Abstract: The present invention relates to the field of neisserial vaccine compositions (particularly gonococcal vaccine compositions) and the use of such compositions in medicine. More particularly, the present invention relates to genetically modified gonococci of strain FA1090 and outer membrane vesicles obtained therefrom. The invention also provides a process for preparing the genetically modified gonococci of the invention as well as immunogenic compositions and vaccines comprising the outer membrane vesicles of the invention.

Abstract: The present invention relates to the field of native outer membrane vesicles (nOMVs), particularly nOMVs having increased levels of lipoproteins on their surface and use of same in immunogenic compositions.

Abstract: The present invention relates to the field of native outer membrane vesicles (nOMVs), particularly nOMVs having increased levels of lipoproteins on their surface and use of same in immunogenic compositions.

Abstract: A first aspect of the invention provides meningococcal outer membrane vesicles in which NHBA is over-expressed. A second aspect of the invention provides meningococcal outer membrane vesicles in which NadA is over-expressed. A third aspect of the invention provides a panel of bacterial strains, each member of which is isogenic except for a single gene which in each strain encodes a different variant antigen of interest.

Abstract: A first aspect of the invention provides meningococcal outer membrane vesicles in which NHBA is over-expressed. A second aspect of the invention provides meningococcal outer membrane vesicles in which NadA is over-expressed. A third aspect of the invention provides a panel of bacterial strains, each member of which is isogenic except for a single gene which in each strain encodes a different variant antigen of interest.

Abstract: New promoters are described to drive transcription in meningococcus e.g. for over-expression of protein antigens for retention in membrane vesicles. Modified porA promoters lack the wild-type poly-G sequence which can cause phase variation. Meningococcal rRNA-coding genes (e.g. for 16S rRNA) can be used to drive transcription of a protein-coding gene. These approaches can be used in combination.

Abstract: A first aspect of the invention provides meningococcal outer membrane vesicles in which NHBA is over-expressed. A second aspect of the invention provides meningococcal outer membrane vesicles in which NadA is over-expressed. A third aspect of the invention provides a panel of bacterial strains, each member of which is isogenic except for a single gene which in each strain encodes a different variant antigen of interest.

Abstract: A first aspect of the invention provides meningococcal outer membrane vesicles in which NHBA is over-expressed. A second aspect of the invention provides meningococcal outer membrane vesicles in which NadA is over-expressed. A third aspect of the invention provides a panel of bacterial strains, each member of which is isogenic except for a single gene which in each strain encodes a different variant of an antigen of interest.

Abstract: New promoters are described to drive transcription in meningococcus e.g. for over-expression of protein antigens for retention in membrane vesicles. Modified porA promoters lack the wild-type poly-G sequence which can cause phase variation. Meningococcal rRNA-coding genes (e.g. for 16S rRNA) can be used to drive transcription of a protein-coding gene. These approaches can be used in combination.

Abstract: A first aspect of the invention provides meningococcal outer membrane vesicles in which NHBA is over-expressed. A second aspect of the invention provides meningococcal outer membrane vesicles in which NadA is over-expressed. A third aspect of the invention provides a panel of bacterial strains, each member of which is isogenic except for a single gene which in each strain encodes a different variant of an antigen of interest.

Abstract: The meningococcal fhbp gene (encoding factor H binding protein) is naturally expressed from two independent transcripts by two differentially regulated promoters. In one transcript it is co-expressed with the neighbouring upstream gene from the Pnmb1869 promoter. The other transcript is monocistronic and is expressed from its own dedicated promoter, Pfhbp, which is activated by the global regulatory protein FNR in response to oxygen-limiting conditions. To increase expression of the monocistronic transcript a constitutively-active FNR mutant is used. The Pfhbp promoter can thus be activated, leading to over-expression of FNR-activated genes, such as fhbp.