Recombinant bacillus subtilis for expressing avian influenza virus HA antigen fragment and PB1-F2 protein in tandem

Abstract

The invention relates to recombinant bacillus subtilis for expressing avian influenza virus HA antigen fragment and PB1-F2 protein in tandem, and belongs to the field of biotechnical genetic engineering. The invention successfully establishes a recombinant bacillus subtilis integrated expression plasmid plnHAPB1-F2 for expressing the avian influenza virus HA-PB1-F2 protein, and successfully achieves chemical conversion and electric shock conversion into bacillus subtilis WB600. Western-blot verification shows that the avian influenza virus HA antigen fragment and the PB1-F2 protein which are expressed in tandem can be successfully expressed in the recombinant bacillus subtilis. After one-day-old SPF chick is immunized through oral administration, a chick body can be stimulated to generate an effective HA-PB1-F2 specific immune response level, and nonspecific immunity is significantly enhanced. The recombinant bacillus subtilis is expected to be successfully developed into a genetic engineering oral vaccine for preventing the highly pathogenic avian influenza of poultry.

Description

[0001] 1. Technical field [0002] The invention relates to a recombinant bacillus subtilis that serially expresses the HA antigen fragment of avian influenza virus and the PB1-F2 protein, and belongs to the field of biotechnology genetic engineering. Specifically including: construction of avian influenza virus HA-PB1-F2 protein integrated expression plasmid pInHAPB1, expression and identification of avian influenza virus HA-PB1-F2 protein, and recombinant Bacillus subtilis can stimulate the expression of chicken bone marrow-derived dendritic cells MHC11 Significant changes occur to induce the maturation of dendritic cells; it can also stimulate the body of SPF chicks to produce effective HA-PB1-F2 specific immune response levels. [0003] 2. Background technology [0004] 1 Research progress of oral mucosal immunity [0005] At present, the most practical and effective way to control bird flu in our country is to use the whole virus inactivated vaccine. The reason is that i...

AI Technical Summary

Problems solved by technology

However, traditional vaccination (intramuscular or subcutaneous injection) has the following disadvantages: ① animal and human viruses need to be cultured in animal cells, which makes the cost of vaccine production very high; ② pathogens in the vaccine may not be available during vaccine production Completely killed or completely attenuated, resulting in a wider spread of the disease; ③The attenuated strain may mutate; ④Some diseases are not well controlled by traditional vaccines (such as AIDS); ⑤It causes the stress response of poultry and affects The growth of animals; ⑥If traditional vaccines are vaccinated multiple times, the vaccine residues in the body will cause the quality of meat products to decline, which will indirectly affect food safety and public health; ⑦Avian influenza infection is mainly through the respiratory tract and gastrointestinal tract. Inactivated oil emulsion vaccine, which cannot stimulate local mucosal immunity in the respiratory tract and digestive tract

However, in practice, oral mucosal immunization is also insufficient. Since the vaccine only acts on the mucosal surface, it can rarely enter the animal body effectively. When the vaccine is easily destroyed, the immune effect is affected, which limits the use and promotion of gastrointestinal mucosal immunity

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