11 results about "Hemagglutination" patented technology

This invention discloses a method for detecting antigen content, comprising the following steps: diluting the test sample and a reference sample to specific concentrations; serially diluting the test sample and reference sample to specific concentrations using a diluent on a 96-well hemagglutination plate; adding sensitized red blood cell suspension to wells of different dilutions of the test sample and reference sample, mixing, allowing to stand, and then determining the agglutination results of each well; scoring and recording the agglutination results of each well; summing the scores of each test sample and recording it as A, and summing the total scores of each reference sample and recording it as B; calculating the antigen content of the test sample according to the formula: antigen content of the reference sample × 2. (A‑B) / 16 This method is convenient and fast. The test results are calculated using the self-developed method and compared with the test results of the reference sample, which can obtain relatively accurate test results and solve the problem of inconsistent test results of different batches of sensitized red blood cell suspensions.

The invention discloses a recombinant nano antibody of a waterfowl H9N2 avian influenza virus, a recombinant expression vector, a recombinant strain and application thereof, and relates to the field of biology. The amino acid sequence of the recombinant nano antibody is SEQ ID NO: 2, and the nucleotide sequence of the recombinant nano antibody is SEQ ID NO: 1. The invention provides a recombinant expression vector containing the coding gene of the recombinant nano-antibody and a recombinant strain for expressing the recombinant nano-antibody. The recombinant nano antibody is applied to preparation of a waterfowl H9N2 avian influenza resisting medicine or a waterfowl H9N2 avian influenza diagnostic reagent. The yield of the recombinant nano antibody reaches 1.5 g / L, the hemagglutination inhibition activity titer for resisting the waterfowl H9N2 avian influenza virus is 4 log2, and the recombinant nano antibody has remarkable biological activity and can be used for preparing a novel nano antibody preparation for preventing and / or treating the waterfowl H9N2 avian influenza.

The invention relates to the technical field of biology, and discloses an influenza A virus H5 protein mutant and application thereof. In order to solve the problems of weak cross immune response to epidemic strains, insufficient stability of wild type HA protein, low immunogenicity and the like of the existing H5N1 vaccine, a stable soluble H5 protein mutant is constructed through a sequence modification strategy. Specifically, the 332th to 380th amino acids in the HA protein of a wild type influenza A virus H5N1 are replaced by SPGCAT, and point mutations T386C, L418P and H456P are introduced to obtain the mutant. The mutant can significantly improve the structural stability of trimer protein, improve the expression level of recombinant protein, broaden the cross protection spectrum, enhance the level of immunogenic hemagglutination inhibition antibodies and improve immune response balance.

The present invention describes hemagglutination inhibition (HAI) assay methods to determine candidate subunit protein vaccines in the absence of using source viruses.

The present invention belongs to the technical field of biomedicine, and specifically relates to a recombinant influenza virus protein, a vaccine, and a preparation method therefor and the use thereof. To overcome the defects of existing influenza vaccines with respect to safety and high toxic side effects, a recombinant influenza virus protein is provided, which has an amino acid sequence as shown in at least one of SEQ ID No. 1 to SEQ ID No. 6. Recombinant hemagglutinin proteins of H1N1 and H3N2 subtypes, and Victoria and Yamagata lineages are expressed and purified by means of an insect baculovirus expression system, and are mixed with an adjuvant to prepare a highly immunogenic recombinant bivalent, trivalent or quadrivalent recombinant influenza virus protein vaccine. The prepared vaccine can induce high levels of specific IgG antibodies and hemagglutination-inhibiting neutralizing antibodies, the addition of adjuvant WGa01 improves the immunogenicity of the vaccine, and the provided vaccine is suitable for people allergic to eggs and has high safety.

The invention provides a method for preparing a Newcastle disease virus antigen by a cell suspension culture process, and relates to the technical field of virus antigen and vaccine preparation. The suspension culture method comprises the following steps: inoculating full-suspension Newcastle disease virus production cells into an F807k basal culture medium according to a certain density for cell culture, adding an NF01d supplementary culture medium after the cell culture is performed for 70-74 hours, adding an F808Vb supplementary culture medium after the cell culture is performed for 94-98 hours, inoculating Newcastle disease virus according to a virus inoculation amount of 0.1-0.5%, and culturing for 20-30 hours. And 38-42 hours after virus inoculation, adding the NF01d supplementary culture medium again, and expressing the Newcastle disease virus antigen at 28-38 DEG C. According to the optimized full-suspension culture process, higher antigen expression quantity can be obtained, the virus yield is improved, the hemagglutination titer of the obtained Newcastle disease virus antigen reaches 12log2 for the first time, and the protective efficacy is improved.

The present invention relates to the field of biological vaccine research and development technology, and in particular, to a VSV vector-based highly pathogenic H5 subtype avian influenza inactivated vaccine and a method for preparing same. The method comprises: using a vesicular stomatitis virus with the deletion of the surface envelope protein gene as a vector, inserting the NA gene and the HA gene of an H5 subtype highly pathogenic avian influenza virus strain between the M gene and the L gene of the vector in the form of an expression cassette, and acquiring a recombinant virus by means of rescue via reverse genetic technology; inoculating the recombinant virus into susceptible cells, culturing for replication and proliferation, and then harvesting a viral solution; inactivating the viral solution to acquire an inactivated viral solution; and adding the inactivated viral solution to a pharmaceutically or veterinarily acceptable carrier, excipient, medium, or adjuvant to acquire an inactivated vaccine. The provided H5 subtype avian influenza inactivated vaccine can induce a high hemagglutination inhibition titer of avian influenza virus on day 21 after chick immunization. The provided inactivated vaccine has good safety and immunogenicity.

The invention discloses a recombinant nano antibody for resisting H9 subtype avian influenza virus HA protein and application of the recombinant nano antibody, and relates to the field of bioengineering, and the amino acid sequence of the recombinant nano antibody is SEQ ID NO: 2; the nucleotide sequence for coding the amino acid sequence of the recombinant nano antibody is SEQ ID NO: 1. The yield of the recombinant nano-antibody is 1.84 mg / mL, the recombinant nano-antibody is only specifically combined with H9 virus and HA protein, has hemagglutination inhibition activity and HI titer of 8.3 log2, is the first nano-antibody with hemagglutination inhibition activity reported at present, has half effective inhibition concentration IC50 of 16.31 mu g / mL, can significantly reduce the detoxification level of the virus in chicks, has high biological activity, and can be used for preparing the recombinant nano-antibody. The strain can be applied to prevention and / or treatment of H9 subtype avian influenza, provides a novel, efficient and customizable biological preparation platform for prevention and control of avian influenza, and has important scientific research value and industrialization prospect.

Provided are an antibody or an antigen-binding fragment thereof that specifically recognizes CD47 and methods of making the same and using the same. The antibodies provided herein exhibit both induction of phagocytosis of cancer cells and have very low to no hemagglutination and phagocytosis of RBCs, showing improved efficacy to toxicity ratio for cancer treatment.

The present invention relates to a chimera formed of peptide epithedes derived from hemagglutinin and neuraminidase characterized in that it consists of SEQ ID NO.4.

This invention relates to the field of bioengineering, and more particularly to sgRNA, MDCK cells, and their applications. This invention provides sgRNA having the nucleotide sequences shown in SEQ ID NO:1 to SEQ ID NO:4. This invention employs a CRISPR-Cas9 gene editing method, which, compared to existing RNAi methods, offers higher specificity and lower off-target risk. Compared to MDCK cells, PCR detection showed a reduction of over 90% in RNA levels in IRF7- / - cells, Western blotting showed a significant decrease in IRF7 protein expression, and viral hemagglutination assays showed higher titers for influenza virus compared to the original cells. Tumorigenicity assays showed that the gene knockout cells retained low tumorigenicity. Compared to existing technologies, the cells of this invention exhibit both low tumorigenicity and significantly increased viral yield, making them suitable for influenza vaccine production.