Temporal Analysis of Brd4 Displacement in the Control of B Cell Survival, Proliferation, and Differentiation

Isabella Y. Kong, Joel S. Rimes, Amanda Light, Izabela Todorovski, Sarah Jones, Eric Morand, Deborah A. Knight, Ylva E. Bergman, Simon J. Hogg, Hendrik Falk, Brendon J. Monahan, Paul A. Stupple, Ian P. Street, Susanne Heinzel, Philippe Bouillet, Ricky W. Johnstone, Philip D. Hodgkin, Stephin J. Vervoort, Edwin D. Hawkins

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3 Citations (Scopus)

Abstract

JQ1 is a BET-bromodomain inhibitor that has immunomodulatory effects. However, the precise molecular mechanism that JQ1 targets to elicit changes in antibody production is not understood. Our results show that JQ1 induces apoptosis, reduces cell proliferation, and as a consequence, inhibits antibody-secreting cell differentiation. ChIP-sequencing reveals a selective displacement of Brd4 in response to acute JQ1 treatment (<2 h), resulting in specific transcriptional repression. After 8 h, subsequent alterations in gene expression arise as a result of the global loss of Brd4 occupancy. We demonstrate that apoptosis induced by JQ1 is solely attributed to the pro-apoptotic protein Bim (Bcl2l11). Conversely, cell-cycle regulation by JQ1 is associated with multiple Myc-associated gene targets. Our results demonstrate that JQ1 drives temporal changes in Brd4 displacement that results in a specific transcriptional profile that directly affects B cell survival and proliferation to modulate the humoral immune response.

Original languageEnglish
Article number108290
Number of pages22
JournalCell Reports
Volume33
Issue number3
DOIs
Publication statusPublished - 20 Oct 2020

Keywords

  • B cells
  • cellular immunology
  • epigenetics

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