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Biology subjects

Cohn, O.

Publications and source records attributed to Cohn, O..

5 recordsLinked to original sources

Single-cell multiomic mapping of genetic predisposition to childhood B-cell acute lymphoblastic leukemia

Inherited genetic variation substantially increases the risk for developing childhood B-cell acute lymphoblastic leukemia (B-ALL), the most common cancer in children, yet the underlying mechanisms remain poorly understood. To address this limitation, we employ a single-cell multiomic framework to functionally dissect common regulatory variants associated with B-ALL risk. Coupling this multiomic analysis with assessment of allelic skews in chromatin accessibility, we reveal the impact of risk alleles and disruptions in transcription factor networks specific to B-cell progenitors, thereby providing mechanistic insights into altered regulatory programs underlying B-ALL predisposition. By constructing long-range variant-to-target gene maps, we identify 34 high-confidence B-ALL susceptibility genes. Among these, we uncover and functionally validate a risk allele that selectively upregulates expression of ELK3, a previously unrecognized regulator of B-cell development and leukemogenesis. Together, these findings establish a comprehensive variant-to-function map of cell state-specific regulatory disruptions underlying inherited predisposition to B-ALL and define new risk mechanisms, which could pave the way for future targeted prevention approaches.

cancer biology↗

Mapping genetic risk mechanisms for immune-mediated diseases across human dendritic cell differentiation

Defining the cell types and mechanisms through which genetic variation operates is essential to understand the biological basis of disease. Although human dendritic cells (DCs) are crucial in regulating immunity, their rarity and limitations in available genomic data have hampered efforts to link inherited disease risk to specific DC subsets. Here, we present a single-cell multi-omic atlas of human DC differentiation from hematopoietic stem and progenitor cells (HSPCs) that includes chromatin accessibility and transcriptomic profiles to infer regulatory networks across DC subsets. By integrating this regulatory architecture with fine-mapped variants from hundreds of complex-trait genome-wide association studies, we systematically map inflammatory, autoimmune, and oncologic disease risk to DC subset-specific variant-to-gene mechanisms. For example, we identify a risk-associated variant that enhances the activity of a PLD4 regulatory element in plasmacytoid DCs, thereby increasing the risk of developing systemic lupus erythematosus and other immune disorders. Collectively, these findings enable a deeper understanding of how complex immune diseases can emerge due to the impact of genetic variation acting in specific DC subsets.

genetics↗

The host transcriptional response to superinfection by influenza virus and streptococcus pneumonia

Secondary bacterial challenges during influenza virus infection ( superinfection) cause excessive mortality and hospitalization. Here we present a longitudinal study of gene-expression changes in murine lungs during superinfection, with an initial influenza A virus (IAV) infection and a subsequent Streptococcus pneumonia (SP) infection. In addition to the well-characterized impairment of the innate immune response, we identified superinfection-specific alterations in endothelial-related genes, including a previously uncharacterized rapid downregulation of particular angiogenic and vascular markers. Superinfection-specific alterations were also evident in the analysis of cellular states related to the hosts immune resistance against pathogens. We found that superinfected mice manifested an excessive rapid induction of immune resistance starting only a few hours after the secondary bacterial challenge. In addition, there was a substantial rewiring of the resistance program: interferon-regulated genes were switched from positive to negative correlations with resistance, whereas genes of fatty-acid metabolism were switched from negative to positive correlations with resistance. Thus, the transcriptional resistance state in superinfection is reprogrammed toward repressed interferon signaling and induced fatty acid metabolism. Our findings suggest new insights into the remodeling of the host defense upon superinfection, providing promising targets for future therapeutic interventions.

systems biology↗

Structure-function conservation between the methyltransferases SETD3 and SETD6

Among the protein lysine methyltransferases family members, it appears that SETD6 is highly similar and closely related to SETD3. The two methyltransferases show high similarity in their structure, which raised the hypothesis that they share cellular functions. Using a proteomic screen, we identified 52 shared interacting-proteins. Gene Ontology (GO) analysis of the shared proteins revealed significant enrichment of proteins involved in transcription. Our RNA-seq data of SETD6 KO and SETD3 KO HeLa cells identified [~]100 up-regulated and down-regulated shared genes. We have also identified a substantial number of genes that changed dramatically in the double KO cells but did not significantly change in the single KO cells. GO analysis of these genes revealed enrichment of apoptotic genes. Accordingly, we show that the double KO cells displayed high apoptotic levels, suggesting that SETD6 and SETD3 inhibit apoptosis. Collectively, our data strongly suggest a functional link between SETD6 and SETD3 in the regulation of apoptosis.

cell biology↗

Distinct gene programs underpinning 'disease tolerance' and 'resistance' in influenza virus infection

When challenged with an invading pathogen, the host defense response is engaged to eliminate the pathogen (resistance) and to maintain health in the presence of the pathogen (disease tolerance). However, the identification of distinct molecular programs underpinning disease tolerance and resistance remained obscure. We exploited transcriptional and physiological monitoring across 33 mouse strains, during in vivo influenza virus infection, to identify two host-defense gene programs - one is associated with hallmarks of disease tolerance and the other with hallmarks of resistance. Both programs constitute generic responses in multiple mouse and human cell types. Our study describes the organizational principles of these programs and validates Arhgdia as a regulator of disease-tolerance states in epithelial cells. We further reveal that the baseline disease-tolerance state in macrophages is associated with the pathophysiological response to injury and infection. Our framework provides a paradigm for the understanding of disease tolerance and resistance at the molecular level.

systems biology↗