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Updated: Aug 13, 2026
09:49
Induction and Assessment of Class Switch Recombination in Purified Murine B Cells
Published on: August 14, 2010
Isolation and characteristics of tonsil centroblasts with reference to Ig class switching
J Feuillard1, D Taylor, M Casamayor-Palleja
1Department of Immunology, University of Birmingham Medical School, UK.
International Immunology
|January 1, 1995
Summary
CD44 expression distinguishes B cells within germinal centers (GCB). CD44- GCB are centroblasts in cell cycle, while CD44low GCB are centrocytes, indicating CD44
Area of Science:
- Immunology
- Cell Biology
Background:
- Germinal centers (GCB) are crucial for adaptive immunity.
- B cells undergo significant differentiation within GCB.
Purpose of the Study:
- To investigate the role of CD44 expression in distinguishing B cell subsets within human tonsil germinal centers.
- To determine the relationship between CD44 expression, cell cycle status, and Ig switch recombination in GCB.
Main Methods:
- Immunohistological analysis of tonsil tissues.
- Flow cytometry to analyze CD44 and CD77 expression on isolated GCB.
- Assessment of cell cycle status and Ig switch recombination in CD44-defined GCB populations.
- Apoptosis assays on cultured GCB fractions.
Main Results:
- CD44 expression levels effectively differentiate centroblasts (CD44-) from centrocytes (CD44low) within GCB.
- CD44- GCB are actively cycling (centroblasts), while CD44low GCB are non-dividing (centrocytes).
- Ig switch recombination occurs independently of centroblast-to-centrocyte maturation and precedes terminal differentiation signals.
Conclusions:
- CD44 is a reliable marker for distinguishing B cell subsets in germinal centers.
- Switch recombination is an early event in B cell maturation within germinal centers.
- Centroblasts exhibit higher dependence on stromal support compared to centrocytes, which require antigen selection signals for survival.
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