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The Viruses
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Hepatitis B surface antigen, (HBsAg) is the common antigen on the surface of each form of the virus particles. HBsAg is found in great excess in infected subjects and therefore is used in diagnostic tests for the virus infection. The major structural core protein (C protein or hepatitis B core antigen) is a 21 kD basic phosphoprotein that contains viral DNA and a polymerase called P protein. The pre-S1-region of the viral genome encodes the L protein. This protein is a minor component of proteins produced, but is an important component of the infectious Dane particle and is important in virus assembly. L proteins are thought to contain receptor recognition domains. The S protein makes up the majority of the HBsAg and is produced in abundance.
Other Double-Stranded RNA Viruses
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
Duquerroy et al. (2009) reported the near-atomic x-ray structure of a PBV—an animal dsRNA virus associated with diarrhea and gastroenteritis in humans. To do this, the PBV VLPs were obtained by expressing the rabbit PBV (rPBV) capsid protein gene in insect Sf9 cells by the baculovirus expression system. The structure was resolved to 3.4 Å and showed a simple core capsid with a distinctive icosahedral arrangement, displaying 60 2-fold symmetric dimers of the coat protein with a new 3D fold. As with many nonenveloped animal viruses, the coat underwent an autoproteolytic cleavage, releasing a posttranslationally modified peptide that remained associated with nucleic acid within the capsid. These data showed that the picobirnavirus particles are capable of disrupting biological membranes in vitro, indicating that its simple capsid had evolved animal cell invasion properties (Duquerroy et al. 2009).
Human Monoclonal Antibodies and Immune Modulation in Viral Hepatitis, Schistosomiasis, and HTLV Infection
Published in Thomas F. Kresina, Immune Modulating Agents, 2020
Thomas F. Kresina, Garry A. Neil, Steven K. H. Foung
Human monoclonal antibodies from both EBV transformed cell lines and heterohybridomas which bind the nucleocapsid component of the hepatitis C virus [57] have been identified. An IgG1 kappa antibody, designated B12.F8, recognized native nucleoprotein expressed in transfected eukaryotic cells. Epitope mapping studies resolved a conformational epitope between residues 27 and 59, indicating that this antibody recognized a B cell epitope within the immunodominant nucleo-protein terminal subregion. Recent antibody engineering studies [58] have generated a recombinant human antibody using the cDNA coding for the Fab fragment of B12.F8. The recombinant antibody, B12Fab, recognized hepatitis C virus core protein produced in transfected cells, indicating that the antibody could be used as a tool for tissue localization of the virus. Furthermore, the antibody function, when displayed to phage particles, provided a basis for experiments of in vitro affinity maturation and selection of viral mutants.
Gut dysbiosis and the clinical spectrum in anti-Ro positive mothers of children with neonatal lupus
Published in Gut Microbes, 2022
Robert M. Clancy, Miranda C. Marion, Hannah C. Ainsworth, Miao Chang, Timothy D. Howard, Peter M. Izmirly, Mala Masson, Jill P. Buyon, Carl D. Langefeld
-We examined taxa showing differential relative abundance between anti-Ro positive mothers and controls for sequence homology of Ro60 and von Willebrand factor type A domain protein (vWFA) from the gut microbe. Ro60, which is also known as TROVE2, has two distinct conserved domains, TROVE and the vWFA. Within the latter, the core protein contains an immunodominant peptide at amino acids 371–381, residing at 15-amino acid which is now recognized as a T cell epitope. Many taxa of the gut mucosa express a bacterial vWFA but we focused solely on those that increased in disease severity. Using a search tool at https://www.ncbi.nlm.nih.gov/protein/advanced, we queried “vwfa” and the specific taxon of interest in the two search fields of the builder feature, which yielded as output the vWFA primary sequence of each candidate taxon. Next, we leveraged the MHC class II binding predictions using the IEDB analysis resource “Consensus tool” with the goal to obtain a value of percentile rank, where a lower number indicates higher binding affinity (http://tools.immuneepitope.org/mhcii/).
Association between IFN-λ 3 Gene Polymorphisms and Outcome of Treatment with Direct Acting Antivirals in Chronic HCV-Infected Egyptian Patients
Published in Immunological Investigations, 2021
Islam El-Garawani, Sobhy Hassab El-Nabi, Marwa Gadallah, Eman Abdelsameea
HCV is an enveloped, small circular, positive-sense and single-stranded ribonucleic acid (RNA) virus with a diameter of 50 nm (Bostan and Mahmood 2010). However, viral core protein modulates gene transcription, cell death, and proliferation in addition to interference in metabolism leading to oxidative stress, liver steatosis, and finally HCC (Mohammad et al. 2017). HCV envelope proteins E1 and E2 are generally glycosylated and have played a major role in cell entry. Protein P7 is responsible for the ion channel and virus assembly (Krekulova et al. 2006). Moreover, the proteins NS3 serine protease and NS5B played a major role in viral replication. The main targets for antiviral drug development are structural proteins, NS5B RNA-dependent RNA polymerase, and NS3 serine protease (De Francesco et al. 2003; Islam et al. 2015).
Can nanotechnology help in the fight against COVID-19?
Published in Expert Review of Anti-infective Therapy, 2020
Gabriela Palestino, Ileana García-Silva, Omar González-Ortega, Sergio Rosales-Mendoza
As for the case of vaccines, the main challenges identified include accelerating the race for testing vaccines candidates based on SARS-CoV-2 VLPs; proving their safety and efficacy in test animals to justify clinical trials. Although several knowledge gaps regarding the tropism and physiopathology of SARS-CoV-2 exist, the VLPs-based vaccine prototypes targeting SARS-CoV-1 and MERS-CoV that have resulted in robust mucosal immune responses are encouraging and will guide the design of effective vaccines against SARS-CoV-2; as this pathogen primarily affects the lungs and it is secreted by the gastrointestinal tract favoring its transmission. In this way, humoral responses in the lungs and the gastrointestinal tract are relevant to fight against the infection by SARS-CoV-2. In addition to testing VLPs resembling SARS-CoV-2 to generate nanovaccine candidates, epitopes from this virus could be expressed in chimeric VLPs (from an unrelated virus). In this manner, unrelated VLPs will function as scaffolds showing the target SARS-CoV-2 epitopes for antigen presentation. In this regard, the Hepatitis B Core Protein has been used as a scaffold; displaying at the immunodominant c/e1 loop region unrelated antigens of some pathogens, which will show the target on the spike structures of the chimeric VLPs [95]. Moreover, the safety evaluation of the vaccine candidates in test animals should be especially focused on discarding antibody-dependent enhancement and eosinophilic infiltration upon the experimental challenge with SARS-CoV-2 [96].