305 results about "Reverse genetics" patented technology

The present invention is reverse genetic operation system of Newcastle disease Lasota low virulent vaccine strain and its application. The system includes one transcription plasmid including the genome cDNA sequence of the low virulent vaccine strain; one or several transcription aiding plasmids including the cDNA sequence coding the nucleoprotein of the low virulent vaccine strain, the cDNA sequence coding the phosphoprotein of the low virulent vaccine strain and the cDNA sequence coding the large polymerase protein of the low virulent vaccine strain; and the host cell of the Newcastle disease Lasota low virulent vaccine strain. Wild viral strain is obtained by means of the reverse genetic operation system. The present invention lays firm foundation for further development of Newcastle disease virus live carrier vaccine and Newcastle disease virus related research.

The invention relates to A type foot-and-mouth disease recombinant vaccine strains prepared by using a reverse genetic manipulation technology and a preparation method and application of the strains. One strain is an A type foot-and-mouth disease recombinant vaccine strain with high titer, antigen matching property and immune protection rate, and the other strain is an A type foot-and-mouth disease recombinant non-pathogenic vaccine strain with high titer, antigen matching property and immune protection rate and without pathogenicity for a host; an antigen nucleotide sequence of each of the vaccine strains is shown as SEQ ID NO: 1; eukaryotic plasmids of viruses can be saved by using a reverse genetic manipulation system; after pigs and cattle are immunized by using the inactivated vaccines prepared from the prepared recombinant vaccine strains, the bodies can be effectively stimulated to produce immune response, and an immune protection effect is provided for the bodies of the pigs and the cattle; through a 10,000-times cattle median infectious dose (BID50) challenge assay of A type AISA topological strains, the immune protection rate reaches 100 percent, and the median protective dose (PD50) is 10.81 to 13.59; and the recombinant vaccine strains can be applied to prevention and control of A type foot-and-mouth disease viruses of China and neighboring countries.

Attenuated influenza virus variants comprising substitutions in NS1 that interfere with viral replication and phosphatidylinositol 3-kinase activation are described. NS1 variant polypeptides, polynucleotides encoding NS1 variant polypeptides, a reverse genetics system for producing attenuated influenza virus NS1 variants, immunogenic compositions comprising live attenuated influenza virus NS1 variants, methods of stimulating an immune response against influenza virus, methods of interfering with influenza virus replication, and methods of treating and preventing influenza virus infection are described.

The invention relates to an attenuated vaccine strain of a VII type new castle disease virus with a mutated L gene which is produced by reverse genetic operation technology and a preparation method thereof, and the invention belongs to the fields of biological products and biological technology. The virulence of the attenuated vaccine strain of the VII type new castle disease virus with the mutated L gene is obviously decreased, simultaneously the attenuated vaccine strain has the characteristics of high titer, stable heritability and high matching with the antigen of the epidemic virus according to the chicken embryo experiment; the preparation method is suitable for large scale production of vaccines, and is used for producing vaccines; compared with the conventional vaccines (gene I and gene II types), the attenuated vaccine strain of the VII type new castle disease virus with the mutated L gene has wide application prospects in the aspects of morbidity and epidemic control of new castle disease.

The present inventors developed 5a / 2a intergenotypic recombinants in which the JFH1 structural genes (Core, E1 and E2), p7 and all of or part of NS2 were replaced by the corresponding genes of the genotype 5a reference strain SA13. Compared to the J6 / JFH control virus, after transfection of in vitro transcripts in Huh7.5 cells, production of infectious viruses was delayed. However, in subsequent viral passages efficient spread of infection and HCV RNA titers as high as for J6 / JFH were obtained. Infectivity titers were at all time points analyzed comparable to J6 / JFH control virus. Sequence analysis of recovered 5a / 2a recombinants from 2 serial passages and subsequent reverse genetic studies revealed adaptive mutations in p7, NS2 and / or NS3. Infectivity of the 5a / 2a viruses was CD81 and SR-BI dependant, and the recombinant viruses could be neutralized by chronic phase sera from patients infected with genotype 5a. Conclusion: The developed 5a / 2a viruses provide a robust in vitro tool for research in HCV genotype 5, including vaccine studies and functional analyses of an increasingly important genotype in South Africa and Europe.

The invention relates to a peste des petits ruminants virus (PPRV) reverse genetic operating system and an application thereof. The PPRV reverse genetic operating system comprises a transcription plasmid and one or more helper plasmids, wherein the transcription plasmid can express the genome full-length cDNA (complementary deoxyribonucleic acid) sequence of the PPRV; and the helper plasmid(s) can express nucleoprotein (N), phosphoprotein (P) and polymerase large protein (L) of the PPRV, and virus replication-permitting host cells of the PPRV. By using the PPRV reverse genetic operating system, the recombined PPRV is successfully saved. The establishment of the PPRV reverse genetic operating technical platform provides an excellent technical platform for the development of PPRV live vector vaccines and the fundamental research related to PPRV.

The invention belongs to the field of plant genetic engineering and discloses application of OsWRKY28 transcription factor gene of rice in improvement of plant disease resistance. In research of functions of the WRKY transcription factor gene OsWRKY28 of rice as shown inthe SEQ ID NO.1 by means of a reverse genetics method, the OsWRKY28 transcription factor gene is found to have positive regulation function for resistance to rice banded sclerotial blight. The OsWRKY28 transcription factor gene is planted on a proper plant expressing carrier to convert cells or rice, and resistance of obtained rice with OsWRKY28 excessive-expression transcription factor to the banded sclerotial blight is evidently improved. Accordingly, disease resistance of rice and other crops can be improved by the OsWRKY28 gene, and new varieties of transgenosis plants resistant to the banded sclerotial blight can be cultured.

The present invention describes a reverse genetic system for Phlebovirus such as Rift Valley fever virus. This system comprised of RNA expression plasmids and protein expression plasmids. Additionally, the present invention also discloses the modification of this system to generate a recombinant virus that expresses a non-viral foreign gene. Furthermore, the present invention discloses the use of this system in the development of anti-Rift Valley fever virus vaccines, screening of antivirals testing for anti RVF immune response and developing marker vaccines for Rift Valley fever virus. We also claim the utility of this approach to other phleboviruses.

The complete genomic sequence of maize fine streak virus (MFSV), a negative-strand RNA virus that infects plants and insects, is disclosed. The inventors have characterized the MFSV genome and identified the leader and trailer sequences, seven open reading frames as well as the functions of some of the encoded proteins, and the gene junction sequences and their functions. Using various functionally important components of the MFSV genome, the inventors have demonstrated that a reverse genetics system of using cloned cDNA to produce infectious viruses can be developed for plant negative-strand RNA viruses. Methods of using the reverse genetic system to produce wild-type or recombinant plant negative-strand RNA viruses, to express genes of interest, and to screen for agents that may affect the production and function of the viruses are disclosed. Further disclosed are various nucleic acid constructs, vectors, genetically engineered cells, and kits useful in the reverse genetics system.