7 results about "Lipid A" patented technology

This invention discloses a single-chain antibody 3G4 that targets and binds to mobile polymyxin resistance proteins and its applications. The amino acid sequence of single-chain antibody 3G4 is shown in SEQ ID NO.2. The mobile polymyxin resistance proteins are MCR-1 and / or MCR-2 proteins. Single-chain antibody 3G4 can specifically bind to the functional catalytic region of the mobile polymyxin resistance proteins, thereby inhibiting their function. Single-chain antibody 3G4, its encoding gene, and an expression vector containing the encoding gene can be used to prepare detection reagents for mobile polymyxin resistance proteins or recombinant bacteria with inhibited polymyxin resistance. The recombinant bacteria are Gram-negative bacteria capable of expressing single-chain antibody 3G4. The single-chain antibody 3G4 provided by this invention can efficiently target polymyxin resistance proteins, blocking their modification of lipid A on the outer membrane of Gram-negative Enterobacteriaceae, thereby reversing bacterial resistance to polymyxins.

The present invention relates to immunogenic compositions comprising Salmonella enterica paratyphoid A serotype outer membrane vesicles (OMV), vaccines comprising said immunogenic compositions, and methods and uses of said immunogenic compositions. The invention also relates to Salmonella paratyphi A bacteria comprising the modified lipid A.

The application discloses a novel Kdo-MPLA adjuvant, relates to the technical field of synthetic biology, and discloses that the adjuvant is composed of monophosphoryl lipid A (MPLA) and Kdo sugar through an alpha-glycosidic bond, the MPLA is a structure of Salmonella lipid A modified by monophosphorylation at a 4' position, and the Kdo sugar is endowed with amphiphilicity, so that the Kdo sugar is self-assembled into a liposome nanoparticle in an aqueous solution; the attenuated strain of Salmonella is edited by double knockout of rfaC and eptA genes: the rfaC knockout blocks the synthesis of LPS core polysaccharide and retains the lipid A-Kdo connection; the eptA knockout obtains monophosphorylated lipid A; after fermentation of the engineering bacteria, high-purity Kdo-MPLA is obtained by using a phenol-chloroform-petroleum ether extraction method, the process is simplified, and the product is uniform; the adjuvant can activate a TLR4 signal pathway and induce a Th1 type immune response, and the levels of inflammatory factors IL-6 and IL-1beta are significantly lower than those of natural LPS, so that the adjuvant is suitable for a mixed preparation of HPV, malaria and other vaccine antigens; and the application overcomes the uncontrollability of hydrolysis and the high cost defect of chemical synthesis of a traditional MPLA chemical extraction process.

The present invention relates to an immunogenic composition containing outer membrane vesicles (OMVs) of Bacillus paratyphi A, a vaccine containing the immunogenic composition, and a method and use of the immunogenic composition. The present invention also relates to Bacillus paratyphi A containing modified lipid A.

The present invention is directed to a method for detecting the presence or absence of a bacterium resistant to a cyclic cationic polypeptide antibiotic, comprising: (a) subjecting a test sample to mass spectrometry analysis and generating a mass spectrum output; wherein said test sample comprises a bacterial membrane or a fragment thereof, wherein the fragment comprises a non-Lipid A component; (b) identifying in said mass spectrum output a first defined peak indicative of the presence of Lipid A modified by phosphoethanolamine, wherein said first defined peak is a peak present in a mass spectrum output for Lipid A modified by phosphoethanolamine and wherein said first defined peak is absent from a corresponding mass spectrum output for native Lipid A; and (c) wherein the presence of said first defined peak indicates the presence of a bacterium resistant to a cyclic cationic polypeptide antibiotic, and wherein the absence of said first defined peak indicates the absence of a bacterium resistant to a cyclic cationic polypeptide antibiotic. This method is also used in a screening method to identify an inhibitor of cyclic cationic polypeptide antibiotic resistance in a bacterium. The matrix solution can contain 2,5-dihydroxybenzoic acid and aids in the selective extraction, co-crystallisation and ionisation of native Lipid A and / or modified Lipid A as an integral part of a bacterial membrane.

The invention pertains to a genetically modified Neisseria bacterium comprising a lipopolysaccharide (LPS) having a lipid A moiety and a modified oligosaccharide core, wherein the modified oligosaccharide core comprises a first oligosaccharide chain coupled to heptose 1 and a second oligosaccharide chain coupled to heptose 2, wherein the first and second oligosaccharide chain comprise a lactose directly coupled to respectively heptose 1 and 2, thereby forming a Neisseria gonorrhoeae 2C7 epitope. The modified bacterium may express a further non-native N. gonorrhoeae antigen, such as MetQ, AniA or NspA. The modified Neisseria bacterium is not Neisseria gonorrhoeae. The bacterium is preferably Neisseria meningitidis, Neisseria lactamica or Neisseria cinerea. The invention further pertains to LPS and OMVs obtained from the genetically modified bacterium, as well as methods for producing said modified bacterium.