Canine distemper virus replication defect strain and establishing method thereof

Abstract

The invention relates to rescuing and verifying of a canine distemper virus replication defect strain of a canine distemper virus. A system comprises a transcription plasmid, one or more auxiliary plasmids and a Vero-SLAM-M cell line, wherein the transcription plasmid pCI-CDV-SD16F can express the genome full-length cDNA sequence of the canine distemper virus prevalent strain SD16F, the plasmid pCI-CDV-SD16F-M subjected to fixed-point mutation is a recombinant plasmid not expressing the protein M, the auxiliary plasmids can express the nucleoprotein (NP), phosphoprotein (P) and large polymerase protein (L) of the canine distemper virus prevalent strain SD16F, and the Vero-SLAM-M cell line can stably express proteins SD16FM. Through the reverse genetic operation system, the recombinant replication defect canine distemper virus is successfully rescued. Through the research, the canine distemper virus prevalent replication defect strain creates convenient conditions for a novel canine distemper virus genetic engineering biological control preparation and provides an excellent technological platform for the canine distemper virus related basic research.

Description

technical field [0001] The invention belongs to the technical field of virus reverse genetic manipulation, and in particular relates to a canine distemper virus replication-deficient strain and a construction method thereof. Background technique [0002] Canine distemper (Canine distemper, CD) is a highly contagious infectious disease that can cause a variety of animals to suffer from. , CDV) infection. Under natural conditions, the most susceptible animals are carnivorous animals such as canidae, mustelidae, and cats, and the mortality rate after infection is extremely high. [0003] CDV is an enveloped single-stranded negative-strand RNA virus, which mainly encodes six structural proteins, namely nucleocapsid protein (NP), phosphoprotein (P), matrix membrane protein (M), fusion protein (F), Hemagglutinin protein (H) and large polymerase protein (L). Immunization is currently the main means of preventing and controlling canine distemper, and inactivated vaccines cannot p...

AI Technical Summary

Problems solved by technology

The vaccine strains of the commercialized canine distemper attenuated vaccines are mostly weakened by continuously passing the isolated strong strains through heterogeneous animals (ferrets, etc.), chicken embryos or cells, such as CDV / R-20 / 8 strains, Onderstepoort strains etc., but the attenuated strains obtained by this attenuation method have the risk of virulence returning to strength, and the vaccine strains have different degrees of pathogenicity to wild animals; the vaccine strains of a small number of commercial canine distemper attenuated vaccines are isolated from nature. The natural attenuated strain obtained by screening, such as the CDV-11 strain used in foxes, is isolated from dogs with a transient increase in body temperature, and is safe for dogs, raccoon dogs, minks, and foxes, but the vaccine strain can be autonomously vaccinated in animals. Replication, risk of shedding virus during immunization, safety to wild animals unknown

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