Project description:By their impact on nuclear organisation, enhancers are master regulators of cell fate. We thus developed double Emu-RAG-deficient, 3’RR-RAG-deficient mice and KOKI-RAG-deficient mice to investigate a potential transcriptional cross-talk between Emu and 3'RR enhancers at the pro-B cell stage.
Project description:Numerous B-cell lymphomas feature translocations linking oncogenes with the IgH locus and epigenetic drugs such as histone deacetylase inhibitors (HDACi) have been approved to treat some of them. In this study we investigated IgH locus transcription in B-cell splenocytes stimulated with LPS and the HDACi SAHA. B-cell development is spatially and temporally regulated with the 3'RR enhancer of the IgH locus as a conductor. 3'RR is composed of 4 enhancer elements with a palindromic structure of great significance. We investigated the role of this palindrome with KOKI mice where the 30Kb structure of the 3'RR has been deleted of its palindromic structure.
Project description:Investigation of B cell lymphomas (IgM+ IgD+) located in various places (lung, mesenteric lymph nodes,…) of three different c-myc Igh transgenic mice. Insertion of c-myc in 5' to Emu (cr), in 5' to Cmu with Emu deletion (hv), and in Calpha (co).
Project description:Class Switch Recombination (CSR) is a DNA recombination reaction that diversifies the effector component of antibody responses. CSR is initiated by activation-induced cytidine deaminase (AID), which targets transcriptionally active immunoglobulin heavy chain (Igh) switch donor and acceptor DNA. The 3’ Igh super-enhancer, 3’ Regulatory Region (3’RR), is essential for acceptor region transcription, but how this function is regulated is unknown. Here we identify the chromatin reader ZMYND8 as an essential regulator of the 3’RR and CSR. In B cells, ZMYND8 binds promoters and super-enhancers, including the 3’RR, and controls its activity by modulating the enhancer transcriptional status. In its absence, there is increased 3’RR polymerase loading, and decreased acceptor region transcription and CSR. In addition to CSR, ZMYND8 deficiency impairs somatic hypermutation (SHM) of Igh, which is also dependent on the 3’RR. Thus ZMYND8 controls Igh diversification in mature B lymphocytes by regulating the activity of the 3’ Igh super-enhancer.
Project description:The IgH 3' regulatory region (3'RR) controls class switch recombination and somatic hypermutation in mice. Similar numbers of B cells are found in spleen of 3'RR-deficient mice and wt mice. We compare their transcriptoma in order to find differences in their maturation status.
Project description:The IgH 3' regulatory region (3'RR) controls class switch recombination and somatic hypermutation in mice. Similar numbers of B cells are found in spleen of 3'RR-deficient mice and wt mice. We compare their transcriptoma in order to find differences in their maturation status. B splenocytes from four wt mice and four 3'RR-deficient mice are investigated. Splenic B cells are purified with anti-B220-coupled beads.