Related Experiment Video
Updated: Aug 8, 2026
Murine Model of CD40-activation of B cells
Published on: March 6, 2010
Analysis of murine CD22 during B cell development: CD22 is expressed on B cell progenitors prior to IgM
A Stoddart1, R J Ray, C J Paige
1Wellesley Hospital Research Institute, Wellesley Central Hospital, Toronto, Ontario, Canada.
Insights
CD22 (Cluster of Differentiation 22) is expressed on B cell progenitors before IgM appears, increasing with B cell maturation. Its levels decrease upon activation, and anti-CD22 antibodies enhance B cell proliferation.
Area of Science:
- Immunology
- Cell Biology
- Developmental Biology
Background:
- CD22 is a B cell-specific glycoprotein crucial for cell adhesion and signaling.
- Its role in B cell interactions and signaling thresholds necessitates understanding its expression patterns.
Purpose of the Study:
- To characterize the expression of murine CD22 throughout B cell development.
- To investigate the functional role of CD22 in B cell signaling and proliferation.
Main Methods:
- Flow cytometry to analyze CD22 surface expression on murine B cell progenitors and mature B cells.
- In vitro culture systems to assess B cell development stages.
- Stimulation of splenic B cells with anti-mu mAb and LPS to study CD22 modulation.
- Assessment of B cell proliferation in response to anti-CD22 antibody treatment.
Main Results:
- CD22 is expressed on B cell progenitors prior to IgM expression, with low density on IL-7-responsive precursors and early B lineage cells.
- CD22 surface density increases with B cell maturation, being high on B220brightIgM+ bone marrow cells and splenic B cells.
- CD22 levels decrease upon activation of mature B cells with anti-mu mAb or LPS.
- Anti-CD22 antibody treatment augments the proliferative response of stimulated B cells.
Conclusions:
- CD22 expression is dynamically regulated during B cell development and maturation.
- CD22 plays a role in modulating B cell signaling thresholds and proliferation.
- Further investigation into CD22's involvement in diverse B cell signaling pathways is warranted.
Abstract:
CD22 is a B cell-restricted glycoprotein involved in cell adhesion and signaling. Since CD22 is likely to play an important role in interactions between B cells and other cells, and in regulating signaling thresholds, we characterized the expression of murine CD22 during different stages of B cell development. In contrast to previous reports, we show that CD22 is expressed on B cell progenitors prior to expression of IgM. IL-7-responsive B cell precursors from the fetal liver and early B lineage cells (B220+IgM-) from the bone marrow both express a low density of surface CD22. The majority of the earliest B cell progenitors (B220+IgM-CD43+) in the bone marrow, however, do not express CD22. As B cells mature, the density of CD22 molecules on the cell surface increases. B220brightIgM+ bone marrow cells express high levels of CD22, as do splenic B cells. The correlation of CD22 levels with B cell maturation is replicated in an in vitro culture system, which distinguishes stages of B cell development based on function. Following activation of mature resting splenic B cells with anti-mu mAb or lipopolysaccharide (LPS), levels of CD22 decrease. Finally, we show that the addition of anti-CD22 mAb augments the proliferative response of both anti-mu- and LPS-stimulated B cells, suggesting a role for CD22 in diverse signaling pathways.
Related Concept Videos
01:23Cells of the Adaptive Immune Response
01:22T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
01:24B Cell Activation and Differentiation
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...