Memory B cells

Memory B cells are an essential reservoir for generating plasma cells during the secondary immune response. They exhibit heterogeneity in terms of isotype usage, immunoglobulin mutation content, and phenotypic marker expression.

Phenotypic subsets of memory B cells are defined by specific markers:

• Mice: CD273 (Programmed cell death 1 ligand 2 (PD-L2)), B7-1, and CD73 (5′-Nucleotidase / Ecto-5′-Nucleotidase (NT5E))


• Humans: CD27 (Tumor necrosis factor receptor superfamily member 7) and Fc receptor-like protein 4 (FcRL4)


• Both Mice and Humans: T-bet / T-box transcription factor 21 (TBX21)

These subsets display marked functional heterogeneity, including the ability to rapidly differentiate into plasma cells or germinal centers during the secondary response.

Memory B cells are found in various locations:

• Spleen


• Blood


• Other lymphoid organs


• Barrier tissues

Recent evidence suggests that some memory B cells may be dedicated to tissue-resident populations.

The major markers of memory B cells include:

• IgD-


• CD20+


• CD27+


• CD40+

References:
Cancro et al. 2021 Immunol Rev 303:
Chi et al. 2024a Cell 187(9): 2052

see also:
Acquired Immune System / Adaptive Immune System
Food Allergy (FA) / Food Sensitivity