Histone methyltransferase DOT1L controls state‐specific identity during B cell differentiation |
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Authors: | Muhammad Assad Aslam,Mir Farshid Alemdehy,Eliza Mari Kwesi Maliepaard,Fitriari Izzatunnisa Muhaimin,Marieta Caganova,Iris N Pardieck,Teun van den Brand,Tibor van Welsem,Iris de Rink,Ji Ying Song,Elzo de Wit,Ramon Arens,Heinz Jacobs,Fred van Leeuwen |
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Abstract: | Differentiation of naïve peripheral B cells into terminally differentiated plasma cells is characterized by epigenetic alterations, yet the epigenetic mechanisms that control B‐cell fate remain unclear. Here, we identified a role for the histone H3K79 methyltransferase DOT1L in controlling B‐cell differentiation. Mouse B cells lacking Dot1L failed to establish germinal centers (GC) and normal humoral immune responses in vivo. In vitro, activated B cells in which Dot1L was deleted showed aberrant differentiation and prematurely acquired plasma cell characteristics. Similar results were obtained when DOT1L was chemically inhibited in mature B cells in vitro. Mechanistically, combined epigenomics and transcriptomics analysis revealed that DOT1L promotes expression of a pro‐proliferative, pro‐GC program. In addition, DOT1L indirectly supports the repression of an anti‐proliferative plasma cell differentiation program by maintaining the repression of Polycomb Repressor Complex 2 (PRC2) targets. Our findings show that DOT1L is a key modulator of the core transcriptional and epigenetic landscape in B cells, establishing an epigenetic barrier that warrants B‐cell naivety and GC B‐cell differentiation. |
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Keywords: | B‐ cell differentiation, DOT1L, germinal center B cell, plasma cell, PRC2 |
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