Biology subjects

Banday, S.

Publications and source records attributed to Banday, S..

4 recordsLinked to original sources

bioRxiv2026

A Distal Super-Enhancer Regulate CD47 Expression and Promotes Macrophage-Mediated Phagocytosis of Ovarian Cancer Cells

CD47 is an innate immune checkpoint that can protect tumor cells from macrophage-mediated clearance, but the regulatory mechanisms underlying its expression in ovarian cancer (OC) remain incompletely understood. Here, we investigated the epigenetic regulation of CD47 expression in OC. Single-cell and spatial transcriptomic analyses indicated preferential CD47 expression in malignant epithelial cells. Integration of publicly available epigenomic datasets revealed a distal regulatory region with enhancer-associated features across ovarian cancer models and HGSOC patient samples. A genome-wide CRISPR-Cas9 screen further implicated PITX2 and EP300 as regulators of CD47 expression. Chromatin immunoprecipitation assays showed PITX2 and EP300 occupancy at candidate enhancer elements within this CD47 regulatory region. Comparative epigenomic analyses suggested that features of this regulatory landscape are also present in fallopian tube epithelial cells and become more prominent in OC. Together, these findings support a PITX2-EP300 regulatory axis associated with CD47 expression and provide evidence for its potential contribution to tumor immune evasion.

cancer biology↗

bioRxiv2026

An ncBAF-ETS2 Chromatin-Remodelling Axis Drives Vascular Smooth Muscle Cell Osteogenic Reprogramming in Vascular Calcification

Introduction: Vascular calcification is a detrimental ageing-related pathology that is markedly accelerated in metabolic disorders. It is driven by osteogenic differentiation of vascular smooth muscle cells (VSMCs), however epigenetic regulatory pathways activated early in this transition remain poorly defined. Methods: An in vitro calcification model was developed using primary human aortic VSMCs cultured with or without mineral stress. Epigenetic changes were assessed using targeted PCR arrays and CUT&RUN sequencing. Key findings were validated in vivo using single-cell sequencing datasets from human large arteries and spatial transcriptomic analysis in atherosclerotic carotid plaques. Transcriptomic and CUT&RUN analyses identified gene targets altered by epigenetic remodelling, and molecular tools were applied to study effects on metabolism, inflammation, apoptosis, and calcification. Results: During early calcification in response to mineral stress, SWI/SNF chromatin remodelling complexes shift toward ncBAF enrichment in pre-osteogenic VSMCs. ncBAF complexes activated transcriptional programs involved in inflammation, apoptosis, and glycolysis-all hallmarks of calcifying VSMCs. The transcription factor ETS2 was identified as a novel component of ncBAF complexes. Disruption of ncBAF or ETS2 impaired osteogenic differentiation and calcification. Notably, ETS2 expression was regulated by ncBAF, forming a positive feedback loop that reinforced VSMC phenotypic switching. Co-activation of ETS2 and ncBAF and the resulting transcriptional shifts were confirmed in human arterial single-cell datasets, with osteogenic/inflammatory clusters showing NFkB and RUNX2 activation. Spatial transcriptomics further suggested that a macrophage-rich microenvironment may promote the differentiation of smooth muscle cells toward an overt osteogenic/inflammatory phenotype. Immunohistochemistry showed that ETS2 levels correlated with calcification severity in human vessels supporting the potential clinical relevance of ETS2. Conclusions: Our findings identify a novel epigenetic mechanism in vascular calcification, where ncBAF and ETS2 cooperate to drive VSMC phenotypic switching. This ncBAF-ETS2 axis represents a potential therapeutic target to modulate VSMC plasticity and intervene early in the progression of cardiovascular calcification.

cell biology↗

bioRxiv2026

Cellular nucleic acid-binding protein (CNBP) dependent cytokine programming shapes host defense against Plasmodium infection

During blood-stage Plasmodium infection, effective immune control hinges on the IL12{beta}-IFN-{gamma} axis, yet how this pathway is transcriptionally tuned in vivo remains incompletely defined. Innate sensing of parasite-derived ligands by pattern-recognition receptors, including Toll like receptors, in dendritic cells and macrophages induces IL-12{beta} production that drives IFN-{gamma} mediated control of infection. Emerging evidence implicates cellular nucleic acid-binding protein (CNBP), a zinc-finger transcriptional regulator, in control of IL12{beta} gene expression in myeloid cells exposed to bacterial and viral infections. Here, we defined the contribution of CNBP in cytokine-driven immunity to Plasmodium infection including both P. falciparum (the major cause of malaria), as well as P. chabaudi and P. berghei ANKA, two rodent species that model human disease. Upon exposure to Plasmodium-infected erythrocytes, CNBP rapidly translocated to the nucleus in mouse and human dendritic cells, bound IL12{beta} promoter, and was required for optimal IL12{beta} induction. Genetic ablation of CNBP in mice and siRNA knockdown of CNBP in human monocyte-derived dendritic cells markedly reduced IL12{beta} production and downstream IFN-{gamma} responses, while TNF- and several other innate cytokines were largely unaffected. In vivo, hematopoietic-specific deletion of CNBP (using vav-iCre; Cnbpfl/fl) resulted in elevated peak parasitemia, impaired parasite clearance, and relapse after initial resolution. Consistent with these outcomes, spleens from mice lacking CNBP in hematopoietic cells exhibited reduced inflammatory remodeling, altered T-cell composition, and transcriptional reprogramming characterized by selective regulation of IL12{beta}-IFN-{gamma} transcripts alongside upregulation of distinct cytotoxic genes. Paradoxically, mice lacking CNBP in hematopoietic cells showed delayed mortality in the lethal infection model, underscoring its context-dependent contributions to host protection and inflammatory pathology. Collectively, these findings position CNBP as a pivotal modulator of the IL12{beta}-IFN-{gamma} axis during malaria, extending its functional repertoire beyond microbial contexts, with potential as a therapeutic target to fine-tune immune responses for enhanced protection with limited immunopathology. Author summaryMalaria remains one of the worlds deadliest infectious diseases, caused by the protozoan Plasmodium that trigger complex immune responses in infected hosts. Effective host defense requires a tightly regulated inflammatory response: too weak and the parasite proliferates unchecked; too strong and the host suffers harmful immunopathology. Central to this balance is the IL12{beta}-IFN-{gamma} signaling axis. In this study, we investigated the role of a transcriptional regulator, known as Cellular Nucleic acid-Binding Protein (CNBP), in shaping the immune response against the Plasmodium parasite. We found that CNBP rapidly responds to parasite exposure, translocates to the nucleus and drives IL12{beta} production in innate immune cells, and promotes downstream IFN-{gamma} driven adaptive immune responses. Mice lacking CNBP in hematopoietic stem cells exhibited changes in transcription of key inflammatory genes; markedly reduced systemic IL12{beta} and IFN-{gamma}, leading to significantly elevated peripheral blood parasitemia and altered immune cell composition. Paradoxically, the absence of CNBP delayed mortality in a lethal infection model and reduced inflammatory responses that are associated with cytokine storm-mediated immunopathology. These findings identify CNBP as a key regulator that fine-tunes protective immunity and inflammatory pathology during malaria, highlighting its potential as a therapeutic target to optimize host defense while limiting harmful inflammation.

immunology↗

bioRxiv2023

Inhibiting the GPI Transamidase Subunit GPAA1 Abolishes CD24 Surface Localization and Enhances Macrophage-Mediated Phagocytosis of Ovarian Cancer Cells

The CD24-Siglec10 signaling axis is an immune checkpoint pathway that shields ovarian cancer cells from phagocytosis by tumor-associated macrophages (TAMs), making it an appealing immunotherapeutic target. Here, we investigate factors influencing CD24 cell surface expression and assess their suitability as drug targets. Using a CRISPR-based knockout screen, we identify GPAA1 (glycosylphosphatidylinositol anchor attachment-1) as a positive regulator of CD24 cell surface expression. GPAA1 is a crucial component of the multi-subunit GPI transamidase complex, which facilitates the attachment of GPI lipid anchor to the C-terminus of CD24, enabling its surface localization. Reducing the activity of GPAA1 in ovarian cancer cells, either by genetic ablation or targeting with an aminopeptidase inhibitor bestatin, disrupts GPI attachment to CD24. This disruption impairs CD24 cell surface localization, enhances phagocytosis by TAMs, and suppresses tumor growth in mice. Our study highlights the potential of GPAA1 targeting as a therapeutic approach for CD24-positive ovarian cancers.

cancer biology↗