scholarly journals Epigenetic Remodeling by Vitamin C Potentiates the Differentiation of Mouse and Human Plasma Cells

2021 ◽  
Author(s):  
Heng-Yi Chen ◽  
Ana Alamonte-Loya ◽  
Fang-Yun Lay ◽  
Eric Johnson ◽  
Edahi Gonzalez-Avalos ◽  
...  

AbstractAscorbate (vitamin C) is an essential micronutrient in humans. The chronic severe deficiency of ascorbate, termed scurvy, has long been associated with increased susceptibility to infections. How ascorbate affects the immune system at the cellular and molecular levels remained unclear. Here, from a micronutrient screen, we identified ascorbate as a potent enhancer for antibody response by facilitating the IL-21/STAT3-dependent plasma cell differentiation in mouse and human B cells. The effect of ascorbate is unique, as other antioxidants failed to promote plasma cell differentiation. Ascorbate is critical during early B cell activation by poising the cells to plasma cell lineage without affecting the proximal IL-21/STAT3 signaling and the overall transcriptome. Consistent with its role as a cofactor for epigenetic enzymes, ascorbate potentiates plasma cell differentiation by remodeling the epigenome via TET (Ten Eleven Translocation), the enzymes responsible for DNA demethylation by oxidizing 5-methylcytosines into 5-hydroxymethylcytosine (5hmC). Genome-wide 5hmC profiling identified ascorbate responsive elements (EAR) at the Prdm1 locus, including a distal element with a STAT3 motif overlapped with a CpG that was methylated and modified by TET in the presence of ascorbate. The results suggest that an adequate level of VC is required for antibody response and highlight how micronutrients regulate the activity of epigenetic enzymes to regulate gene expression. Our findings imply that epigenetic enzymes can function as sensors to gauge the availability of metabolites and influence cell fate decisions.

2021 ◽  
Author(s):  
Ashley N. Barlev ◽  
Susan Malkiel ◽  
Annemarie L. Dorjée ◽  
Jolien Suurmond ◽  
Betty Diamond

AbstractFcγRIIB is an inhibitory receptor expressed throughout B cell development. Diminished expression or function is associated with lupus in mice and humans, in particular through an effect on autoantibody production and plasma cell differentiation. Here, we analysed the effect of B cell-intrinsic FcγRIIB expression on B cell activation and plasma cell differentiation.Loss of FcγRIIB on B cells (Fcgr2b cKO mice) led to a spontaneous increase in autoantibody titers. This increase was most striking for IgG3, suggestive of increased extrafollicular responses. Marginal zone (MZ) and IgG3+ B cells had the highest expression of FcγRIIB and the increase in serum IgG3 was linked to increased MZ B cell signaling and activation in the absence of FcγRIIB. Likewise, human circulating MZ-like B cells had the highest expression of FcγRIIB, and their activation was most strongly inhibited by engaging FcγRIIB. Finally, marked increases in IgG3+ plasma cells and B cells were observed during extrafollicular plasma cell responses with both T-dependent and T-independent antigens in Fcgr2b cKO mice. The increased IgG3 response following immunization of Fcgr2b cKO mice was lost in MZ-deficient Notch2/Fcgr2b cKO mice.Thus, we present a model where high FcγRIIB expression in MZ B cells prevents their hyperactivation and ensuing autoimmunity.Graphical abstract


Blood ◽  
2010 ◽  
Vol 115 (9) ◽  
pp. 1718-1726 ◽  
Author(s):  
Ghyath Maarof ◽  
Laurence Bouchet-Delbos ◽  
Hélène Gary-Gouy ◽  
Ingrid Durand-Gasselin ◽  
Roman Krzysiek ◽  
...  

Abstract Complex molecular mechanisms control B-cell fate to become a memory or a plasma cell. Interleukin-24 (IL-24) is a class II family cytokine of poorly understood immune function that regulates the cell cycle. We previously observed that IL-24 is strongly expressed in leukemic memory-type B cells. Here we show that IL-24 is also expressed in human follicular B cells; it is more abundant in CD27+ memory B cells and CD5-expressing B cells, whereas it is low to undetectable in centroblasts and plasma cells. Addition of IL-24 to B cells, cultured in conditions shown to promote plasma cell differentiation, strongly inhibited plasma cell generation and immunoglobulin G (IgG) production. By contrast, IL-24 siRNA increased terminal differentiation of B cells into plasma cells. IL-24 is optimally induced by BCR triggering and CD40 engagement; IL-24 increased CD40-induced B-cell proliferation and modulated the transcription of key factors involved in plasma cell differentiation. It also inhibited activation-induced tyrosine phosphorylation of signal transducer and activator of transcription-3 (STAT-3), and inhibited the transcription of IL-10. Taken together, our results indicate that IL-24 is a novel cytokine involved in T-dependent antigen (Ag)–driven B-cell differentiation and suggest its physiologic role in favoring germinal center B-cell maturation in memory B cells at the expense of plasma cells.


2020 ◽  
Vol 32 (10) ◽  
pp. 683-690
Author(s):  
Kentaro Fujii ◽  
Shinya Tanaka ◽  
Takanori Hasegawa ◽  
Masashi Narazaki ◽  
Atsushi Kumanogoh ◽  
...  

Abstract Antibodies produced by plasma cells are critical for protection from infection. It has been demonstrated that global epigenetic modification, such as changes in DNA methylation, occurs during differentiation of plasma cells from B cells. However, the precise mechanisms by which DNA methylation controls plasma cell differentiation are not fully understood. We examined the effect of deficiency of DNA demethylases, Tet2 and Tet3, on B-cell activation and plasma cell differentiation, by generating conditional Tet2/3 double-KO (Tet dKO) B cells. We found that Tet dKO B cells failed to differentiate into plasma cells upon immunization with antigens. Tet dKO B cells proliferated normally and were capable of generating cells with IRF4int, but not with IRF4hi, the majority of which were CD138+ plasma cells. IRF4 overexpression rescued the defect of Tet dKO B cells in plasma cell differentiation, suggesting that Tet2/3-dependent high IRF4 expression is required for plasma cell differentiation. We identified CpG sites in the Irf4 locus that were demethylated specifically in plasma cells and in a Tet2/3-dependent manner. Our results suggest that Tet2/3-dependent demethylation of these CpG sites is dispensable for initial IRF4 expression but is essential for high IRF4 expression which is prerequisite for plasma cell differentiation.


2014 ◽  
Vol 211 (11) ◽  
pp. 2199-2212 ◽  
Author(s):  
Bettina Grötsch ◽  
Sebastian Brachs ◽  
Christiane Lang ◽  
Julia Luther ◽  
Anja Derer ◽  
...  

The cornerstone of humoral immunity is the differentiation of B cells into antibody-secreting plasma cells. This process is tightly controlled by a regulatory gene network centered on the transcriptional repressor B lymphocyte–induced maturation protein 1 (Blimp1). Proliferation of activated B cells is required to foster Blimp1 expression but needs to be terminated to avoid overshooting immune reactions. Activator protein 1 (AP-1) transcription factors become quickly up-regulated upon B cell activation. We demonstrate that Fra1, a Fos member of AP-1, enhances activation-induced cell death upon induction in activated B cells. Moreover, mice with B cell–specific deletion of Fra1 show enhanced plasma cell differentiation and exacerbated antibody responses. In contrast, transgenic overexpression of Fra1 blocks plasma cell differentiation and immunoglobulin production, which cannot be rescued by Bcl2. On the molecular level, Fra1 represses Blimp1 expression and interferes with binding of the activating AP-1 member c-Fos to the Blimp1 promoter. Conversely, overexpression of c-Fos in Fra1 transgenic B cells releases Blimp1 repression. As Fra1 lacks transcriptional transactivation domains, we propose that Fra1 inhibits Blimp1 expression and negatively controls plasma cell differentiation through binding to the Blimp1 promoter. In summary, we demonstrate that Fra1 negatively controls plasma cell differentiation by repressing Blimp1 expression.


Cell Reports ◽  
2020 ◽  
Vol 33 (9) ◽  
pp. 108452
Author(s):  
Tuan Qi ◽  
Mengmeng Sun ◽  
Chao Zhang ◽  
Pengda Chen ◽  
Changchun Xiao ◽  
...  

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Benjamin G. Barwick ◽  
Christopher D. Scharer ◽  
Ryan J. Martinez ◽  
Madeline J. Price ◽  
Alexander N. Wein ◽  
...  

2021 ◽  
Vol 207 (11) ◽  
pp. 2660-2672
Author(s):  
Jennifer L. Barnas ◽  
Jennifer Albrecht ◽  
Nida Meednu ◽  
Diana F. Alzamareh ◽  
Cameron Baker ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3242-3242
Author(s):  
John De Vos ◽  
Dirk Hose ◽  
Thierry Reme ◽  
Hartmut Goldschmidt ◽  
Jean-Francois Rossi ◽  
...  

Abstract Seven purified peripheral blood memory B-cells (BM), seven in-vitro-generated polyclonal plasmablastic cells (PPC) and seven purified bone marrow mature plasma cells (BMPC) were studied by oligonucleotide microarrays. All samples were obtained from healthy volunteers. The gene expression profiling of these samples was determined with Affymetrix pan genomic U133A + B arrays (44 928 oligonucleotide probesets). We determined that 2313 genes were differentially expressed between these three B cell categories (P 〈 0.01 by a Kruskal-Wallis test and a ratio between two categories 〉 3). These 2313 genes were classified into six categories, according to the expression profile: early plasma cell genes (EPC), late plasma cell genes (LPC), genes lost early during plasma cell differentiation (LEPC), genes lost late during plasma cell differentiation (LLPC), genes upregulated only in plasmablasts (PBO) and genes lost only in plasmablasts (LPBO). As expected, Ig transcripts where essentially classified as EPC. As a corollary, genes involved in protein synthesis or degradation, transmembrane transporters and metabolism genes were overrepresented in EPC genes. Interestingly, genes involved in intercellular communication and extracellular matrix were enriched in LPC, highlighting the fact that mature plasma cells develop tight interactions with the bone marrow environment. Of note, genes involved in cell cycle are upregulated mainly in plasmablasts, whereas antiapoptotic genes are lost in plasmablasts only. Mains genes known to be involved in plasma cell differentiation display an expression profile in agreement with published data, as illustrated for transcription factors in Figure 1, validating this DNA microarray dataset. However most of these 2313 genes have either never been described yet or have no yet been linked to plasma cell differentiation. The description of those genes among our genome whose expression vary most during plasma cell differentiation will be an essential step in understanding the biology of a cell type essential to immune defenses and involved in deadly diseases. Figure 1: Transcription factors involved in plasma cell differentiation. Color indicates the expression profile category. For each gene is given the ratio of the mean expression value in plasma cell samples (PPC and BMPC) to the mean expression value in BM. UPR: Unfolded Protein Response. Figure 1:. Transcription factors involved in plasma cell differentiation. Color indicates the expression profile category. For each gene is given the ratio of the mean expression value in plasma cell samples (PPC and BMPC) to the mean expression value in BM. UPR: Unfolded Protein Response.


Author(s):  
Shan Zeng ◽  
Qian Qiu ◽  
Yi Zhou ◽  
Youjun Xiao ◽  
Jingnan Wang ◽  
...  

Background and purpose: To investigate the role of bromodomain-containing protein 4 (Brd4) in regulating B cell differentiation and its therapeutic potential for B cell-mediated autoimmune diseases such as systemic lupus erythematosus (SLE). Experimental Approach: Human and murine B cells were purified and cultured with different stimuli. B cell surface markers, proliferation and apoptosis were estimated by flow cytometry. Gene expression was measured by quantitative real-time PCR. Brd4 binding sites were analysed by the luciferase reporter assay and the chromatin immunoprecipitation (ChIP) assay. PFI-1 or JQ1 was used to inhibit Brd4. Mice with B cell-specific deletion of the Brd4 gene (Brd4flox/floxCD19-Cre+/-) and MRL/lpr mice were used to perform the in vivo experiments. Key Results: Brd4 inhibition suppressed plasmablast-mediated plasma cell differentiation but did not influence proliferation or apoptosis in healthy human and murine CD19+ B cells. PFI-1 treatment reduced the secretion of IgG and IgM in the supernatants of costimulation-induced B cells. Mechanistically, Brd4 regulates the terminal differentiation of B cells into plasma cells by targeting BLIMP1 by directly binding and activating the endogenous BLIMP1 promoter. Interestingly, PFI-1 treatment decreased the percentages of plasmablasts and plasma cells from patients with SLE. PFI-1 administration reduced the percentages of plasma cells, hypergammaglobulinemia and attenuated nephritis in MRL/lpr mice. Pristane-injected Brd4flox/floxCD19-Cre+/- mice exhibited improved nephritis and reduced percentages of plasma cells. Conclusions and Implications: Brd4 is an essential factor in regulating plasma cell differentiation. Brd4 inhibition may be a potential new strategy for the treatment of B cell-associated autoimmune disorders, including SLE.


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