Project description:The generation of high-affinity antibodies requires germinal center (GC) development and differentiation of long-lived plasma cells in a multilayered process that is tightly controlled by the activity of multiple transcription factors. Here, we reveal a new layer of complexity by demonstrating that dynamic changes in Id3 and E-protein activity govern both GC and plasma cell differentiation. We show that down-regulation of Id3 in B cells is essential for releasing E2A and E2-2, which in a redundant manner are required for antigen-induced B cell differentiation. We demonstrate that this pathway controls the expression of multiple key factors, including Blimp1, Xbp1, and CXCR4, and is therefore critical for establishing the transcriptional network that controls GC B cell and plasma cell differentiation.
Project description:Humoral immunity requires the generation of high-affinity antibodies, which involves the generation of germinal centres (GC) promoting class switch and affinity maturation of antigen-specific B cells, and the differentiation of long-lived plasma cells. This multi-layered process is tightly controlled by the activity of a transcriptional network including Bcl6, essential for the development of GC, and Blimp1, required for the differentiation of plasma cells. Here, we reveal an additional layer of complexity by demonstrating that dynamic changes in E-protein activity mediated by Id3 govern both GC and plasma cell differentiation. We show that down-regulation of Id3 expression in B cells in essential for releasing E2A and E2-2, the combined activity of which is required for both GC B cell and plasma cell differentiation. We demonstrate that this pathway controls the expression of multiple key factors required for antigen-induced B cell differentiation, including Blimp1, Xbp1, Mef2b and CXCR4 and is therefore critical for establishing the transcriptional network that controls GC B cell and plasma cell differentiation. Genome binding of transcription factor E2A
Project description:Humoral immunity requires the generation of high-affinity antibodies, which involves the generation of germinal centres (GC) promoting class switch and affinity maturation of antigen-specific B cells, and the differentiation of long-lived plasma cells. This multi-layered process is tightly controlled by the activity of a transcriptional network including Bcl6, essential for the development of GC, and Blimp1, required for the differentiation of plasma cells. Here, we reveal an additional layer of complexity by demonstrating that dynamic changes in E-protein activity mediated by Id3 govern both GC and plasma cell differentiation. We show that down-regulation of Id3 expression in B cells in essential for releasing E2A and E2-2, the combined activity of which is required for both GC B cell and plasma cell differentiation. We demonstrate that this pathway controls the expression of multiple key factors required for antigen-induced B cell differentiation, including Blimp1, Xbp1, Mef2b and CXCR4 and is therefore critical for establishing the transcriptional network that controls GC B cell and plasma cell differentiation. Transcriptional profiling of wild type, Id3 knockout and E2A/E22 double knockout B cells using RNA sequencing
Project description:Humoral immunity requires the generation of high-affinity antibodies, which involves the generation of germinal centres (GC) promoting class switch and affinity maturation of antigen-specific B cells, and the differentiation of long-lived plasma cells. This multi-layered process is tightly controlled by the activity of a transcriptional network including Bcl6, essential for the development of GC, and Blimp1, required for the differentiation of plasma cells. Here, we reveal an additional layer of complexity by demonstrating that dynamic changes in E-protein activity mediated by Id3 govern both GC and plasma cell differentiation. We show that down-regulation of Id3 expression in B cells in essential for releasing E2A and E2-2, the combined activity of which is required for both GC B cell and plasma cell differentiation. We demonstrate that this pathway controls the expression of multiple key factors required for antigen-induced B cell differentiation, including Blimp1, Xbp1, Mef2b and CXCR4 and is therefore critical for establishing the transcriptional network that controls GC B cell and plasma cell differentiation.
Project description:Humoral immunity requires the generation of high-affinity antibodies, which involves the generation of germinal centres (GC) promoting class switch and affinity maturation of antigen-specific B cells, and the differentiation of long-lived plasma cells. This multi-layered process is tightly controlled by the activity of a transcriptional network including Bcl6, essential for the development of GC, and Blimp1, required for the differentiation of plasma cells. Here, we reveal an additional layer of complexity by demonstrating that dynamic changes in E-protein activity mediated by Id3 govern both GC and plasma cell differentiation. We show that down-regulation of Id3 expression in B cells in essential for releasing E2A and E2-2, the combined activity of which is required for both GC B cell and plasma cell differentiation. We demonstrate that this pathway controls the expression of multiple key factors required for antigen-induced B cell differentiation, including Blimp1, Xbp1, Mef2b and CXCR4 and is therefore critical for establishing the transcriptional network that controls GC B cell and plasma cell differentiation.
Project description:Higher- or lower-affinity GC B cells are directed to plasma cell or recycling GC cell fates; however, how commitment to the plasma cell fate takes place is unclear. By using the level of Bcl6 as a marker, we found that a population of light zone (LZ) GC cells, Bcl6loCD69hi with IRF4 and higher-affinity BCRs or Bcl6hiCD69hi with lower- affinity BCRs, favored the plasma cell or recycling GC cell fate, respectively. Mechanistically, CD40 acted as a dose-dependent regulator for Bcl6loCD69hi cell formation. Furthermore, we found that ICAM1 and SLAM levels on Bcl6loCD69hi cells were higher than on Bcl6hiCD69hi cells, thereby affording more stable TFH-GC B cell contacts, while attenuating this contact down-regulated IRF4. These data support the model that commitment to the plasma cell begins in the GC, and suggest that stability and possibly duration of TFH-GC B cell contacts are key for formation of plasma cell-prone precursor GC cells.
Project description:E-proteins are TCR-sensitive transcription factors essential for intrathymic T cell transitions. Here, we show that deletion of E-proteins leads to both enhanced peripheral TGF-?-induced regulatory T (iT reg) cell and thymic naturally arising T reg cell (nT reg cell) differentiation. In contrast, deletion of Id proteins results in reduced nT reg cell differentiation. Mechanistic analysis indicated that decreased E-protein activity leads to de-repression of signaling pathways that are essential to Foxp3 expression. Decreased E-protein binding to an IL-2R? enhancer locus facilitated TCR-induced IL-2R? expression. Similarly, decreased E-protein activity facilitated TCR-induced NF-?B activation and generation of c-Rel. Consistent with this, microarray analysis indicated that cells with E-protein depletion that are not yet expressing Foxp3 exhibit activation of the IL-2 and NF-?B signaling pathways as well as enhanced expression of many of the genes associated with Foxp3 induction. Finally, studies using Nur77-GFP mice to monitor TCR signaling showed that TCR signaling strength sufficient to induce Foxp3 differentiation is accompanied by down-regulation of E-protein levels. Collectively, these data suggest that TCR stimulation acts in part through down-regulation of E-protein activity to induce T reg cell lineage development.