scholarly journals Disparity between Levels of In Vitro Neutralization of Vaccinia Virus by Antibody to the A27 Protein and Protection of Mice against Intranasal Challenge

2008 ◽  
Vol 82 (16) ◽  
pp. 8022-8029 ◽  
Author(s):  
Christiana N. Fogg ◽  
Jeffrey L. Americo ◽  
Patricia L. Earl ◽  
Wolfgang Resch ◽  
Lydia Aldaz-Carroll ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Severe Disease ◽  
Neutralizing Antibody ◽  
Surface Proteins ◽  
Early Evaluation ◽  
Virus Attachment ◽  
Virus Adsorption ◽  
Mouse Cells ◽  
Selection Of

ABSTRACT Immunization with recombinant proteins may provide a safer alternative to live vaccinia virus for prophylaxis of poxvirus infections. Although antibody protects against vaccinia virus infection, the mechanism is not understood and the selection of immunogens is daunting as there are dozens of surface proteins and two infectious forms known as the mature virion (MV) and the enveloped virion (EV). Our previous studies showed that mice immunized with soluble forms of EV membrane proteins A33 and B5 and MV membrane protein L1 or passively immunized with antibodies to these proteins survived an intranasal challenge with vaccinia virus. The present study compared MV protein A27, which has a role in virus attachment to glycosaminoglycans on the cell surface, to L1 with respect to immunogenicity and protection. Although mice developed similar levels of neutralizing antibody after immunizations with A27 or L1, A27-immunized mice exhibited more severe disease upon an intranasal challenge with vaccinia virus. In addition, mice immunized with A27 and A33 were not as well protected as mice receiving L1 and A33. Polyclonal rabbit anti-A27 and anti-L1 IgG had equivalent MV-neutralizing activities when measured by the prevention of infection of human or mouse cells or cells deficient in glycosaminoglycans or by adding antibody prior to or after virus adsorption. Nevertheless, the passive administration of antibody to A27 was poorly protective compared to the antibody to L1. These studies raise questions regarding the basis for antibody protection against poxvirus disease and highlight the importance of animal models for the early evaluation of vaccine candidates.

scholarly journals Polyamine Depletion Abrogates Enterovirus Cellular Attachment

2019 ◽  
Vol 93 (20) ◽  
Author(s):  
Thomas M. Kicmal ◽  
Patrick M. Tate ◽  
Courtney N. Dial ◽  
Jeremy J. Esin ◽  
Bryan C. Mounce
Keyword(s):  
Rna Viruses ◽  
Severe Disease ◽  
Coxsackievirus B3 ◽  
Human Pathogens ◽  
Polyamine Biosynthesis ◽  
Virus Attachment ◽  
Significant Public Health ◽  
Approved Drugs

ABSTRACT Polyamines are small polycationic molecules with flexible carbon chains that are found in all eukaryotic cells. Polyamines are involved in the regulation of many host processes and have been shown to be implicated in viral replication. Depletion of polyamine pools in cells treated with FDA-approved drugs restricts replication of diverse RNA viruses. Viruses can exploit host polyamines to facilitate nucleic acid packaging, transcription, and translation, but other mechanisms remain largely unknown. Picornaviruses, including Coxsackievirus B3 (CVB3), are sensitive to the depletion of polyamines and remain a significant public health threat. We employed CVB3 as a model system to investigate a potential proviral role for polyamines using a forward screen. Passaging CVB3 in polyamine-depleted cells generated a mutation in capsid protein VP3 at residue 234. We show that this mutation confers resistance to polyamine depletion. Through attachment assays, we demonstrate that polyamine depletion limits CVB3 attachment to susceptible cells, which is rescued by incubating virus with polyamines. Furthermore, the capsid mutant rescues this inhibition in polyamine-depleted cells. More divergent viruses also exhibited reduced attachment to polyamine-depleted cells, suggesting that polyamines may facilitate attachment of diverse RNA viruses. These studies inform additional mechanisms of action for polyamine-depleting pharmaceuticals, with implications for potential antiviral therapies. IMPORTANCE Enteroviruses are significant human pathogens that can cause severe disease. These viruses rely on polyamines, small positively charged molecules, for robust replication, and polyamine depletion limits infection in vitro and in vivo. The mechanisms by which polyamines enhance enteroviral replication are unknown. Here, we describe how Coxsackievirus B3 (CVB3) utilizes polyamines to attach to susceptible cells and initiate infection. Using a forward genetic screen, we identified a mutation in a receptor-binding amino acid that promotes infection of polyamine-depleted cells. These data suggest that pharmacologically inhibiting polyamine biosynthesis may combat virus infection by preventing virus attachment to susceptible cells.

scholarly journals An alphavirus replicon-derived candidate vaccine against Rift Valley fever virus

2009 ◽  
Vol 137 (9) ◽  
pp. 1309-1318 ◽  
Author(s):  
M. T. HEISE ◽  
A. WHITMORE ◽  
J. THOMPSON ◽  
M. PARSONS ◽  
A. A. GROBBELAAR ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fluorescent Antibody ◽  
Severe Disease ◽  
Neutralizing Antibody ◽  
Fever Virus ◽  
Antibody Responses ◽  
Valley Fever

SUMMARYRift Valley fever virus (RVFV) is a mosquito-transmitted bunyavirus (genusPhlebovirus) associated with severe disease in livestock and fatal encephalitis or haemorrhagic fever in a proportion of infected humans. Although live attenuated and inactivated vaccines have been used in livestock, and on a limited scale in humans, there is a need for improved anti-RVFV vaccines. Towards this goal, Sindbis virus replicon vectors expressing the RVFV Gn and Gc glycoproteins, as well as the non-structural nsM protein, were constructed and evaluated for their ability to induce protective immune responses against RVFV. These replicon vectors were shown to produce the RVFV glycoproteins to high levelsin vitroand to induce systemic anti-RVFV antibody responses in immunized mice, as determined by RVFV-specific ELISA, fluorescent antibody tests, and demonstration of a neutralizing antibody response. Replicon vaccination also provided 100% protection against lethal RVFV challenge by either the intraperitoneal or intranasal route. Furthermore, preliminary results indicate that the replicon vectors elicit RVFV-specific neutralizing antibody responses in vaccinated sheep. These results suggest that alphavirus-based replicon vectors can induce protective immunity against RVFV, and that this approach merits further investigation into its potential utility as a RVFV vaccine.

scholarly journals Structures of Two Human Astrovirus Capsid/Neutralizing Antibody Complexes Reveal Distinct Epitopes and Inhibition of Virus Attachment to Cells

2021 ◽  
Author(s):  
Lena Ricemeyer ◽  
Nayeli Aguilar-Hernández ◽  
Tomás López ◽  
Rafaela Espinosa ◽  
Sarah Lanning ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Severe Disease ◽  
Neutralizing Antibody ◽  
Host Cells ◽  
Viral Gastroenteritis ◽  
Receptor Binding Site ◽  
Virus Attachment ◽  
Human Astroviruses ◽  
Human Astrovirus

Human astrovirus is an important cause of viral gastroenteritis worldwide. Young children, the elderly, and the immunocompromised are especially at risk for contracting severe disease. However, no vaccines exist to combat human astrovirus infection. Evidence points to the importance of antibodies in enabling protection of healthy adults from reinfection. To develop an effective subunit vaccine that broadly protects against diverse astrovirus serotypes, we must understand how neutralizing antibodies target the capsid surface at the molecular level. Here, we report the structures of the human astrovirus capsid spike domain bound to two neutralizing monoclonal antibodies. These antibodies bind two distinct conformational epitopes on the spike surface. We add to existing evidence that the human astrovirus capsid spike contains a receptor-binding domain and demonstrate that both antibodies neutralize human astrovirus by blocking virus attachment to host cells. We identify patches of conserved amino acids that overlap or border the antibody epitopes and may constitute a receptor-binding site. Our findings provide a basis to develop therapies that prevent and treat human astrovirus gastroenteritis. Importance Human astroviruses infect nearly every person in the world during childhood and cause diarrhea, vomiting, and fever. Despite the prevalence of this virus, little is known about how antibodies block virus infection. Here, we determined crystal structures of the astrovirus capsid protein in complex with two virus-neutralizing antibodies. We show that the antibodies bind two distinct sites on the capsid spike domain; however, both antibodies block virus attachment to human cells. Importantly, our findings support the use of the human astrovirus capsid spike as an antigen in a subunit-based vaccine to prevent astrovirus disease.

scholarly journals Rapid selection of HIV envelopes that bind to neutralizing antibody B cell lineage members with functional improbable mutations

2021 ◽  
Author(s):  
Olivia Swanson ◽  
Brianna Rhodes ◽  
Avivah Wang ◽  
Shi-Mao Xia ◽  
Robert Parks ◽  
...  
Keyword(s):  
B Cell ◽  
Neutralizing Antibodies ◽  
Cell Lineage ◽  
Neutralizing Antibody ◽  
Developmental Pathways ◽  
Broadly Neutralizing Antibodies ◽  
Minimal Subset ◽  
Functional Features ◽  
Selection Of

SummaryElicitation of broadly neutralizing antibodies (bnAbs) by an HIV vaccine will involve priming the immune system to activate antibody precursors, followed by boosting immunizations to select for antibodies with functional features required for neutralization breadth. The higher the number of mutations necessary for function, the more convoluted are the antibody developmental pathways. HIV bnAbs acquire a large number of somatic mutations, but not all mutations are functionally important. Here we identified a minimal subset of mutations sufficient for the function of the V3-glycan bnAb DH270.6. Using antibody library screening, candidate envelope immunogens that interacted with DH270.6-like antibodies containing this set of key mutations were identified and selected in vitro. Our results demonstrate that less complex B cell evolutionary pathways than those naturally observed exist for the induction of HIV bnAbs by vaccination, and establish rational approaches to identify boosting sequential envelope candidate immunogens.

scholarly journals Rapid and Broad Immune Efficacy of a Recombinant Five-Antigen Vaccine against Staphylococcus aureus Infection in Animal Models

Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 134 ◽  
Author(s):  
Hao Zeng ◽  
Feng Yang ◽  
Qiang Feng ◽  
Jinyong Zhang ◽  
Jiang Gu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Severe Disease ◽  
Lethal Dose ◽  
Protein A ◽  
Surface Proteins ◽  
Staphylococcal Protein A ◽  
Humoral Immune ◽  
Aureus Infection

Staphylococcus aureus (S. aureus) is a leading cause of both healthcare-and community-associated infections globally, which result in severe disease and readily developing antibiotic resistance. Developing an efficacious vaccine against S. aureus is urgently required. In the present study, we selected five conserved antigens, including the secreted factors α-hemolysin (Hla), staphylococcal enterotoxin B (SEB) and the three surface proteins staphylococcal protein A (SpA), iron surface determinant B N2 domain (IsdB-N2) and manganese transport protein C (MntC). They were all well-characterized virulence factor of S. aureus and developed a recombinant five-antigen S. aureus vaccine (rFSAV), rFSAV provided consistent protection in S. aureus lethal sepsis and pneumonia mouse models, and it showed broad immune protection when challenged with a panel of epidemiologically relevant S. aureus strains. Meanwhile, rFSAV immunized mice were able to induce comprehensive cellular and humoral immune responses to reduce bacterial loads, inflammatory cytokine expression, inflammatory cell infiltration and decrease pathology after challenge with a sub-lethal dose of S. aureus. Moreover, the importance of specific antibodies in protection was demonstrated by antibody function tests in vitro and in vivo. Altogether, our data demonstrate that rFSAV is a potentially promising vaccine candidate for defensing against S. aureus infection.

scholarly journals Structural basis of Chikungunya virus inhibition by monoclonal antibodies

2020 ◽  
Vol 117 (44) ◽  
pp. 27637-27645
Author(s):  
Qun Fei Zhou ◽  
Julie M. Fox ◽  
James T. Earnest ◽  
Thiam-Seng Ng ◽  
Arthur S. Kim ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Chikungunya Virus ◽  
Neutralizing Antibody ◽  
Structural Basis ◽  
Chikv Infection ◽  
Receptor Binding Site ◽  
Viral Pathogen ◽  
Virus Attachment

Chikungunya virus (CHIKV) is an emerging viral pathogen that causes both acute and chronic debilitating arthritis. Here, we describe the functional and structural basis as to how two anti-CHIKV monoclonal antibodies, CHK-124 and CHK-263, potently inhibit CHIKV infection in vitro and in vivo. Our in vitro studies show that CHK-124 and CHK-263 block CHIKV at multiple stages of viral infection. CHK-124 aggregates virus particles and blocks attachment. Also, due to antibody-induced virus aggregation, fusion with endosomes and egress are inhibited. CHK-263 neutralizes CHIKV infection mainly by blocking virus attachment and fusion. To determine the structural basis of neutralization, we generated cryogenic electron microscopy reconstructions of Fab:CHIKV complexes at 4- to 5-Å resolution. CHK-124 binds to the E2 domain B and overlaps with the Mxra8 receptor-binding site. CHK-263 blocks fusion by binding an epitope that spans across E1 and E2 and locks the heterodimer together, likely preventing structural rearrangements required for fusion. These results provide structural insight as to how neutralizing antibody engagement of CHIKV inhibits different stages of the viral life cycle, which could inform vaccine and therapeutic design.

scholarly journals Selection of Vaccinia Virus-Neutralizing Antibody from a Phage-Display Human-Antibody Library

2019 ◽  
Vol 29 (4) ◽  
pp. 651-657 ◽  
Author(s):  
Yong Won Shin ◽  
Ki-Hwan Chang ◽  
Gwang-Won Hong ◽  
Sang-Gu Yeo ◽  
Youngmee Jee ◽  
...  
Keyword(s):  
Phage Display ◽  
Vaccinia Virus ◽  
Neutralizing Antibody ◽  
Human Antibody ◽  
Antibody Library ◽  
Selection Of

scholarly journals Evaluation the resistance of cocoa clones (Theobroma cacaoL.)

2014 ◽  
Vol 30 (1) ◽  
Author(s):  
Agung Wahyu Susilo ◽  
Indah Anita Sari
Keyword(s):  
Plant Pathology ◽  
Clonal Selection ◽  
Field Evaluation ◽  
Lesion Size ◽  
Phytophthora Palmivora ◽  
Early Evaluation ◽  
In Vitro Inoculation ◽  
The Stability ◽  
Selection Of

Acceleration on clonal selection of cocoa resistance to pod rot (Phytophthora palmivora)was carried out by early evaluation of the resistance using laboratory test. This research has objective to select the promising clone resistance to P. palmivora for field evaluation. Trials were carried out at the Laboratory of Plant Pathology at the Indonesian Coffee and Cocoa Research Institute using in-vitro inoculation. Isolate of P. palmivorawere collected from the infected pods at Jatirono Estate, Banyuwangi then inoculated to three mature pods of each tested clones. Trials were carried out in two steps to confirm the stability of performance of the resistance. A total of 41 clones were tested in these trials. However due to the availability of pod sample was limited then at 1st trial 31 clones were tested and at 2nd trial 37 clones were tested, both of the test using 27 same clones. The assessed variables were lesion size on pod surface due to Phytophthorainfection at 1st to 7th day after inoculation. The lesion sizes were significantly different among tested clones that performing any variability of the resistance. The variability were grouped into five groups as the resistant classification by which three clones were identified, namely Jano/IV/4/13 (TSH 858 x ICS 13), Jano next to I/7 and Kate/I/10/18 (Sulawesi 01 x TSH 858) consistently performing lowest size of the lesion compared to Sca 6 that could be selected as the resistant clones for field evaluation. Key words: cocoa clones, resistance, pod inoculation, Phytophthora palmivora

Some Structural Features of Metaphase Chromosomes of Mice and Men

1967 ◽  
Vol 25 ◽  
pp. 190-191
Author(s):  
Godfrey C. Hoskins ◽  
Betty B. Hoskins
Keyword(s):  
Electron Microscopy ◽  
Electron Micrographs ◽  
Structural Features ◽  
Metaphase Chromosomes ◽  
The Future ◽  
Of Mice And Men ◽  
Mouse Cells ◽  
Human And Mouse

Metaphase chromosomes from human and mouse cells in vitro are isolated by micrurgy, fixed, and placed on grids for electron microscopy. Interpretations of electron micrographs by current methods indicate the following structural features.Chromosomal spindle fibrils about 200Å thick form fascicles about 600Å thick, wrapped by dense spiraling fibrils (DSF) less than 100Å thick as they near the kinomere. Such a fascicle joins the future daughter kinomere of each metaphase chromatid with those of adjacent non-homologous chromatids to either side. Thus, four fascicles (SF, 1-4) attach to each metaphase kinomere (K). It is thought that fascicles extend from the kinomere poleward, fray out to let chromosomal fibrils act as traction fibrils against polar fibrils, then regroup to join the adjacent kinomere.

Human Adenovirus Uptake by Preirnplantation Mouse Embryos

1972 ◽  
Vol 30 ◽  
pp. 268-269
Author(s):  
D. G. Chase ◽  
W. Winters ◽  
L. Piko
Keyword(s):  
Hela Cells ◽  
Human Adenovirus ◽  
Mouse Embryos ◽  
Equilibrium Density ◽  
Cell Stage ◽  
Virus Attachment ◽  
Preimplantation Mouse Embryos ◽  
Embryo Culture Medium ◽  
Preimplantation Mouse ◽  
Mouse Cells

Although the outlines of human adenovirus entry and uncoating in HeLa cells has been clarified in recent electron microscope studies, several details remain unclear or controversial. Furthermore, morphological features of early interactions of human adenovirus with non-permissive mouse cells have not been extensively documented. In the course of studies on the effects of human adenoviruses type 5 (AD-5) and type 12 on cultured preimplantation mouse embryos we have examined virus attachment, entry and uncoating. Here we present the ultrastructural findings for AD-5.AD-5 was grown in HeLa cells and purified by successive velocity gradient and equilibrium density gradient centrifugations in CsCl. After dialysis against PBS, virus was sedimented and resuspended in embryo culture medium. Embryos were placed in culture at the 2-cell stage in Brinster's medium.

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