Target cell specificity fusion protein serving as porcine reproductive and respiratory syndrome viral vaccine antigen and vaccine composition

Abstract

The invention discloses target cell specificity fusion protein serving as a porcine reproductive and respiratory syndrome viral vaccine antigen and a vaccine composition. The target cell specificity fusion protein is composed of an amino acid sequence of adenylate cyclase of bordetella lack of an N-terminal enzymatic structural domain and amino acid sequences of the antigen, wherein the amino acid sequences of the antigen comprise the nucleoprotein partial sequence of the porcine reproductive and respiratory syndrome viruses, the partial sequence of membrane protein (M protein) and the partial sequence of M protein GP5. The amino acid sequences of the antigen are located at the N-terminal of the amino acid sequence of adenylate cyclase of bordetella lack of the N-terminal enzymatic structural domain. The fusion protein can successfully induce cellular immune responses and antibody production of animal bodies, can perform a huge effect in the field of producing vaccines by applying medicine compositions composed of BPAC-CM5RM5 fusion protein and carriers or adjuvant in future, and can further prevent porcine reproductive and respiratory syndromes from happening.

Description

technical field [0001] The invention relates to a target cell-specific fusion protein subunit vaccine capable of inducing cellular immunity and neutralizing antibody response to porcine reproductive and respiratory syndrome virus in pigs. Background technique [0002] Porcine reproductive and respiratory syndrome (porcinereproductiveandrespiratorysyndrome, PRRS) is an acute infectious disease caused by porcinereproductiveandrespiratorysyndromevirus (porcinereproductiveandrespiratorysyndromevirus, PRRSV) infection, which leads to reproductive disorders in sows, and mainly respiratory tract infection for pigs of different ages . The virus is a single-stranded positive-sense RNA virus that readily infects T-cells, dendritic cells, monocytes or macrophages. Once a pig herd is infected with PRRSV, it will destroy its alveolar macrophages (porcinealveolarmacrophages, PAMs) and pulmonary intravascular macrophages (pulmonaryintravascularmacrophages, PIMs), resulting in a decrease i...

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Problems solved by technology

[0004] Although there are already PRRSV vaccines on the market, some studies have shown that PRRS outbreaks may still occur in pig farms with complete vaccine immunization programs, indicating that existing vaccines may not be able to provide cross-protection against wild PRRSV infection

In addition, PRRSV also has the phenomenon of antibody-dependent enhancement (antibody-dependentenhancement, ADE), which makes the non-neutralizing antibodies produced by traditional inactivated vaccines not only have no protective effect, but make the infection more severe and cause more serious infections. Infected animals have no obvious symptoms, but the immunity of infected animals is reduced and it is easy to cause secondary infection, resulting in decreased production performance and increased mortality

[0005] Although live attenuated vaccines of PRRSV have been released, because PRRSV is an RNA virus, the efficacy of live attenuated vaccines often loses their protective efficacy with the mutation of wild strains.

Because PRRSV is easy to damage the host’s immune system, and the current vaccine cannot control the epidemic safely, effectively and stably, reducing the ADE effect to improve antibody protection and cellular immune response is the focus of future PRRSV vaccine development

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