The EUROclass trial: defining subgroups in common variable immunodeficiency

Blood ◽  
2008 ◽  
Vol 111 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Claudia Wehr ◽  
Teemu Kivioja ◽  
Christian Schmitt ◽  
Berne Ferry ◽  
Torsten Witte ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Common Variable Immunodeficiency ◽  
Multicenter Trial ◽  
Memory B Cells ◽  
Granulomatous Disease ◽  
B Cell Differentiation ◽  
Cell Subpopulations ◽  
Common Variable

The heterogeneity of common variable immunodeficiency (CVID) calls for a classification addressing pathogenic mechanisms as well as clinical relevance. This European multicenter trial was initiated to develop a consensus of 2 existing classification schemes based on flowcytometric B-cell phenotyping and the clinical course. The clinical evaluation of 303 patients with the established diagnosis of CVID demonstrated a significant coincidence of granulomatous disease, autoimmune cytopenia, and splenomegaly. Phenotyping of B-cell subpopulations confirmed a severe reduction of switched memory B cells in most of the patients that was associated with a higher risk for splenomegaly and granulomatous disease. An expansion of CD21low B cells marked patients with splenomegaly. Lymphadenopathy was significantly linked with transitional B-cell expansion. Based on these findings and pathogenic consideration of B-cell differentiation, we suggest an improved classification for CVID (EUROclass), separating patients with nearly absent B cells (less than 1%), severely reduced switched memory B cells (less than 2%), and expansion of transitional (more than 9%) or CD21low B cells (more than 10%). Whereas the first group contains all patients with severe defects of early B-cell differentiation, severely reduced switched memory B cells indicate a defective germinal center development as found in inducible constimulator (ICOS) or CD40L deficiency. The underlying defects of expanded transitional or CD21low B cells remain to be elucidated. This trial is re-gistered at http://www.uniklinik-freiburg.de/zks/live/uklregister/Oeffentlich.html as UKF000308.

Regulation of CCR6 chemokine receptor expression and responsiveness to macrophage inflammatory protein-3α/CCL20 in human B cells

Blood ◽  
2000 ◽  
Vol 96 (7) ◽  
pp. 2338-2345 ◽  
Author(s):  
Roman Krzysiek ◽  
Eric A. Lefevre ◽  
Jérôme Bernard ◽  
Arnaud Foussat ◽  
Pierre Galanaud ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Chemokine Receptor ◽  
Memory B Cells ◽  
Receptor Expression ◽  
B Cell Differentiation ◽  
Hematopoietic Stem ◽  
Inflammatory Protein ◽  
Macrophage Inflammatory Protein

Abstract The regulation of CCR6 (chemokine receptor 6) expression during B-cell ontogeny and antigen-driven B-cell differentiation was analyzed. None of the CD34+Lin− hematopoietic stem cell progenitors or the CD34+CD19+ (pro-B) or the CD19+CD10+ (pre-B/immature B cells) B-cell progenitors expressed CCR6. CCR6 is acquired when CD10 is lost and B-cell progeny matures, entering into the surface immunoglobulin D+ (sIgD+) mature B-cell pool. CCR6 is expressed by all bone marrow–, umbilical cord blood–, and peripheral blood–derived naive and/or memory B cells but is absent from germinal center (GC) B cells of secondary lymphoid organs. CCR6 is down-regulated after B-cell antigen receptor triggering and remains absent during differentiation into immunoglobulin-secreting plasma cells, whereas it is reacquired at the stage of post-GC memory B cells. Thus, within the B-cell compartment, CCR6 expression is restricted to functionally mature cells capable of responding to antigen challenge. In transmigration chemotactic assays, macrophage inflammatory protein (MIP)-3α/CC chemokine ligand 20 (CCL20) induced vigorous migration of B cells with differential chemotactic preference toward sIgD− memory B cells. These data suggest that restricted patterns of CCR6 expression and MIP-3α/CCL20 responsiveness are integral parts of the process of B-lineage maturation and antigen-driven B-cell differentiation.

scholarly journals Favorable efficacy of rituximab in ANCA-associated vasculitis patients with excessive B cell differentiation

2020 ◽  
Author(s):  
Yusuke Miyazaki ◽  
Shingo Nakayamada ◽  
Satoshi Kubo ◽  
Yuichi Ishikawa ◽  
Maiko Yoshikawa ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Selection Criteria ◽  
Memory B Cells ◽  
Phenotypic Characterization ◽  
B Cell Differentiation ◽  
Color Flow ◽  
Anca Associated Vasculitis ◽  
Cell Phenotypes

Abstract Objectives: B-cell depletion by rituximab (RTX) is an effective treatment for anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV). However, peripheral B cell phenotypes and the selection criteria for RTX therapy in AAV remain unclear.Methods: Phenotypic characterization of circulating B cells was performed by 8-color flow cytometric analysis in 54 newly diagnosed AAV patients (20 granulomatosis with polyangiitis and 34 microscopic polyangiitis). Patients were considered eligible to receive intravenous cyclophosphamide pulse (IV-CY) or RTX. All patients also received high-dose glucocorticoids (GC). We assessed circulating B cell phenotypes and evaluated the efficacy after 6 months of treatment. Results: There were no significant differences in the rate of clinical improvement, relapses, or serious adverse events between patients receiving RTX and IV-CY. The rate of Birmingham Vasculitis Activity Score (BVAS)-improvement at 6 months tended to be higher in the RTX group than in the IV-CY group. The proportion of effector or class-switched memory B cells increased in 24 out of 54 patients (44%). The proportions of peripheral T and B cell phenotypes did not correlate with BVAS at baseline. However, among peripheral B cells, the proportion of class-switched memory B cells negatively correlated with the rate of improvement in BVAS at 6 months after treatment initiation (r = -0.28, p = 0.04). Patients with excessive B cell differentiation were defined as those in whom the proportion of class-switched memory B cells or IgD-CD27- B cells among all B cells was >2 SDs higher than the mean in the HCs. The rate of BVAS-remission in patients with excessive B cell differentiation was significantly lower than that in patients without. In patients with excessive B cell differentiation, the survival rate, the rate of BVAS-remission, and dose reduction of GC were significantly improved in the RTX group compared to those in the IV-CY group after 6 months of treatment. Conclusions: The presence of excessive B cell differentiation was associated with treatment resistance. However, in patients with circulating B cell abnormality, RTX was effective and increased survival compared to IV-CY. The results suggest that multi-color flow cytometry may be useful to determine the selection criteria for RTX therapy in AAV patients. (349/350 words)

scholarly journals IL-21 regulates germinal center B cell differentiation and proliferation through a B cell–intrinsic mechanism

2010 ◽  
Vol 207 (2) ◽  
pp. 365-378 ◽  
Author(s):  
Dimitra Zotos ◽  
Jonathan M. Coquet ◽  
Yang Zhang ◽  
Amanda Light ◽  
Kathy D'Costa ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Affinity Maturation ◽  
Memory B Cells ◽  
Target Cells ◽  
B Cell Differentiation ◽  
Follicular Helper

Germinal centers (GCs) are sites of B cell proliferation, somatic hypermutation, and selection of variants with improved affinity for antigen. Long-lived memory B cells and plasma cells are also generated in GCs, although how B cell differentiation in GCs is regulated is unclear. IL-21, secreted by T follicular helper cells, is important for adaptive immune responses, although there are conflicting reports on its target cells and mode of action in vivo. We show that the absence of IL-21 signaling profoundly affects the B cell response to protein antigen, reducing splenic and bone marrow plasma cell formation and GC persistence and function, influencing their proliferation, transition into memory B cells, and affinity maturation. Using bone marrow chimeras, we show that these activities are primarily a result of CD3-expressing cells producing IL-21 that acts directly on B cells. Molecularly, IL-21 maintains expression of Bcl-6 in GC B cells. The absence of IL-21 or IL-21 receptor does not abrogate the appearance of T cells in GCs or the appearance of CD4 T cells with a follicular helper phenotype. IL-21 thus controls fate choices of GC B cells directly.

scholarly journals Favorable efficacy of rituximab in ANCA-associated vasculitis patients with excessive B cell differentiation

2020 ◽  
Author(s):  
Yusuke Miyazaki ◽  
Shingo Nakayamada ◽  
Satoshi Kubo ◽  
Yuichi Ishikawa ◽  
Maiko Yoshikawa ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Selection Criteria ◽  
Memory B Cells ◽  
Phenotypic Characterization ◽  
B Cell Differentiation ◽  
Color Flow ◽  
Anca Associated Vasculitis ◽  
Cell Phenotypes

Abstract Objectives: B-cell depletion by rituximab (RTX) is an effective treatment for anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV). However, peripheral B cell phenotypes and the selection criteria for RTX therapy in AAV remain unclear.Methods: Phenotypic characterization of circulating B cells was performed by 8-color flow cytometric analysis in 54 newly diagnosed AAV patients (20 granulomatosis with polyangiitis and 34 microscopic polyangiitis). Patients were considered eligible to receive intravenous cyclophosphamide pulse (IV-CY) or RTX. All patients also received high-dose glucocorticoids (GC). We assessed circulating B cell phenotypes and evaluated the efficacy after 6 months of treatment. Results: There were no significant differences in the rate of clinical improvement, relapses, or serious adverse events between patients receiving RTX and IV-CY. The proportion of effector or class-switched memory B cells increased in 24 out of 54 patients (44%). The proportions of peripheral T and B cell phenotypes did not correlate with BVAS at baseline. However, among peripheral B cells, the proportion of class-switched memory B cells negatively correlated with the rate of improvement in BVAS at 6 months after treatment initiation (r = -0.28, p = 0.04). Patients with excessive B cell differentiation were defined as those in whom the proportion of class-switched memory B cells or IgD-CD- B cells among all B cells was >2 SDs higher than the mean in the HCs. The rate of Birmingham Vasculitis Activity Score (BVAS) remission in patients with excessive B cell differentiation was significantly lower than that in patients without. In patients with excessive B cell differentiation, the survival rate, the rate of BVAS remission, and dose reduction of GC were significantly improved in the RTX group compared to those in the IV-CY group after 6 months of treatment. Conclusions: The presence of excessive B cell differentiation was associated with treatment resistance. However, in patients with circulating B cell abnormality, RTX was effective and increased survival compared to IV-CY. The results suggest that multi-color flow cytometry may be useful to determine the selection criteria for RTX therapy in AAV patients.

scholarly journals Single-Cell Atlas of Common Variable Immunodeficiency reveals germinal center-associated epigenetic dysregulation in B cell responses

2021 ◽  
Author(s):  
Javier Rodriguez-Ubreva ◽  
Anna Arutyunyan ◽  
Marc Jan Bonder ◽  
Lucia Del Pino-Molina ◽  
Stephen Clark ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cell ◽  
Single Cell ◽  
Common Variable Immunodeficiency ◽  
Immune Cell ◽  
B Cell Differentiation ◽  
Memory B Cell ◽  
Wide Range ◽  
Mz Twins ◽  
Common Variable

Common variable immunodeficiency (CVID), the most prevalent symptomatic primary immunodeficiency, is characterized by impaired terminal B-cell differentiation and defective antibody responses. Incomplete genetic penetrance and a wide range of phenotypic expressivity in CVID suggest the participation of additional pathogenic mechanisms. Monozygotic (MZ) twins discordant for CVID are uniquely valuable for studying the contribution of epigenetics to the disease. We used single-cell epigenomics and transcriptomics to create a cell census of naive-to-memory B cell differentiation in a pair of CVID-discordant MZ twins. Our analysis identifies DNA methylation, chromatin accessibility and transcriptional defects in memory B cells that mirror defective cell-cell communication defects following activation. These findings were validated in a cohort of CVID patients and healthy donors. Our findings provide a comprehensive multi-omics map of alterations in naive-to-memory B-cell transition in CVID and reveal links between the epigenome and immune cell cross-talk. Our resource, publicly available at the Human Cell Atlas, paves the way for future diagnosis and treatments of CVID patients.

Differentiation-Stage-Specific Expression of MicroRNAs in B-Lymphocytes and Diffuse Large B-Cell Lymphomas (DLBCL)

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 805-805 ◽  
Author(s):  
Raquel Malumbres ◽  
Robert Tibshirani ◽  
Elena Cubedo ◽  
Kristopher A Sarosiek ◽  
Xiaoyu Jiang ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Memory B Cells ◽  
Microrna Expression ◽  
B Cell Differentiation ◽  
Cell Of Origin ◽  
Specific Expression ◽  
Differentiation Stage

Abstract B-cell development and differentiation are complex processes controlled by distinct programs of transcriptional control. A large set of transcriptional factors together or in succession control this process and their deregulation may result in block of differentiation or malignant transformation. MicroRNAs are small RNAs that orchestrate cellular functions by modulating the level of their targeted proteins by either translational arrest or transcript degradation, and play a key role in cell differentiation, apoptosis, proliferation and cancer development. An increasing number of transcription factors are being found targeted by microRNAs. Emerging evidence suggests that differentiation stage-specific expression of microRNAs occurs in the hematopoietic system and during T cell differentiation. Only limited information exists on microRNA expression in normal B cell differentiation and its malignant counterparts. Herein we analyzed microRNA expression profiles in distinct peripheral B cell differentiation stages-naïve, germinal center (GC) centroblasts and memory cells as well as tonsilar T cells. Furthermore, microRNA profiling was performed in germinal center-like (GCB-like) and activated B-cell-like (ABC-like) DLBCL cell lines originating from distinct B-cell differentiation stages. RNA, extracted with mirVana kit (AMBION) from B cell subsets and T cells enriched from normal tonsils was hybridized on LC Sciences (Houston, TX) microarrays harboring 470 human microRNAs probes (Sanger miRBase Release 9.1). Expression of selected microRNAs was confirmed by ABI RT-PCR methodology. Unsupervised clustering of microRNAs with values present in at least 50% of the samples (122 probes) resulted in perfect differentiation-stage clustering of samples. Application of Statistical Analysis of Microarrays (SAM) and Prediction Analysis of Microarrays (PAM) methods (FDR= 10%) identified a 47 microRNA cell of origin classifier for B-cells differentiation stage; 27 of these microRNAs were upregulated and 20 downregulated in centroblasts compared to memory B-cells. MicroRNAs belonging to paralog microRNA clusters (e.g. miR17-92-1, miR363-106a and miR25-106b) demonstrated similar patterns of expression in specific differentiation stages. To identify specific microRNA targets, miRanda, TargetScan and PicTar programs were used. To experimentally confirm the targets, we assessed the effects of specific microRNAs on the expression levels of targeted proteins and on the luciferase reporter under the control of the wild type and mutated 3′ UTR regions of putative target genes. Using this experimental approach we identified lymphocyte-stage-specific microRNAs which expression inversely correlated and might regulate the expression of LMO2, BLIMP1 and IRF4 proteins distinctively expressed at different differentiation stages of B lymphocytes. For example, miR223, which expression is low in GC cells but is high in naïve and memory B cells, downregulates the expression of LMO2. We next analyzed microRNA expression in DLBCL cell lines. Clustering analysis, using the 47 microRNA cell of origin classifier perfectly classified GCB-like and ABC-like cell lines. Interestingly, the expression of microRNAs in both GCB-like and ABC-like DLBCL cell lines was more similar to normal centroblasts than to memory B cells, suggesting that both may originate from distinct subpopulations of GC lymphocytes. The similarity of microRNA expression in cell lines to centroblasts was striking, with only 16 microRNAs (1 upregulated and 15 downregulated in cell lines) showing noticeable differences in levels of expression compared to normal cells. These microRNAs might be involved in the process of lymphoma transformation. SAM analysis aimed to differentiate GCB-like and ABC-like cell lines identified 11 microRNAs, only 3 of which were present in the cell of origin classifier. This observation suggests that there is also a difference in expression of microRNAs not directly related to the distinct cell of origin between the DLBCL subtypes. In summary, our results demonstrate that the microRNA profile changes during the GC reaction as well as during malignant transformation. Specific microRNAs can regulate key transcription factors controlling the processes of lymphocyte differentiation and transformation.

scholarly journals Memory B Cells Are Biased Towards Terminal Differentiation: A Strategy That May Prevent Repertoire Freezing

1997 ◽  
Vol 186 (6) ◽  
pp. 931-940 ◽  
Author(s):  
Christophe Arpin ◽  
Jacques Banchereau ◽  
Yong-Jun Liu
Keyword(s):  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Plasma Cell ◽  
Plasma Cells ◽  
Cell Clone ◽  
Terminal Differentiation ◽  
Memory B Cells ◽  
B Cell Differentiation

Isolation of large numbers of surface IgD+CD38− naive and surface IgD−CD38− memory B cells allowed us to study the intrinsic differences between these two populations. Upon in vitro culture with IL-2 and IL-10, human CD40–activated memory B cells undergo terminal differentiation into plasma cells more readily than do naive B cells, as they give rise to five- to eightfold more plasma cells and three- to fourfold more secreted immunoglobulins. By contrast, naive B cells give rise to a larger number of nondifferentiated B blasts. Saturating concentrations of CD40 ligand, which fully inhibit naive B cell differentiation, only partially affect that of memory B cells. The propensity of memory B cells to undergo terminal plasma cell differentiation may explain the extensive extra follicular plasma cell reaction and the limited germinal center reaction observed in vivo after secondary immunizations, which contrast with primary responses in carrier-primed animals. This unique feature of memory B cells may confer two important capacities to the immune system: (a) the rapid generation of a large number of effector cells to efficiently eliminate the pathogens; and (b) the prevention of the overexpansion and chronic accumulation of one particular memory B cell clone that would freeze the available peripheral repertoire.

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