Analysis of Antigen-Specific Human Memory B Cell Populations Based on In Vitro Polyclonal Stimulation.

Area of Science:

• Immunology
• Cell Biology

Background:

• Memory B cells (MBCs) are crucial for robust secondary antibody responses against infections and vaccines.
• While advanced sequencing offers single-cell insights, characterizing antigen-reactive MBC populations remains vital for assessing B cell immunity.
• In vitro polyclonal stimulation followed by antigen-specific measurement is a key method for MBC analysis.

Purpose of the Study:

• To present a straightforward and effective strategy for in vitro MBC stimulation.
• To utilize the ELISpot assay for quantifying antigen-specific MBC populations post-stimulation.
• To discuss broader applications of in vitro MBC stimulation techniques.

Main Methods:

• In vitro polyclonal stimulation of peripheral blood mononuclear cells (PBMCs) to induce MBC division and differentiation into antibody-secreting cells (ASCs).
• Application of the ELISpot assay to enumerate MBC-derived ASCs specific to particular antigens.
• Protocols for stimulating unfractionated PBMCs and smaller cell numbers in 96-well plates are provided.

Main Results:

• The described strategy enables efficient in vitro MBC stimulation.
• The ELISpot assay effectively quantifies the size of antigen-specific MBC populations.
• The method provides insights into the precursor MBC pool and antibody characteristics.

Conclusions:

• This protocol offers a simple, reliable method for assessing antigen-specific MBC populations.
• The technique is valuable for evaluating B cell immunity and responses to vaccination or infection.
• Further applications in MBC analysis can be explored using this stimulation strategy.