Blachly, J. | bioRxiv Science

bioRxiv2026

CD200R1 Marks a Branchpoint During Human Natural Killer Cell Development in Tonsils

Human natural killer (NK) cells arise from common innate lymphoid cell (ILC) progenitor and precursor populations that are selectively enriched within secondary lymphoid tissues (SLTs) and that complete their terminal differentiation through stages of progressively lineage-restricted downstream developmental intermediates. We identify two subsets of tonsil CD94/NKG2A+NKp80- (stage 4A) NK-cell development intermediates that show differential expression of the inhibitory receptor, CD200R1. Ex vivo single-cell transcriptomic, DNA methylation, phenotypic, and functional analyses demonstrate that CD200R1 stage 4A cells represent an immature, oligopotent precursor population enriched for tissue-resident and cytokine-responsive programs. In contrast, CD200R1- stage 4A cells show more restricted NK-cell developmental potential concomitant with features of mature NK cells. These findings help to refine the human NK cell developmental pathway in tonsils and highlight CD200R1 as a useful marker delineating an uncommitted developmental state linking microenvironmental cues to NK-cell maturation and plasticity.

immunology↗

bioRxiv2020

HDAC1 regulates the chromatin landscape to establish transcriptional dependencies in chronic lymphocytic leukemia

HDAC1 is a key regulator of gene expression in cancer. We identified a critical role for HDAC1 in establishing the transcriptional dependencies essential for survival in chronic lymphocytic leukemia (CLL) by profiling HDAC1 with BRD4, H3K27Ac superenhancers, H4K9Ac, chromatin accessibility signatures, Pol2 measurements and expression signatures to generate a regulatory chromatin landscape. Superenhancers marked by high levels of acetylation and BRD4 paradoxically also recruited the highest levels of HDAC1. HDAC inhibition poisoned transcription at these loci to selectively disrupt B-cell transcription factors and B-cell receptor signaling. HDAC1 was also recruited genome-wide at promoters without superenhancers to repress expression; HDAC inhibition induces these genes which include key microRNA networks that reciprocally downregulate CLL specific survival and driver genes. Our work provides a compelling rationale for profiling HDAC1 across cancers to characterize its role in driving the transcriptional dysregulation that is a hallmark of most cancers and develop epigenetic therapeutic strategies. SignificanceOur work definitively establishes the composition of the regulatory chromatin that enables HDAC1 to function as an activator and repressor at distinct target genes within the same tumor to drive transcriptional dysregulation and allow the expression of B cell specific signaling and survival networks that are critical for survival.

cancer biology↗