Glad that the preprint on identifying and characterizing rare tumor-reactive T cells in multiple myeloma & AML patients is out now doi.org/10.1101/2025.... Single-cell TCR and transcriptome profiling & immunopeptidomics revealed conserved programs and shared non-canonical antigens.

Liquid-liquid phase separation of HP1? Not in our mouse fibroblasts… This paper by the Fabian Erdel group offers a fresh perspective on how this can be reconciled with seemingly conflicting reports: The phase separation propensity of HP1 decreases from yeast → fly → mouse. doi.org/10.1038/s414...

3/ Great joint effort with Philipp Mallm and the Single Cell Open Lab @dkfz.bsky.social, led by Anne Rademacher, Alik Huseynov, and Michele Bortolomeazzi, with key contributions from our colleagues at KiTZ Heidelberg, supported by the @mspacealliance.bsky.social program of @hlsalliance.bsky.social.

2/ Using medulloblastoma cryosections, we analyzed sensitivity, specificity, and spatial signal patterns to distinguish background from rare-cell signals. We also show how reimaging slides improves cell segmentation—and enables additional transcript and protein readouts from the same section.

How do transcription compartments form — and does phase separation drive gene expression? I enjoyed discussing these questions with @akispapantonis.bsky.social a lot, and we put our thoughts together for @naturerevgenet.bsky.social, now out at rdcu.be/erP1u

From enhancer hijacking to ecDNA and onco-condensates – we review how changes in nuclear architecture drive oncogenic gene expression by disrupting enhancer–promoter communication. doi.org/10.1002/ijc..... Kudos to Isabelle Seufert, @claire-vrgs.bsky.social and Sina Wille 👏

A mechanism for maintaining and spreading H3K9me3 in heterochromatin from the Fejes Toth and Aravin labs that depends on the local H3K9me3 density: HP1 dimers recruit SetDB1 to chromatin by simultaneously binding H3K9me3 on histone H3 and auto-methylated SetDB1. www.biorxiv.org/content/10.1...

💻 7/ Our mathematical modeling showed it could be beautifully simple: Each repeat unit independently switches between silent/active states. No fancy mechanisms needed - basic ligand binding math explains everything we see, with no evidence for HP1α phase separation in our mouse fibroblasts.

🔍 6/ Looking up close with super-resolution microscopy revealed: HP1α sits in small ~50 nm clusters that persist during activation. Just good old chromatin binding at work, with additional HP1α molecules recruited through protein-protein interactions.

🔬 2/ We systematically analyzed how chromocenter structure, HP1α binding, histone marks and transcription respond to the recruitment of transcriptional activators with different strengths (VP16, p65, VPR).

🧬 1/ Heterochromatin protein 1 (HP1) still surprises us after all these years: It simply sticks to chromatin when pericentric heterochromatin domains – the chromocenters – are activated in mouse fibroblasts and acts as a local rather than global repressor. New preprint: doi.org/10.1101/2024...