º£½ÇÆƽâ°æ

Neural cells in the adult human central nervous system (CNS) display extensive transcriptional heterogeneity. How different layers of epigenetic regulation underpin this heterogeneity is poorly understood. Here we profile, at the single-nuclei epigenomic level, distinct regions of the adult human CNS, for chromatin accessibility and simultaneously for the histone modifications H3K27me3 and H3K27ac. We unveil a putative SOX10 enhancer and primed chromatin signatures at HOX loci in spinal-cord-derived human oligodendroglia (OLG) and astrocytes, but not microglia. These signatures in adult OLG were reminiscent of developmental profiles but were decoupled from robust gene expression. Moreover, using high-resolution Micro-C, we show that induced pluripotent stem-cell-derived human OLGs exhibit a HOX chromatin architecture compatible with the primed chromatin in adult OLGs, bearing a strong resemblance not only to OLG developmental architecture but also to high-grade pontine gliomas. Thus, epigenetic memory from developmental states in adult OLG not only enables them to promptly transcribe Hox family genes during regeneration but also makes them susceptible to gliomagenesis. Single-nucleus epigenomic maps of the adult human brain and spinal cord reveal that adult oligodendroglia retain developmental chromatin patterns, suggesting a molecular memory that may shape repair processes and cancer vulnerability.

SummaryFollicular lymphoma (FL) is an indolent non-Hodgkin lymphoma of germinal center origin, which presents with significant biologic and clinical heterogeneity. Using RNA-seq on B cells sorted from 87 FL biopsies, combined with machine-learning approaches, we identify 3 transcriptional states that divide the biological ontology of FL B cells into inflamed, proliferative, and chromatin-modifying states, with relationship to prior GC B cell phenotypes. When integrated with whole-exome sequencing and immune profiling, we find that each state was associated with a combination of mutations in chromatin modifiers, copy-number alterations to TNFAIP3, and T follicular helper cells (Tfh) cell interactions, or primarily by a microenvironment rich in activated T cells. Altogether, these data define FL B cell transcriptional states across a large cohort of patients, contribute to our understanding of FL heterogeneity at the tumor cell level, and provide a foundation for guiding therapeutic intervention. Graphical abstract Highlights?B cells from follicular lymphoma exhibit 3 distinct transcriptional states?FL B cells differ by enhanced inflammation, proliferation, or chromatin remodeling?Tumor cell states correlate with unique immune-microenvironment features?Unique mutation and CNV profiles highlight potential genetic causes of heterogeneity Krull et al. analyzed bulk transcriptional, genomic, and immune profiles of B cells from follicular lymphoma and reveal 3 distinct transcriptional states. These cell states underscore the inherent variability of FL tumors, independent of stroma, and implicate intrinsic differences as an underpinning to FL heterogeneity.

BACKGROUND Emerging evidence of antibody-independent functions, as well as the clinical efficacy of anti-CD20 depleting therapies, helped to reassess the contribution of B cells during multiple sclerosis (MS) pathogenesis. OBJECTIVE To investigate whether CD19+ B cells may share expression of the serine-protease granzyme-B (GzmB), resembling classical cytotoxic CD8+ T lymphocytes, in the peripheral blood from relapsing-remitting MS (RRMS) patients. METHODS In this study, 104 RRMS patients during different treatments and 58 healthy donors were included. CD8, CD19, Runx3, and GzmB expression was assessed by flow cytometry analyses. RESULTS RRMS patients during fingolimod (FTY) and natalizumab (NTZ) treatment showed increased percentage of circulating CD8+GzmB+ T lymphocytes when compared to healthy volunteers. An increase in circulating CD19+GzmB+ B cells was observed in RRMS patients during FTY and NTZ therapies when compared to glatiramer (GA), untreated RRMS patients, and healthy donors but not when compared to interferon-$\beta$ (IFN). Moreover, regarding Runx3, the transcriptional factor classically associated with cytotoxicity in CD8+ T lymphocytes, the expression of GzmB was significantly higher in CD19+Runx3+-expressing B cells when compared to CD19+Runx3- counterparts in RRMS patients. CONCLUSIONS CD19+ B cells may exhibit cytotoxic behavior resembling CD8+ T lymphocytes in MS patients during different treatments. In the future, monitoring cytotoxic" subsets might become an accessible marker for investigating MS pathophysiology and even for the development of new therapeutic interventions."