Measuring Influenza Neuraminidase Inhibition Antibody Titers by Enzyme-linked Lectin Assay

Overview

This article describes the enzyme-linked lectin assay (ELLA) for measuring influenza neuraminidase (NA)-inhibition antibody titers in sera. The assay utilizes peanut agglutinin to quantify galactose residues that become accessible when NA removes sialic acid from fetuin-coated plates.

Key Study Components

Area of Science

• Immunology
• Virology
• Assay Development

Background

• Neuraminidase is a glycoprotein on the influenza virus surface.
• Measuring antibody responses to neuraminidase is crucial for vaccine research.
• The ELLA provides a practical platform for high-throughput analysis.
• Reassortant influenza viruses are used to avoid interference from hemagglutinin antibodies.

Purpose of Study

• To measure functional antibody titers against neuraminidase.
• To assess antibody responses post-influenza vaccination or infection.
• To establish a reliable method for large-scale serum sample analysis.

Methods Used

• Preparation of virus dilutions in a 96-well plate.
• Washing fetuin-coated plates and adding serum samples.
• Incubation and optical density measurement at 490 nm.
• Determining the 50% endpoint titer from the assay results.

Main Results

• Representative results show percent inhibition of neuraminidase activity.
• Identified serum dilutions that resulted in significant inhibition.
• Demonstrated the assay's effectiveness in measuring antibody responses.

Conclusions

• The ELLA is a valuable tool for assessing neuraminidase inhibition.
• It can facilitate research into vaccine efficacy and immune responses.
• Future applications may enhance understanding of influenza immunity.

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