52 results about "O antigen synthesis" patented technology

An object of the present invention is to provide a means for producing an antigenic component with the retained native antigenicity using a cell-free protein synthesis. In particular, it is an object to provide a means for producing an antigenic component without depending on codon usage, like expressing an antigenic component from a gene containing a large amount of AT. The present inventors have made a strenuous study to solve the matters described above and successfully completed the present invention by preparing an antigenic component with the retained antigenicity, in particular a malaria antigen useful for manufacturing a malaria vaccine, through a system with the use of a wheat embryo among cell-free protein synthesis means.

The invention relates to a multivalent vaccine for preventing and treating the infectious diseases of a pig, in particular to a combined vaccine for treating and preventing porcine circovirus type 2 and porcine parvovirus and a preparation method thereof. The multivalent vaccine selects and uses the porcine circovirus type 2 and the porcine parvovirus. The preparation method comprises the following steps of: culturing the porcine circovirus type 2, inactivating and concentrating; culturing the porcine parvovirus, inactivating and concentrating; mixing the two antigen components by proportion, and adding adjuvants to prepare into the vaccine. The bivalent vaccine prepared by the invention is convenient in use and is safer, and the immune effect is superior to that ofcombination of two single vaccines.

The invention discloses a salmonella choleraesuis C500 strain having deletion of asd and realizing expression of lacI. According to the salmonella choleraesuis C500 strain, the salmonella choleraesuisC500 strain is adopted as the carrier, gene modification is carried out on the chromosomes of the salmonella choleraesuis C500 strain, so that the asd gene of the salmonella choleraesuis C500 has deletion, the salmonella choleraesuis C500 delta asd deletion strain is constructed, meanwhile, the araC PBAD-lacI sequence is placed in the deleted asd gene reading frame, so that while the C500 strainhas the deletion of the asd gene, the araC PBAD-lacI expression cassette is introduced, and the LacI protein can be expressed while arabinose exists; in addition, an EGFP expression plasmid pYA4514-EGFP containing the Ptrc promoter is constructed, and the negative regulation effect of LacI for the Ptrc promoter is detected through the western blot experiment. The invention provides the brand-new C500 strain realizing the regulatable expression of the exogenous antigenic gene based on a balanced-lethal system and the expression plasmid, and a foundation is laid for the expression of the exogenous antigenic component by utilizing the C500 strain in the future.

New preparative approach of dry powder vaccines for mucosal (e.g. nasal) administration for the purpose of human or animal immunization; it requires spraying a vaccine liquid dispersion, previously mixed with a sub-micron particulate adjuvant, onto a solid carrier while blending the mixture, followed by drying in mild conditions; the sub-micron particulate adjuvant is an O/W nanoemulsion stabilized with a polysaccharide. Improved dry powder vaccines are obtained in form of aggregated antigen-carrier particles, whereby the antigen is finely and firmly dispersed within the carrier; once in contact with the mucosal surface, the product quickly dissociates and releases the antigen component.

The invention provides a helicobacter pylori mutant strain capable of stimulating immune response and a construction method and application of the helicobacter pylori mutant strain, and belongs to thetechnical field of bioengineering. The mutant strain provided by the invention does not contain a gene futB for encoding glycosyltransferase in an O antigen synthesis process, meanwhile, a lipid A structure is modified, related synthesis genes lpxE and lpxF are knocked out, and the preservation number of the strain is CCTCC NO: M 2020028. The helicobacter pylori outer membrane vesicle vaccine canefficiently stimulate a host to generate immune response and secrete the outer membrane vesicle, so that the helicobacter pylori outer membrane vesicle has the characteristic of high vaccine efficacy. Meanwhile, the method can effectively enable helicobacter pylori lipid A to be recognized by TLR4 again, enables lipid A to have adjuvant activity, and can better serve antigen presentation. The method can be used for constructing novel helicobacter pylori antigen presenting plasmids, antigen protein is presented to periplasmids of bacteria or exposed to the surface of an outer membrane of the bacteria through different strategies, and therefore the efficiency of immunoreaction generated by host recognition of a target antigen is improved.

The invention provides an O-antigen specific nucleotide to Escherichia coli O167 and Shigella boydii3, which is the whole sequence of gene cluster controlling O-antigen synthesis in Escherichia coli O167 and Shigella boydii3, such as separating nucleotide sequence of SEQ ID NO:1 , Escherichia coli O167 being 12864 base, Shigella boydii3 being 12199 base, or one or several base substituted, defected or inserted SEQ ID NO:1 and at same time have same function with SEQ ID NO:1, also comprise oligonucleotide of glycosyltransferase gene and oligosaccharide disposing gene derived from O-antigen gene cluster of Escherichia coli O167 and Shigella boydii3. It is validated that oligonucleotide is highly specific to Escherichia coli O167 and Shigella boydii3 O-antigen. The invention also discloses Escherichia coli O167 and Shigella boydii3 detection and identification method using inventive oligonucleotide.

We constructed S. Gallinarum strains deleted for the global regulatory gene fur (FIG. 1) and evaluated their virulence and protective efficacy in Rhode Island Red chicks and Brown Leghorn layers. The fur deletion mutant was a virulent and, when delivered orally to chicks, elicited excellent protection against lethal S. Gallinarum challenge. We also examined the effect of a pmi mutant and a combination of fur deletions with mutations in the pmi and rfaH genes, which affect O-antigen synthesis, and ansB, whose product inhibits host T cell responses. The ΔAfur Δpmi and Δfur ΔansB double mutants were attenuated, but not protective when delivered orally to chicks. However, a Δpmi Δfur strain was substantially immunogenic when administrated intramuscularly. Altogether our results show that the fur gene is essential for virulence of S. Gallinarum and the fur mutant is effective as a live recombinant vaccine against fowl typhoid.

Provided are a cra4S1 gene, an encoded cra4S1 protein, and a vaccine or drug containing the cra4S1 protein or a fragment thereof. A nucleotide sequence of the cra4S1 gene is represented by SEQ ID NO. 1. The vaccine combines the specific target of an outer membrane protein of Porphyromonas gingivalis and the antigen component of the bacterial conserved region, which has an immune prevention and protection effect on the body.

The invention relates to the field of fusobacterium necrophorum vaccines, and in particular relates to a fusobacterium necrophorum antigen, a preparation method of the fusobacterium necrophorum antigen, and a vaccine prepared by adopting the fusobacterium necrophorum antigen. The preparation method of the fusobacterium necrophorum antigen comprises the following steps: carrying out enzymolysis on fusobacterium necrophorum by adopting pancreatin, carrying out centrifugation to obtain a supernate, and carrying out inactivation treatment on the supernate to obtain the fusobacterium necrophorum antigen. Through multiple times of experiments, the method of lysing the thallus by adopting pancreatin is adopted, the obtained lysed product is separated, so that endotoxin and other invalid ingredients are removed, and the effective antigenic components are reserved; the vaccine prepared by adopting the fusobacterium necrophorum antigen obtained through the inactivation treatment overcomes the defects that after the inoculation of the existing vaccine, hardening easily forms at the injected part, and the side reactions including local swelling and pain, heating and the like occur; and the prepared vaccine is stable and reliable in immune performance.

The invention provides an Escherichia coli O125 O-antigen specific nucleotide, which is the whole sequence of gene cluster controlling O-antigen synthesis, nucleotide sequence of SEQ ID NO:1 being 14206 base, or one or several base substituted, defected or inserted SEQ ID NO:1 and at same time have same function with SEQ ID NO:1, also comprise oligonucleotide of glycosyltransferase gene and oligosaccharide disposing gene derived from Escherichia coli O125 O-antigen gene cluster. It is validated that oligonucleotide is highly specific to Escherichia coli O125 O-antigen. The invention also discloses Escherichia coli O125 detection and identification method using inventive oligonucleotide.

An effective Pseudomonas aeruginosa vaccine may require one or several antigenic components, and so various antigens of P. aeruginosa are identified for use in immunisation. These polypeptides may optionally be used in combination with other nosocomial antigens.