scholarly journals Monoclonal Antibodies Specific for the Hemagglutinin-Neuraminidase Protein Define Neutralizing Epitopes Specific for Newcastle Disease Virus Genotype 2.VII from Egypt.

2020 ◽  
Author(s):  
Ibrahim Moharam ◽  
Olayinka Asala ◽  
Sven Reiche ◽  
Timm Harder ◽  
Hafez Hafez ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Receptor Binding ◽  
Newcastle Disease ◽  
Haemagglutination Inhibition ◽  
Antigenic Drift ◽  
Virus Genotype ◽  
Genotype 2 ◽  
Depth Analysis

Abstract Background:Newcastle disease is a devastating disease in poultry caused by Newcastle disease virus (NDV), a paramyxovirus endemic in many regions of the world despite intensive vaccination. Phylogenetic analysis reveal ongoing evolution of the predominant circulating genotype 2.VII, and the relevance of potential antigenic drift is under discussion. To investigate variation within neutralization-sensitive epitopes within the protein responsible for receptor binding, i.e. the Heamagglutinin-Neuraminidase (HN) spike protein, we were interested to established genotype-specific monoclonal antibodies (MAbs). Methods:An HN-enriched fraction of a gradient-purified NDV genotype 2.VII was prepared and successfully employed to induced antibodies in BalbC mice that recognize conformationally intact sites reactive by haemagglutination inhibition (HI). For subsequent screening of mouse hybridoma cultures, an NDV-ELISA was established that utilize Concanavalin A (ConA-ELISA) coupled Glycoproteins that was proven to present conformation-dependent epitopes.Results:Six out of nine selected MAbs were able to block receptor binding as demonstrated by HI-activity. One MAb recognized an epitope only present in the homologue virus while four other MAbs showed weak reactivity to selected other genotypes. On the other hand, one broadly cross-reacting MAb reacted with all genotypes tested and resembled the reactivity profile of genotype specific polyclonal antibody preparations that point to minor antigenic differences between tested NDV genotpyes.Conclusions:These results point to the concurrent presence of variable and conserved epitopes within the HN-molecule of NDV. The described protocol should help to generate MAbs to a variety of NDV strains and enable in depth analysis of the antigenic profiles of different genotypes.

scholarly journals Monoclonal antibodies specific for the hemagglutinin-neuraminidase protein define neutralizing epitopes specific for Newcastle disease virus genotype 2.VII from Egypt

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Ibrahim Moharam ◽  
Olayinka Asala ◽  
Sven Reiche ◽  
Hafez Hafez ◽  
Martin Beer ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Receptor Binding ◽  
Newcastle Disease ◽  
Haemagglutination Inhibition ◽  
Antigenic Drift ◽  
Virulent Newcastle Disease Virus ◽  
Genotype 2 ◽  
Depth Analysis

Abstract Background Newcastle disease is a devastating disease in poultry caused by virulent Newcastle disease virus (NDV), a paramyxovirus endemic in many regions of the world despite intensive vaccination. Phylogenetic analyses reveal ongoing evolution of the predominant circulating genotype 2.VII, and the relevance of potential antigenic drift is under discussion. To investigate variation within neutralization-sensitive epitopes within the protein responsible for receptor binding, i.e. the Hemagglutinin-Neuraminidase (HN) spike protein, we were interested in establishing genotype-specific monoclonal antibodies (MAbs). Methods An HN-enriched fraction of a gradient-purified NDV genotype 2.VII was prepared and successfully employed to induce antibodies in BalbC mice that recognize conformationally intact sites reactive by haemagglutination inhibition (HI). For subsequent screening of mouse hybridoma cultures, an NDV-ELISA was established that utilizes Concanavalin A (ConA-ELISA) coupled glycoproteins proven to present conformation-dependent epitopes. Results Six out of nine selected MAbs were able to block receptor binding as demonstrated by HI activity. One MAb recognized an epitope only present in the homologue virus, while four other MAbs showed weak reactivity to selected other genotypes. On the other hand, one broadly cross-reacting MAb reacted with all genotypes tested and resembled the reactivity profile of genotype-specific polyclonal antibody preparations that point to minor antigenic differences between tested NDV genotpyes. Conclusions These results point to the concurrent presence of variable and conserved epitopes within the HN molecule of NDV. The described protocol should help to generate MAbs against a variety of NDV strains and to enable in depth analysis of the antigenic profiles of different genotypes.

scholarly journals Newcastle Disease Virus Establishes Persistent Infection in Tumor Cells In Vitro: Contribution of the Cleavage Site of Fusion Protein and Second Sialic Acid Binding Site of Hemagglutinin-Neuraminidase

2017 ◽  
Vol 91 (16) ◽  
Author(s):  
Udaya S. Rangaswamy ◽  
Weijia Wang ◽  
Xing Cheng ◽  
Patrick McTamney ◽  
Danielle Carroll ◽  
...  
Keyword(s):  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Receptor Binding ◽  
Newcastle Disease ◽  
Persistent Infection ◽  
Cleavage Site ◽  
Protein Cleavage ◽  
F Protein ◽  
Sialic Acid Binding

ABSTRACT Newcastle disease virus (NDV) is an oncolytic virus being developed for the treatment of cancer. Following infection of a human ovarian cancer cell line (OVCAR3) with a recombinant low-pathogenic NDV, persistent infection was established in a subset of tumor cells. Persistently infected (PI) cells exhibited resistance to superinfection with NDV and established an antiviral state, as demonstrated by upregulation of interferon and interferon-induced genes such as myxoma resistance gene 1 (Mx1) and retinoic acid-inducing gene-I (RIG-I). Viruses released from PI cells induced higher cell-to-cell fusion than the parental virus following infection in two tumor cell lines tested, HT1080 and HeLa, and remained attenuated in chickens. Two mutations, one in the fusion (F) protein cleavage site, F117S (F117S), and another in hemagglutinin-neuraminidase (HN), G169R (HN169R), located in the second sialic acid binding region, were responsible for the hyperfusogenic phenotype. F117S improves F protein cleavage efficiency, facilitating cell-to-cell fusion, while HN169R possesses a multifaceted role in contributing to higher fusion, reduced receptor binding, and lower neuraminidase activity, which together result in increased fusion and reduced viral replication. Thus, establishment of persistent infection in vitro involves viral genetic changes that facilitate efficient viral spread from cell to cell as a potential mechanism to escape host antiviral responses. The results of our study also demonstrate a critical role in the viral life cycle for the second receptor binding region of the HN protein, which is conserved in several paramyxoviruses. IMPORTANCE Oncolytic Newcastle disease virus (NDV) could establish persistent infection in a tumor cell line, resulting in a steady antiviral state reflected by constitutively expressed interferon. Viruses isolated from persistently infected cells are highly fusogenic, and this phenotype has been mapped to two mutations, one each in the fusion (F) and hemagglutinin-neuraminidase (HN) proteins. The F117S mutation in the F protein cleavage site improved F protein cleavage efficiency while the HN169R mutation located at the second receptor binding site of the HN protein contributed to a complex phenotype consisting of a modest increase in fusion and cell killing, lower neuraminidase activity, and reduced viral growth. This study highlights the intricate nature of these two mutations in the glycoproteins of NDV in the establishment of persistent infection. The data also shed light on the critical balance between the F and HN proteins required for efficient NDV infection and their role in avian pathogenicity.

Concanavalin A- Sandwich-ELISA for the detection of antibodies against Newcastle disease virus (NDV) in chicken

2019 ◽  
Author(s):  
T.R. Kannaki ◽  
E. Priyanka ◽  
Santosh Haunshi
Keyword(s):  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Concanavalin A ◽  
Newcastle Disease ◽  
Indirect Elisa ◽  
Sandwich Elisa ◽  
Haemagglutination Inhibition ◽  
Con A ◽  
Serum Samples ◽  
Serum Dilution

Concanavalin A (Con A), a lectin interacts with carbohydrate moieties of viruses and provide stable and sensitive detection when used as a capture agent. Indirect ELISA methods need purified Newcastle disease virus (NDV) or recombinant antigens for adsorption, whereas use of Con A as capture agent will enable the use of non-purified and non-concentrated virus as antigen replacing costly and time-consuming virus purification step. Con A based sandwich ELISA with non-purified NDV whole virus antigen with single serum dilution format has been developed in this study. The optimum concentrations of the capture agent, Con A and non-purified antigen preparations were determined by checker-board titration. Briefly, microplates were coated with predetermined optimum concentration of ConA (0.5 mg/ml; 50µg per well) and incubated for 18h at 4°C. After washing, allantoic fluid with Newcastle disease virus (NDV) LaSota (HA titre, 210) at a constant predetermined dilution (1:1; 50µl) was coated and incubated for 45 min at 37°C, followed by blocking with 2 % bovine serum albumin for 45 min at 37°C. The antigen coated plates were used in the detection of antibody titre against NDV in serum samples at single serum dilution of 1: 500. Then, wells were added with goat anti-chicken IgG horseradish peroxidase conjugate and incubated for 1h at 37°C, followed by addition of TMB substrate and the plates were read spectrophotometrically at 450 nm. ELISA antibody titres were determined by standard serial dilution of positive sera and endpoints were calculated by a subtraction method. By using positive negative threshold curve (PNT), intercept and slope of the standard curve were calculated. Total of 271 random chicken serum samples were analyzed for antibodies against NDV by Haemagglutination inhibition assay (HI), indirect ELISA and compared with the Con A- S- ELISA developed in this study. The Con A-S-ELISA showed a high coefficient of correlation (r=0.85, n=271, P less than 0.01) and an agreement of ê=0.99 with the commercially available Indirect-ELISA. The relative sensitivity and specificity were 98% and 85% respectively in comparison to HI test. Hence, the Con A-S-ELISA is a simple, easy and effective for monitoring serum antibody levels against NDV.

Sign in / Sign up

Export Citation Format

Share Document