13 results about "Defective virus" patented technology

The invention relates to compositions and methods for the preparation, manufacture and therapeutic use of oncolytic defective virus compositions and methods of in vivo synthesis thereof. The composition includes a first nucleic acid construct encoding a self-amplifying mRNA (sa-mRNA) encoding at least one gene of interest (GOI) or a plurality of GOIs, a second nucleic acid construct encoding an mRNA encoding at least one virus structural protein, and at least one payload delivery system.

The high pathogenicity of the rift valley fever virus limits the research on the pathogenic mechanism and prevention, control and treatment products of the rift valley fever virus, the offspring replication-deficient virus particles are successfully saved through a reverse genetic manipulation technology, and the virus particles do not have the capacity of multiple rounds of infection on common cells; stable replication and passage can only be realized in a cell line for providing exogenous envelope glycoprotein; in addition, the virus particle carries an exogenous indication protein and can indicate cell infection. The Rift Valley fever virus-like particle provided by the invention can be used as a Rift Valley fever biosafety secondary laboratory research platform, the establishment of the virus particle greatly simplifies tedious procedures in the Rift Valley fever virus research process, and paves a way for screening of Rift Valley fever virus neutralizing antibodies, research and development of candidate vaccines and research of pathogenic mechanisms of the Rift Valley fever viruses.

The invention discloses establishment and application of a flavivirus replication-dependent RNA (Ribonucleic Acid) recombination experiment system, and belongs to the technical field of biology. The RNA recombination system comprises two components: a tembusu virus E gene deleted subgenome replicon CQW1-delta E, and a defective virus genome CQW1-delta NS1 or MM1775-delta NS1 with a part of NS1 gene sequence deleted. The two components cannot generate progeny viruses independently, but after the two components are co-transfected, a large number of recombinant progeny viruses can be generated within several days after transfection due to RNA recombination, the recombination efficiency is extremely high, continuous passage is not needed, the construction period is greatly shortened, and the production cost is saved; meanwhile, the generated progeny virus can form plaques on cells, and by means of plaque counting, the method can be applied to quantitative measurement of the RNA recombination efficiency and analysis of key factors influencing the tembusu virus RNA recombination.

The invention relates to compositions and methods for the preparation, manufacture and therapeutic use of oncolytic defective virus compositions and methods of in vivo synthesis thereof. The composition includes a first nucleic acid construct encoding a self-amplifying mRNA (sa-mRNA) encoding at least one gene of interest (GOI) or a plurality of GOIs, a second nucleic acid construct encoding an mRNA encoding at least one virus structural protein, and at least one payload delivery system.

The application discloses a kind of establishment and application of flavivirus replication-dependent RNA recombination experimental system, belong to the field of biotechnology.The RNA recombination system includes two components: tanbusu virus E gene deletion subgenomic replicon CQW1-ΔE, and the defective virus genome CQW1-ΔNS1 or MM1775-ΔNS1 missing partial NS1 gene sequence.The two components cannot produce progeny virus alone, but after co-transfection, due to RNA recombination, a large number of recombinant progeny viruses can be produced within a few days after transfection, the recombination efficiency is extremely high, and continuous passage is not required, greatly shortening the construction cycle and saving production costs;At the same time, the progeny virus can form plaques on cells, and the efficiency of RNA recombination can be quantitatively measured by plaque counting, and the key factors affecting tanbusu virus RNA recombination can be analyzed.

The invention relates to compositions and methods for the preparation, manufacture and therapeutic use of oncolytic defective virus compositions and methods of in vivo synthesis thereof. The composition includes a first nucleic acid construct encoding a self-amplifying mRNA (sa-mRNA) encoding at least one gene of interest (GOI) or a plurality of GOIs, a second nucleic acid construct encoding an mRNA encoding at least one virus structural protein, and at least one payload delivery system.

The invention belongs to the technical field of biology, and particularly discloses a cell line capable of stably expressing an nsP4 gene and application of the cell line in preparation of a replication-deficient chikungunya virus. The inventor uses retrovirus for expressing CHIKV nsP4 to infect hamster kidney cells (hamster kidney cells), after puromycin screening, verification of passage stability of monoclonal cells, protein expression stability, replication-deficient virus titer and the like is carried out, finally, a cell line which can be used for continuous passage of CHIKV replication-deficient viruses and has high titer is obtained, and the preservation number is CCTCC NO: C2025281. The replication-deficient virus CHIKV-delta nsP4 generated by the RNA of the nsP4 gene deleted from the trans-complementary CHIKV of the cell line has good safety, immunogenicity and immune protection efficacy, can effectively resist the challenge infection of wild viruses, and can be used for preparing a safe and effective CHIKV novel vaccine candidate strain.

The invention belongs to the technical field of biomedicine, and particularly relates to an enhanced specific promoter and application thereof. In order to solve the problems that the safety of ICP6 wild herpes virus is poor, the replication ability of ICP6 defective virus is poor, and the oncolytic effect needs to be improved, the invention provides a core starting element, the nucleotide sequence of which is as shown in SEQ ID NO.5; or a nucleic acid molecule which has one or more base insertion, deletion and / or substitution mutation in a nucleotide sequence shown in SEQ ID NO.5 and still has a promoter function. The core promoter element or promoter can specifically express the ICP6 gene in tumor cells infected with the herpes simplex virus, so that the replication capacity of the recombinant oncolytic virus is improved, the oncolytic activity and tumor selectivity of the recombinant oncolytic virus are improved, and the core promoter element or promoter also shows relatively good safety in a mouse model; the method is suitable for developing oncolytic viruses or virus vectors.

The invention belongs to the technical field of molecular biology, and particularly relates to a preparation method and application of virions. According to the invention, a reverse genetic technology is utilized to construct a rift valley heat replication defective virus-like particle for visual tracking of virus infection dynamics. The virion is only subjected to amplification passage in NSm-Gn-Gc expression cells, only one round of infection occurs in other cells, amplification passage cannot be performed, the infectivity of the rift valley fever virus is reduced, and the operation difficulty and the exposure risk are reduced. According to the quantum dot-labeled particles, real-time visualization of infection dynamics is realized, and dynamic characteristics of virus invasion links are accurately quantified. The content of the invention can be expanded to animal models for tracking tissue organs that a single virion initially targets when invading a host in a non-replication state. A novel technical platform is established for exploring an infection replication mechanism of the rift valley fever virus, and an important reference is provided for tracking research of other high-pathogenicity viruses.

A method for preparing an infectious, recombinant virus vector comprises the steps of: (a) infecting host cells with a first virus comprising an encapsidation defective adenovirus (edAd), the edAd comprising a first defective virus genome; (b) incubating the infected host cells in a culture medium for a period of time sufficient for producing infectious virus particles; and (c) recovering infectious virus particles secreted into a culture supernatant, wherein the edAd or the host cells comprise a second defective virus genome engineered to express a target gene of interest, wherein the edAd or the host cells comprise nucleic acid sequences sufficient for expressing adenovirus (Ad) helper genes necessary for replication of the defective virus DNA; and wherein the edAd or the host cells comprise nucleic acid sequences sufficient from expressing helper functions necessary for producing infectious, replication defective virus particles corresponding to the second virus.

The invention relates to compositions and methods for the preparation, manufacture and therapeutic use of oncolytic defective virus compositions and methods of in vivo synthesis thereof. The composition includes a first nucleic acid construct encoding a self-amplifying mRNA (sa-mRNA) encoding at least one gene of interest (GOI) or a plurality of GOIs, a second nucleic acid construct encoding an mRNA encoding at least one virus structural protein, and at least one payload delivery system.

The invention relates to compositions and methods for the preparation, manufacture and therapeutic use of oncolytic defective virus compositions and methods of in vivo synthesis thereof. The composition includes a first nucleic acid construct encoding a self-amplifying mRNA (sa-mRNA) encoding at least one gene of interest (GOI) or a plurality of GOIs, a second nucleic acid construct encoding an mRNA encoding at least one virus structural protein, and at least one payload delivery system.

The invention relates to a construction method of a recombinant baculovirus shuttle vector Bacmid '. The method comprises the following steps: cloning a lacZ alpha-attTn7 sequence into a baculovirus transfer vector subjected to reverse amplification, so as to obtain a recombinant plasmid pBacPAK8-lacZ alpha-attTn7; the recombinant virus AcNPV-lacZalpha-attTn7 is obtained by co-transfecting Sf9 cells with a defective virus Bacmid, and a recombinant virus AcNPV-lacZalpha-attTn7 is generated; carrying out amplification and ultra-high-speed centrifugation on the obtained recombinant virus, and extracting through phenol chloroform to obtain virus DNA (Deoxyribonucleic Acid); the recombinant baculovirus shuttle vector Bacmid'is obtained by co-transforming competent cells of recombinant virus DNA (deoxyribonucleic acid) and pBvBAC (obtained by cloning Vcat, miniF and Chitinase to pUC19), and carrying out recombinant cloning by utilizing blue-white spot screening. According to the present invention, the miniF replicon co-localized with lacZalpha-attTn7 is separated, such that the recombinant baculovirus shuttle vector Bacmid'with the high gene cloning stability is successfully constructed; according to the technology, the expression stability of the exogenous gene is remarkably improved, and a powerful research tool is provided for vaccine development and virology application based on the baculovirus vector.