6results about How to "Good immune effect" patented technology

The application discloses a phosphoric acid modified protein or polypeptide, a preparation method thereof and application thereof in vaccines, and belongs to the field of protein phosphoric acid modification. The preparation method of the phosphoric acid modified protein or polypeptide is as follows: a compound containing an aldehyde group and a phosphate group is subjected to nucleophilic reaction with a protein or polypeptide to form a Schiff base; a reducing agent is used to reduce the Schiff base, and after post-treatment, the phosphoric acid modified protein or polypeptide is obtained. After the phosphoric acid modified protein product prepared by the method is prepared into a vaccine with an aluminum hydroxide adjuvant and mice are immunized, the antibody titer is significantly increased. This is of great significance for increasing the immune effect, reducing the inoculation dose, saving the antigen amount and improving the immune response of some people or in specific conditions.

This invention belongs to the field of genetic engineering technology, specifically relating to a double-gene-deleted serotype 5 Haemophilus parasuis attenuated vaccine strain, its construction method, and its application. This invention mainly utilizes modern genetic engineering principles and molecular biology techniques to delete the cpxA and cpxR genes, potential virulence factors of HPS, constructing the HN1570 double-gene-deleted strain HPS5△cpxAR. This double-gene-deleted strain was deposited at the China General Microbiological Culture Collection Center (CGMCC) on June 16, 2023, with accession number CGMCC NO: 45596. Compared with the parent strain, this double-gene-deleted strain exhibits significantly reduced virulence while maintaining the same immunogenicity. The attenuated live vaccine prepared from this strain as an antigen provides 100% protection against serotype 5 infection and good cross-protection against other serotypes and untyped Haemophilus parasuis infections. Furthermore, the vaccine preparation process eliminates the need for inactivation and inactivation testing, simplifying the preparation method and increasing production efficiency. This lays the foundation for further development of novel, highly effective genetically engineered live vaccines that provide high cross-protection efficacy.

This invention belongs to the field of feed additive technology, specifically relating to a microalgae compound feed additive for alleviating weaning stress in calves and its preparation method. The microalgae compound feed additive comprises the following raw materials in parts by weight: 5-10 parts microalgae powder, 2-6 parts unsaturated fatty acid / modified montmorillonite complex, 0.7-1.2 parts probiotics, and 0.3-0.5 parts walnut shell extract. This microalgae compound feed additive can improve the fragile intestinal barrier function and immunity of weaned calves, enhance their growth performance, and thus improve breeding efficiency.

This invention relates to the field of animal immunology, and more particularly to an antigen that enhances the immune response to Newcastle disease virus (NDV), its preparation method, and its application. The antigen is a fusion protein obtained by expressing the Ii-key-F-Fc recombinant vector using engineered bacteria, named the Ii-key-F-Fc fusion protein. The Ii-key-F-Fc recombinant vector is obtained by splicing three major antigenic epitope fragments from the NDV F protein and then tandemly connecting them with chicken IgY Fc and Ii-key. This invention constructs the pCold-TF-Ii-key-F-Fc prokaryotic expression plasmid by tandemly connecting the novel chicken vector Ii-key-Fc with the F antigenic epitope, and then expresses the fusion protein using an E. coli expression system to obtain a new antigen that enhances the immune response in poultry. This provides a new approach for developing a novel NDV vaccine and a new strategy for improving the immune response of subunit vaccines in poultry.

The application discloses an antibacterial peptide Ajaponin of Japanese eel and application thereof. The antibacterial peptide Ajaponin is composed of 21 amino acids and has a molecular weight of 2693.29 Dalton. The antibacterial peptide Ajaponin contains 7 positively charged amino acid residues, has a hydrophobicity of 0.316 and an isoelectric point of 11.45. The antibacterial peptide Ajaponin is a novel cationic short peptide, has good water solubility, high antibacterial activity, low toxicity and other advantages, is composed of limited amino acid residues, has compact structure, is easy to synthesize and purify, and is convenient for large-scale production and application. In addition, the antibacterial peptide Ajaponin contains multiple positively charged amino acid residues, is beneficial to interaction with negative charges of bacterial cell membranes, destroys the membrane integrity, and thus plays a role in rapid bacteriostasis and sterilization.

This invention discloses a pre-fusion F protein of respiratory syncytial virus (RSV) and its applications. The pre-fusion F protein is a recombinant pre-fusion F protein of RSV modified with amino acid mutations. The mutation modification method is selected from any of the following: (1) point mutation of amino acids based on the full-length sequence of wild-type pre-fusion F protein; (2) first deleting the transmembrane / intracellular region of the full-length sequence of wild-type pre-fusion F protein, and then attaching the fibritin / Throm / 6his / Stretaq sequence to its C-terminus, and then mutating K at amino acid position 75 to C and S at amino acid position 215 to C. This invention utilizes protein genetic engineering techniques to rationally optimize the amino acid sequence of the pre-fusion F protein of RSV. Compared with the wild-type F protein, the pre-fusion F recombinant protein modified with amino acid mutations has improved stability and immunogenicity.