Abstract: The invention pertains to a complex of an OMV, a vertebrate antimicrobial peptide (AMP) and an antigen, wherein the AMP is non-covalently complexed with the OMV and wherein the antigen is conjugated to the AMP. Preferably, the antigen is covalently linked to the AMP. The invention further concerns the induction of an immune response using the complex of the invention as well as a method for producing the complex of the invention.

Abstract: The present invention relates to the fields of medical microbiology and vaccines. In particular the invention relates to a process wherein the spontaneous release of bacterial outer membrane vesicles (OMV) of Gram-negative bacteria is stimulated by application of a dissolved oxygen tension (DOT) that is higher than a physiological DOT. The thus produced OMVs are for use in vaccines. The invention further relates to OMV obtainable by said process, and to a pharmaceutical composition comprising such OMV. The present invention further relates to the use of OMV of the present invention as a medicament in particular for use in a method for eliciting an immune response.

Abstract: The present invention relates to neisserial LPS having a hexa-acylated lipid A moiety, wherein the hexa-acylated lipid A moiety is modified as compared to the lipid A moiety of a wild-type neisserial LPS in that it comprises a palmitoleoyl instead of a lauroyl secondary acyl chain on the glucosamine at the non-reducing end of the lipid A moiety. The invention further relates to mixtures of the hexa-acylated LPS with the corresponding penta-acylated LPS, lacking a secondary acyl chain on the glucosamine at the non-reducing end of the lipid A moiety. The invention also relates to neisserial bacteria that have been genetically modified to reduce expression of the endogenous 1pxL1 gene and to introduce expression of a heterologous thermosensitive 1pxP gene for producing the hexa- and penta-acylated LPS.

Abstract: The present invention relates to neisserial LPS having a tetra-acylated lipid A moiety, wherein the tetra-acylated lipid A moiety is modified as compared to the lipid A moiety of a wild-type neisserial LPS in that it lacks one of the secondary acyl chains and lacks a primary acyl chain on the 3-position of the glucosamine at the reducing end of the lipid A moiety. The invention further relates to neisserial bacteria that have been genetically modified to reduce expression of either one of the endogenous lpxL1 or lpxL2 genes and to introduce expression of a heterologous pagL gene. The neisserial LPS of the invention has TLR4 agonist properties and is therefore useful in compositions for inducing or stimulating immune responses, such as vaccines, as well as in other forms of immunotherapy.

Abstract: The present invention relates to neisserial LPS having a hexa-acylated lipid A moiety, wherein the hexa-acylated lipid A moiety is modified as compared to the lipid A moiety of a wild-type neisserial LPS in that it comprises a palmitoleoyl instead of a lauroyl secondary acyl chain on the glucosamine at the non-reducing end of the lipid A moiety. The invention further relates to mixtures of the hexa-acylated LPS with the corresponding penta-acylated LPS, lacking a secondary acyl chain on the glucosamine at the non-reducing end of the lipid A moiety. The invention also relates to neisserial bacteria that have been genetically modified to reduce expression of the endogenous lpxL1 gene and to introduce expression of a heterologous thermosensitive lpxP gene for producing the hexa- and penta-acylated LPS.

Abstract: The current invention lies in the field of medicine and more specifically in the field of vaccinology. The current invention concerns a novel Bordetella LPS and a modified bacterium of the genus Bordetella comprising such modified LPS. The LPS of the invention has a reduced endotoxicity in comparison to an unmodified Bordetella LPS. The modified LPS of the invention is therefore particularly suitable for use in inducing or stimulating an immune response in a subject, wherein the immune response is induced or stimulated against a Bordetella infection. The modified Bordetella LPS of the invention is obtainable by introducing in a Bordetella cell the expression of a heterologous acyl transferase. In particular, the modified Bordetella cell of the invention has an increased expression of an heterologous LpxA, LpxL or LpxD acyl transferase.