scholarly journals Complementary Signaling through flt3 and Interleukin-7 Receptor α Is Indispensable for Fetal and Adult B Cell Genesis

2003 ◽  
Vol 198 (10) ◽  
pp. 1495-1506 ◽  
Author(s):  
Ewa Sitnicka ◽  
Cord Brakebusch ◽  
Inga-Lill Martensson ◽  
Marcus Svensson ◽  
William W. Agace ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Target Genes ◽  
Plasma Cells ◽  
Tyrosine Kinase Receptor ◽  
Gamma Chain ◽  
Interleukin 7 ◽  
Adult Mice ◽  
Cell Genesis ◽  
Cell Commitment

Extensive studies of mice deficient in one or several cytokine receptors have failed to support an indispensable role of cytokines in development of multiple blood cell lineages. Whereas B1 B cells and Igs are sustained at normal levels throughout life of mice deficient in IL-7, IL-7Rα, common cytokine receptor gamma chain, or flt3 ligand (FL), we report here that adult mice double deficient in IL-7Rα and FL completely lack visible LNs, conventional IgM+ B cells, IgA+ plasma cells, and B1 cells, and consequently produce no Igs. All stages of committed B cell progenitors are undetectable in FL−/− × IL-7Rα−/− BM that also lacks expression of the B cell commitment factor Pax5 and its direct target genes. Furthermore, in contrast to IL-7Rα−/− mice, FL−/− × IL-7Rα−/− mice also lack mature B cells and detectable committed B cell progenitors during fetal development. Thus, signaling through the cytokine tyrosine kinase receptor flt3 and IL-7Rα are indispensable for fetal and adult B cell development.

Critical and Complementary Role of FLT3 and Interleukin 7-Receptor Alpha Signaling in T Lymphocyte Development.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 112-112 ◽  
Author(s):  
Natalija Buza-Vidas ◽  
Henrik Ahlenius ◽  
Corrado M. Cilio ◽  
Marcus Svensson ◽  
William Agace ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
T Cell Development ◽  
Cell Development ◽  
Tyrosine Kinase Receptor ◽  
Thymocyte Development ◽  
Interleukin 7 ◽  
Cell Genesis ◽  
Cell Commitment ◽  
Deficient Mice

Abstract We recently demonstrated that signaling through the cytokine tyrosine kinase receptor flt3 and interleukin-7 receptor a (IL-7Ra) is indispensable for fetal and adult B cell commitment and development (Sitnicka et al., J. Exp. Med. 198: 1495, 2003). These receptors are also implicated to be important in regulation of T cell development, but their potential interdependence remains unexplored. We recently showed that flt3 ligand (FL)-deficient mice have reduced levels of early thymic progenitors as well as the common lymphoid progenitor (CLP) (Sitnicka et al., Immunity, 17:463, 2002). In the present study we investigated T cell development in mice deficient in FL and IL-7Ra expression. Strikingly, when compared to FL−/− and IL-7Ra−/− mice, FL−/−xIL-7Ra−/− (double deficient) mice (8-10 week old) lack visible lymph nodes and Peyer’s Patches. Thymic cellularity was dramatically reduced to only 0.3% of FL−/− and wild type (WT) controls and to only 4% of IL-7Ra−/− mice. In agreement with previous studies, IL-7Ra−/− thymocytes revealed a partial block at the progression from the DN2 (CD4−CD8−CD44+CD25+) to DN3 (CD4−CD8−CD44−CD25+) stage, while in FL−/−xIL-7Ra−/− mice DN1 (CD4−CD8−CD44+CD25−), DN2 and DN3 thymic progenitors were undetectable. Thus, severe reductions in early thymocyte development in FL−/−xIL-7Ra−/− mice support a similar role for cross talk between these two signaling pathways in T cell development as recently demonstrated for B cell genesis.

miRNA Analysis Identifies a Unique Expression in Waldenström Macroglobulinemia B Cells and Plasma Cells

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 620-620
Author(s):  
Sherine F. Elsawa ◽  
Anne J Novak ◽  
Deanna Grote ◽  
Thomas E Witzig ◽  
Stephen M. Ansell
Keyword(s):  
B Cells ◽  
B Cell ◽  
Expression Pattern ◽  
Mirna Expression ◽  
Target Genes ◽  
Plasma Cells ◽  
Mirna Signature ◽  
Variance Stabilization ◽  
Healthy Donors ◽  
B Lineage

Abstract MicroRNAs (miRNAs) are small noncoding RNAs that are approximately 20–22 nucleotides with critical functions in cell growth, survival, and differentiation. These conserved sequences can regulate expression of multiple genes and are often tissue specific and dysregulated in malignancies. Thus, miRNA profiling has been used to create signatures for many solid tumors. These profiles have been used to classify tumors and to help predict survival and outcome. In the present study, we utilized the DiscovArray miRNA profiling service (Asuragen Services, Austin, TX) which utilizes a custom-manufactured Affymetrix GeneChip® from Ambion that covers miRNAs derived from the Sanger miRBase (http://microrna.sanger.ac.uk/sequences/index.shtml) and over 11,000 predicted miRNAs derived from published reports. The signal processing implemented was a multi-step process involving probe-specific signal detection calls, background estimation and correction, constant variance stabilization and global normalization. For each probe, an estimated background value was subtracted derived from the median signal of a set of G-C-matched anti-genomic controls. Arrays within a specific experiment were normalized together according to variance stabilization method. Detection calls were based on a Wilcoxon rank-sum test of the miRNA probe signal compared to the distribution of signals from GC-content matched anti-genomic probes. For statistical hypothesis testing, a two-sample t-test, with assumption of equal variance, was applied. One-way ANOVA was used for multiple group comparison. Probes were considered to be differentially expressed based on two criteria: a p-value of < 0.001 and glog2 difference > 1. miRNA expression was analyzed in all malignant B lineage cells (CD19+ CD138+) (n=8), malignant B cells alone (CD19+) (n=6) and plasma cells alone (CD138+) (n=3) from Waldenström macroglobulinemia (WM) patients. The expression was compared to malignant CD19+ B cells from chronic lymphocytic leukemia (CLL) patients (n=5), malignant plasma cells (CD138+) from multiple myeloma (MM) patients (n=5) and to B lineage cells (CD19+ CD138+) (n=4), CD19+ B-lymphocytes (n=3) and CD138+ plasma cells (n=6) from healthy donors. Data analysis based on a total of approximately 11,000 miRNAs analyzed shows that CD19+ CD138+ cells (double sorting) from WM patients did not cluster as a unique group. Some samples had a pattern similar to CLL, some similar to MM and others similar to CD19+ CD138+ cells from healthy controls. This lack of clear signature was observed by others in gene expression profiling and CGH arrays. We therefore hypothesized this lack of clustering was due to the lymphoplasmacytic nature of WM cells and therefore we analyzed B cells (CD19+) and plasma cells (CD138+) separately. miRNA expression in B cells (CD19+) identifies a signature in normal B cells that is absent in both WM B cells (CD19+) and CLL cells. There is also a set of miRNAs that are absent in normal B cells that are expressed in WM B cells and CLL. In addition, WM B cells had a unique miRNA signature that is unique compared to CLL and normal B cells. An additional set of miRNAs were expressed and clustered only in CLL patients. Similar to B cells, plasma cell (CD138+) analysis in WM, MM and healthy donors shows a clustering pattern that identifies normal plasma cells from MM plasma cells. WM plasma cells had a miRNA signature that is unique only to WM patients, however, a subset of miRNAs shared an expression pattern with MM plasma cells. While miRNAs can target multiple genes, some of the genes that are targets of the miRNAs identified in this analysis include XBP-1, Blimp-1, IRF-4, Bcl-6 and TACI. These target genes are known to be important in B cell and plasma cell development. In summary, we have analyzed miRNA expression in malignant B cells (CD19+) and malignant plasma cells (CD138+) from WM patients and compared their expression pattern to their normal counterpart as well as malignant counterpart in CLL B cells and MM plasma cells. Our analysis shows that WM B cells have a miRNA signature unique to WM only and one that is shared by CLL cells. Similarly, WM plasma cells have a unique miRNA signature but also has some miRNAs that are shared by malignant plasma cells in MM. These miRNAs target genes involved in B cell differentiation. Analysis of the functional roles of these miRNAs will and their regulation will further our understanding of the regulation of B cells development in normal and malignant conditions.

scholarly journals Molecular functions of the transcription factors E2A and E2-2 in controlling germinal center B cell and plasma cell development

2016 ◽  
Vol 213 (7) ◽  
pp. 1201-1221 ◽  
Author(s):  
Miriam Wöhner ◽  
Hiromi Tagoh ◽  
Ivan Bilic ◽  
Markus Jaritz ◽  
Daniela Kostanova Poliakova ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Plasma Cell ◽  
Germinal Center ◽  
Target Genes ◽  
Plasma Cells ◽  
Regulatory Region ◽  
Cell Development ◽  
E Proteins ◽  
Cell Immunity

E2A is an essential regulator of early B cell development. Here, we have demonstrated that E2A together with E2-2 controlled germinal center (GC) B cell and plasma cell development. As shown by the identification of regulated E2A,E2-2 target genes in activated B cells, these E-proteins directly activated genes with important functions in GC B cells and plasma cells by inducing and maintaining DNase I hypersensitive sites. Through binding to multiple enhancers in the Igh 3′ regulatory region and Aicda locus, E-proteins regulated class switch recombination by inducing both Igh germline transcription and AID expression. By regulating 3′ Igk and Igh enhancers and a distal element at the Prdm1 (Blimp1) locus, E-proteins contributed to Igk, Igh, and Prdm1 activation in plasmablasts. Together, these data identified E2A and E2-2 as central regulators of B cell immunity.

Regulation of B-cell commitment to plasma cells or to memory B cells

1997 ◽  
Vol 9 (4) ◽  
pp. 235-240 ◽  
Author(s):  
Yong-Jun Liu ◽  
Jacques Banchereau
Keyword(s):  
B Cells ◽  
B Cell ◽  
Plasma Cells ◽  
Memory B Cells ◽  
Cell Commitment

scholarly journals Spi-B inhibits human plasma cell differentiation by repressing BLIMP1 and XBP-1 expression

Blood ◽  
2008 ◽  
Vol 112 (5) ◽  
pp. 1804-1812 ◽  
Author(s):  
Heike Schmidlin ◽  
Sean A. Diehl ◽  
Maho Nagasawa ◽  
Ferenc A. Scheeren ◽  
Remko Schotte ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Cell Differentiation ◽  
B Cells ◽  
B Cell ◽  
Plasma Cell ◽  
Target Genes ◽  
Plasma Cells ◽  
Terminal Differentiation ◽  
Transactivation Domain ◽  
Plasma Cell Differentiation

Abstract The terminal differentiation of B cells into antibody-secreting plasma cells is tightly regulated by a complex network of transcription factors. Here we evaluated the role of the Ets factor Spi-B during terminal differentiation of human B cells. All mature tonsil and peripheral blood B-cell subsets expressed Spi-B, with the exception of plasma cells. Overexpression of Spi-B in CD19+ B cells inhibited, similar to the known inhibitor BCL-6, the expression of plasma cell–associated surface markers and transcription factors as well as immunoglobulin production, ie, in vitro plasma cell differentiation. The arrest in B-cell differentiation enforced by Spi-B was independent of the transactivation domain, but dependent on the Ets-domain. By chromatin immunoprecipitation and assays using an inducible Spi-B construct BLIMP1 and XBP-1 were identified as direct target genes of Spi-B mediated repression. We propose a novel role for Spi-B in maintenance of germinal center and memory B cells by direct repression of major plasma cell factors and thereby plasma cell differentiation.

scholarly journals POS1223 RAS GUANYL RELEASING PROTEIN 1 (RASGRP1) IN PERIPHERAL B CELLS LINKS RA TO COVID-19

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 895.2-895
Author(s):  
S. Hannawi ◽  
F. Alqutami ◽  
M. Y. Hachim
Keyword(s):  
Rheumatoid Arthritis ◽  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Plasma Cells ◽  
Immune Cell ◽  
In Silico Analysis ◽  
Differentially Expressed ◽  
Transcriptional Enhancer ◽  
Activated T Cells

Background:Changes in the B cell subpopulations is a hallmark of the antiviral response against SARS-CoV-2 and is associated with COVID-19 severity (1). Recently our group showed common derangement observed in rheumatoid arthritis (RA) and COVID-19 (2). In RA, synovium attracts potentially autoreactive—B cells and plasma cells that play a central role in RA pathogenesis (3). We were interested to know the similarity in B cell’s transcriptomic changes specific to RA and COVID-19.Objectives:Identify similar upregulated genes in synovium and B cells in RA and at the same time are differentially expressed in B cells infected with SARS-CoV-2 or from COVID-19 patients.Methods:RNAseq dataset (GSE89408) of (218) samples isolated from joint synovial biopsies from subjects with and without rheumatoid arthritis were retrieved from GEO online database. Differentially expressed genes (DRGs) specific to RA were identified after exclusion of those upregulated in Osteoarthritis or other joint condition samples in the same dataset. The RA specific genes were intersected with DEGs between B cells from healthy versus RA as extracted from (GSE110999) dataset. The shortlisted genes specifically upregulated in B cells of RA were identified and were explored in B cells COVID-19 transcriptome datasets using (https://metascape.org/COVID).Results:60 genes were found to be specifically upregulated in RA synovium and B cells and are changed in B cells infected with SARS-CoV-2 or from COVID-19 patients, Figure (1-A). Those genes were involved in interferon signaling, antiviral and immune cell activation. RASGRP1 was common between B cells of RA and COVID-19 and might play a role in the pathogenesis of both, Figure (1-B). RASGRP1 controls ERK/MAPK kinase cascade needed in B-/T-cell differentiation and development. It is vital to protect against viral infection and the autoimmune associated proliferation of activated T-cells like RA (4). We checked its level in another dataset (GSE152641) of the whole blood RNASeq of 62 COVID-19 patients and 24 healthy controls. RASGRP1 was significantly down in COVID-19 compared to healthy control, Figure (1-C).Conclusion:SARS-CoV-2 impair B and T’s cells’ immune response through its action on RASGRP1 and that can be a novel mechanistic explanation of how the virus decreases immune cells and impair the B cell’s humoral immunity.References:[1]Sosa-Hernández VA, Torres-Ruíz J, Cervantes-Díaz R, Romero-Ramírez S, Páez-Franco JC, Meza-Sánchez DE, et al. B Cell Subsets as Severity-Associated Signatures in COVID-19 Patients. Frontiers in Immunology. 2020;11(3244).[2]Hachim MY, Hachim IY, Naeem KB, Hannawi H, Al Salmi I, Hannawi S. C-C chemokine receptor type 5 links COVID-19, rheumatoid arthritis, and Hydroxychloroquine: in silico analysis. Translational Medicine Communications. 2020;5(1):14.[3]Doorenspleet ME, Klarenbeek PL, de Hair MJ, van Schaik BD, Esveldt RE, van Kampen AH, et al. Rheumatoid arthritis synovial tissue harbours dominant B-cell and plasma-cell clones associated with autoreactivity. Ann Rheum Dis. 2014;73(4):756-62.[4]Molineros JE, Singh B, Terao C, Okada Y, Kaplan J, McDaniel B, et al. Mechanistic Characterization of RASGRP1 Variants Identifies an hnRNP-K-Regulated Transcriptional Enhancer Contributing to SLE Susceptibility. Frontiers in Immunology. 2019;10(1066).Disclosure of Interests:None declared

scholarly journals Dimethyl fumarate as a first- vs second-line therapy in MS

2018 ◽  
Vol 5 (6) ◽  
pp. e508 ◽  
Author(s):  
Elsebeth Staun-Ram ◽  
Eiman Najjar ◽  
Anat Volkowich ◽  
Ariel Miller
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Activation ◽  
Plasma Cells ◽  
Dimethyl Fumarate ◽  
Functional Markers ◽  
Immunomodulatory Effects ◽  
Immune Profile ◽  
Line Therapy ◽  
B Cell Subsets

ObjectiveTo elucidate the immunomodulatory effects of dimethyl fumarate (DMF) on B cells in patients with relapsing MS receiving DMF as a “1st-line” vs “2nd-line” therapy.MethodsB cells were isolated from 43 patients with MS at baseline and after 15-week DMF therapy. Phenotype and functional markers and cytokine profile were assessed by flow cytometry. Analysis included clinical and MRI parameters recorded during a 1-year follow-up.Results1st-line and 2nd-line patients presented several differences in their baseline immune profile, which corresponded with differences in their immunologic response to DMF treatment. DMF reduced the proportions of B cells and CD8 T cells whereas increased monocytes. DMF reduced memory B cells, including plasma cells in 2nd-line patients only, whereas strongly increased transitional B cells. Several IL10+ B-cell subsets and TGFβ+ B cells were increased. Proinflammatory LTα+ and TNFα+ B cells were reduced, while IL4+ B cells elevated, whereas IFNγ+ B cells showed opposite effects in 1st-line and 2nd-line patients. HLA and ICAM-1 expression was increased, but % CD86+ B cells reduced. The expression of B-cell activating factor receptor and the proportion of activated CD69 B cells were increased.ConclusionsDMF is associated with increased transitional and IL10+ and TGFβ+ regulatory B cells and a shift toward a more anti-inflammatory immune profile. Cell activation with reduced costimulatory capacity may induce immune hyporesponsiveness. Carryover effects of preceding therapies in 2nd-line patients and the stage of disease influence the immune profile of the patients and the immunomodulatory effects of DMF.

scholarly journals Differential Regulation of Mouse B Cell Development by Transforming Growth Factor β1

2002 ◽  
Vol 9 (2) ◽  
pp. 86-95 ◽  
Author(s):  
Denise A. Kaminski ◽  
John J. Letterio ◽  
Peter D. Burrows
Keyword(s):  
B Cells ◽  
Growth Factor ◽  
B Cell ◽  
Transforming Growth Factor ◽  
Plasma Cells ◽  
Population Analysis ◽  
Cell Development ◽  
B Cell Development

Transforming growth factor β (TGFβ) can inhibit thein vitroproliferation, survival and differentiation of B cell progenitors, mature B lymphocytes and plasma cells. Here we demonstrate unexpected, age-dependent reductions in the bone marrow (BM) B cell progenitors and immature B cells in TGFβ1-/-mice. To evaluate TGFβ responsiveness during normal B lineage development, cells were cultured in interleukin 7 (IL7)±TGFβ. Picomolar doses of TGFβ1 reduced pro-B cell recoveries at every timepoint. By contrast, the pre-B cells were initially reduced in number, but subsequently increased compared to IL7 alone, resulting in a 4-fold increase in the growth rate for the pre-B cell population. Analysis of purified BM sub-populations indicated that pro-B cells and the earliest BP1-pre-B cells were sensitive to the inhibitory effects of TGFβ1. However, the large BP1+pre-B cells, although initially reduced, were increased in number at days 5 and 7 of culture. These results indicate that TGFβ1 is important for normal B cell developmentin vivo, and that B cell progenitors are differentially affected by the cytokine according to their stage of differentiation.

scholarly journals Regulation of the germinal center gene program by interferon (IFN) regulatory factor 8/IFN consensus sequence-binding protein

2005 ◽  
Vol 203 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Chang Hoon Lee ◽  
Mark Melchers ◽  
Hongsheng Wang ◽  
Ted A. Torrey ◽  
Rebecca Slota ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Transcriptional Activation ◽  
Germinal Center ◽  
Target Genes ◽  
Fluorescent Protein ◽  
Binding Protein ◽  
Consensus Sequence ◽  
B Cell Lymphoma ◽  
Regulatory Factor

Interferon (IFN) consensus sequence-binding protein/IFN regulatory factor 8 (IRF8) is a transcription factor that regulates the differentiation and function of macrophages, granulocytes, and dendritic cells through activation or repression of target genes. Although IRF8 is also expressed in lymphocytes, its roles in B cell and T cell maturation or function are ill defined, and few transcriptional targets are known. Gene expression profiling of human tonsillar B cells and mouse B cell lymphomas showed that IRF8 transcripts were expressed at highest levels in centroblasts, either from secondary lymphoid tissue or transformed cells. In addition, staining for IRF8 was most intense in tonsillar germinal center (GC) dark-zone centroblasts. To discover B cell genes regulated by IRF8, we transfected purified primary tonsillar B cells with enhanced green fluorescent protein–tagged IRF8, generated small interfering RNA knockdowns of IRF8 expression in a mouse B cell lymphoma cell line, and examined the effects of a null mutation of IRF8 on B cells. Each approach identified activation-induced cytidine deaminase (AICDA) and BCL6 as targets of transcriptional activation. Chromatin immunoprecipitation studies demonstrated in vivo occupancy of 5′ sequences of both genes by IRF8 protein. These results suggest previously unappreciated roles for IRF8 in the transcriptional regulation of B cell GC reactions that include direct regulation of AICDA and BCL6.

scholarly journals Optimized Protocols for in Vitro T Cell-Dependent and T Cell-Independent Activation for B Cell Differentiation Studies Using Limited Cells

2021 ◽  
Author(s):  
Casper Marsman ◽  
Dorit Verhoeven
Keyword(s):  
Cell Differentiation ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Plasma Cells ◽  
Cell Formation ◽  
B Cell Differentiation ◽  
Differentiation Potential ◽  
Human B Cell

Background/methods: For mechanistic studies, in vitro human B cell differentiation and generation of plasma cells are invaluable techniques. However, the heterogeneity of both T cell-dependent (TD) and T cell-independent (TI) stimuli and the disparity of culture conditions used in existing protocols makes interpretation of results challenging. The aim of the present study was to achieve the most optimal B cell differentiation conditions using isolated CD19+ B cells and PBMC cultures. We addressed multiple seeding densities, different durations of culturing and various combinations of TD stimuli and TI stimuli including B cell receptor (BCR) triggering. B cell expansion, proliferation and differentiation was analyzed after 6 and 9 days by measuring B cell proliferation and expansion, plasmablast and plasma cell formation and immunoglobulin (Ig) secretion. In addition, these conditions were extrapolated using cryopreserved cells and differentiation potential was compared. Results: This study demonstrates improved differentiation efficiency after 9 days of culturing for both B cell and PBMC cultures using CD40L and IL-21 as TD stimuli and 6 days for CpG and IL-2 as TI stimuli. We arrived at optimized protocols requiring 2500 and 25.000 B cells per culture well for TD and TI assays, respectively. The results of the PBMC cultures were highly comparable to the B cell cultures, which allows dismissal of additional B cell isolation steps prior to culturing. In these optimized TD conditions, the addition of anti-BCR showed little effect on phenotypic B cell differentiation, however it interferes with Ig secretion measurements. Addition of IL-4 to the TD stimuli showed significantly lower Ig secretion. The addition of BAFF to optimized TI conditions showed enhanced B cell differentiation and Ig secretion in B cell but not in PBMC cultures. With this approach, efficient B cell differentiation and Ig secretion was accomplished when starting from fresh or cryopreserved samples. Conclusion: Our methodology demonstrates optimized TD and TI stimulation protocols for more indepth analysis of B cell differentiation in primary human B cell and PBMC cultures while requiring low amounts of B cells, making them ideally suited for future clinical and research studies on B cell differentiation of patient samples from different cohorts of B cell-mediated diseases.

Sign in / Sign up

Export Citation Format

Share Document