Transcriptomic analysis of in vitro induced germinal centre-like B cells and plasmablast differentiation
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ABSTRACT: To elucidate molecular mechanisms that regulate the terminal differentiation of B cells into plasmablasts, we analysed how the B cell transcriptome changes during an in vitro culture system that mimics the germinal centre response (known as iGB culture). By culturing B cells on feeder cells expressing CD40L and B-cell activating factor BAFF in the presence of interleukin 4 and interleukin 21, this system allows class switch recombination to IgG1-producing cells and formation of CD138+ TACI+ B220low CD19int/low plasmablasts.
Project description:To understand the role of LSD1 in B cell differentiation, mice with B cell conditional deletion of LSD1 were intravenously inoculated with LPS. After 3 days, B220+GL7-CD138- naïve B cells and CD138+ plasmablasts were FACS-sorted from the spleens and RNA-seq was performed to identify LSD1-target regulated genes.
Project description:To understand the role of LSD1 in B cell differentiation, mice with B cell conditional deletion of LSD1 were intravenously inoculated with LPS. After 3 days, B220+GL7-CD138- naïve B cells and CD138+ plasmablasts were FACS-sorted from the spleens and RNA-seq was performed to identify LSD1-target regulated chromatin.
Project description:The goal of this study is to analysis the gene expression alterations along the time of hiGC culture. We established a hiGC model by following the protocol previously reported by Kitamura et al. Naïve B cells purified from human PBMC pools underwent two phases of growth under the activation of CD40L, BAFF, IL-4 and subsequently IL-21.
Project description:Splenic Marginal Zone B cells mount innate-like T cell-independent (TI) antibody responses to blood-borne antigens upon receiving activation signals from TACI-engaging factors BAFF and APRIL. The transcriptome analysis of splenic Marginal Zone (MZ) B cells was performed to verify which transcriptional programs are enhanced in the innate-like MZ B cell subset and to study the involvement of mTOR in MZ B cells activated via TACI.
Project description:Both multiple myeloma (MM) and systemic lupus erythematosus (SLE) are characterized with abnormal production of plasma cells. In both diseases, the process of B cells differentiate into plasmablast/plasma cell is disordered. Despite the continuous research on the development of prognostic factors and introduction of new agents, dysregulation of plasmablast/plasma cells in MM and SLE is still uncontrolled. Thus, it is necessary to explore the novel therapeutic target to plasmablast/plasma cells. We and other researchers have shown that BAFF inhibitor atacicept (TACI-IgG), leads to some degree of B cell depletion. BAFF-specific targeted therapy specifically affects early-stage B cells in the periphery without affecting late-stage compartments such as plasma cells. Specifically depletion of plasma cells could hold great potential for the treatment of autoimmune diseases. To explore the novel therapeutic target to plasma cells, we determined the gene expression profile in B cells (mainly plasma cells) from atacicept (TACI-IgG)-treated lupus-prone MRL/lpr mice by affymetrix microarrays.
Project description:The CEL files of this study are additional to the GSE32583 and GSE44691; they are microarrays of lupus nephritis NZBW mouse model at 30 wks old, or treated with CTX+CTLAIg+anti-CD154 (early and late after remission) or Ad-TACI-Ig+CTLA4Ig (late after remission) and NZM2410 treated with Ad-BAFF-R-Ig.
Project description:Naive resting B-cells were purified from bone marrow from C57BL/6 mice using flow cytometry sorting. Naive B cells were activated with LPS and harvested 3 hours, 10 hours or 33 hours after the LPS treatment. Expanded activated B cells (CD22+ CD138-) and plasmablasts (CD22- CD138+) were also harvested on day 4 post-stimulation.
Project description:To understand the role of LSD1 in marginal zone B cell development, CD93+ transitional B cells were enriched from the spleens of mice with B cell conditional deletion of LSD1, the cells were cultured for 3 days in the presence of OP9-DL1 cells and BAFF, and day 0 B220+CD93+ transitional B cells and day 3 B220+CD21+CD1d+ ex vivo-derived marginal zone B cells were FACS-sorted and RNA-seq was performed to identify LSD1-target regulated genes.
Project description:Common variable immunodeficiency (CVID) is the most prevalent form of symptomatic primary immunodeficiency in humans. The genetic cause of CVID is still unknown in about 70% of cases. 10% of CVID patients carry heterozygous mutations in the tumor necrosis factor receptor superfamily member 13B gene (TNFRSF13B), encoding TACI. Mutations in TNFRSF13B alone may not be sufficient for the development of CVID, as 1% of the healthy population carry these mutations. The common hypothesis is that TACI mutations are not fully penetrant and additional factors contribute to the development of CVID. To determine these additional factors, we investigated the perturbations of transcription factor (TF) binding and the transcriptome profiles in unstimulated and CD40L/IL21-stimulated naïve B cells from CVID patients harboring the C104R mutation in TNFRSF13B and compared them to their healthy relatives with the same mutation. In addition, the proteome of stimulated naïve B cells was investigated. For functional validation, intracellular protein concentrations were measured by flow cytometry. Our analysis revealed 8% less accessible chromatin in unstimulated naïve B cells and 25 % less accessible chromatin in class-switched memory B cells from affected and unaffected TACI mutation carriers compared to healthy donors. The most enriched TF binding motifs in TACI mutation carriers involved members from the ETS, IRF and NF-B TF families. Validation experiments supported dysregulation of the NF-B and MAPK pathways. In steady state, naïve B cells had increased cell death pathways and reduced cell metabolism pathways; while after stimulation, enhanced immune responses and decreased cell survival was detected. Using a multi-omics approach, our findings provide valuable insights into the impaired biology of naïve B cells from TACI mutation carriers.
Project description:Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by production of various pathogenic autoantibodies. Increased type I interferon signature is suggested as a trigger of the disease. Previous studies identify increased plasmablasts in peripheral blood of SLE patients. In spite of the unique cellular properties of the plasmablasts compared with other B cell subsets and plasma cells, the biological characteristics of SLE plasmblast remain unknown and few therapeutic strategies targeting SLE plasmablasts have been applicated. We performed microarray analysis of naive, memory B cells and plasmablasts (CD38+CD43+ B cells) freshly isolated from healthy controls and active SLE (n=4, each) to find the unique biological properties of SLE plasmablast.