Biology subjects

Das, P.

Publications and source records attributed to Das, P..

At least 19 recordsLinked to original sources

bioRxiv2026

Enzyme Activation of Triggerable Polymeric Lysosome Targeting Chimeras

Targeted protein degradation (TPD) has been highly effective for intracellular targets, but extending this approach to extracellular and membrane-bound proteins remains difficult because most extracellular TPD (eTPD) strategies depend on ligand-targeting receptors (LTRs) whose expression and recycling vary across tissues. Existing LTR-independent, multivalent platforms expand the scope of eTPDs by eliminating this dependence on LTRs and enabling cancer-selective designs. Layering in an additional degree of selectivity through endogenously activatable triggers, such as overexpressed enzymes, can enhance the tissue tropism of the LTR-independent platforms and widen therapeutic window. Here we report triggerable polymeric lysosome targeting chimeras (tPolyTACs), which combine antibody-defined targeting with locally triggered covalent capture. tPolyTACs conjugate monoclonal antibodies to phosphatase-cleavable substrates that, upon engagement of endogenous cell-surface phosphatases, unmask a reactive quinone methide electrophile, covalently trapping the target complex and driving its clathrin-mediated internalization and autolysosomal degradation. We show tPolyTAC-mediated degradation of the membrane proteins EGFR, PD-L1, and cMET, and demonstrate that para-substituted electrophiles outperform ortho-substituted analogues likely due to more favorable active-site positioning. These results establish tPolyTACs as a modular, covalent, enzyme-responsive platform that resolves the efficiency-selectivity trade-off limitations in extracellular degradation.

cell biology↗

bioRxiv2026

IRES-mediated translation of delta160p53 regulates p53 functions and fine-tunes cancer homeostasis

Mutations in p53 and its 12 isoforms can alter its functions. As N-terminally truncated isoforms of p53 (delta40p53, delta133p53, and delta160p53) participate in tetramer formation, they are important regulators of cancer fate. Although delta40p53- and delta133p53-mediated regulation of cancer is well reported, the mechanism underlying delta160p53 production and its functional role remains unclear. We investigated the internal ribosomal entry site (IRES)-mediated translation of {Delta}160p53 and its role in cancer regulation. As differential synthesis of delta160p53 was observed under different stress conditions, IRES-mediated translation of this isoform was demonstrated using bicistronic luciferase constructs. No cryptic promoters or splicing sites were detected in the IRES sequence. Cell death and late apoptosis were significantly decreased, while proliferation, the number of cells in the S phase, and drug resistance were induced by delta160p53. Furthermore, delta160p53 did not induce p53-responsive promoters. RNA sequencing analysis of delta160p53 overexpression showed similar results, along with the inhibition of other tumor suppressor genes. Overall, our results provide insights into IRES-mediated translation of delta160p53, which can be considered a novel target for cancer treatment.

molecular biology↗

bioRxiv2026

DCGAN-Based Synthetic MRI Augmentation for Data-centric Brain Tumor Segmentation

Accurate brain tumor segmentation from magnetic resonance imaging (MRI) remains a challenging task because supervised deep learning models require large quantities of annotated data, which are expensive and time-consuming to obtain. This study investigates whether synthetic MRI images generated using a Deep Convolutional Generative Adversarial Network (DCGAN) can improve U-Net-based brain tumor segmentation using synthetic data augmentation. Experiments were performed on the LGG-MRI dataset comprising 3,929 image-mask pairs. A baseline U-Net was first trained using the original training dataset. Synthetic MRI images were subsequently generated using a DCGAN, and threshold-derived pseudo-masks were assigned to the generated images to construct an augmented training dataset. The same U-Net architecture was then retrained using the augmented dataset and evaluated on an identical held-out test set. Compared with the baseline model, DCGAN-based augmentation increased the Dice coefficient from 0.2067 to 0.3037 and the Intersection over Union (IoU) from 0.1243 to 0.1918, while reducing the final test loss from 0.0474 to 0.0275. These results indicate that synthetic MRI augmentation was associated with improved segmentation performance under the experimental conditions of this study. However, the reliance on threshold-derived pseudo-labels and evaluation on a single dataset limit the generalizability of the results. The proposed workflow provides a reproducible implementation for evaluating DCGAN-based synthetic data augmentation in supervised brain tumor segmentation and establishes a baseline for future studies employing more reliable annotation strategies and broader experimental validation.

bioengineering↗

bioRxiv2026

Neurophysiological Functional Connectivity Changes during Difficult Listening in Older and Younger Adults

Older adults often report increased difficulty understanding speech in noisy listening environments. These difficulties are thought to arise from neurophysiological changes associated with aging, including at the level of cortex. Speech comprehension is believed to rely on coordinated activity across distributed cortical regions, mediated by the directional flow of neural signals - their functional connectivity. This connectivity can be analyzed within specific frequency bands, e.g., Delta and Theta, each thought to play a distinct role in speech and language processing. Here, we utilize the Network Localized Granger Causality (NLGC) framework applied to magnetoencephalography (MEG) data to simultaneously estimate cortical source current activities and the their directed functional connectivity. Whole-brain connectivity graphs were analyzed using graph-cluster enhancement and cluster testing. Temporal Response Functions (TRFs) were obtained by relating NLGC-derived neural current estimates to the speech stimulus presented to listeners. The band-specific networks we identify are consistent with the canonical "dual-stream" model of the auditory processing pathway. Delta-band networks primarily involve temporofrontal connections, whereas Theta-band networks showed stronger temporoparietal connectivity. These cortical networks are shown to evolve as listening conditions become increasingly adverse, incorporating frontoparietal areas associated with attention orienting and control. We find that older adults exhibit increased connectivity within areas of the ventral and dorsal auditory streams across all listening conditions, suggesting increased cortical recruitment to support speech comprehension. Although older adults exhibit enhanced time-locked responses to the speech stimulus, these responses did not significantly coincide with their connectivity patterns (and similarly for younger adults), indicating that their connectivity increases are not explained by central gain mechanisms. Together, our findings demonstrate age- and condition-dependent reorganization of speech-related cortical connectivity across neurophysiological frequency bands.

neuroscience↗

bioRxiv2026

Breast cancer stem cells mediated CD8+ T cell exhaustion among different molecular subtypes of breast cancer regulated via NOTCH1/RBPJ/PD-L1 axis

BackgroundBreast cancer stem cells (BCSCs) contribute significantly to breast cancer (BC) mortality among women globally. It underpins tumor heterogeneity in BC by driving variations in stemness potential and altering immune microenvironment. However, how BCSCs, subpopulations of breast cancer cells from distinct molecular subtypes differentially modulate CD8 T-cell exhaustion and immune dysfunction remain unclear. MethodsWe conducted our study from patients with BC of four subtypes. MACS sorted (Lin-CD44+CD24-) BCSCs were prepared for mammosphere formation assay from mastectomies samples. Flow-cytometry was used to analyze breast cancer stem cells (BCSCs). Immunofluorescence, immunohistochemistry, Real Time and Reverse Transcriptase PCR array, Chromatin-immunoprecipitation assay, Transwell, ELISA, Western blotting, Cloning, Transfection, Knockdown, chromatin immunoprecipitation approaches were used to investigate the underlying mechanisms. ResultsHere, we report that BCSCs actively participate in tumor progression by modulating effector CD8 T-cells. Triple-negative breast cancer (TNBC), being the subtype with the most adverse outcomes, sustains the enrichment of stem cell regulating transcription factors like NANOG, OCT4 and SOX2 compared to HER2, Luminal B, and Luminal A subtypes. Tumor from TNBC patients exhibited an exhausted phenotype within CD8 T-cell infiltrates with PD1high TIM3high LAG3 high IFN{gamma}low signature. BCSCs induced increased proportion of exhausted CD8 T-cells, predominantly in the TNBC subtype. Cell-surface Notch1 expression was upregulated in BCSCs across all molecular BC subtypes, with the highest elevation observed in TNBC. Knockdown or inhibition of Notch1 downregulated stemness-associated genes and diminished CSC-mediated induction of CD8 T-cell exhaustion. Cumulatively, these findings suggest that assessment of high Notch1 and Nanog frequency within BCSCs can guide Notch1-targeted therapies and may formulate for new combinatorial treatment strategies to improve patient outcomes. Additionally, therapeutic targeting of BCSC-intrinsic NOTCH1-NANOG/NOTCH1-PD-L1 axis could represent an effective strategy to reduce stemness programs and alter BCSC-driven CD8 T-cell exhaustion, majorly in aggressive subtypes such as TNBC. ConclusionsBCSCs aggressiveness is perpetuated through Notch1-mediated axis. Targeting Notch1 would reduce stemness (majorly NANOG), survival, as well as prevent CD8 T-cell exhaustion (upregulating PD-1, TIM3, LAG3), thereby weakening tumor progression.

cancer biology↗

bioRxiv2026

Mesenchymal-derived neural progenitors underlie local insulin production and neuronal transdifferentiation during retina regeneration

In humans, retinal-neuron death, optic-nerve injuries, and associated neurodegenerative diseases, such as glaucoma and age-related macular degeneration, often lead to permanent vision loss. While the capacity for regeneration is low in the human nervous system, including the retina, some non-mammalian vertebrate species, including zebrafish, are capable of endogenous neuronal regeneration after injury. Unlike mammals, zebrafish do not form a scar that inhibits axonal and neuronal regeneration after injury. Rather, they harbor neural progenitor and stem-cell populations allowing regeneration of entire parts of the nervous system and restoration of tissue integrity and function. In the zebrafish retina, cycling neural progenitor cells of the ciliary marginal zone and quiescent resident neural stem cells (the latter of which are also called Muller glial cells) participate in neuronal regeneration following different types of injury. In this study, we report the identification of a novel, additional cellular source participating in neuronal regeneration of neurons in the zebrafish retina after genetic ablation of retinal ganglion cells. Before injury, these progenitor cells express molecular markers of neural-crest-cell and/or fibroblast identity, such as sox10, pdgfrb, and eya2, while after neuronal ablation they also express proneural factors including the ascl1a and olig2 genes. Combining genetic ablation of neurons with photoconversion or Cre/Lox-dependent genetic lineage tracing of sox10-expressing cells, we demonstrated that these cells can differentiate into post-mitotic retinal neurons in the ganglion cell layer (GCL) in the absence of cell proliferation. We also showed, surprisingly, that this progenitor population locally produces insulin mRNA, and that insulin signaling is involved in the accumulation of mesenchymal-derived neural progenitors in the GCL and in their subsequent transdifferentiation into RGCs. This work reveals an unexpected and novel cellular mechanism of transdifferentiation, dependent on a neural-crest-derived mesenchymal cell population, participating in neuronal regeneration in the zebrafish retina. The discovery of this plastic cell population could potentially lead to new strategies to promote the formation of new neurons in the mammalian retina.

developmental biology↗

bioRxiv2026

Putative Herbicolin A, an antifungal lipopeptide produced by Pantoea agglomerans APC 4211 is a promising biocontrol agent against food spoilage fungi

Fungal contamination of food with yeast and moulds is associated with major economic losses due to spoilage and also poses health risks in the form of mycotoxin production. The strain Pantoea agglomerans APC 4211 isolated from leaves of Ilex aquifolium (holly tree) has broad spectrum antifungal activity against a variety of food spoilage fungi. Genomic analysis of the strain confirmed the presence of biosynthetic gene clusters potentially encoding for the enzymatic machinery required for the production of the antifungal lipopeptide herbicolin A. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis of the cell-free supernatant (CFS) confirmed the presence of molecular masses corresponding to herbicolin A (1300.8 Da), and herbicolin B (1138 Da). Purified herbicolin A has desirable properties for biotechnological applications, including potent antifungal activity against a range of spoilage fungi, thermal stability and resistance to proteases. Herbicolin A has low cytotoxicity against epithelial cell lines and has minimum inhibitory concentrations (MICs) lower than those of some commercial antifungal drugs (0.2 - 2.5 {micro}g/ml). In a model dairy system (10% skim milk), herbicolin A demonstrated excellent solubility and stability, effectively eliminating Aspergillus niger and Penicillium notatum at a concentration of 5 {micro}g/mL. In conclusion, herbicolin A is a potent, naturally occurring antifungal agent with the potential to be applied as a biopreservative in food systems, providing a safe, clean-label, and efficient compound for synthetic preservatives replacement. HighlightsO_LIHerbicolin A has a strong potential as a natural preservative for food protection C_LIO_LIHerbicolin A shows lower MICs than several antifungal agents C_LIO_LIHerbicolin A is stable under heat and resistant to proteolytic degradation C_LIO_LIHerbicolin A has strong solubility and stability in a model dairy system C_LIO_LIHerbicolin A indicates low cytotoxicity against epithelial cell lines C_LI Data summaryThe authors confirm all supporting data, code and protocols have been provided within the article or through supplementary data files.

microbiology↗

bioRxiv2026

Corepressor NCoR1-mediated regulation of mucin dynamics governs gut inflammation

Inflammatory bowel disease (IBD), comprising Ulcerative colitis (UC) and Crohns Disease, is a chronic relapsing immune-mediated inflammatory disorder of the gut. The intestinal mucus layer is a protective barrier that safeguards direct exposure of epithelium to luminal microbes and antigens. A prolonged disruption of the mucus layer may contribute to the development of IBD. Loss of mucin-producing goblet cells is a hallmark of UC. The underlying molecular mechanism controlling goblet regulation remains poorly understood. In the current work, we show a key role for NCoR1 (Nuclear corepressor 1) in goblet cell regulation. A specific downregulation of NCoR1 in intestinal crypts and goblet cells was observed in human UC and mice models. While NCoR1 was upregulated during goblet cell differentiation, inflammatory cues downregulated its expression. Experimental loss of NCoR1 resulted in exacerbated disease in a murine model of colitis, whereas its upregulation via Vitamin D led to a rescue. ChIP-seq led to the identification of KLF-16, a transcription factor, as a target of NCoR1. NCoR1 -KLF16 regulatory axis regulated key goblet cell proteins, including MUC2. Mechanistically, the regulation of MUC2 is modulated by the NCoR1-KLF16 axis, via mTOR signalling. In conclusion, this work shows a critical involvement of NCoR1-KLF16 in governing goblet cell function and intestinal homeostasis.

molecular biology↗

bioRxiv2026

Functionalization and Antimicrobial Evaluation of Azadirachta indica Leaf-Synthesized Silver Nanoparticles with Amoxicillin

The authors have withdrawn this manuscript on administrative grounds to ensure full compliance with institutional requirements regarding the dissemination of thesis-derived research prior to completion of the degree evaluation process. This withdrawal does not reflect any concern about the validity, integrity, accuracy, or reproducibility of the data, methods, or conclusions presented in the manuscript, which stand as reported. The work is intended to be made available again, either as a revised preprint or through peer-reviewed publication, once the relevant institutional requirements have been completed. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

microbiology↗

bioRxiv2026

Synthesis of Biogenic Silver Nanoparticles with Aqueous Extract of Azadirachta indica Seed and Its Antimicrobial Activity on MDR and ESBL-Producing Escherichia coli.

The authors have withdrawn this manuscript on administrative grounds to ensure full compliance with institutional requirements regarding the dissemination of thesis-derived research prior to completion of the degree evaluation process. This withdrawal does not reflect any concern about the validity, integrity, accuracy, or reproducibility of the data, methods, or conclusions presented in the manuscript, which stand as reported. The work is intended to be made available again, either as a revised preprint or through peer-reviewed publication, once the relevant institutional requirements have been completed.. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

microbiology↗

bioRxiv2026

Biological Synthesis of Silver Nanoparticles with Aqueous Extract of Azadirachta indica Leaf and Its Antimicrobial Activity on Uropathogenic MDR and ESBL Producing Escherichia coli.

BackgroundThe plethora of Escherichia coli (E. coli) strains that show multidrug resistance (MDR) has risen. The production of extended-spectrum beta-lactamases (ESBL) enzymes has greatly aided in this. There have been speculations on the effectiveness of silver nanoparticles in treating drug-resistant infections. AimThis research aims to utilize Azadirachta indica (neem) leaf extract for the production of silver nanoparticles (AI-AgNPs), considering its medicinal and antimicrobial properties. Additionally, this research intends to evaluate the efficacy of these nanoparticles on resistant E. coli infections. MethodThe antimicrobial activities and cytotoxicity of silver nanoparticles synthesized using neem leaves extract were tested on MDR and ESBL producing E. coli strains, as well as on Human Embryonic Kidney-293 (HEK-239) cell line, respectively. The characterization of silver nanoparticles was done by UV-Vis Spectrophotometry, Fourier-transform infrared spectrometry (FTIR), Dynamic Light Scattering-Zeta Potential (DLS-Zeta), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and Energy Dispersive X-Ray Spectroscopy (EDAX). ResultsThe synthesized nanoparticles were spherical, smooth, and stable with an average size of approximately 74 nm. The Minimum inhibitory concentration (MIC) of AI-AgNPs was 9.5 {micro}g/ml, and the Minimum bactericidal concentration (MBC) was 121 {micro}g/ml. The IC50 value for AgNPs was 369 {micro}g/mL for HEK-293 cell line exposure. ConclusionThis study showed that the biosynthesis of silver nanoparticles from A. indica extract is highly effective, exhibiting strong antibacterial activity against multidrug-resistant bacteria while exhibiting low toxicity to normal human kidney cells. Hence, biosynthesized silver nanoparticles may be useful as antimicrobial materials for infection control because of their remarkable antibacterial activity.

microbiology↗

bioRxiv2026

Coronin1A regulates tumor microenvironment in colitis-associated colorectal cancer in a SUMO-dependent way

Inflammatory bowel disease (IBD), comprising Crohns disease and Ulcerative colitis, is a group of multifactorial illnesses with persistent gastrointestinal inflammation and a series of undesirable consequences. IBD patients have a three times higher risk of developing colitis-associated colorectal cancer (CAC). A higher mutational burden due to persistent inflammation acts as a driver of dysplasia and even tumorigenesis. While the pathological sequence is known, the molecular mechanisms underlying the transition from chronic inflammation to CAC remain largely elusive. Post-translational modification- SUMOylation plays an integral role in shaping gut inflammation as well as several forms of cancers, including sporadic colorectal cancer. In this study, the contribution of SUMOylation to CAC pathogenesis was characterized. In the AOM-DSS CAC mice model and human IBD patient specimens, SENP5, but not other deSUMOylases, shows an altered expression. Notably, both SENP5 expression dynamics and alterations in the SUMOylome occur in chronically inflamed and neoplastic colon tissues. SENP5 interactome analysis identified Coronin1A (Coro1A), an actin-binding protein predominantly expressed in immune cells. Coro1A also shows a state-specific, distinct expression pattern in the colon. Interestingly, in contrast to wild-type mice, Coro 1A knockout mice were resistant to polyp formation, with reduced cell proliferation, oncogene expression, and epithelial-to-mesenchymal transition (EMT) gene activation, and reduced extracellular matrix (ECM) development and fibrosis, suggesting its integral role in tumorigenesis. WT mice with chronically inflamed colons and polyps have a higher number of M2-like macrophages, with increased abundance of Coro1A, suggesting a role of Coro1A in modulating the tissue microenvironment toward a pro-tumorigenic state. Mechanistically, Coro1A physically interacts with TGF-{beta} RI and regulates TGF-{beta}-TGF-{beta} RI signalling endosome stability, thereby controlling TGF-{beta}-mediated macrophage polarization. Detailed in vitro experiments revealed stabilization of Coro 1A through its interaction with SUMOylated Raftlin protein. Overall, Coro 1A is necessary and sufficient for TGF-{beta} signalling, macrophage polarization, and tumorigenesis in CAC.

cancer biology↗

bioRxiv2026

Insights on Human Dimensions of Freshwater Fish Conservation in Jharkhand and Bihar, India

Conservation outcomes in the socio-economically disadvantaged regions are strongly influenced by human behaviour, social norms, and existing governance mechanisms. This study examined stakeholder attitudes, perceptions, values, norms and decision-making processes associated with the conservation of freshwater fishes in two neighbouring states in Eastern India - Jharkhand and Bihar. An approach integrating the Conservation Planning Framework (CPF) with the Theory of Planned Behaviour (TPB) and Social Values (SV) enabled the development of four interlinked themes: "livelihood and economic prioritisation over conservation", "constraints on participation", "values and conservation willingness" and "erosion of social and cultural memories of mahseer", indicative of a process of dual extinction faced by these iconic freshwater fishes. Despite the widespread positive attitudes of the stakeholders towards native fishes and freshwater ecosystems, conservation intentions and actions in both states were found to be negatively influenced by feeble communication, prioritisation of aquaculture, institutional rigidity, inadequate conservation education, limited actual behavioural control (ABC) and subjective norms-driven livelihood pressures. However, the presence of active fishermen cooperative societies and stronger relational values among the local communities makes Jharkhand better equipped to implement participatory governance and stakeholder-involved conservation engagement plans. By strategically linking CPF, TPB, and SV, this study demonstrates how human attitudes, behaviour, social norms, and institutional structures interact to shape freshwater fish conservation outcomes in regions where livelihood needs intersect with conservation priorities, thereby offering actionable insights for managing the native freshwater fish diversity.

ecology↗

bioRxiv2026

Regulation of BCL11A DNA binding and expression in human erythrocyte precursor HUDEP-2 cells

BCL11A is a transcription factor crucial for neurodevelopment and hematopoiesis. It regulates the developmental switch from fetal hemoglobin (HbF) to adult hemoglobin and is a major therapeutic target for sickle cell disease and {beta}-thalassemia. BCL11A exists in multiple isoforms, including the L isoform (containing a single two-finger ZF2-3 DNA-binding domain) and the XL isoform (containing two arrays: the two-finger ZF2-3 and the three-finger ZF4-6). We used three approaches to investigate BCL11A functions. First, we examined DNA recognition by BCL11A, which preferentially binds the short 6-bp DNA motif TGNCCA. ZF4-6 recognizes all four variants of this motif with distinct strand-specific interactions: TGTCCA on the top strand, TG(A/C)CCA on the complementary strand, and the palindromic TGGCCA on either strand. ZF2-3 also binds TGTCCA from the top strand, featuring a unique thymine interaction by ZF2 Phe388. Motif multiplicity within BCL11A binding sites may promote BCL11A oligomerization by enabling multiple ZF arrays to engage DNA simultaneously. Second, we treated HUDEP-2 cells (which express adult hemoglobin) with inhibitors targeting three epigenetic silencing marks - DNA methylation, histone H3 lysine 9 methylation or H3 lysine 27 methylation. All treatments, individually or in combination, increased HbF expression to varying degrees. Notably, FTX6058 markedly reduced BCL11A transcription and translation (likely via effects on LIN28B), while EML741 caused a partial reduction. Third, we screened 213 pomalidomide- and lenalidomide-derived compounds and quantified proportions of HbF+ cells by flow cytometry. Effects of four compounds were analyzed by protein mass spectrometry. Although BCL11A levels themselves were unchanged, all four compounds selectively decreased levels of known pomalidomide targets, with consistently decreased levels of the zinc-finger proteins IKZF1 and ZFP91. Together, our studies clarify how BCL11A recognizes DNA, how its expression can be modulated epigenetically, and how small-molecule degraders influence its regulatory network, providing new avenues for HbF reactivation therapies.

biochemistry↗

bioRxiv2026

AI-designed nuclease performs robust knock out, base editing and prime editing in plants

Genome-editing applications in biological organisms rely on a limited set of naturally occurring enzymes. Artificial intelligence (AI) is transforming protein design. Here, building on the AI-designed nuclease OpenCRISPR-1, we establish the plant-optimized AI-designed editors (PAiD) as a versatile genome-editing platform in plants. PAiD supports NHEJ-mediated indel generation, adenine and cytosine base editing, and prime editing, with robust performance across multiple loci comparable to SpCas9. These results highlight the translational potential of AI-designed nucleases for plant genome engineering.

plant biology↗

bioRxiv2026

ISG15 orchestrates dynamic crosstalk between mitochondrial fat oxidation and type 1 interferon in myeloid cells

In contrast to Krebs cycle intermediates, the role of mitochondrial fatty acid oxidation (FAO) in immunometabolism remains incompletely characterized. Studying primary bone marrow-derived macrophages (BMDMs), we show that IFN-{beta} and STING activation augments FAO and associated enzymes carnitine palmitoyltransferase 1a (CPT1a) and acetyl-CoA acetyltransferase 1 (ACAT1). Depleting BMDM Cpt1a reduces FAO and dampens type 1 interferon (IFN) signaling due to decreased histone H3-K9/K14 acetylation, supporting the prior finding of an epigenetic role of FAO in sustaining type 1 IFN. Interestingly, FAO induction by IFN was dynamic as a heightened IFN response suppressed FAO, suggesting a concurrent negative-feedback mechanism. This FAO blunting correlated with increased expression of interferon-stimulated gene 15 (ISG15), a ubiquitin-like modifier known to modulate metabolic proteins through ISGylation. This immune-metabolic signature was similarly operational in mice infected with lymphocytic choriomenigitis virus (LCMV) with temporal discordance between ISG15 levels and FAO. The role of ISG15 in this negative feedback was shown with increased FAO and type 1 IFN response in Isg15 knockout BMDMs. Parallely, endogenous co-immunoprecipitation showed interactions between ISG15 and CPT1a/ACAT1. This ISG15-FAO regulatory interaction was also evident in systemic lupus erythematosus (SLE)-associated interferonopathy and in primary monocytes from SLE individuals that exhibited increased ISG15 levels and reduced FAO rates. Collectively, these findings support a model in which type 1 IFN initially enhances FAO to amplify interferon production, but excessive IFN-signaling induces ISG15-mediated inhibition of FAO, a putative feedback loop that restrains inflammation and preserves immune homeostasis. Together these data identify a novel biphasic FAO-dependent immunometabolic regulatory program. Graphical Summary O_FIG O_LINKSMALLFIG WIDTH=190 HEIGHT=200 SRC="FIGDIR/small/700051v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@13f572eorg.highwire.dtl.DTLVardef@174b6aeorg.highwire.dtl.DTLVardef@1856483org.highwire.dtl.DTLVardef@89e5a6_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIType 1 IFN rewires myeloid cell metabolism towards FAO. C_LIO_LIFAO epigenetically fuels Type 1 1IFN response. C_LIO_LIEffect of IFN on FAO is dynamic: inducing FAO at low concentrations while suppressing it during a heightened IFN response. C_LIO_LIEnhanced Type 1 IFN response produces ISG15 which ISGylates key enzymes of FAO altering their stability C_LIO_LIISG15 negatively regulates FAO to control Type 1 IFN homeostasis in a negative feedback loop. C_LI

immunology↗

bioRxiv2026

A highly stringent high-throughput screening assay for identifying transcription-modulating agents of HIV-1 latency

HIV-1 latency remains a central obstacle to curing infection, and current latency-modulating agents (LMAs) suffer from poor specificity and inconsistent efficacy. To enable discovery of small molecules (SMs) that directly target the viral master transcriptional regulatory circuit (MTRC), we developed a highly stringent, dual-reporter high-throughput screening (HTS) assay based on a natural HIV-1 subtype C long terminal repeat (LTR) variant, LRhR-HC, which exhibits markedly reduced transcriptional noise and a high activation threshold. We engineered Jurkat cells to stably harbour two independent reporter cassettes driven by the tough-to-activate LRhR-HC-LTR and the canonical LR-HHC-LTR, enabling simultaneous detection of latency-promoting and latency-reversing activities through both fluorescent and secreted enzymatic reporters. This dual-reporter line responded robustly and predictably to conventional latency-reversal agents (LRAs) and latency-promoting agents (LPAs), validating assay responsiveness. Z'-factor measurements demonstrated excellent assay performance, with values ranging from approximately 0.7 across different formats, confirming a strong dynamic range and reproducibility. Screening of the 1,520-compound Prestwick chemical library (PCL), which includes FDA-approved drugs, identified 27 candidate LPAs, including known agents such as Spironolactone and Aminacrine, thereby validating the assay specificity while revealing several novel inhibitory molecules. A mechanistically focused panel of 10 additional compounds yielded two putative LPAs and one LRA, with secondary analyses confirming their latency-modulating activities and cytotoxicity profiles. Collectively, this HIV-1C-derived dual-reporter platform provides a stringent and flexible HTS system for identifying LMAs with potential applications in both block-and-lock and shock-and-kill cure strategies.

molecular biology↗

bioRxiv2025

From Attitudes to Actions: Bridging Conservation Planning Framework, Theory of Planned Behaviour and Social Values to Protect Charismatic Freshwater Fishes, the Mahseer

Mahseers are a group of iconic freshwater fishes native to the waterbodies of South, East, and South-East Asia, with significant ecological, socio-cultural, and livelihood value. The complexity of the socio-ecological contexts in which the mahseer conservation occurs demand an approach integrating behavioural dimensions of the individuals and groups directly or indirectly involved in it and social and cultural values they hold for these fishes with the conservation planning and implementation processes for better results. This study examined different facets of the mahseer conservation across three environmentally, geographically, and socio-culturally distinct Indian states - Karnataka, Assam, and Uttarakhand under a framework integrating Conservation Planning Framework (CPF) with the Theory of Planned Behaviour (TPB) and Social Values (SV). Across all the focal states, three key themes were constructed - consensus between stakeholders, communication and collaboration, and values and moral responsibility. Our analyses revealed that while shared ecological concerns offered an opportunity for the collective conservation actions, inter-stakeholder conflicts, communication gaps, hesitation to collaborate, top-down governance, and restricted decision-making autonomy available to tribal and local communities acted as the barriers. Stakeholders from all three states demonstrated strong pro-conservation attitudes, moral responsibility, perceived capability to implement the conservation plans and culturally embedded value for mahseer, rooted in religious beliefs, tribal and local identities and recreational traditions. However, on ground analysis revealed a low actual behavioural control amongst many stakeholders limiting translation of the positive elements present in their attitudes and values into tangible conservation outcomes. Our observations emphasise formalising community-based co-management, strengthening inter-departmental coordination, building conservation capacity, adopting socio-culturally grounded communication strategies and repositioning community fishing events as socio-ecological heritage to ensure stakeholder compliance of the existing mahseer conservation plans and improve its success. Furthermore, aligning conservation planning with behavioural drivers and social values could offer more vital insights for formulating inclusive strategies and policies for protecting mahseers and managing their habitats.

ecology↗