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
Affiliations
Isabella Y. Kong
Walter and Eliza Hall Institute of Medical Research, The University of Melbourne, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia
Joel S. Rimes
Walter and Eliza Hall Institute of Medical Research, The University of Melbourne, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia
Amanda Light
Walter and Eliza Hall Institute of Medical Research, The University of Melbourne, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia
Izabela Todorovski
Cancer Therapeutics and Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, VIC, Australia
Sarah Jones
Centre for Inflammatory Diseases, School of Clinical Sciences, Monash University, Parkville, VIC 3052, Australia
Eric Morand
Centre for Inflammatory Diseases, School of Clinical Sciences, Monash University, Parkville, VIC 3052, Australia
Deborah A. Knight
Cancer Therapeutics and Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, VIC, Australia
Ylva E. Bergman
Cancer Therapeutics CRC (CTx), Melbourne, VIC 3000, Australia; Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
Simon J. Hogg
Cancer Therapeutics and Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, VIC, Australia
Hendrik Falk
Walter and Eliza Hall Institute of Medical Research, The University of Melbourne, 1G Royal Parade, Parkville, VIC 3052, Australia; Cancer Therapeutics CRC (CTx), Melbourne, VIC 3000, Australia
Brendon J. Monahan
Walter and Eliza Hall Institute of Medical Research, The University of Melbourne, 1G Royal Parade, Parkville, VIC 3052, Australia; Cancer Therapeutics CRC (CTx), Melbourne, VIC 3000, Australia
Paul A. Stupple
Cancer Therapeutics CRC (CTx), Melbourne, VIC 3000, Australia; Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
Ian P. Street
Walter and Eliza Hall Institute of Medical Research, The University of Melbourne, 1G Royal Parade, Parkville, VIC 3052, Australia; Cancer Therapeutics CRC (CTx), Melbourne, VIC 3000, Australia
Susanne Heinzel
Walter and Eliza Hall Institute of Medical Research, The University of Melbourne, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia
Philippe Bouillet
Walter and Eliza Hall Institute of Medical Research, The University of Melbourne, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia
Ricky W. Johnstone
Cancer Therapeutics and Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, VIC, Australia
Philip D. Hodgkin
Walter and Eliza Hall Institute of Medical Research, The University of Melbourne, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia
Stephin J. Vervoort
Cancer Therapeutics and Cancer Immunology Program, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia; Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, VIC, Australia; Corresponding author
Edwin D. Hawkins
Walter and Eliza Hall Institute of Medical Research, The University of Melbourne, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia; Corresponding author
Summary: 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.