scholarly journals Enhancement of neutralizing activity of influenza virus-specific antibodies by serum components

Virology ◽  
2006 ◽  
Vol 352 (2) ◽  
pp. 418-426 ◽  
Author(s):  
Krystyna Mozdzanowska ◽  
JingQi Feng ◽  
Mark Eid ◽  
Darya Zharikova ◽  
Walter Gerhard
Keyword(s):  
Influenza Virus ◽  
Specific Antibodies ◽  
Neutralizing Activity ◽  
Serum Components

scholarly journals A Novel Gene Delivery Vector of Agonistic Anti-Radioprotective 105 Expressed on Cell Membranes Shows Adjuvant Effect for DNA Immunization Against Influenza

2020 ◽  
Vol 11 ◽  
Author(s):  
Tatsuya Yamazaki ◽  
Mrityunjoy Biswas ◽  
Kouyu Kosugi ◽  
Maria Nagashima ◽  
Masanori Inui ◽  
...  
Keyword(s):  
Influenza Virus ◽  
B Cells ◽  
Intracellular Signaling ◽  
Transmembrane Domain ◽  
Lethal Dose ◽  
Influenza Virus Infection ◽  
Target Antigen ◽  
Dna Immunization ◽  
Adjuvant Effect ◽  
Specific Antibodies

Radioprotective 105 (RP105) (also termed CD180) is an orphan and unconventional Toll-like receptor (TLR) that lacks an intracellular signaling domain. The agonistic anti-RP105 monoclonal antibody (mAb) can cross-link RP105 on B cells, resulting in the proliferation and activation of B cells. Anti-RP105 mAb also has a potent adjuvant effect, providing higher levels of antigen-specific antibodies compared to alum. However, adjuvanticity is required for the covalent link between anti-RP105 mAb and the antigen. This is a possible obstacle to immunization due to the link between anti-RP105 mAb and some antigens, especially multi-transmembrane proteins. We have previously succeeded in inducing rapid and potent recombinant mAbs in mice using antibody gene-based delivery. To simplify the covalent link between anti-RP105 mAb and antigens, we generated genetic constructs of recombinant anti-RP105 mAb (αRP105) bound to the transmembrane domain of the IgG-B cell receptor (TM) (αRP105-TM), which could enable the anti-RP105 mAb to link the antigen via the cell membrane. We confirmed the expression of αRP105-TM and the antigen hemagglutinin, which is a membrane protein of the influenza virus, on the same cell. We also found that αRP105-TM could activate splenic B cells, including both mature and immature cells, depending on the cell surface RP105 in vitro. To evaluate the adjuvanticity of αRP105-TM, we conducted DNA immunization in mice with the plasmids encoding αRP105-TM and hemagglutinin, followed by challenge with an infection of a lethal dose of an influenza virus. We then obtained partially but significantly hemagglutinin-specific antibodies and observed protective effects against a lethal dose of influenza virus infection. The current αRP105-TM might provide adjuvanticity for a vaccine via a simple preparation of the expression plasmids encoding αRP105-TM and of that encoding the target antigen.

scholarly journals Cervicovaginal Neutralizing Antibodies to Herpes Simplex Virus (HSV) in Women Seropositive for HSV Types 1 and 2

2003 ◽  
Vol 10 (3) ◽  
pp. 388-393 ◽  
Author(s):  
Francois-Xavier Mbopi-Kéou ◽  
Laurent Bélec ◽  
Julie Dalessio ◽  
Jérôme Legoff ◽  
Gérard Grésenguet ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Neutralizing Antibodies ◽  
Female Genital Tract ◽  
African Women ◽  
Specific Antibodies ◽  
Neutralizing Activity ◽  
Simplex Virus ◽  
Hiv Negative ◽  
Hsv 1

ABSTRACT Antibodies to herpes simplex virus type 1 (HSV-1) and HSV-2 of the immunoglobulin G (IgG) and IgA isotypes were detected in the cervicovaginal secretions (CVS) of 77 HSV-1- and HSV-2-seropositive but clinically asymptomatic African women by type-specific enhanced chemiluminescence Western blotting (ECL-WB). Of the 77 subjects, 34 were HIV negative, shedding HSV-2 DNA in their genital secretions; 20 were HIV positive, shedding HSV-2 DNA; and 23 were HIV negative, not shedding HSV-2 DNA. HSV-specific IgG was detected in CVS of nearly 70% of the women studied. HSV-specific IgA was found in CVS of 50% of the women studied. The distribution of CVS HSV-specific antibodies to each HSV type was highly heterogeneous, with a slight predominance of detectable IgG to HSV-1 (59%) over IgG to HSV-2 (41%), whereas the frequency of detectable IgA to HSV-1 (39%) was similar to that of IgA to HSV-2 (36%). The presence of detectable HSV-specific antibodies was inversely associated with HSV-2 DNA genital asymptomatic shedding but was not affected by HIV seropositivity. In addition, 13 of 77 (17%) CVS samples showed neutralizing activity against HSV-2, as assessed by an HSV-2 in vitro infectivity reduction assay. Neutralizing activity in CVS was associated with the presence of IgG and/or IgA antibodies to HSV-1 and/or to HSV-2 by ECL-WB. Among women whose CVS showed HSV-2-neutralizing activity, the specific activity of HSV-specific neutralizing antibodies was substantially (fivefold) higher in HSV-2 DNA shedders than in nonshedders. In conclusion, HSV-specific antibodies are frequently detected in CVS of asymptomatic African women seropositive for HSV-1 and HSV-2. A subset of these women had functional neutralizing activity against HSV-2 in their CVS. The origin of these antibodies and their role in HSV-2 disease of the female genital tract remain to be determined.

scholarly journals An Optimized High-Throughput Neutralization Assay for Hepatitis E Virus (HEV) Involving Detection of Secreted Porf2

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 64 ◽  
Author(s):  
Chang Liu ◽  
Wei Cai ◽  
Xin Yin ◽  
Zimin Tang ◽  
Guiping Wen ◽  
...  
Keyword(s):  
High Throughput ◽  
Hepatitis E Virus ◽  
Hepatitis E ◽  
Neutralization Assay ◽  
The Novel ◽  
Specific Antibodies ◽  
Neutralizing Activity ◽  
Elisa Kit ◽  
Neutralizing Capacity ◽  
Potential Threshold

Hepatitis E virus (HEV) is a common cause of acute hepatitis worldwide. Current methods for evaluating the neutralizing activity of HEV-specific antibodies include immunofluorescence focus assays (IFAs) and real-time PCR, which are insensitive and operationally complicated. Here, we developed a high-throughput neutralization assay by measuring secreted pORF2 levels using an HEV antigen enzyme-linked immunosorbent assay (ELISA) kit based on the highly replicating HEV genotype (gt) 3 strain Kernow. We evaluated the neutralizing activity of HEV-specific antibodies and the sera of vaccinated individuals (n = 15) by traditional IFA and the novel assay simultaneously. A linear regression analysis shows that there is a high degree of correlation between the two assays. Furthermore, the anti-HEV IgG levels exhibited moderate correlation with the neutralizing titers of the sera of vaccinated individuals, indicating that immunization with gt 1 can protect against gt 3 Kernow infection. We then determined specificity of the novel assay and the potential threshold of neutralizing capacity using anti-HEV IgG positive sera (n = 27) and anti-HEV IgG negative sera (n = 23). The neutralizing capacity of anti-HEV IgG positive sera was significantly stronger than that of anti-HEV IgG negative. In addition, ROC curve analysis shows that the potential threshold of neutralizing capacity of sera was 8.07, and the sensitivity and specificity of the novel assay was 88.6% and 100%, respectively. Our results suggest that the neutralization assay using the antigen ELISA kit could be a useful tool for HEV clinical research.

scholarly journals Sequential Infection in Ferrets with Antigenically Distinct Seasonal H1N1 Influenza Viruses Boosts Hemagglutinin Stalk-Specific Antibodies

2015 ◽  
Vol 90 (2) ◽  
pp. 1116-1128 ◽  
Author(s):  
Greg A. Kirchenbaum ◽  
Donald M. Carter ◽  
Ted M. Ross
Keyword(s):  
Influenza Virus ◽  
Receptor Binding ◽  
Specific Antibody ◽  
H1n1 Virus ◽  
H1n1 Influenza ◽  
Influenza Viruses ◽  
Specific Antibodies ◽  
Antibody Titers ◽  
Sequential Infection ◽  
Virus Isolates

ABSTRACTBroadly reactive antibodies targeting the conserved hemagglutinin (HA) stalk region are elicited following sequential infection or vaccination with influenza viruses belonging to divergent subtypes and/or expressing antigenically distinct HA globular head domains. Here, we demonstrate, through the use of novel chimeric HA proteins and competitive binding assays, that sequential infection of ferrets with antigenically distinct seasonal H1N1 (sH1N1) influenza virus isolates induced an HA stalk-specific antibody response. Additionally, stalk-specific antibody titers were boosted following sequential infection with antigenically distinct sH1N1 isolates in spite of preexisting, cross-reactive, HA-specific antibody titers. Despite a decline in stalk-specific serum antibody titers, sequential sH1N1 influenza virus-infected ferrets were protected from challenge with a novel H1N1 influenza virus (A/California/07/2009), and these ferrets poorly transmitted the virus to naive contacts. Collectively, these findings indicate that HA stalk-specific antibodies are commonly elicited in ferrets following sequential infection with antigenically distinct sH1N1 influenza virus isolates lacking HA receptor-binding site cross-reactivity and can protect ferrets against a pathogenic novel H1N1 virus.IMPORTANCEThe influenza virus hemagglutinin (HA) is a major target of the humoral immune response following infection and/or seasonal vaccination. While antibodies targeting the receptor-binding pocket of HA possess strong neutralization capacities, these antibodies are largely strain specific and do not confer protection against antigenic drift variant or novel HA subtype-expressing viruses. In contrast, antibodies targeting the conserved stalk region of HA exhibit broader reactivity among viruses within and among influenza virus subtypes. Here, we show that sequential infection of ferrets with antigenically distinct seasonal H1N1 influenza viruses boosts the antibody responses directed at the HA stalk region. Moreover, ferrets possessing HA stalk-specific antibody were protected against novel H1N1 virus infection and did not transmit the virus to naive contacts.

scholarly journals Nanobodies With In Vitro Neutralizing Activity Protect Mice Against H5N1 Influenza Virus Infection

2011 ◽  
Vol 203 (8) ◽  
pp. 1063-1072 ◽  
Author(s):  
Lorena Itatí Ibañez ◽  
Marina De Filette ◽  
Anna Hultberg ◽  
Theo Verrips ◽  
Nigel Temperton ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza Virus Infection ◽  
H5n1 Influenza Virus ◽  
Neutralizing Activity ◽  
H5n1 Influenza

scholarly journals Development of an enzyme-linked immunosorbent assay (ELISA) for the detection of specific antibodies against an H7N7 and an H3N8 equine influenza virus

1984 ◽  
Vol 93 (3) ◽  
pp. 609-620 ◽  
Author(s):  
M. S. Denyer ◽  
J. R. Crowther ◽  
R. C. Wardley ◽  
R. Burrows
Keyword(s):  
Influenza Virus ◽  
Immunosorbent Assay ◽  
Solid Phase ◽  
Allantoic Fluid ◽  
Influenza Viruses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Equine Influenza Virus ◽  
Serum Samples ◽  
Specific Antibodies ◽  
Equine Influenza

SummaryThis paper describes a solid-phase microtitre plate enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to equine influenza viruses. Using egg-grown influenza viruses as the antigens attached to the solid phase, crossreactions were observed between an H7N7 equine virus (designated A1) and an H3N8 equine influenza virus (designated A2) when untreated antisera were tested. Absorption of antisera with egg-grown A/Porcine/Shope/1/33 influenza virus eliminated cross-reactive antibodies so that specific detection of anti-equine influenza A1 or A2 antibodies was possible.Examination of horse sera following vaccination with A1 and/or A2 isolates showed that antibodies were produced against antigen associated with egg allantoic fluid as well as against virus. Such antibodies were eliminated following the absorption of antisera with porcine influenza virus. Results using sera from horses with known vaccination histories confirmed that the ELISA preferentially detected antibodies homologous to the antigen attached to the solid phase and methods to evaluate the current serological state of individual horses by relating the titres of specific antibodies against equine influenza A1 and A2 isolates are shown. This ELISA provides a simple and rapid method of assessing specific antibodies from horse sera and offers advantages over the ‘routine’ HI and SRH assessments since it gives high precision, is economical of reagents and has the capacity to handle large numbers of serum samples.

scholarly journals Influenza Virus–induced Dendritic Cell Maturation Is Associated with the Induction of Strong T Cell Immunity to a Coadministered, Normally Nonimmunogenic Protein

2003 ◽  
Vol 198 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Marie K. Brimnes ◽  
Laura Bonifaz ◽  
Ralph M. Steinman ◽  
Thomas M. Moran
Keyword(s):  
T Cells ◽  
Influenza Virus ◽  
T Cell ◽  
Lymph Nodes ◽  
Mhc Class Ii ◽  
T Cell Immunity ◽  
Mediastinal Lymph Nodes ◽  
Specific Antibodies ◽  
Cell Immunity ◽  
Ifn Γ

We evaluated the proposal that during microbial infection, dendritic cells (DCs) undergo maturation and present a mixture of peptides derived from the microbe as well as harmless environmental antigens. Mice were exposed to an aerosol of endotoxin free ovalbumin (OVA) in the absence or presence of influenza virus. In its absence, OVA failed to induce B and T cell responses and even tolerized, but with influenza, OVA-specific antibodies and CD8+ cytolytic T lymphocytes developed. With or without infection, OVA was presented selectively in the draining mediastinal lymph nodes, as assessed by the comparable proliferation of infused, CD8+ and CD4+, TCR transgenic T cells. In the absence of influenza, these OVA-specific T cells produced little IL-2, IL-4, IL-10, and IFN-γ, but with infection, both CD4+ and CD8+ T cells made high levels of IL-2 and IFN-γ. The OVA plus influenza-treated mice also showed accelerated recovery to a challenge with recombinant vaccinia OVA virus. CD11c+ DCs from the mediastinal lymph nodes of infected mice selectively stimulated both OVA- and influenza-specific T cells and underwent maturation, with higher levels of MHC class II, CD80, and CD86 molecules. The relatively slow (2–3 d) kinetics of maturation correlated closely to the time at which OVA inhalation elicited specific antibodies. Therefore respiratory infection can induce DC maturation and simultaneously B and T cell immunity to an innocuous antigen inhaled concurrently.

scholarly journals Prefusion F–specific antibodies determine the magnitude of RSV neutralizing activity in human sera

2015 ◽  
Vol 7 (309) ◽  
pp. 309ra162-309ra162 ◽  
Author(s):  
Joan O. Ngwuta ◽  
Man Chen ◽  
Kayvon Modjarrad ◽  
M. Gordon Joyce ◽  
Masaru Kanekiyo ◽  
...  
Keyword(s):  
Specific Antibodies ◽  
Neutralizing Activity ◽  
Human Sera
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