6 results about "Defective virus" patented technology

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 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.