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Updated: Aug 8, 2026
Optimization of a Quantitative Micro-neutralization Assay
Published on: December 14, 2016
Human cell lines used in a micro neutralization test for measuring influenza-neutralizing antibodies
C M Mittelholzer1, K A Brokstad, K Pauksens
1Broegelmann Research Laboratory, The Gade Institute, University of Bergen, Bergen, Norway. camilla.mittelholzer@mtc.ki.se
Insights
A new influenza virus neutralization test (NT) using human HS27 cells offers a sensitive and stable assay. This method detected immune responses comparable to, and in some cases better than, the gold standard HAI assay.
Area of Science:
- Virology
- Immunology
- Cell Biology
Background:
- Developing sensitive and reliable influenza virus neutralization assays is crucial for understanding immune responses.
- Traditional assays often rely on specific cell lines like Madin-Darby Canine Kidney (MDCK) cells.
- Evaluating alternative cell lines for improved assay performance is an ongoing area of research.
Purpose of the Study:
- To develop and evaluate an in situ influenza virus neutralization test (NT) using enzyme-linked immunosorbent assay (ELISA) for antigen measurement.
- To compare the performance of human fibroblast (HS27) and salivary gland epithelial duct (HSG) cells against MDCK cells for influenza NT.
Main Methods:
- An in situ neutralization test (NT) was developed, incorporating ELISA for influenza antigen detection.
- Two human cell lines (HS27, HSG) and a standard canine cell line (MDCK) were used for comparison.
- The assay was evaluated using viral production, titration, and analysis of patient samples from a zanamivir study.
Main Results:
- Lower viral production in HS27 and HSG cells influenced assay results compared to MDCK cells.
- Optimizing infectious dose allowed for a sensitive and stable NT using HS27 cells with low ELISA background.
- The HS27 NT demonstrated higher titres and more pronounced differences than the haemagglutinin inhibition (HAI) assay, revealing heterologous responses.
Conclusions:
- The HS27 cell line provides a sensitive and stable platform for influenza virus neutralization testing.
- This HS27-based NT is a valuable tool for analyzing humoral responses to influenza, potentially outperforming the HAI assay.
- The developed NT can detect subtle immune responses, including heterologous titre rises, after influenza infection.
Abstract:
An in situ neutralization test (NT) including ELISA for the measurement of influenza antigen was developed and evaluated. Two human cell lines, fibroblasts (HS27) cells and salivary gland epithelial duct (HSG) cells, were compared with Madin-Darby Canine Kidney (MDCK) cells. The viral production in the human cell lines was lower than that for MDCK cells, which influenced the results of the assay in the HSG and HS27 cells. However, when lowering the infectious dose, the NT using HS27 cells gave a sensitive and stable assay with low background in the ELISA. The NT titres were very low when using HSG cells compared to MDCK cells. The HS27 NT was used to analyze the humoral response after an influenza A infection in patients from a placebo-controlled zanamivir study. We found no differences in NT titres between patients treated with zanamivir or placebo. The MDCK and HS27 NT gave higher titres and more pronounced titre differences than the gold standard haemagglutinin inhibition (HAI) assay. Compared to the HAI assay, the sensitive NT using HS27 cells also revealed heterologous NT-titre rises after influenza infection in the patients.
