Monoclonal antibodies IAH-CC51, BB6-11C9.6 and B-Ly4 are routinely used to detect CD21 orthologue on the surface of porcine B lymphocytes. Cross-reactive studies show that IAH-CC51 and B-Ly4 recognize only a portion of B cells that are positive for pan-specific BB6-11C9.6. This indicates that CD21 is always present on all mature B cells but can be expressed in at least two differential forms, and these were assigned as CD21(a) and CD21(b). We used IAH-CC51 together with anti-CD2 to define four subpopulations of B cells. Ontogenetic and in vitro culture studies, analysis of cell size, expression of CD11b and class-switched phenotype together with measurement of proliferation and cell death, revealed that these subsets represent distinct populations. Phenotypic and functional features collectively suggest that CD21(b+) B cells are less mature than CD21(b-). The present work is the first to show that distinct subsets of mature B cells can express differential forms of CD21.
- MeSH
- apoptóza MeSH
- epitopy imunologie MeSH
- kultivované buňky MeSH
- monoklonální protilátky imunologie MeSH
- podskupiny B-lymfocytů klasifikace imunologie MeSH
- prasata imunologie MeSH
- receptory komplementu 3d imunologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Increased proportions of naive B cell subset and B cells defined as CD27(neg)CD21(neg)CD38(neg) are frequently found in patients with common variable immunodeficiency (CVID) syndrome. Current methods of polychromatic flow cytometry and PCR-based detection of k deletion excision circles allow for fine definitions and replication history mapping of infrequent B cell subsets. We have analyzed B cells from 48 patients with CVID and 49 healthy controls to examine phenotype, frequency, and proliferation history of naive B cell subsets. Consistent with previous studies, we have described two groups of patients with normal (CVID-21norm) or increased (CVID-21lo) proportions of CD27(neg)CD21(neg)CD38(neg) B cells. Upon further analyses, we found two discrete subpopulations of this subset based on the expression of CD24. The B cell subsets showed a markedly increased proliferation in CVID-21lo patients as compared with healthy controls, suggesting developmental arrest rather than increased bone marrow output. Furthermore, when we analyzed CD21(pos) naive B cells, we found two different subpopulations based on IgM and CD24 expression. They correspond to follicular (FO) I and FO II cells previously described in mice. FO I subset is significantly underrepresented in CVID-21lo patients. A comparison of the replication history of naive B cell subsets in CVID patients and healthy controls implies refined naive B cell developmental scheme, in which human transitional B cells develop into FO II and FO I. We propose that the CD27(neg)CD21(neg)CD38(neg) B cells increased in some of the CVID patients originate from the two FO subsets after loss of CD21 expression.
- MeSH
- antigen CD24 * biosyntéza genetika MeSH
- běžná variabilní imunodeficience * imunologie metabolismus patologie MeSH
- buněčná diferenciace imunologie MeSH
- dítě MeSH
- dospělí MeSH
- fenotyp MeSH
- G0 fáze * imunologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- počet lymfocytů MeSH
- podskupiny B-lymfocytů imunologie klasifikace patologie MeSH
- proliferace buněk MeSH
- regulace genové exprese * imunologie MeSH
- senioři MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH