Clinical and surveillance testing for the SARS-CoV-2 virus relies overwhelmingly on RT-qPCR-based diagnostics, yet several popular assays require 2-3 separate reactions or rely on detection of a single viral target, which adds significant time, cost, and risk of false-negative results. Furthermore, multiplexed RT-qPCR tests that detect at least two SARS-CoV-2 genes in a single reaction are typically not affordable for large scale clinical surveillance or adaptable to multiple PCR machines and plate layouts. We developed a RT-qPCR assay using the Luna Probe Universal One-Step RT-qPCR master mix with publicly available primers and probes to detect SARS-CoV-2 N gene, E gene, and human RNase P (LuNER) to address these shortcomings and meet the testing demands of a university campus and the local community.
View Article and Find Full Text PDFSaliva is an attractive specimen type for asymptomatic surveillance of COVID-19 in large populations due to its ease of collection and its demonstrated utility for detecting RNA from SARS-CoV-2. Multiple saliva-based viral detection protocols use a direct-to-RT-qPCR approach that eliminates nucleic acid extraction but can reduce viral RNA detection sensitivity. To improve test sensitivity while maintaining speed, we developed a robotic nucleic acid extraction method for detecting SARS-CoV-2 RNA in saliva samples with high throughput.
View Article and Find Full Text PDFSaliva is an attractive specimen type for asymptomatic surveillance of COVID-19 in large populations due to its ease of collection and its demonstrated utility for detecting RNA from SARS-CoV-2. Multiple saliva-based viral detection protocols use a direct-to-RT-qPCR approach that eliminates nucleic acid extraction but can reduce viral RNA detection sensitivity. To improve test sensitivity while maintaining speed, we developed a robotic nucleic acid extraction method for detecting SARS-CoV-2 RNA in saliva samples with high throughput.
View Article and Find Full Text PDFCommonly used RT-qPCR-based SARS-CoV-2 diagnostics require 2-3 separate reactions or rely on detection of a single viral target, adding time and cost or risk of false-negative results. Currently, no test combines detection of widely used SARS-CoV-2 E- and N-gene targets and a sample control in a single, multiplexed reaction. We developed the IGI-LuNER RT-qPCR assay using the Luna Probe Universal One-Step RT-qPCR master mix with publicly available primers and probes to detect SARS-CoV-2 N gene, E gene, and human RNase P (NER).
View Article and Find Full Text PDFBackground: The outbreak of novel avian H7N9 influenza virus infections in China in 2013 has demonstrated the continuing threat posed by zoonotic pathogens. Deciphering the immune response during natural infection will guide future vaccine development.
Methods: We assessed the induction of heterosubtypic cross-reactive antibodies induced by H7N9 infection against a large panel of recombinant hemagglutinins and neuraminidases by quantitative enzyme-linked immunosorbent assay, and novel chimeric hemagglutinin constructs were used to dissect the anti-stalk or -head humoral immune response.
Infection with influenza virus induces antibodies to the viral surface glycoproteins hemagglutinin and neuraminidase, and these responses can be broadly protective. To assess the breadth and magnitude of antibody responses, we sequentially infected mice, guinea pigs and ferrets with divergent H1N1 or H3N2 subtypes of influenza virus. We measured antibody responses by ELISA of an extensive panel of recombinant glycoproteins representing the viral diversity in nature.
View Article and Find Full Text PDFTo evaluate the antigenic relationship between bat mumps virus (BMV) and the JL5 vaccine strain of mumps virus (MuVJL5), we rescued a chimeric virus bearing the F and HN glycoproteins of BMV in the background of a recombinant JL5 genome (rMuVJL5). Cross-reactivity and cross-neutralization between this chimeric recombinant MuV bearing the F and HN glycoproteins of BMV (rMuVJL5-F/HNBMV) virus and rMuVJL5 were demonstrated using hyperimmune mouse serum samples and a curated panel of human serum. All mouse and human serum samples that were able to neutralize rMuVJL5 infection had cross-neutralizing activity against rMuVJL5-F/HNBMV.
View Article and Find Full Text PDFManduca sexta, known as the tobacco hornworm or Carolina sphinx moth, is a lepidopteran insect that is used extensively as a model system for research in insect biochemistry, physiology, neurobiology, development, and immunity. One important benefit of this species as an experimental model is its extremely large size, reaching more than 10 g in the larval stage. M.
View Article and Find Full Text PDFPathogenic H7N9 avian influenza viruses continue to represent a public health concern, and several candidate vaccines are currently being developed. It is vital to assess if protective antibodies are induced following vaccination and to characterize the diversity of epitopes targeted. Here we characterized the binding and functional properties of twelve H7-reactive human antibodies induced by a candidate A/Anhui/1/2013 (H7N9) vaccine.
View Article and Find Full Text PDFIn the early spring of 2013, Chinese health authorities reported several cases of H7N9 influenza virus infections in humans. Since then the virus has established itself at the human-animal interface in Eastern China and continues to cause several hundred infections annually. In order to characterize the antibody response to the H7N9 virus we generated several mouse monoclonal antibodies against the hemagglutinin of the A/Shanghai/1/13 (H7N9) virus.
View Article and Find Full Text PDFSeasonal influenza virus vaccines are generally effective at preventing disease, but need to be well matched to circulating virus strains for maximum benefit. Influenza viruses constantly undergo antigenic changes because of their high mutation rate in the immunodominant haemagglutinin (HA) head domain, which necessitates annual re-formulation and re-vaccination for continuing protection. In case of pandemic influenza virus outbreaks, new vaccines need to be produced and quickly distributed.
View Article and Find Full Text PDFUnlabelled: Between November 2013 and February 2014, China reported three human cases of H10N8 influenza virus infection in the Jiangxi province, two of which were fatal. Using hybridoma technology, we isolated a panel of H10- and N8-directed monoclonal antibodies (MAbs) and further characterized the binding reactivity of these antibodies (via enzyme-linked immunosorbent assay) to a range of purified virus and recombinant protein substrates. The H10-directed MAbs displayed functional hemagglutination inhibition (HI) and neutralization activity, and the N8-directed antibodies displayed functional neuraminidase inhibition (NI) activity against H10N8.
View Article and Find Full Text PDFInsect Biochem Mol Biol
November 2015
The order of Lepidoptera has historically been crucial for chemosensory research, with many important advances coming from the analysis of species like Bombyx mori or the tobacco hornworm, Manduca sexta. Specifically M. sexta has long been a major model species in the field, especially regarding the importance of olfaction in an ecological context, mainly the interaction with its host plants.
View Article and Find Full Text PDFThree cases of influenza A(H10N8) virus infection in humans have been reported; 2 of these infected persons died. Characterization of the receptor binding pattern of H10 hemagglutinin from avian and human isolates showed that both interact weakly with human-like receptors and maintain strong affinity for avian-like receptors.
View Article and Find Full Text PDFCurrent influenza virus vaccines provide solid protection from infection with viruses that are well matched with the vaccine strains. However, they do not protect efficiently against drifted or shifted strains. We developed an antigen based on the conserved stalk domain of the influenza virus hemagglutinin and tested its efficacy as a vaccine in a mouse virus challenge model.
View Article and Find Full Text PDFUnlabelled: In an attempt to assess the cross-protective potential of the influenza virus neuraminidase (NA) as a vaccine antigen, different subtypes of recombinant NA were expressed in a baculovirus system and used to vaccinate mice prior to lethal challenge with homologous, heterologous, or heterosubtypic viruses. Mice immunized with NA of subtype N2 were completely protected from morbidity and mortality in a homologous challenge and displayed significantly reduced viral lung titers. Heterologous challenge with a drifted strain resulted in morbidity but no mortality.
View Article and Find Full Text PDFThree human cases of H10N8 viruses were reported in China in late 2013 and early 2014, two of which were fatal. This was the first time the H10N8 subtype has been detected in humans and no vaccine candidates or antibody therapy has been developed for these viruses so far. We developed an H10N8 vaccine candidate virus based on A/Jiangxi-Donghu/346/13 that can also be used in a murine challenge model for vaccine and monoclonal antibody research.
View Article and Find Full Text PDFUnlabelled: Influenza virus infections are a major public health concern and cause significant morbidity and mortality worldwide. Current vaccines are effective but strain specific due to their focus on the immunodominant globular head domain of the hemagglutinin (HA). It has been hypothesized that sequential exposure of humans to hemagglutinins with divergent globular head domains but conserved stalk domains could refocus the immune response to broadly neutralizing epitopes in the stalk.
View Article and Find Full Text PDFEmerging H7N9 influenza virus infections in Asia have once more spurred the development of effective prepandemic H7 vaccines. However, many vaccines based on avian influenza viruses--including H7--are poorly immunogenic, as measured by traditional correlates of protection. Here we reevaluated sera from an H7N1 human vaccine trial performed in 2006.
View Article and Find Full Text PDFThe recent outbreak of H7N9 influenza virus infections in humans in China has raised concerns about the pandemic potential of this strain. Here, we test the efficacy of H3 stalk-based chimeric hemagglutinin universal influenza virus vaccine constructs to protect against H7N9 challenge in mice. Chimeric hemagglutinin constructs protected from viral challenge in the context of different administration routes as well as with a generic oil-in-water adjuvant similar to formulations licensed for use in humans.
View Article and Find Full Text PDFHuman infections with a novel influenza A H7N9 subtype virus were reported in China recently. The virus caused severe disease with high mortality rates and it raised concerns over its pandemic potential. Here, we assessed in the mouse model protective efficacy of single immunisations with low vaccine doses of insect cell-derived H7 virus-like particles, consisting of hemagglutinin and matrix protein.
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