20 results about "Lipid A" patented technology

The invention discloses a salmonella typhimurium EN-VNP strain based on flagellin and LPS attenuation as well as a preparation method and application of the salmonella typhimurium EN-VNP strain, and particularly relates to the technical field of biology. The bacterial strain is formed by sequentially knocking out or silencing flagellin genes fliC and fljB, a phosphoethanolamine transferase gene eptA, a 4-amino-4-deoxy-L-arabinose transferase gene arnT and phosphotransferase yeiU on the basis of a salmonella VNP 20009 bacterial strain, and knocking in or overexpressing a phosphotransferase gene lpxE. The salmonella typhimurium EN-VNP strain disclosed by the invention has relatively high safety, the attenuated strain does not contain flagellin, and a lipid A molecule of LPS only retains one phosphate group, so that the safety of the strain is improved, and the strain is more suitable for serving as a vaccine and a drug delivery carrier.

The present invention discloses a recombinant Escherichia coli capable of efficiently producing monophospholipid A vaccine adjuvant, belonging to the fields of genetic engineering and synthetic biology. The present invention knocks out 132 genes related to membrane wall surface molecules, phospholipid and glucose transport, phosphoethanolamine modification and enoyl-ACP reductase in Escherichia coli MG1655, expresses lipid A modification genes FnlpxE, SepagP and SepagL, and constructs strain MW021 / pTEPL. The growth performance of MW021 / pTEPL is greatly improved and antibiotics and inducers are no longer required during the fermentation process; in a 2-L fermentation tank system, the highest OD of MW021 / pTEPL growth is 600 It can reach 38.54, and can produce 13.84g / L of dry cells and about 88.99mg / L of total lipid A; total lipid A contains only two structures, namely MPL and D-MPLA.

The invention belongs to the technical field of biological medicines, and particularly relates to a universal vaccine constructed by taking lipopolysaccharide or analogues thereof as universal antigens and adjuvants, the vaccine can establish inherent immune memory and adaptive immune memory at the same time after being inoculated, instant quick prevention and control can be realized aiming at sudden epidemic situations, and the immunologic function of the vaccine is improved. And a plurality of diseases can be prevented or treated. Besides, the lipopolysaccharide analogue and an amphiphilic substance are assembled into nanoparticles by utilizing the hydrophobicity of a lipid A structure of the lipopolysaccharide analogue and the hydrophilicity of a glycosyl group, and through ligand modification, the targeting property of the vaccine to antigen presenting cells is improved, and the safety of the lipopolysaccharide or the analogue thereof in application to universal vaccines, adjuvants and medicines is improved.

An in vitro method of detecting one or more endotoxins of one or more pathogens in a sample, comprising the steps of a. coating a lipid binding protein on a substrate or capturing a lipid binding protein on a capture molecule immobilized on a substrate, b. contacting the lipid binding protein, thus coated or captured, with the sample, c. detecting whether an endotoxin binds to the lipid binding protein, wherein the one or more endotoxins comprise a lipid A moiety and O- polysaccharide moiety, wherein the lipid binding protein is capable of binding the lipid A moiety of an endotoxin, and characterized in that the lipid binding protein is a mammalian protein and preferably is a murine or human protein.

The present invention discloses a recombinant Escherichia coli capable of producing a monophosphate lipid A vaccine adjuvant, belonging to the fields of genetic engineering and synthetic biology. The present invention knocks out the mlaE and pldA genes of the phospholipid transport system on the Escherichia coli MG1655 genome, the hns gene that regulates PagP expression, and sequentially integrates the FnlpxE gene from Francisella and the SepagL gene from Salmonella by deletion and replacement of other phospholipid transport-related gene clusters ybgC-cpoB and letAB, thereby obtaining the recombinant bacterium WZM012. Through simple fermentation, the WZM012 strain can efficiently synthesize hexaacylated monophosphate lipid A (MPL), producing 32.76 mg / L of MPL in 24 hours of fermentation, with the proportion of MPL in the total lipid A reaching 70%.

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 invention discloses a method for carrying out low endotoxin transformation on salmonella choleraesuis and application of the method, and relates to the field of vaccine.Lipid A of a salmonella choleraesuis attenuated strain SC014 is modified through a genetic engineering technology, low endotoxin transformation is carried out on the salmonella choleraesuis, and a salmonella choleraesuis mutant with low endotoxin is successfully constructed. The modified salmonella choleraesuis and the outer membrane vesicle thereof can effectively activate immune response while obviously reducing the activity of endotoxin, so that the safety and the effectiveness are both considered, and a new thought and a new method are provided for developing a novel vaccine.

The invention belongs to the technical field of biology, and discloses an endotoxin attenuated escherichia coli expression strain which lacks WaaF, WaaC and LpxM and carries at least one of exogenous genes lpxE and lpxF. According to the invention, by preparing the escherichia coli expression strain lacking WaaF, WaaC and LpxM genes at the same time, the dephosphorylation rate of lipoid A of the expression strain is increased, the phosphorylation ability of lipoid A is reduced, and meanwhile, the phosphorylation ability of lipoid A is improved. Through common deletion of the genes, the resistance of the strain to polymyxin B is obviously improved. In addition, the invention further discloses a construction method of the endotoxin weakened escherichia coli expression strain and application of the endotoxin weakened escherichia coli expression strain.

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.

To provide a novel treatment method for benign nervous system tumors, including schwannomas; and to provide a composition for use in the treatment method.SOLUTION: Provided herein are methods for a treating a subject having or at risk of having a benign nervous system tumor. The methods include administering to the subject a therapeutically effective amount of a composition comprising live attenuated Salmonella bacteria, optionally in combination with an immune checkpoint inhibitor and / or angiogenesis inhibitor. Preferably, the attenuated Salmonella is an attenuated strain of S. typhimurium, e.g., Salmonella enterica serovar typhimurium strain VNP20009 with modified lipid A (msbB-) and purine auxotrophic mutation (purI-).SELECTED DRAWING: None

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.

An in vitro method of detecting one or more endotoxins of one or more pathogens in a sample, comprising the steps of a. coating a lipid binding protein on a substrate or capturing a lipid binding protein on a capture molecule immobilized on a substrate, b. contacting the lipid binding protein, thus coated or captured, with the sample, c. detecting whether an endotoxin binds to the lipid binding protein, wherein the one or more endotoxins comprise a lipid A moiety and O- polysaccharide moiety, wherein the lipid binding protein is capable of binding the lipid A moiety of an endotoxin, and characterized in that the lipid binding protein is a mammalian protein and preferably is a murine or human protein.

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.

Metastable liposomal formulations for hydrophobic drug delivery to a tissue or tissue lumen such the bladder have been developed. These are at least one micron in diameter and formed of one or more lipids having entrapped in the lipid a hydrophobic therapeutic, prophylactic or diagnostic agent. The greater stability of these liposomes, as well as the enhanced transfer of entrapped agent into the adjacent tissue, provides for better delivery, especially of hydrophobic agents such as tacrolimus which does not penetrate tissue well. The metastable liposomal formulations can be administered locally, preferably by instillation, or topically, for example, by spraying or painting, to a tissue or tissue lumen such as the bladder in need of treatment.

The invention discloses a preparation method and application of salmonella choleraesuis bionic vesicles capable of being used for oral delivery of double antigens, and relates to the field of vaccines.Lipid A of a salmonella choleraesuis attenuated strain SC014 is modified through a genetic engineering technology, low-endotoxin salmonella choleraesuis engineering bacteria are obtained, then SpyCatcher and SpG are expressed on the surfaces of the salmonella choleraesuis engineering bacteria at the same time through ClyA, and the salmonella choleraesuis bionic vesicles are obtained. According to the present invention, the subunit vaccine model GDH-SpyTag and gD-Fc of the clinically common mixed infection pathogen Streptococcus suis and Pseudorabies virus (PRV) can be respectively coupled, and the negative electricity characteristic of the surface of the subunit vaccine model GDH-SpyTag and gD-Fc are used to wrap the subunit vaccine model GDH-SpyTag and gD-Fc by using the cationic compound COS so as to protect the antigen from being damaged by the gastrointestinal tract environment after the oral immunization; and the presentation of the antigen to digestive tract mucosa immune cells is promoted.

Described herein are methods of synthesizing ionizable amine lipids, such as Lipid A: Formula (I) with increased overall purity, process robustness and an applied impurity control strategy, leading to a substantially pure Lipid A product. Intermediate compounds and methods of synthesizing intermediate compounds are also described.

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.

The invention belongs to the technical field of food engineering, and discloses a pH-responsive intestinal targeted sustained-release flavone liposome as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing the lipid A and the lipid B to form an organic phase solution, and mixing the organic phase solution and a water phase buffer solution in a microfluidic manner to prepare a blank liposome L; (2) adding a buffer solution to adjust the pH value of the external water phase of the blank liposome L to 7.0-7.4, dissolving flavone in the buffer solution with the pH value of 7.0-7.4 to form a flavone water phase, and mixing the blank liposome L with the external water phase with the pH value of 7.0-7.4 with the flavone water phase in a microfluidic manner to prepare liposome LF; (3) mixing the lipidosome LF and a chitosan solution in a micro-fluidic manner, so as to prepare lipidosome CH-LF; (4) mixing the lipidosome CH-LF with a sodium alginate solution in a micro-fluidic manner, so as to prepare a lipidosome SA-CH-LF; and (5) freeze-drying the liposome SA-CH-LF to obtain a flavone liposome finished product.