Recombinant gene VIII-type Newcastle disease virus attenuated strain

Abstract

The invention relates to the technical fields of veterinarian virus molecule biology and immunity, and discloses a recombinant gene VIII-type Newcastle disease virus attenuated strain NDV-rHR09-LaSota-HN. A preservation number of the attenuated strain NDV-rHR09-LaSota-HN is CCTCC (China Center For Type Culture Collection) NO: V201830. The research shows that the NDV-rHR09-LaSota-HN strain is weakin toxicity, the MDT is greater than 120h, the ICPI value is 0.026, an immunity test proves that the Newcastle disease virus attenuated strain has a good immunity protection effect on Newcastle disease virulent strain; and compared with the conventional vaccine strain LaSota, the NDV-rHR09-LaSota-HN strain is inoculated to one-day SPF chicken, and the antibody level and the protection effect on the prevalent virulent strain counteracting toxic substances of the chicken after three weeks are better or not poorer than a reference group.

Description

Technical field [0001] The invention relates to the field of veterinary virus molecular biology technology and immunology technology. It uses a reverse genetic operation platform to screen the obtained gene type Ⅷ strain on the basis of F gene mutation and then replace the HN gene fragment to obtain a recombinant strain An attenuated strain of genotype VIII Newcastle disease virus. Background technique [0002] Newcastle disease virus (NDV) is a huge hazard to the world's poultry breeding industry. It can infect a variety of poultry and often causes huge economic losses in the poultry industry.[Alexander,DJ2001.GordonMemorial Lecture.Newcastle disease.Br Poult Sci 42:5-22.]. The virus is taxonomically classified as a member of the Paramyxoviridae, Paramyxovirinae, and Avulavirus [Mayo, M.A. 2002. Virus taxonomy-Houston 2002. Arch Virol 147: 1071-1076.]. Newcastle disease virus has an envelope, and the genome is a single-stranded, negative-stranded, unsegmented RNA virus. The ge...

AI Technical Summary

Problems solved by technology

In the process of disease control, the use of vaccines is the most effective and economical method. Newcastle disease vaccines have been used for decades. Due to the widespread use of ND vaccines, the disease has basically been effectively controlled. However, clinically, SARS The occurrence of type ND is still relatively common, and ND is still one of the main diseases threatening the poultry industry. The reasons for immunization failure include unreasonable immunization procedures and the existence of immunosuppressive diseases, and the genotypes and differences between vaccine strains and epidemic strains Antigenic mismatch may be one of the main reasons, which shows that conventional vaccines cannot provide ideal protection against NDV challenge

Judging from the epidemic characteristics of ND in my country in recent years, most of the clinically isolated NDV strains belong to genotype VII[Liu, X.F., H.Q.Wan, X.X.Ni, Y.T.Wu, and W.B.Liu. disease isolated from outbreaks inchicken and goose flocks in some regions of China during 1985-2001.Archives of Virology, 2003,148(7):1387-1403.], while the genotypes of conventional ND vaccine strains are mainly type I and type II ( Such as V4, LaSota, etc.), the conventional ND vaccine strains are far from NDV epidemic strains in genetic distance, which causes a large number of poultry to shed virus in the early stage when the virulent infection occurs, resulting in the occurrence of atypical ND

At present, the gene VIII strain is still prevalent in many countries and regions such as Africa, South Asia, and Southeast Asia. It has also been isolated and found in my country in the past 80 years, and the vaccines used are still attenuated strains of genes I and II from the existing reports. There is no vaccine strain matching VIII type, so it is of great economic value to create an attenuated vaccine strain of NDV gene VIII type

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