Related Experiment Video
Updated: Jul 27, 2026
09:25
Detection and Enrichment of Rare Antigen-specific B Cells for Analysis of Phenotype and Function
Published on: February 16, 2017
12.4K
Development of a novel flow cytometry method for detecting pneumococcal-specific B cells.
Irene Tzovara1, Ioanna Papadatou1, Marianna Tzanoudaki2
1Department of Infectious Diseases - Immunobiology and Vaccinology Research Lab, "Aghia Sophia" Children's Hospital, 1st Department of Pediatrics - National and Kapodistrian University of Athens, Athens, Greece.
Summary
A new multimer bead method enhances detection of pneumococcal polysaccharide-specific B cells using flow cytometry. This sensitive and specific approach improves antigen-specific B cell analysis for vaccine development.
Area of Science:
- Immunology
- Cell Biology
- Vaccinology
Background:
- Flow cytometry is vital for analyzing B cell responses to infection and vaccination.
- Existing methods for detecting polysaccharide-specific B cells lack optimal sensitivity and applicability.
- There is a need for improved techniques to study B cell immunophenotypes and kinetics.
Purpose of the Study:
- To develop and validate a novel multimer bead-based flow cytometry method for detecting pneumococcal polysaccharide (PS)-specific B cells.
- To enhance the sensitivity and specificity of antigen-specific B cell identification.
- To provide a versatile tool for studying B cell responses to various antigens.
Main Methods:
- Chemically biotinylated pneumococcal polysaccharide (PS) was conjugated to anti-biotin beads.
- The PS-conjugated beads were further labeled with phycoerythrin (PE)-conjugated anti-biotin antibody to create a PS-multimer probe.
- Titration assays determined optimal ratios for PS-bead conjugate and PS-multimer to cell staining.
- Specificity was validated using a competition assay with unbound PS.
Main Results:
- The PS-multimer method demonstrated significantly enhanced detection of PS-specific B cells compared to a PS-PE monomer.
- Signal amplification was observed due to the multimeric nature of the probe and increased antigen epitope availability.
- A competition assay confirmed the method's specificity, with signal decreasing in a dose-dependent manner with increasing PS concentrations.
- The method proved sensitive, specific, and easily applicable without requiring B cell pre-enrichment.
Conclusions:
- The developed bead-based flow cytometry approach is a sensitive and specific method for identifying antigen-specific B cells.
- This technique offers enhanced signal detection and clear results, applicable to polysaccharides and potentially other antigens.
- The method can aid in understanding long-term protection mechanisms, improving vaccine strategies, and guiding future vaccine development.
