Use of Recombinant Nucleoproteins in Enzyme-Linked Immunosorbent Assays for Detection of Virus-Specific Immunoglobulin A (IgA) and IgG Antibodies in  Influenza Virus A- or B-Infected Patients

The nucleoprotein genes of influenza virus A/Netherlands/018/94 (H3N2) and influenza virus B/Harbin/7/94 were cloned into the bacterial expression vector pMalC to yield highly purified recombinant influenza virus A and B nucleoproteins. With these recombinant influenza nucleoproteins, enzyme-linked immunosorbent assays (ELISAs) were developed for the detection of influenza virus A- and B-specific immunoglobulin A (IgA) and IgG serum antibodies. Serum samples were collected at consecutive time points after the onset of clinical symptoms from patients with confirmed influenza virus A or B infections. Nucleoprotein-specific IgA antibodies were detected in 41.2% of influenza virus A-infected patients and in 66.7% of influenza virus B-infected patients on day 6 after the onset of clinical symptoms. In serum samples taken on day 21 (influenza virus A-infected patients) or day 28 (influenza virus B-infected patients), nucleoprotein-specific IgA antibodies could be detected in 58.8 and 58.3% of influenza virus A- and B-infected patients, respectively. At the same time, IgG antibody rises were detected in 88.2% of influenza virus A-infected patients and in 95.8% of influenza virus B-infected patients. On comparison, hemagglutination inhibition assays detected antibody titer rises in 81.3 and 72.7% of patients infected with influenza viruses A and B, respectively. In contrast to the detection of nucleoprotein-specific IgG antibodies or hemagglutination-inhibiting antibodies, the detection of nucleoprotein-specific IgA antibodies does not require paired serum samples and therefore can be considered an attractive alternative for the rapid serological diagnosis of influenza.

Download Full-text

Measurement of Chlamydia pneumoniae-Specific Immunoglobulin A (IgA) Antibodies by the Microimmunofluorescence (MIF) Method: Comparison of Seven Fluorescein-Labeled Anti-Human IgA Conjugates in an In-House MIF Test Using One Commercial MIF and One Enzyme Immunoassay Kit

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.10.1.8-12.2003 ◽

2003 ◽

Vol 10 (1) ◽

pp. 8-12 ◽

Cited By ~ 17

Author(s):

Mika Paldanius ◽

Aini Bloigu ◽

Maija Leinonen ◽

Pekka Saikku

Keyword(s):

Enzyme Immunoassay ◽

Chlamydia Pneumoniae ◽

Immunoglobulin A ◽

Method Comparison ◽

Serum Samples ◽

Iga Antibodies ◽

Specific Immunoglobulin ◽

Antibody Titers ◽

Iga Antibody

ABSTRACT For the serological diagnosis of acute Chlamydia pneumoniae infection, the microimmunofluorescence (MIF) test is the most commonly used method and also the “gold standard” for the measurement of immunoglobulin G (IgG) and IgM antibodies. The role of IgA antibodies in diagnosis has not been established. Commercially available fluorescein-labeled anti-human IgA conjugates have not been systematically compared to each other, and this situation may cause considerable variations in IgA results. Therefore, we tested 261 serum samples from 122 patients with pneumonia for IgA antibodies by using six α-chain-specific anti-IgA conjugates in our in-house MIF test, one commercial MIF test, and one enzyme immunoassay (EIA). Interfering IgG antibodies were removed with Gullsorb reagent before the measurement of IgA antibodies. Altogether, 14 significant IgA antibody increases in serum samples between the acute phase and the convalescent phase were detected by at least one of the conjugates in the MIF test, while no increases were found in the IgA EIA. Only one patient showed a significant IgA antibody increase with all of the fluorescein-labeled conjugates. Five significant titer changes were detected by at least two conjugates, and in nine instances, the titer increase was detected by one conjugate only. The titer agreement indicated by kappa coefficients was very good or good for all of the fluorescein-labeled conjugates and the EIA with low antibody titers but decreased with increasing titers.

Download Full-text

Antibodies to Highly Pathogenic A/H5Nx (Clade 2.3.4.4) Influenza Viruses in the Sera of Vietnamese Residents

Pathogens ◽

10.3390/pathogens10040394 ◽

2021 ◽

Vol 10 (4) ◽

pp. 394

Author(s):

Tatyana Ilyicheva ◽

Vasily Marchenko ◽

Olga Pyankova ◽

Anastasia Moiseeva ◽

Tran Thi Nhai ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Wide Spectrum ◽

Influenza Viruses ◽

Serum Samples ◽

Socialist Republic ◽

Highly Pathogenic ◽

Virus Variant ◽

Human Sera ◽

Hemagglutinin Inhibition

To cause a pandemic, an influenza virus has to overcome two main barriers. First, the virus has to be antigenically new to humans. Second, the virus has to be directly transmitted from humans to humans. Thus, if the avian influenza virus is able to pass the second barrier, it could cause a pandemic, since there is no immunity to avian influenza in the human population. To determine whether the adaptation process is ongoing, analyses of human sera could be conducted in populations inhabiting regions where pandemic virus variant emergence is highly possible. This study aimed to analyze the sera of Vietnamese residents using hemagglutinin inhibition reaction (HI) and microneutralization (MN) with A/H5Nx (clade 2.3.4.4) influenza viruses isolated in Vietnam and the Russian Federation in 2017–2018. In this study, we used sera from 295 residents of the Socialist Republic of Vietnam collected from three groups: 52 samples were collected from households in Nam Dinh province, where poultry deaths have been reported (2017); 96 (2017) and 147 (2018) samples were collected from patients with somatic but not infectious diseases in Hanoi. In all, 65 serum samples were positive for HI, at least to one H5 virus used in the study. In MN, 47 serum samples neutralizing one or two viruses at dilutions of 1/40 or higher were identified. We postulate that the rapidly evolving A/H5Nx (clade 2.3.4.4) influenza virus is possibly gradually adapting to the human host, insofar as healthy individuals have antibodies to a wide spectrum of variants of that subtype.

Download Full-text

Diagnosis of Dengue Virus Infection by Detection of Specific Immunoglobulin M (IgM) and IgA Antibodies in Serum and Saliva

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.10.2.317-322.2003 ◽

2003 ◽

Vol 10 (2) ◽

pp. 317-322 ◽

Cited By ~ 83

Author(s):

Angel Balmaseda ◽

María G. Guzmán ◽

Samantha Hammond ◽

Guillermo Robleto ◽

Carolina Flores ◽

...

Keyword(s):

Dengue Virus ◽

Immunoglobulin M ◽

Antibody Detection ◽

Enzyme Linked Immunosorbent Assay ◽

Control Group ◽

Serum Samples ◽

Diagnostic Modality ◽

Iga Antibodies ◽

Specific Immunoglobulin ◽

Feasible Alternative

ABSTRACT To evaluate alternative approaches to the serological diagnosis of dengue virus (DEN) infection, the detection of DEN-specific immunoglobulin M (IgM) and IgA antibodies in serum and saliva specimens was assessed in 147 patients with symptoms of DEN infection seen at the Ministry of Health in Nicaragua. Seventy-two serum samples were determined to be positive for anti-DEN antibodies by IgM capture enzyme-linked immunosorbent assay, the routine diagnostic procedure. Serum and saliva specimens were obtained from 50 healthy adults as additional controls. IgM was detected in the saliva of 65 of the 72 serum IgM-positive cases, 6 of the 75 serum IgM-negative cases, and none of the control group, resulting in a sensitivity of 90.3% and a specificity of 92.0% and demonstrating that salivary IgM is a useful diagnostic marker for DEN infection. Detection of IgA in serum may be another feasible alternative for the diagnosis of DEN infection, with serum IgA found in 68 (94.4%) of the IgM-positive cases. In contrast, detection of IgA in saliva was not found to be a useful tool for DEN diagnosis in the present study. Further studies of the kinetics of antibody detection in another set of 151 paired acute- and convalescent-phase serum samples showed that DEN-specific IgA antibodies were detected in more acute-phase samples than were IgM antibodies. Thus, we conclude that DEN-specific IgA in serum is a potential diagnostic target. Furthermore, given that saliva is a readily obtainable, noninvasive specimen, detection of DEN-specific salivary IgM should be considered a useful, cheaper diagnostic modality with similar sensitivity and specificity to IgM detection in serum.

Download Full-text

Detection of severe acute respiratory syndrome coronavirus 2 and influenza viruses based on CRISPR-Cas12a

Experimental Biology and Medicine ◽

10.1177/1535370220963793 ◽

2020 ◽

pp. 153537022096379

Author(s):

Oraphan Mayuramart ◽

Pattaraporn Nimsamer ◽

Somruthai Rattanaburi ◽

Naphat Chantaravisoot ◽

Kritsada Khongnomnan ◽

...

Keyword(s):

Influenza Virus ◽

Severe Acute Respiratory Syndrome ◽

Influenza A ◽

Limit Of Detection ◽

Cross Reactivity ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

Influenza Virus A ◽

B Virus

Due to the common symptoms of COVID-19, patients are similar to influenza-like illness. Therefore, the detection method would be crucial to discriminate between SARS-CoV-2 and influenza virus-infected patients. In this study, CRISPR-Cas12a-based detection was applied for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus, and influenza B virus which would be a practical and attractive application for screening of patients with COVID-19 and influenza in areas with limited resources. The limit of detection for SARS-CoV-2, influenza A, and influenza B detection was 10, 103, and 103 copies/reaction, respectively. Moreover, the assays yielded no cross-reactivity against other respiratory viruses. The results revealed that the detection of influenza virus and SARS-CoV-2 by using RT-RPA and CRISPR-Cas12a technology reaches 96.23% sensitivity and 100% specificity for SARS-CoV-2 detection. The sensitivity for influenza virus A and B detections was 85.07% and 94.87%, respectively. In addition, the specificity for influenza virus A and B detections was approximately 96%. In conclusion, the RT-RPA with CRISPR-Cas12a assay was an effective method for the screening of influenza viruses and SARS-CoV-2 which could be applied to detect other infectious diseases in the future.

Download Full-text

Bioluminescence-Based Neuraminidase Inhibition Assay for Monitoring Influenza Virus Drug Susceptibility in Clinical Specimens

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01086-13 ◽

2013 ◽

Vol 57 (11) ◽

pp. 5209-5215 ◽

Cited By ~ 10

Author(s):

Henju Marjuki ◽

Vasiliy P. Mishin ◽

Katrina Sleeman ◽

Margaret Okomo-Adhiambo ◽

Tiffany G. Sheu ◽

...

Keyword(s):

Influenza Virus ◽

Point Of Care ◽

Drug Susceptibility ◽

Influenza Viruses ◽

Clinical Specimens ◽

Influenza Virus A ◽

Oseltamivir Resistance ◽

Resistance Markers ◽

The Difference ◽

Inhibitor Resistance

ABSTRACTThe QFlu prototype bioluminescence-based neuraminidase (NA) inhibition (NI) assay kit was designed to detect NA inhibitor (NAI)-resistant influenza viruses at point of care. Here, we evaluated its suitability for drug susceptibility assessment at a surveillance laboratory. A comprehensive panel of reference viruses (n= 14) and a set of 90 seasonal influenza virus A and B isolates were included for testing with oseltamivir and/or zanamivir in the QFlu assay using the manufacturer-recommended protocol and a modified version attuned to surveillance requirements. The 50% inhibitory concentrations (IC50s) generated were compared with those of NI assays currently used for monitoring influenza drug susceptibility, the fluorescent (FL) and chemiluminescent (CL) assays. To provide proof of principle, clinical specimens (n= 235) confirmed by real-time reverse transcription (RT)-PCR to contain influenza virus A(H1N1)pdm09 and prescreened for the oseltamivir resistance marker H275Y using pyrosequencing were subsequently tested in the QFlu assay. All three NI assays were able to discriminate the reference NA variants and their matching wild-type viruses based on the difference in their IC50s. Unless the antigenic types were first identified, certain NA variants (e.g., H3N2 with E119V) could be detected among seasonal viruses using the FL assays only. Notably, the QFlu assay identified oseltamivir-resistant A(H1N1)pdm09 viruses carrying the H275Y marker directly in clinical specimens, which is not feasible with the other two phenotypic assays, which required prior virus culturing in cells. Furthermore, The QFlu assay allows detection of the influenza virus A and B isolates carrying established and potential NA inhibitor resistance markers and may become a useful tool for monitoring drug resistance in clinical specimens.

Download Full-text

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

Journal of Hygiene ◽

10.1017/s0022172400065189 ◽

1984 ◽

Vol 93 (3) ◽

pp. 609-620 ◽

Cited By ~ 4

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.

Download Full-text

Prevalence of Antibodies against Seasonal Influenza A and B Viruses in Children in Netherlands

Clinical and Vaccine Immunology ◽

10.1128/cvi.00396-10 ◽

2011 ◽

Vol 18 (3) ◽

pp. 469-476 ◽

Cited By ~ 112

Author(s):

R. Bodewes ◽

G. de Mutsert ◽

F. R. M. van der Klis ◽

M. Ventresca ◽

S. Wilks ◽

...

Keyword(s):

Influenza Virus ◽

Influenza A ◽

Influenza Virus Infection ◽

Population Based ◽

Influenza Viruses ◽

Serum Samples ◽

Cross Sectional ◽

Population Based Study ◽

Influenza A H1n1 ◽

First Time

ABSTRACTTo gain insight into the age at which children become infected with influenza viruses for the first time, we analyzed the seroprevalence of antibodies against influenza viruses in children 0 to 7 years of age in the Netherlands. Serum samples were collected during a cross-sectional population-based study in 2006 and 2007 and were tested for the presence of antibodies against influenza A/H1N1, A/H3N2, and B viruses representative of viruses present in previous influenza seasons using the hemagglutination inhibition assay. The seroprevalence of antibodies to influenza virus was higher in children 1 to 6 months of age than in children 7 to 12 months of age, which likely reflects the presence of maternally derived antibodies. The proportion of study subjects >1 year of age with detectable antibodies against influenza viruses gradually increased with age until they reached the age of 6 years, when they all had antibodies to at least one influenza A virus. These findings may have implications for the development of vaccination strategies aiming at the protection of young children against seasonal and/or pandemic influenza virus infection.

Download Full-text

Longitudinal monitoring of SARS-CoV-2-specific immune responses

10.1101/2021.08.14.21262042 ◽

2021 ◽

Author(s):

Heike Rebholz ◽

Ralf J. Braun ◽

Titas Saha ◽

Oliver Harzer ◽

Miriam Schneider ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

Immunoglobulin G ◽

Immunoglobulin A ◽

Comprehensive View ◽

Iga Antibodies ◽

Specific Immunoglobulin ◽

Second Peak

The Lower Austrian Wachau region was an early COVID-19 hotspot of infection. As previously reported, in June 2020, after the first peak of infections, we determined that 8.5% and 9.0% of the participants in Weissenkirchen and surrounding communities in the Wachau region were positive for SARS-CoV-2-specific immunoglobulin G (IgG) and immunoglobulin A (IgA) antibodies, respectively. Here, we present novel data obtained eight months later (February 2021) from Weissenkirchen, after the second peak of infection, with 25.0% (138/552) and 23.6% (130/552) of participants that are positive for IgG and IgA, respectively. In participants with previous IgG/IgA positivity (June 2020), we observed a 24% reduction in IgG levels, whereas the IgA levels remained stable in February 2021. This subgroup was further analyzed for SARS-CoV-2-induced T cell activities. Although 76% (34/45) and 76% (34/45) of IgG positive and IgA positive participants, respectively, showed specific T cell activities, those were not significantly correlated with the levels of IgG or IgA. Thus, the analyses of antibodies cannot surrogate the measurement of T cell activities. For a comprehensive view on SARS-CoV-2-triggered immune responses, the measurement of different classes of antibodies should be complemented with the determination of T cell activities.

Download Full-text

Human Interferon Inducible Transmembrane Protein 3 (IFITM3) Inhibits Influenza Virus A Replication and Inflammation by Interacting with ABHD16A

10.21203/rs.3.rs-78811/v1 ◽

2020 ◽

Author(s):

Liang Chen ◽

Zhu Limei ◽

Chen Jun

Keyword(s):

Influenza Virus ◽

Confocal Microscopy ◽

Influenza Viruses ◽

Expression Level ◽

Hek293 Cells ◽

Human Interferon ◽

Yeast Two Hybrid ◽

Related Factors ◽

Influenza Virus A ◽

Two Hybrid

Abstract Background: Studies have shown that human interferon inducible transmembrane proteins (hIFITMs) family proteins have broad-spectrum antiviral capabilities. Preliminary studies in our laboratory have preliminarily proved that hIFITMs have the effect of inhibiting influenza viruses. In order to further study its mechanism and role in the occurrence and development of influenza A, relevant studies have relevant studies have been carried out.Methods: Fluorescence quantitative polymerase chain reaction (PCR) detection, yeast two-hybrid test and optical confocal microscopy were used to investigate the effect of hIFITM3 on influenza virus A (IVA) replication, the interaction with human abhydrolase domain containing 16A (hABHD16A) and the expression of inflammation-related factors.Results: In HEK293 cells, overexpression of hIFITM3 protein significantly inhibited the replication of IVA at 24h, 48h, and 72h; yeast two-hybrid experiment proved that hIFITM3 interacts with hABHD16A; laser confocal microscopy observations showed that hIFITM3 and hABHD16A co-localized in cell membrane area; the expression level of inflammation-related factors in cells overexpressing hIFITM3 or hABHD16A was detected by fluorescence quantitative PCR, and the results showed that the mRNA levels of interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor (TNF)-a and for cyclooxygenase 2 (COX2) were significantly increased. But when hIFITM3/hABHD16A was co-expressed, the mRNA expression levels of these cytokines were significantly reduced except COX2. When influenza virus infected cells co-expressing hIFITM3/hABHD16A, the expression level of inflammatory factors decreased compared with the control group, indicating that hIFITM3 can play an important role in regulating inflammation balance.Conclusions: This study confirmed that hIFITM3 has an effect of inhibiting IVA replication. Furthermore, it was found that hIFITM3 interacts with hABHD16A, following which it can better inhibit the replication of influenza virus and the inflammatory response caused by the disease process.

Download Full-text