Sheep aphthous virus virulence gene vir deletion mutant strain and preparation method and application thereof

Abstract

The invention relates to a mutant strain of the virulence gene VIR of aphthous ulcer virus and its preparation method and application. The preparation method comprises the method of cloning the gene fragment containing the VIR virulence gene of ORFV-SHZ1 strain and the flanking sequence by using the PCR method, and deleting it by the enzymatic cutting method. Remove the VIR virulence gene, insert the expression cassette with the late promoter P11 of vaccinia virus and the LacZ reporter gene at the deletion site, and construct a recombinant shuttle vector with the LacZ gene as a selection marker; transfect the recombinant shuttle vector into ORFV-infected Vero Homologous recombination was carried out in the cells, and the recombinant virus ORFV-ΔVIR-LacZ with deletion of the VIR virulence gene was obtained by plaque screening and purification. The invention quickly reduces the virulence of ORFV by means of genetic engineering, provides technical support for the research and development of ORF vaccines, has the characteristics of short production cycle, no need for domestication, convenient and quick operation, etc., and can be widely used.

Description

technical field [0001] The invention relates to the field of genetic engineering applied to veterinary biotechnology, in particular to an attenuated oral ulcer virus vaccine and a preparation method thereof. Background technique [0002] Sheep aphthous sore is also called sheep contagious pustular (Contagious Ethyma, CE), contagious pustular dermatitis (Contagious pustular dermatitis, CPD), sheep contagious pustular (Ecthyma Contagiosum) etc., is caused by sheep oral ulcer virus (Orf virus, ORFV) is a contagious infectious disease of sheep and goats. Clinically, erythema, papules, nodules, blisters, pustules, ulcers, and warty thick scabs are formed on the skin and mucous membranes of the lips, tongue, nose, and breasts. as a feature. The disease is transmitted through direct contact, and lambs aged 3 to 6 months are the most susceptible, and are often popular in groups; deer, camels, musk oxen, and humans can also be infected. The disease is widely prevalent in countries ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to address the shortcomings of the existing artificially domesticated attenuated strains of aphthus virus, such as the long cycle and the easy change of immunogenicity, by adopting genetic engineering methods through the virulence gene VIR (interferon resistancegene, interferon resistance factor) of aphthus aphthus virus. Deletion is performed to achieve a rapid reduction in its virulence, providing a preparation method for attenuated vaccines with significantly reduced virulence but still maintaining good immunogenicity

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