Influenza Pseudovirus
Influenza Pseudovirus - Related Videos
02:22
Production of Pseudovirus Using Plasmid Transfection in Human Cells
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2026
Source: Chang, X., et al. Preparation of Pseudo-Typed H5 Avian Influenza Viruses with Calcium Phosphate Transfection Method and Measurement of Antibody Neutralizing Activity. J. Vis. Exp. (2021)This video demonstrates the production of influenza pseudoviruses in human cells using calcium phosphate-mediated plasmid transfection, enabling safe generation of single-cycle viral particles for downstream applications such as antibody neutralization assays under biosafety level 2 conditions.
03:09
Determining Optimal Target Cell Density Using a Luciferase-Based Pseudovirus Infection Assay
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2026
Source: Chang, X., et al. Preparation of Pseudo-Typed H5 Avian Influenza Viruses with Calcium Phosphate Transfection Method and Measurement of Antibody Neutralizing Activity. J. Vis. Exp. (2021)This video demonstrates a luciferase-based pseudovirus titration assay to determine the optimal target cell density for maximum infection. By comparing luminescence across cell densities, the method ensures high assay sensitivity and reproducibility for downstream applications.
02:45
Production and Collection of Pseudovirus Particles Using Mammalian Cell Culture
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2026
Source: Jamieson, T. R., et al. Detection of SARS-CoV-2 Neutralizing Antibodies using High-Throughput Fluorescent Imaging of Pseudovirus Infection. J. Vis. Exp. (2021)This video demonstrates the procedure for infecting mammalian cells with green fluorescent protein (GFP)-encoding pseudovirus, monitoring viral replication and spread by fluorescence microscopy, and collecting virus-containing supernatant for downstream applications.
02:01
Assessing Pseudovirus Infection Using Luciferase Reporter Assay
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2026
Source: Chang, X., et al. Preparation of Pseudo-Typed H5 Avian Influenza Viruses with Calcium Phosphate Transfection Method and Measurement of Antibody Neutralizing Activity. J. Vis. Exp. (2021).This video demonstrates a luciferase-based assay to quantify pseudovirus infection in epithelial cells. The pseudovirus encodes the luciferase gene, which is expressed in infected cells. After washing, and cells are incubated with lysis buffer at an ultra-low temperature, and then thawed to induce lysis.
03:25
Quantification of Pseudovirus Particles by Plaque Assay
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2026
Source: Jamieson, T. R., et al., Detection of SARS-CoV-2 Neutralizing Antibodies using High-Throughput Fluorescent Imaging of Pseudovirus Infection. J. Vis. Exp. (2021)This video describes the virus plaque assay using coronavirus pseudovirus particles. The diluted pseudovirus is added to a monolayer of mammalian cells, followed by incubation with a methylcellulose overlay. Plaques formed by infected cells are counted visually to determine the infectious virus titer.
FAQs
Entry depends on two linked events: hemagglutinin first recognizes sialic acid receptors, then endosomal acidification triggers membrane fusion. This sequence allows the particle core to enter the cell and deliver its reporter genes. Studying these stages separately helps investigators examine influenza entry biology under controlled conditions rather than measuring the full viral life cycle.
Reporter output provides an indirect readout of successful entry. If neutralizing antibodies block hemagglutinin or an entry inhibitor interferes with the entry pathway, the reporter signal decreases. Because the particles are replication-defective, the measured signal reflects the initial entry event and reporter delivery, not production of infectious progeny.
Compared with replication-competent influenza virus, this system focuses on surface-protein-mediated entry while avoiding completion of the viral replication cycle. That distinction can reduce biosafety requirements and support controlled experiments on receptor usage, membrane fusion, and inhibition. It is therefore suited to entry-centered questions rather than observations that require infectious progeny.
An assay links an engineered particle bearing influenza surface proteins with a reporter system and then assesses reporter signal after entry. Key variables include hemagglutinin binding to sialic acid receptors, endosomal acidification, and exposure to antibodies or entry inhibitors. Changes in signal provide a way to compare how these conditions affect the entry process.
For vaccine evaluation, the assay can test whether vaccine-induced antibodies neutralize influenza entry. A reduced reporter signal indicates that antibody activity has interfered with the modeled entry process. This provides a controlled readout for comparing neutralizing responses without requiring the assay to follow replication and spread by complete influenza virus.
Antibody characterization uses signal reduction to examine how effectively antibodies prevent entry, while antiviral screening tests whether compounds inhibit that process. Receptor studies can focus on hemagglutinin recognition of sialic acid, and entry studies can examine the acidification-dependent fusion step. Together, these applications connect molecular mechanism with measurable assay output.