scholarly journals Functional and structural characterization of a two-MAb cocktail for delayed treatment of enterovirus D68 infections

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chao Zhang ◽  
Cong Xu ◽  
Wenlong Dai ◽  
Yifan Wang ◽  
Zhi Liu ◽  
...  
Keyword(s):  
Therapeutic Agent ◽  
Structural Basis ◽  
Delayed Treatment ◽  
Acute Flaccid Myelitis ◽  
Virus Like Particle ◽  
Enterovirus D68 ◽  
Further Development ◽  
Potent Neutralization ◽  
Sialic Acid Receptor

AbstractEnterovirus D68 (EV-D68) is an emerging pathogen associated with respiratory diseases and/or acute flaccid myelitis. Here, two MAbs, 2H12 and 8F12, raised against EV-D68 virus-like particle (VLP), show distinct preference in binding VLP and virion and in neutralizing different EV-D68 strains. A combination of 2H12 and 8F12 exhibits balanced and potent neutralization effects and confers broader protection in mice than single MAbs when given at onset of symptoms. Cryo-EM structures of EV-D68 virion complexed with 2H12 or 8F12 show that both antibodies bind to the canyon region of the virion, creating steric hindrance for sialic acid receptor binding. Additionally, 2H12 binding can impair virion integrity and trigger premature viral uncoating. We also capture an uncoating intermediate induced by 2H12 binding, not previously described for picornaviruses. Our study elucidates the structural basis and neutralizing mechanisms of the 2H12 and 8F12 MAbs and supports further development of the 2H12/8F12 cocktail as a broad-spectrum therapeutic agent against EV-D68 infections in humans.

scholarly journals Development and structural characterization of a two-MAb cocktail for delayed treatment of enterovirus D68 infections

2020 ◽  
Author(s):  
Zhong Huang ◽  
Chao Zhang ◽  
Cong Xu ◽  
Wenlong Dai ◽  
Yifan Wang ◽  
...  
Keyword(s):  
Therapeutic Agent ◽  
Cell Binding ◽  
Delayed Treatment ◽  
Acute Flaccid Myelitis ◽  
Virus Like Particle ◽  
Enterovirus D68 ◽  
Different Strains ◽  
Further Development ◽  
Potent Neutralization

Abstract Enterovirus D68 (EV-D68) is an emerging pathogen associated with respiratory diseases and/or acute flaccid myelitis. Here, two MAbs, 2H12 and 8F12, raised against EV-D68 virus-like particle (VLP), showed distinct preference in binding VLP and virion and in neutralizing different strains. The 2H12/8F12 cocktail exhibited balanced and potent neutralization effects and conferred broader protection in mice than single MAbs when given at onset of symptoms. Cryo-EM structures of EV-D68 virion complexed with 2H12 or 8F12 showed that both antibodies bind to south rim of the canyon and obscure the canyon, blocking virus–cell binding. Additionally, 2H12 binding could partially impair virions and trigger uncoating, resulting in premature viral RNA release. We also captured an uncoating intermediate induced by 2H12 binding, not detected before in picornaviruses. Our study elucidates neutralizing mechanisms of the MAbs and supports further development of the 2H12/8F12 cocktail as a broad-spectrum therapeutic agent against EV-D68 infections in humans.

scholarly journals Characterization of a Broadly Reactive Monoclonal Antibody against Norovirus Genogroups I and II: Recognition of a Novel Conformational Epitope

2007 ◽  
Vol 81 (22) ◽  
pp. 12298-12306 ◽  
Author(s):  
Tomoyuki Shiota ◽  
Michio Okame ◽  
Sayaka Takanashi ◽  
Pattara Khamrin ◽  
Makiko Takagi ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Conformational Epitope ◽  
The Novel ◽  
Antigen Specificity ◽  
Virus Like Particle ◽  
The Family ◽  
Immunological Diagnosis ◽  
Further Development

ABSTRACT Norovirus, which belongs to the family Caliciviridae, is one of the major causes of nonbacterial acute gastroenteritis in the world. The main human noroviruses are of genogroup I (GI) and genogroup II (GII), which were subdivided further into at least 15 and 18 genotypes (GI/1 to GI/15 and GII/1 to GII/18), respectively. The development of immunological diagnosis for norovirus had been hindered by the antigen specificity of the polyclonal antibody. Therefore, several laboratories have produced broadly reactive monoclonal antibodies, which recognize the linear GI and GII cross-reactive epitopes or the conformational GI-specific epitope. In this study, we characterized the novel monoclonal antibody 14-1 (MAb14-1) for further development of the rapid immunochromatography test. Our results demonstrated that MAb14-1 could recognize 15 recombinant virus-like particles (GI/1, 4, 8, and 11 and GII/1 to 7 and 12 to 15) and showed weak affinity to the virus-like particle of GI/3. This recognition range is the broadest of the existing monoclonal antibodies. The epitope for MAb14-1 was identified by fragment, sequence, structural, and mutational analyses. Both terminal antigenic regions (amino acid positions 418 to 426 and 526 to 534) on the C-terminal P1 domain formed the conformational epitope and were in the proximity of the insertion region (positions 427 to 525). These regions contained six amino acids responsible for antigenicity that were conserved among genogroup(s), genus, and Caliciviridae. This epitope mapping explained the broad reactivity and different titers among GI and GII. To our knowledge, we are the first group to identify the GI and GII cross-reactive monoclonal antibody, which recognizes the novel conformational epitope. From these data, MAb14-1 could be used further to develop immunochromatography.

scholarly journals Structural Basis for Potent Neutralization of Betacoronaviruses by Single-domain Camelid Antibodies

2020 ◽  
Author(s):  
Daniel Wrapp ◽  
Dorien De Vlieger ◽  
Kizzmekia S. Corbett ◽  
Gretel M. Torres ◽  
Wander Van Breedam ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Cross Reactivity ◽  
Vital Role ◽  
Single Domain ◽  
Structural Basis ◽  
Highly Pathogenic ◽  
Isolation And Characterization ◽  
Single Domain Antibodies ◽  
Potent Neutralization

ABSTRACTThe pathogenic Middle East respiratory syndrome coronavirus (MERS-CoV), severe acute respiratory syndrome coronavirus (SARS-CoV-1) and COVID-19 coronavirus (SARS-CoV-2) have all emerged into the human population with devastating consequences. These viruses make use of a large envelope protein called spike (S) to engage host cell receptors and catalyze membrane fusion. Because of the vital role that these S proteins play, they represent a vulnerable target for the development of therapeutics to combat these highly pathogenic coronaviruses. Here, we describe the isolation and characterization of single-domain antibodies (VHHs) from a llama immunized with prefusion-stabilized coronavirus spikes. These VHHs are capable of potently neutralizing MERS-CoV or SARS-CoV-1 S pseudotyped viruses. The crystal structures of these VHHs bound to their respective viral targets reveal two distinct epitopes, but both VHHs block receptor binding. We also show cross-reactivity between the SARS-CoV-1 S-directed VHH and SARS-CoV-2 S, and demonstrate that this cross-reactive VHH is capable of neutralizing SARS-CoV-2 S pseudotyped viruses as a bivalent human IgG Fc-fusion. These data provide a molecular basis for the neutralization of pathogenic betacoronaviruses by VHHs and suggest that these molecules may serve as useful therapeutics during coronavirus outbreaks.

Enterovirus D-68 Molecular Virology, Epidemiology, and Treatment: an update and way forward

2020 ◽  
Vol 20 ◽  
Author(s):  
Mahmoud Ahmed Ebada ◽  
Notila Fayed ◽  
Souad Alkanj ◽  
Ahmed Wadaa Allah
Keyword(s):  
Current Knowledge ◽  
Rna Virus ◽  
Neurological Diseases ◽  
Cross Reactivity ◽  
Serological Tests ◽  
Molecular Virology ◽  
Acute Flaccid Myelitis ◽  
The Family ◽  
Pcr Products ◽  
Enterovirus D68

: Enterovirus D68 (EV-D68) is a single-stranded positive-sense RNA virus, and it is one of the family Picornaviridae. Except for EV-D68, the family Picornaviridae has been illustrated in literature. EV-D68 was first discovered and isolated in California, USA, in 1962. EV-D68 has resulted in respiratory disorders’ outbreaks among children worldwide, and it has been detected in cases of various neurological diseases such as acute flaccid myelitis (AFM). A recent study documented a higher number of EV-D68 cases associated with AFM in Europe in 2016 compared to the 2014 outbreak. EV-D68 is mainly diagnosed by quantitative PCR, and there is an affirmative strategy for EV-D68 detection by using pan-EV PCR on the untranslated region and/or the VP1 or VP2, followed by sequencing of the PCR products. Serological tests are limited due to cross-reactivity of the antigens between the different serotypes. Many antiviral drugs for EV-D68 have been evaluated, and showed promising results. In our review, we discuss the current knowledge about EV-D68 and its role in the development of AFM.

scholarly journals Application of Dynamic and Static Light Scattering for Size and Shape Characterization of Small Extracellular Nanoparticles in Plasma and Ascites of Ovarian Cancer Patients

2021 ◽  
Vol 22 (23) ◽  
pp. 12946
Author(s):  
Ksenija Kogej ◽  
Darja Božič ◽  
Borut Kobal ◽  
Maruša Herzog ◽  
Katarina Černe
Keyword(s):  
Ovarian Cancer ◽  
Light Scattering ◽  
Spherical Particles ◽  
Radius Of Gyration ◽  
Non Invasive ◽  
Peritoneal Washing ◽  
Angular Dependency ◽  
Shape Characterization ◽  
Further Development

In parallel to medical treatment of ovarian cancer, methods for the early detection of cancer tumors are being sought. In this contribution, the use of non-invasive static (SLS) and dynamic light scattering (DLS) for the characterization of extracellular nanoparticles (ENPs) in body fluids of advanced serous ovarian cancer (OC) and benign gynecological pathology (BP) patients is demonstrated and critically evaluated. Samples of plasma and ascites (OC patients) or plasma, peritoneal fluid, and peritoneal washing (BP patients) were analyzed. The hydrodynamic radius (Rh) and the radius of gyration (Rg) of ENPs were calculated from the angular dependency of LS intensity for two ENP subpopulations. Rh and Rg of the predominant ENP population of OC patients were in the range 20–30 nm (diameter 40–60 nm). In thawed samples, larger particles (Rh mostly above 100 nm) were detected as well. The shape parameter ρ of both particle populations was around 1, which is typical for spherical particles with mass concentrated on the rim, as in vesicles. The Rh and Rg of ENPs in BP patients were larger than in OC patients, with ρ ≈ 1.1–2, implying a more elongated/distorted shape. These results show that SLS and DLS are promising methods for the analysis of morphological features of ENPs and have the potential to discriminate between OC and BP patients. However, further development of the methodology is required.

scholarly journals Characterization of the Common japonica-Originated Genomic Regions in the High Yielding Varieties Developed from Inter-Subspecific Crosses in Rice (Oryza sativa L.)

2020 ◽  
Author(s):  
Jeonghwan Seo ◽  
So-Myeong Lee ◽  
Jae-Hyuk Han ◽  
Na-Hyun Shin ◽  
Yoon Kyung Lee ◽  
...  
Keyword(s):  
Molecular Breeding ◽  
Snp Markers ◽  
Yield Potential ◽  
Breeding Programs ◽  
Wx Gene ◽  
High Yielding Varieties ◽  
Indica And Japonica Subspecies ◽  
Genomic Regions ◽  
Further Development

The inter-subspecific crossing between indica and japonica subspecies in rice have been utilized to improve yield potential in temperate rice. In this study, a comparative study of the genomic regions in the eight high yielding varieties (HYVs) was conducted with those of the four non-HYV varieties. NGS mapping on the Nipponbare reference genome identified a total of 14 common genomic regions of japonica-originated alleles. Interestingly, the HYVs shared the japonica-originated genomic regions on the nine chromosomes, although they were developed from different breeding programs. A panel of 94 varieties was classified into four varietal groups with the 39 SNP markers from 39 genes residing the japonica-originated genomic regions and 16 additional trait-specific SNPs. As expected, the japonica originated genomic regions were present only in JAP and HYV groups with exceptions for Chr4-1 and Chr4-2. The Wx gene located within Chr6-1 was present in HYV and JAP variety groups, while the yield-related genes were conserved as indica alleles in HYVs. The japonica-originated genomic regions and alleles shared by HYVs can be employed in molecular breeding programs for further development of HYVs in rice.

Genetic analysis of Enterovirus D68 associated with pneumonia in children from South India

2021 ◽  
Vol 70 (5) ◽  
Author(s):  
Ramachandran Erathodi Sanjay ◽  
Sasidharanpillai Sabeena ◽  
Sudandiradas Robin ◽  
John T. Shaji ◽  
M. P. Jayakrishnan ◽  
...  
Keyword(s):  
South India ◽  
Single Case ◽  
Respiratory Illness ◽  
Neurological Complications ◽  
The Novel ◽  
Acute Flaccid Myelitis ◽  
Sporadic Cases ◽  
Enterovirus D68 ◽  
Kerala State ◽  
Unique Amino Acid

EV-D68 is an emerging enterovirus infection associated with severe acute respiratory illness (SARI), acute flaccid myelitis (AFM) and acute flaccid paralysis (AFP). While EV-D68 outbreaks and sporadic cases are reported globally, a single case has been reported from India. The present study aims to investigate the molecular epidemiology and clinical characteristics of EV-D68-associated SARI cases from South India. We screened influenza-negative archived throat swab specimens from Influenza-Like Illness (ILI) and SARI cases (n=959; 2016 to 2018 period) for enteroviruses by pan-enterovirus real-time RT-PCR. Thirteen samples positive for enteroviruses were typed by PCR and sequencing based on VPI, VP2 and/or 5′NCR regions. One EV-D68 RNA sample was subjected to next-generation sequencing for whole genome characterisation. Among 13 enterovirus cases, four were ECHO-11, three EV-D68, two CV-A16 and one each EV-71, CV-B1, CV-B2 and CV-A9. All three cases of EV-D68 infection were reported in children below 2 years of age from Kerala state of South India during June and July 2017. The patients developed pneumonia without any neurological complications. Sequencing based on VPI and 5′NCR regions showed that EV-D68 strains belong to the novel subclade B3. The EV-D68 complete genome identified with two unique amino acid substitutions in VP1 (T-246-I) and 3D (K-344-R) regions. This study reiterates the EV-D68 novel subclade B3 circulation in India and indicates the urgent need for structured EV-D68 surveillance in the country to describe the epidemiology.

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