Characterization of rotavirus specific B cells and their relation with serological memory

Area of Science:

• Immunology
• Cell Biology
• Vaccinology

Background:

• Memory B cells (mBc) are crucial for long-term immunity and serological memory.
• Understanding the relationship between circulating mBc and antibody levels is essential for vaccine development.
• Existing methods for quantifying mBc have limitations in evaluating different subsets.

Purpose of the Study:

• To quantify circulating rotavirus (RV) and Tetanus toxin (TT) memory B cells (mBc) in healthy adults.
• To compare the performance of a limiting dilution assay (LDA) and a flow cytometry assay (FCA) for mBc quantification.
• To investigate the correlation between specific mBc subsets and corresponding plasma immunoglobulin levels.

Main Methods:

• Quantification of circulating total, RV, and TT mBc using both LDA and FCA in healthy adults.
• Evaluation of both CD27+ and CD27- mBc subsets by both assays.
• Correlation analysis between mBc counts and plasma immunoglobulin concentrations (IgG, IgA).

Main Results:

• RV mBc were found in CD27- IgG+ and CD27+ IgM+ subsets.
• FCA yielded higher RV mBc counts than LDA, with no significant correlation between the two methods for total RV mBc.
• TT IgG mBc and RV IgA mBc counts from FCA and LDA correlated with corresponding plasma antibody levels, with a lower mBc/immunoglobulin ratio for TT IgG mBc.

Conclusions:

• The study highlights discrepancies between LDA and FCA in quantifying RV mBc, suggesting assay-specific considerations.
• Correlations between specific mBc subsets and plasma immunoglobulins indicate their role in maintaining serological memory.
• Findings contribute to a better understanding of circulating mBc and serological memory, aiding in the development of improved correlates of protection against RV disease.