide, and/or a LukAB dimer polypeptide, wherein the LukA polypeptide, the LukB polypeptide, and/or the LukAB dimer polypeptide have one or more amino acid substitutions, deletions, or a combination thereof.

An objective is to provide an Fc-modified antibody or the like having a long serum half-life according to a CCAP method, more specifically, an antibody or the like where IgBP is bound to only one site, based on findings of the inventors. Provided is an objective antibody or the like by purification and production of an Fc-modified antibody or the like with a column bound to an Fc region of an antibody. Specifically, an antibody where only one of two binding sites of Fc is selectively modified is provided by allowing an IgBP-bound antibody produced by a CCAP method to adsorb to a carrier of an IgBP-immobilized column, or forming a state where only one Fc of an antibody is bound to an IgBP binding column and then adding a peptide reagent for CCAP to the column to perform a reaction of a CCAP method in the column.

Disclosed herein are isolated and purified Staphylococcus aureus bi-component leukocidin, referred to herein as LukAB, and its components LukA and LukB, antibodies specific to LukA, antibodies specific to LukB, therapeutic compositions containing LukA and/or LukB, or anti-LukA and/or anti-LukB antibodies, uses of the compositions to treat acute inflammatory conditions or S. aureus infection, methods for identifying inhibitors of LukAB-mediated cytotoxicity of human phagocytes, and methods for using LukAB as a marker to predict severity of S. aureus infection.

Disclosed herein are isolated and purified Staphylococcus aureus bi-component leukocidin, referred to herein as LukAB, and its components LukA and LukB, antibodies specific to LukA, antibodies specific to LukB, therapeutic compositions containing LukA and/or LukB, or anti-LukA and/or anti-LukB antibodies, uses of the compositions to treat acute inflammatory conditions or S. aureus infection, methods for identifying inhibitors of LukAB-mediated cytotoxicity of human phagocytes, and methods for using LukAB as a marker to predict severity of S. aureus infection.

Disclosed herein are fusion polypeptides comprising: (i) a fragment antigen comprising an epitope of a target protein antigen; and (ii) a complement binding polypeptide. The disclosure also provides fusion polynucleotides (e.g., mRNA) encoding the same. Also disclosed herein are methods of making and using the fusion polypeptides and fusion polynucleotides of the present disclosure.

Disclosed herein are fusion polypeptides comprising: (i) a fragment antigen comprising an epitope of a target protein antigen; and (ii) a complement binding polypeptide. The disclosure also provides fusion polynucleotides (e.g., mRNA) encoding the same. Also disclosed herein are methods of making and using the fusion polypeptides and fusion polynucleotides of the present disclosure.

The present application provides methods and uses of O-oligosaccharyltransferase (O-OTases) for generating vaccines. In particular, the present application provides a method of synthesizing a glycoprotein comprising glycosylation of pilin-like protein ComP using a Pg1L.sub.ComP O-OTase. Uses of glycoproteins synthesized by glycosylating ComP using Pg1L.sub.ComP O-OTase, particularly for the preparation of vaccines and the like, including a vaccine to Streptococcus, is also provided.

In certain embodiments, the present invention provides novel antibody purification methods and systems using a potentially simple and cost-efficient means. In some embodiments, customized Z-33 derived from Staphylococcus aureus Protein A is used to construct immuno-amphiphile molecules which can assemble into immunofibers in aqueous solution with bioactive epitopes on the surface and have IgG binding ability.

Disclosed is chimeric polypeptides derived from S. aureus proteins having SEQ ID NOs: 1-9 and 139-146. The chimeric polypeptides are useful as immunogens for providing protective immunity against S. aureus infection. Also disclosed are compositions, methods of treatment and prophylaxis, nucleic acids and vectors comprising the nucleic acids.

Disclosed is chimeric polypeptides derived from S. aureus proteins having SEQ ID NOs: 1-9 and 139-146. The chimeric polypeptides are useful as immunogens for providing protective immunity against S. aureus infection. Also disclosed are compositions, methods of treatment and prophylaxis, nucleic acids and vectors comprising the nucleic acids.