eprintid: 10110061 rev_number: 21 eprint_status: archive userid: 608 dir: disk0/10/11/00/61 datestamp: 2020-09-15 09:58:39 lastmod: 2021-12-07 23:56:17 status_changed: 2020-09-15 09:58:39 type: article metadata_visibility: show creators_name: Solanki, A creators_name: Yánez, DC creators_name: Lau, C-I creators_name: Rowell, J creators_name: Barbarulo, A creators_name: Ross, S creators_name: Sahni, H creators_name: Crompton, T title: The transcriptional repressor Bcl6 promotes pre-TCR induced differentiation to CD4+CD8+ thymocyte and attenuates Notch1 activation ispublished: inpress divisions: UCL divisions: B02 divisions: C08 divisions: D09 divisions: D13 divisions: G24 note: This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed. abstract: Pre-TCR signal transduction is required for developing thymocytes to differentiate from CD4-CD8- double negative (DN) to CD4+CD8+ double positive (DP) cell. Notch signalling is required for T-cell fate specification and must be maintained throughout β-selection, but inappropriate Notch activation in DN4 and DP cells is oncogenic. Here, we show that pre-TCR signalling leads to increased expression of the transcriptional repressor Bcl6 and that Bcl6 is required for differentiation to DP. Conditional deletion of Bcl6 from thymocytes reduced pre-TCR-induced differentiation to DP cell, disrupted expansion and enrichment of icTCRβ+ cells within the DN population and increased DN4 cell death. It also increased Notch1 activation and Notch-mediated transcription in the DP population. Thus, Bcl6 is required in thymocyte development for efficient differentiation from DN3 to DP cell and to attenuate Notch1 activation in DP cells. Given the importance of inappropriate NOTCH1 signalling in T-ALL, and the involvement of Bcl6 in other types of leukaemia, this study is important to our understanding of T-ALL. date: 2020-09-09 date_type: published publisher: The Company of Biologists official_url: https://doi.org/10.1242/dev.192203 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1812955 doi: 10.1242/dev.192203 lyricists_name: Crompton, Tessa lyricists_name: Ross, Susan lyricists_name: Rowell, Jasmine lyricists_name: Yanez Marcayata, Diana lyricists_id: TCROM00 lyricists_id: SEROS53 lyricists_id: JEROW76 lyricists_id: YANEZ87 actors_name: Austen, Jennifer actors_id: JAUST66 actors_role: owner full_text_status: public publication: Development citation: Solanki, A; Yánez, DC; Lau, C-I; Rowell, J; Barbarulo, A; Ross, S; Sahni, H; Solanki, A; Yánez, DC; Lau, C-I; Rowell, J; Barbarulo, A; Ross, S; Sahni, H; Crompton, T; - view fewer <#> (2020) The transcriptional repressor Bcl6 promotes pre-TCR induced differentiation to CD4+CD8+ thymocyte and attenuates Notch1 activation. Development 10.1242/dev.192203 <https://doi.org/10.1242/dev.192203>. (In press). Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10110061/1/dev.192203.full.pdf