Project description:The MHC class II transactivator (CIITA) is essential for the expression of MHC-II genes. CIITA functions as a transcriptional activator when bound to genes although repressive roles have been reported at some loci in other cell types. To define the role of CIITA in gene regulation in human B cells, we performed ChIP-seq for CIITA using three independent antibodies, the histone marks H3K4me3 and H3K27ac, and ATAC-seq in the Raji human B cell line. Additionally, we profiled H3K27ac and ATAC-seq in the CIITA-null RJ2.2.5 cell line. A core set of CIITA peaks were identified that overlapped in all antibodies. Using the H3K27ac, H3K4me3, and ATAC-seq profiles generated in CIITA+ Raji and CIITA-null RJ2.2.5 cells CIITA dependent chromatin modifications were identified. These data define the CIITA regulated genes in human B cells.
Project description:CIITA is the master regulator of MHC II gene expression and hence the adaptive immune response. CIITA expression itself is tightly regulated by three cell type-specific promoters, pI, pIII, and by pIV. Here, we demonstrate that the telomere-binding protein and transcriptional activator ZBTB48 directly binds to both the critical activating elements within CIITA pIII and is essential for its gene expression. ZBTB48 establishes open chromatin at CIITA pIII upstream of activating H3K4me3 modifications both priming CIITA transcription for IFNg-induction and ensuring constitutive expression in primary murine B cells. Hence, ZBTB48 acts as a molecular on-off-switch for B-cell-specific CIITA expression.
Project description:CIITA is the master regulator of MHC II gene expression and hence the adaptive immune response. CIITA expression itself is tightly regulated by three cell type-specific promoters, pI, pIII, and by pIV. Here, we demonstrate that the telomere-binding protein and transcriptional activator ZBTB48 directly binds to both the critical activating elements within CIITA pIII and is essential for its gene expression. ZBTB48 establishes open chromatin at CIITA pIII upstream of activating H3K4me3 modifications both priming CIITA transcription for IFNg-induction and ensuring constitutive expression in primary murine B cells. Hence, ZBTB48 acts as a molecular on-off-switch for B-cell-specific CIITA expression.
Project description:CIITA is the master regulator of MHC II genes expression and hence the adaptive immune response. CIITA expression itself is tightly regulated by three cell type-specific promoters, pI, pIII, and by pIV, and can also be induced by IFNg in non-immune cells. While key regulatory elements have been identified within these promoters, knowledge of transcription factors regulating CIITA is incomplete. Here, we demonstrate that the telomere-binding protein and transcriptional activator ZBTB48 directly binds to both critical activating elements within CIITA pIII and is essential for its gene expression. ZBTB48 establishes open chromatin at CIITA pIII upstream of activating H3K4me3 modifications both priming CIITA transcription for IFNg-induction and ensuring constitutive expression in primary murine B cells. Hence, ZBTB48 acts as a molecular on-off-switch for B-cell-specific CIITA expression.
Project description:CIITA is the master regulator of MHC II gene expression and hence the adaptive immune response. CIITA expression itself is tightly regulated by three cell type-specific promoters, pI, pIII, and by pIV. Here, we demonstrate that the telomere-binding protein and transcriptional activator ZBTB48 directly binds to both the critical activating elements within CIITA pIII and is essential for its gene expression. ZBTB48 establishes open chromatin at CIITA pIII upstream of activating H3K4me3 modifications both priming CIITA transcription for IFNg-induction and ensuring constitutive expression in primary murine B cells. Hence, ZBTB48 acts as a molecular on-off-switch for B-cell-specific CIITA expression.
Project description:Bulk RNAseq analysis was done on single cell clones of U2OS cells either expressing exogeonous CIITA or an empty vector control to identify genes regulated by CIITA expression.
Project description:Acute myeloid leukemia cell lines were treated with the hypomethylating agent decitabine and interferon gamma to investigate if these treatments induce HLA II gene expression. Cells carrying either control or CIITA-targeting sgRNAs were used to test the dependence of the HLA II induction on CIITA.
Project description:Osteolytic destruction is a hallmark of multiple myeloma, resulting from activation of osteoclast mediated bone resorption and reduction of osteoblast-mediated bone formation. However, the molecular mechanism underlying the differentiation and activity of osteoclasts and osteoblasts within a myelomatous microenvironment remains unclear. Here, we demonstrate that the osteocyte-expressed major histocompatibility complex class II transactivator (CIITA) contributes to myeloma-induced bone lesions. CIITA upregulates the secretion of osteolytic cytokines from osteocytes through acetylation at histone 3 lysine 14 in the promoter of TNFSF11 (encoding RANKL) and SOST (encoding sclerostin), leading to enhanced osteoclastogenesis and decreased osteoblastogenesis. In turn, myeloma cell–secreted 2-deoxy-D-ribose, the product of thymidine catalyzed by the function of thymidine phosphorylase, upregulates CIITA expression in osteocytes through the STAT1/IRF1 signaling pathway. Our work thus broadens the understanding of myeloma-induced osteolysis and indicates a potential strategy for disrupting tumor-osteocyte interaction to prevent, or treat patients with, myeloma bone disease.
Project description:Description of differentially expressed genes between KMH2 CIITA-BX648577 knockdown cultures and non-silencing controls To determine the change in gene expression after siRNA interference with the fusion transcript CIITA-BX 648577 identified in KMH2 cells.