| abstract |
The invention discloses a recombinant Newcastle disease virus heat-resistant vaccine strain for expressing an avian adenovirus type 4 truncated Fiber2 protein, and a preparation method and application thereof, belonging to the field of vaccine genetic engineering. The invention adopts the reverse genetic operation technology of RNA virus to carry out gene modification on NDV LaSota strain at the level of transcription plasmid, firstly, the HN gene is replaced by the HN gene of a heat-resistant TS09-C strain, and then, the truncated Fiber2 gene (961-1440bp) of the avian adenovirus type 4 is inserted between the P gene and the M gene. The transformed transcription plasmid is transfected into a host cell, and the NDV rLS-tFib2-C strain is rescued and obtained. The vaccine strain has remarkable heat-resistant property, can greatly reduce the dependence on a cold chain system, saves storage and transportation cost and improves the heat stability of the vaccine. The vaccine strain expresses not the complete Fiber2 protein, but only intercepts partial region thereof, thus pertinently enhancing the immune protection effect of the vaccine. Can be used for preparing bigeminal heat-resistant live vaccine for avian Ankara disease and Newcastle disease. |