China
Africa
Explore chapters and articles related to this topic
Order Tymovirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
The same strategy was used to express a single-chain antibody fragment (scFv) against the herbicide 3-(3,4-dichlorophenyl)-1,1-dimethylurea, or diuron, as a fusion to the PVX coat (Smolenska et al. 1998). The mosaic virions accumulated in inoculated N. clevelandii plants and assembled to give virions carrying the antibody fragment on their surface. The aim of such PVX-antibody particles would be remediation of contaminated soil and waterways. However, the recombinant virus remained infective, so careful precautions would be necessary before releasing it into the environment. This study differed from other attempts using the PVX as a vector to express scFv (Franconi et al. 1999; Roggero et al. 2001), where the scFv and coat genes were not fused and no scFv-carrying mosaic PVX particles were expected.
Adenoviral Vectors for Gene Therapy of Inherited and Acquired Disorders of the Lung
Published in Kenneth L. Brigham, Gene Therapy for Diseases of the Lung, 2020
David T. Curiel, Robert I. Garver
The details of plasmid design and common methods of use have been described in recent reviews (18,19) and therefore will not be reiterated in detail here (Fig. 1). In brief, the most widely used method involves three major steps. First, the new coding sequence with appropriate transcriptional start and stop regulatory sequences is added to a multiple cloning site within the deleted El region of a plasmid containing a portion of the left-hand (5') end of the adenovirus genome. Second, this plasmid vector containing the new coding sequence is cotransfected into 293 cells with a second plasmid that contains the entire adenovirus genome with an El deletion modified to contain a “stuffer fragment” of plasmid DNA. The stuffer fragment not only contains the plasmid origin of replication and antibiotic resistance gene for bacterial propagation, but it is sufficiently large to prevent that adenoviral DNA from being packaged into a stable viral particle. Homologous recombination occurs be tween the two plasmids so that the El region containing the coding sequence of interest replaces the plasmid stuffer within the otherwise intact genome, and the E1 proteins made by the 293 cells activate the recombinant genome replication with the result that recombinant virus is made. The third step is a series of plaque purifications with screening assays at each step to eliminate undesired wild type virus that is generated by homologous recombination between the viral sequences within 293 cells and the adenoviral plasmid with the stuffer fragment.
Application of Bioresponsive Polymers in Gene Delivery
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Tamgue Serges William, Drashti Pathak, Deepa H. Patel
To achieve it, two major systems have been used for a while; viral and non-viral mediated systems. Viral mediated system is based on the uses of various viruses as carriers to insert genetic sequence into the host cell. The viruses have the ability to cross cell barriers and insert their genetic material inside the host cell. Some examples of viruses used include retroviral vectors as human immunodeficiency virus (HIV), adeno-associated virus (AAV), herpes simplex virus (HSV), Epstein Barr virus (EBV), adeno-viruses (AV), hepatitis B virus (HBV), Moloney murine leukemia virus (MoMLV). Creating a viral vector involves producing a recombinant virus lacking replication but maintaining its ability to infect cells [2]. These viral vectors are generally efficient tools of transfection but they possess some disadvantages like high production cost, difficulty in targeting to certain cells, size limitation of DNA constructs safety concerns, immunogenic reactions, toxic side effects, and possibility of triggering oncogenes, possibility to revert back or to retain an infectious form. The tentative to overcome such drawbacks has opened the gates to exploration of alternatives methods, which are non-viral mediated systems. In the recent past, non-viral mediated gene transfer has gained much more interest as potentially safe and effective methods to transfer genes in a wide range of genetic disease.
Oncolytic adenovirus with MUC16-BiTE shows enhanced antitumor immune response by reversing the tumor microenvironment in PDX model of ovarian cancer
Published in OncoImmunology, 2022
Qiuman Wang, Xinyue Ma, Huan Wu, Chen Zhao, Jingying Chen, Rongrong Li, Shi Yan, Yingwei Li, Qing Zhang, Kun Song, Cunzhong Yuan, Beihua Kong
We investigated viral replication ability and oncolytic property in the absence of human T cells. Infection of HEY cells with parental OAd and the recombinant OAd-MUC16-BiTE virus yielded similar amounts of viral genomes as measured by qPCR, which peaked on the third day after infection (Figure 1(c) and Supplemental Figure S3). The cytotoxicity of the recombinant virus was also comparable with that of parental OAd in most cases (Figure 1(d)). Therefore, the BiTE transgene slightly affected viral replication kinetics and oncolytic activity. Notably, OAd showed strong oncolytic activity in all tested OC cell lines, except for SKOV3 cells that showed partial resistance and were killed more slowly;17 increasing the dose of viruses did not influence this resistance (Figure 1(d)).
The Development of Human Papillomavirus (HPV) Vaccines and Current Barriers to Implementation
Published in Immunological Investigations, 2021
Rebecca Butterfield, Salimah Dhanani
The recognition that viruses can cause human cancers has been pivotal in the development of vaccination strategies as a tool for cancer prevention. Vaccines using live attenuated or inactivated virions have been successful for other infectious diseases and serve as the basis for the current pediatric vaccination schedule; however, virions cannot be used for HPV vaccine for two reasons. Firstly, proliferating the virus on a large scale is not only challenging but also is cost ineffective. More importantly, however, viral genomes contain oncogenes that cause the very cancers the HPV vaccine is intended to prevent. Therefore, the HPV vaccine was designed around recombinant virus-like particles (VLPs). The type-specific HPV VLPs closely resemble the L1 major capsid protein but contain no viral DNA and therefore are non-oncogenic and noninfectious. The VLPs induce high titers of virion neutralizing antibodies. These neutralizing antibodies are genotype specific, and since they account for most of the protection, the protection is also genotype specific (Schiller et al. 2018).
Research progress in the development of porcine reproductive and respiratory syndrome virus as a viral vector for foreign gene expression and delivery
Published in Expert Review of Vaccines, 2020
Guo Dai, Mei Huang, To Sing Fung, Ding Xiang Liu
Despite their application potential, current PRRSV-based vectors suffer from two main drawbacks. First, some recombinant PRRSVs are not genetically stable, and the inserted genes(s) may be partially or completely lost during viral propagation in cultured cells. The genetic stability of a recombinant virus would be determined by multiple factors, including the size of the inserted fragment, the genomic position of the fragment inserted, and the biochemical and biophysical features of the products encoded by the inserted genes. Alternatively, it may reflect an intrinsic nature of the viral genome: get rid of any additional sequence in order to safeguard the integrity of their original compact genome. Second, the size limit for a heterologous sequence has not been systemically determined. Previous studies have shown that recombinant PRRSVs with large insertions are either non-viable or unstable, but size limits may also vary for different insertion sites and different PRRSV strains under consideration.