China
Africa
Explore chapters and articles related to this topic
Order Picornavirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
Lin YJ et al. (2015) produced the EV71 VLPs in enoki mushrooms Flammulina velutipes. Polycistronic expression vectors harboring the glyceraldehyde-3-phospho-dehydrogenase promoter to codrive the EV71 P1 and 3C genes using the 2A peptide of porcine teschovirus-1 were constructed and introduced into Flammulina velutipes via Agrobacterium tumefaciens-mediated transformation. The P1 and 3C genes were integrated into the chromosomal DNA through a single insertion, and their resulting mRNAs were transcribed. The resulting EV71 VLPs were composed of the four subunit proteins digested from the P1 polyprotein by 3C protease. The 3D reconstruction of the EV71 VLPs was performed to confirm their similarity to the EV71 virions (Lin YJ et al. 2015).
Ecology
Published in Paul Pumpens, Single-Stranded RNA Phages, 2020
The phage MS2 was used in the study on the recovery of viral RNA from oral fluid of pigs, a prospective source to determine herd health and documenting the circulation of viruses in commercial swine populations (Jones and Muehlhauser 2014). Furthermore, the study on hog carcasses was enriched by other indicators, such as porcine adenovirus and porcine teschovirus, and significant correlations were observed between the viable FRNA phages and porcine adenovirus and between the FRNA phages and porcine teschovirus but not between adenovirus and teschovirus at the various stages of pork processing (Jones and Muehlhauser 2017). It was concluded that the FRNA phages could be a preferred indicator in the pork slaughter process, as they also provided an indication of infectivity. Remarkably, the viable group II and III phages were generally not detected at the earlier stages of the slaughter process, but they appeared after evisceration and in the retail pork samples.
Enterovirus
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Taxonomically, the genus Enterovirus falls under the family Picornaviridae, which currently consists of 35 genera of small, nonenveloped, single-stranded positive-sense ribonucleic acid (RNA) viruses, including Ampivirus, Aphthovirus, Aquamavirus, Avihepatovirus, Avisivirus, Cardiovirus, Cosavirus, Dicipivirus, Enterovirus, Erbovirus, Gallivirus, Harkavirus, Hepatovirus, Hunnivirus, Kobuvirus, Kunsagivirus, Limnipivirus, Megrivirus, Mischivirus, Mosavirus, Oscivirus, Parechovirus, Pasivirus, Passerivirus, Potamipivirus, Rabovirus, Rosavirus, Sakobuvirus, Salivirus, Sapelovirus, Senecavirus, Sicinivirus, Teschovirus, Torchivirus, and Tremovirus [6,7].
Malignant tissues produce divergent antibody glycosylation of relevance for cancer gene therapy effectiveness
Published in mAbs, 2020
Dominik Brücher, Vojtech Franc, Sheena N. Smith, Albert J. R. Heck, Andreas Plückthun
To produce the antibodies in the desired host-cells, we encoded both heavy and light chains of the same antibody under the control of a single promoter, using a furin site followed by a self-cleaving 2A site (Figure 2a), to provide approximately equimolar expression of both chains. To test whether homogeneous backbone production with no residual side products is obtained, we tested the homogeneity and purity of three different 2A site variants (Figure 2a), which originated from three different viruses, namely foot-and-mouth disease virus (F2A), porcine teschovirus-1 (P2A) and thosea asigna virus (T2A). The heavy chain is linked at its C-terminus to a furin site, followed by the 2A site, followed by the signal sequence of the light chain (Figure 2a, Sup. Fig. 1 and 2). Briefly, ribosome skipping leads to a cleavage between the 2A sequence and the light chain signal sequence, followed by removal of the 2A sequence by furin, followed by carboxypeptidase trimming of the four basic amino acids on the C-terminus of the heavy chain.
Rapid production of a chimeric antibody-antigen fusion protein based on 2A-peptide cleavage and green fluorescent protein expression in CHO cells
Published in mAbs, 2019
Hans Van der Weken, Eric Cox, Bert Devriendt
Self-cleaving 2A peptides are short, highly conserved sequences of 18–22 amino acids derived from viruses, such as foot-and-mouth disease virus (F2A), equine rhinitis A virus (E2A), porcine teschovirus-1 (P2A) and thosea asigna virus (T2A). They mediate “cleavage” of polypeptides during translation by steric hindrance, resulting in ribosomes skipping the formation of a glycyl-propyl (G-P) peptide bond at the C-terminus of the 2A peptide.20,21 After successful skipping, the 2A peptide remains bound to the upstream protein and often a furin cleavage site is inserted to remove the remaining peptides. The use of 2A peptide cleavage mostly leads to higher expression levels compared to IRES-based expression,13 but can also lead to generation of aggregates due to incorrect cleavage and folding.16 Efficiency of correct cleavage and antibody production is highly dependent on the cell line used and 2A peptide sequence. T2A peptide cleavage in addition to a GSG sequence (GT2A) showed the highest cleavage efficiency and antibody expression levels in CHO cells.20
Liver-directed gene-based therapies for inborn errors of metabolism
Published in Expert Opinion on Biological Therapy, 2021
Pasquale Piccolo, Alessandro Rossi, Nicola Brunetti-Pierri
Given the low rate of integration achieved even if nucleases are used, expression of the edited gene by its own regulatory sequences within its physiologic genomic context may not be sufficient to achieve the therapeutic threshold. To enhance expression of the therapeutic gene, integration in genomic safe harbor sites under the control of strong promoters has been investigated [70–72] and AAV-mediated targeted integration of a promoterless transgene has been directed within the albumin locus in murine models of hemophilia B [73] and Crigler-Najjar syndrome [74]. This strategy exploits spontaneous HDR to integrate a cDNA preceded by a sequence encoding the porcine teschovirus-1 2A peptide (P2A) [75] at the 3ʹ end of Alb gene coding sequence (Figure 1(c)). While the albumin promoter ensures robust liver-specific expression of the transgene, the P2A allows ribosomal skipping and expression of the transgene and albumin as separated proteins, without affecting serum albumin levels. Although risks of ITR-driven transactivation of neighboring genes are not eliminated [14], the lack of promoter in the vector genome makes this approach safer in case of unwanted integration of the vector genome in the proximity of proto-oncogenes. Although this approach resulted in on-target integration in up to 1% of hepatocytes [73], high levels of expression driven by the albumin promoter might be sufficient to result in clinical benefit for several disorders with lower therapeutic thresholds. In contrast, for diseases requiring higher levels of transgene expression, promoterless transgenes have been combined with engineered nucleases to increase the integration rate [76–82].