Salmonella paratyphi A polysaccharide modified nanoparticles and application thereof

Abstract

The invention discloses salmonella paratyphi A polysaccharide modified nanoparticles and application thereof. The nanoparticles are salmonella paratyphi A polysaccharide modified protein. The proteinis a) or b) or c) or d) as follows: a) protein composed of an amino acid sequence as shown in SEQ ID No.3; b) fusion protein obtained by fusing a protein label at a carboxyl terminal or / and an amino terminal of the protein shown in a); and c) protein obtained by substituting and / or deleting and / or adding one or more amino acid residues in the amino acid sequence as shown in SEQ ID No.3. Animal experiments show that the antibody level and the protection effect are obviously improved compared with those of single polysaccharide and polysaccharide connected with CTB. It is indicated that a nanoscale polysaccharide conjugate vaccine with higher potential can be prepared by using a biological method, and a direction is provided for the development of the polysaccharide conjugate vaccine in thenext step.

Description

technical field [0001] The invention relates to a fusion protein that can be self-assembled into protein nanoparticles and its application, belonging to the field of biomedicine. Background technique [0002] Vaccines play an important role in the prevention of pathogenic bacterial infections. The new generation of vaccine products (subunit vaccines) have higher safety due to their single and clear ingredients, but these vaccines often have low immunogenicity, and will be rapidly diluted and degraded by body fluids after injection, so Often some adjuvant and suitable delivery system are required to promote a maximal immune response. In recent years, research has continuously found that the immune effect can be significantly improved by expanding the size of the vaccine to the nanometer level, especially the vaccine with the nanometer as the carrier has been continuously applied, and its main feature is that it can replace the adjuvant. It can stimulate cellular immunity an...

AI Technical Summary

Problems solved by technology

[0004] At present, there is no Salmonella paratyphi A vaccine on the market, and the method commonly used in the current research to prepare polysaccharide-conjugated vaccines is a chemical method, that is, by extracting and activating the polysaccharide of Salmonella paratyphi A, and then expressing it with a purified and similarly activated vector Proteins are chemically cross-linked. This method is complicated and expensive, resulting in generally high prices, and the product is not uniform, resulting in difficulties in quality control.

In addition, because the preparation of the vaccine is completed through chemical reactions, monomeric proteins are often used, and it is difficult for the carrier protein to make the vaccine reach the nanometer level.

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