Biology subjects

Mukherjee, D.

Publications and source records attributed to Mukherjee, D..

At least 19 recordsLinked to original sources

bioRxiv2026

High-throughput microfluidic encapsulation of cells in extracellular matrix microbeads for microtissue engineering.

Microfluidics-assisted encapsulation of cells in hydrogel microbeads has found diverse applications in tissue engineering, disease modelling, and drug testing. However, upscaled production of submillimeter-sized microbeads, each encapsulating optimally tens to hundreds of living cells, remains a challenge. Excessive viscous stresses or non-homogeneous crosslinking reactions hamper droplet monodispersity, hydrogel integrity, and/or cell viability. Herein, we present a device consisting of (i) tens of parallel step-emulsifiers arranged radially around the hydrogel inlet and (ii) an in-flow UV crosslinking system capable of continuous generation and crosslinking of up to around 45000 microbeads/min, each encapsulating N~50 cells, at cell viability exceeding 80%. We use gelatin methacryloyl (GelMA) as the biomaterial of choice and establish a unique sweet spot in terms of UV wavelength, irradiance, and exposure time- the latter controlled via the net applied flow rate and the length of the UV-exposed microchannel- at which we achieve an optimal balance between long-term microbead stability and cell viability. In particular, we observe a strong correlation between reduced cell viability and poor crosslinking efficiency, the latter attributed to the presence of a spontaneous core-shell structure. We further study the impact of added methacrylated hyaluronic acid (HAMA) and extracellular matrix (ECM) on cell proliferation and microtissue formation in the case of triple-negative breast cancer (TNBC) cells for future application in drug testing. The upscaled production of the encapsulated microtissues demonstrated here provides new perspectives for both drug testing and cell therapies where the precision in microenvironment formulation as well as production throughput remain of primary importance.

bioengineering↗

bioRxiv2026

TGF-β- and IL-1-dependent fibroblast states differentially shape pancreatic cancer microenvironments and metastasis

Pancreatic ductal adenocarcinoma (PDAC) contains heterogeneous cancer-associated fibroblast (CAF) populations, including interleukin 1 (IL-1)-dependent inflammatory CAFs (iCAFs) and transforming growth factor beta (TGF-{beta})-dependent myofibroblastic CAFs (myCAFs), whose functions at primary and metastatic sites remain incompletely defined. Here, we genetically disrupted IL-1 or TGF-{beta} signalling in fibroblast activation protein (FAP)-expressing CAFs arising from a shared cellular origin to determine how myCAF and iCAF states shape PDAC progression and microenvironments. Depletion of TGF-{beta}-dependent myCAFs, but not IL-1-dependent iCAFs, did not alter primary tumour growth or local metastatic dissemination but significantly reduced liver and lung metastases. Matched primary tumours and liver metastasis analyses also revealed site-specific stromal responses to TGF-{beta} signalling disruption. Experimental models of liver metastasis colonisation and outgrowth indicated that the reduced metastatic phenotype was linked primarily to alterations within pancreatic tumours rather than to impaired malignant cell outgrowth at metastatic sites. Single-cell RNA-sequencing of myCAF-depleted primary tumours revealed extensive transcriptional reprogramming across fibroblast, immune and malignant compartments, highlighting the complexity of assigning myCAF-to-malignant cell signalling mechanisms in vivo. To resolve this crosstalk, we co-cultured PDAC organoids with pancreatic stellate cells engineered to remain in myCAF or iCAF states. Cross-model transcriptomic analyses, together with genetic and pharmacological perturbation studies, showed that myCAF-derived TGF-{beta} directly promotes epithelial-to-mesenchymal transition signalling in PDAC malignant cells, providing a candidate mechanism for the reduced metastasis observed upon myCAF depletion in vivo. These findings reveal distinct, context-dependent roles for TGF-{beta}- and IL-1-dependent CAF states and identify myCAF-derived TGF-{beta} signalling as a stromal mechanism promoting malignant cell plasticity.

cancer biology↗

bioRxiv2026

Long lasting alterations of feeding by adolescent obesity

The prevalence of obesity is increasing worldwide, especially amongst younger populations. As both brain and body are still under development, numerous studies have shown that adolescence is an especially sensitive period for the impact of external insults including unbalanced diets. To better understand and prevent the vulnerability to obesity and maladaptive food choice, it is crucial to explore the long-term impact of adolescent exposure to obesogenic diets on different feeding behaviours. To address this, we gave mice access to an obesogenic diet with a very high-fat content (vHFD) specifically during adolescence and investigated the long-lasting impact on feeding at adulthood months after a switch to a healthy diet. Using specific feeding tests, we found that both males and females vHFD-exposed mice exhibited an increased intake of both standard food and palatable high-fat foods, without impacting preference for non-caloric food rewards. Importantly, these sex-dependent alterations are not fully correlated with diet-induced weight gain but may support long-term vulnerability to overeating and the development or maintenance of obesity.

neuroscience↗

bioRxiv2026

UV-induced translation capacity is regulated developmentally in fungi.

In fast-growing cells, most RNA molecules encode ribosomal subunits. During growth arrest caused by DNA damage, ribosome biogenesis is reduced because it is a highly energy-demanding process. Here, we report that, in two filamentous fungi, UV radiation significantly induces ribosome levels and translation capacity. This UV-induced response is developmentally regulated and occurs after filament formation. Translation induction modestly but significantly enhances both UV survival and repair. While some of the mRNAs that are differentially associated with ribosomes following UV exposure are associated with DNA repair, most of them belong to modules involved in protein folding and gene expression. TOR signaling is required for the immediate UV induction of ribosome biogenesis genes. However, we provide evidence that UV induces mechanisms that operate either upstream of or in parallel with TOR. These findings suggest a novel type of response to DNA damage, in which the primary aim is to protect the integrity of gene expression from the detrimental effects of UV radiation on transcription.

microbiology↗

bioRxiv2026

Modeling Particle Transport In Biomedical Flows Using Implicit Geometry Representations

Computational analysis of physiological and biomedical systems necessitate efficient geometry representations for high fidelity model predictions, including patient or device specificity. Particle-based Lagrangian computational approaches comprise a valuable approach to gain insights from quantitative velocity and pressure data from computational models. Examples include particle dynamics and transport in human vasculature for diseases such as stroke, thrombosis, and embolisms; and modern targeted drug delivery systems in the vascular network and respiratory airways. However, current particle simulation approaches can bear significant computational expense that scales with both number of particles and background fluid mesh resolution. A significant determinant of this computational expense is the contact resolution between particles and anatomically realistic vessel wall. Here, we develop an efficient particle dynamics model that leverages an implicit representation of real anatomical features using a signed distance field to efficiently resolve particle-wall contact. We outline the underlying algorithmic details, followed by a systematic illustration of performance and accuracy using simplified and analytically defined geometries and flow fields. Subsequently, we present a representative simulation of embolic particles along a human vascular segment where we compare our distance field-based approach against classical wall-contact checks based on assessing particle boundary intersection with triangulated surface mesh. Our approach transforms the underlying Lagrangian contact detection operation into an equivalent Eulerian operation, significantly speeding up bulk particle dynamics computations without significantly impacting accuracy or geometric fidelity.

bioengineering↗

bioRxiv2026

Cross-species graph-embedding unmasks the ageing microenvironment as a key determinant of pancreatic cancer malignant cell biology and therapy response

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis and is characterised by an extensive pro-tumorigenic stroma. Although most PDAC cases occur in older patients, the impact of ageing on malignant-stromal interactions and therapy response remains poorly understood. Here, we established orthotopically-grafted organoid-derived PDAC models across three murine age groups to characterise changes in the PDAC stroma and malignant cells with ageing. Cross-species analyses of tumour transcriptomes using a graph-embedding approach showed that integrating mouse models of different ages better captures the diversity of human PDAC, and that aged models more faithfully recapitulate the biology of older patients with PDAC. We also demonstrated that aged PDAC models have a more inflammatory stroma than that of younger tumours, shaping the malignant cell transcriptome. Finally, graph-embedding identified IRAK4 as a candidate therapeutic vulnerability in aged, but not young, KRAS- and p53-mutant PDAC, which we validated in preclinical drug studies. These findings highlight how ageing is a critical determinant of PDAC biology and associated therapeutic vulnerabilities, which should be an important consideration when designing disease models for preclinical development of precision therapies.

cancer biology↗

bioRxiv2026

Adolescent obesity induces sex-specific alterations of action control

The prevalence of obesity is rising worldwide in young people and is associated with poor long-term health outcomes. To counter obesity, weight loss strategies especially involve changes in feeding behaviors and food choice. However, the high level of relapse to unhealthy dietary habits represents an important challenge, suggesting long-term alterations of decision-making and food-seeking processes. Previous studies showed that adolescence is critical for the development of decision-making functions. Thus, it is essential to understand the precise impact of the exposure to obesogenic diets during this life stage on the different processes underlying flexible control of food-seeking actions. To address this, we gave mice access to high-fat diets (HFDs) with different fat contents during adolescence and investigated the long-lasting impact on action control at adulthood after a switch to a healthy diet. We uncovered important sex differences. In both males and females, exposure to HFD with very high-fat content (60%) promoted habitual behavior, which is less flexible to adapt to changes in outcome value or action-outcome relationships. In contrast, exposure to HFD with lower fat content (45%) impaired action control based on the updating of outcome value in males only, while impairing action control based on the updating of action-outcome relationships in females only. These findings highlight how the consumption of obesogenic diets during adolescence has long-lasting, diet- and sex-dependent effects on decision-making processes, promoting habitual responses to food. These changes may support long-term vulnerability for mental and physiological health conditions. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/702500v2_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@73aab1org.highwire.dtl.DTLVardef@1cb8110org.highwire.dtl.DTLVardef@1866a5dorg.highwire.dtl.DTLVardef@1b11d2c_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2026

Eco-friendly approach to indenodiazepinones from o-formylynones and o-phenylenediamines: Novel pharmacophoric constructs and their anti-bacterial activity

We have conceptualised and executed an efficient, eco-friendly, one-flask, synthetic approach of general applicability to functionally enriched and potentially pharmacophoric tetracyclic indenodiazepinones through a base-mediated reaction cascade between a multifunctional o-formylynones and commercial o-phenylenediamines. The pertinence of this operationally simple, no-waste protocol, embodying many green and sustainable features, has been scoped with 26 variegated examples. This controlled one-pot assembly of novel tetracyclic indenodiazepinones with an unusual placement of an olefin through a reaction cascade involving Schiff base formation, intramolecular aza-Michael addition and a Mannich reaction between o-formylynones and o-phenylenediamines rapidly generates a diverse library poised for exploring their therapeutic potential and medicinal chemistry applications. The newly accessed indenodiazepinones exhibit promising antibacterial activities against many microorganisms and are non-cytotoxic even at higher concentrations. Interestingly, one of the compounds, 3v did not develop resistance in Salmonella Typhimurium (STM) upon repeated exposure to sub-lethal doses up to the 160th cycle, whereas resistance against clinically used antibacterial ciprofloxacin was attained at the 128th cycle. These preliminary findings open avenues towards the development of novel antimicrobial agents with enhanced durability against drug resistance and these efforts are disclosed in this report. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=133 SRC="FIGDIR/small/697289v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@1d1d9beorg.highwire.dtl.DTLVardef@2e8560org.highwire.dtl.DTLVardef@36742eorg.highwire.dtl.DTLVardef@105ae7c_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2025

Efficient elimination of microbial infections in wounds using plasma activated water hydrogel

Surgical site infections are among the most common postoperative complications and remain a major global health concern, further intensified by increasing antimicrobial resistance. Plasma-activated water (PAW) has emerged as a novel antimicrobial strategy, though earlier studies suggested its activity depends on an acidic pH. To overcome this limitation, we previously developed a high-strength, neutral pH-buffered formulation (hs-PAbW) optimized for human clinical use, which preserved strong antimicrobial properties. In the present work, we created a hydrogel incorporating hs-PAbW at a bactericidal yet non-cytotoxic concentration (hs-PAbW-20) and evaluated its therapeutic performance in mouse wound models. In Balb/c mice, hs-PAbW-20 gel markedly reduced Pseudomonas aeruginosa and Staphylococcus aureus loads, demonstrating efficacy comparable to neomycin and soframycin. The gel also enhanced wound closure by regulating key genes involved in tissue repair. In a diabetic C57BL/6 model, hs-PAbW-20 gel similarly lowered P. aeruginosa burden and accelerated healing. Collectively, these results highlight hs-PAbW-20 gel as a promising next-generation wound therapy capable of addressing the shortcomings of traditional antibiotic-based treatments.

microbiology↗

bioRxiv2025

Atypical activation and molecular glue-like dimerization mechanism of an intrinsically-biased chemokine receptor

CXCR7, also known as atypical chemokine receptor 3 (ACKR3), is a naturally-biased, {beta}-arrestin-coupled seven transmembrane receptor (7TMR) that lacks productive coupling with heterotrimeric G-proteins. Despite a critical involvement in cancer metastasis, cardiovascular pathophysiology, and inflammatory disorders, the molecular basis of non-canonical activation and functional divergence of CXCR7 remains elusive. Here, we present a complete landscape of CXCR7 activation using a series of cryo-EM structures, and discover an atypical activation mechanism that is distinct from prototypical GPCRs. CXCR7 is maintained in a basal conformation by a unique tripartite ionic-lock involving TM5-TM6, in contrast to a broadly conserved TM3-TM6 ionic-lock in GPCRs, which is disrupted upon receptor activation. Importantly, activation of CXCR7 results in a constricted pocket and distinct surface topology on the intracellular side compared to prototypical GPCRs. Serendipitously, we capture novel dimeric arrangements of CXCR7 with an inter-protomer stitching by a native phospholipid serving as a molecular glue, and identify previously unanticipated extrahelical allosteric sites on the receptor. Surprisingly, in an intermediate state structure of CXCR7, the second extracellular loop (ECL2) displays a self-blocking conformation, in stark contrast to ECL2-mediated self-activating mechanism reported recently for some orphan GPCRs. Finally, we unequivocally establish CXCR7 as an atypical opioid receptor via a large peptide library screening and structure elucidation in complex with distinct opioid peptides imparting full receptor activation. In summary, our study elucidates an atypical mechanism of CXCR7 activation, and establishes it as an alternative, non-canonical opioid receptor target with potential for novel pain therapeutics.

biochemistry↗

bioRxiv2025

Adventitial leptin receptor-expressing fibroblasts are preferential contributors to fibrotic remodeling of the heart post infarction

BackgroundCardiac fibrosis, a hallmark of heart failure and an unmet clinical need, arises from pathological activation of pre-existing cardiac fibroblasts (CFs), but the contribution of CF heterogeneity to this process remains unclear. MethodsMurine models were used to lineage trace or deplete a specific sub-population of CFs at baseline and after myocardial infarction (MI). Transcriptional and epigenetic differences between fibroblast subsets were assessed using next-generation sequencing. Conservation in humans was evaluated through single-cell RNA-seq datasets and histological examination. ResultsIn mice, fibroblasts were the sole cardiac cell type expressing the signaling-capable isoform of the leptin receptor (LepR). LepR+ CFs emerged neonatally, occupied a defined niche in the coronary adventitia, exhibited enhanced hedgehog signaling, and responded to leptin. After MI, LepR-Cre+ CFs proliferated more than interstitial CFs, became a predominant fibroblast lineage in the scar, and their genetic ablation reduced fibrosis while improving function. LepR+ CFs were also detected in the human heart, where they were embedded in an adipocyte-rich niche. ConclusionsThese findings identify adventitial fibroblasts as key drivers of pathological remodeling and demonstrate that fibroblasts, rather than cardiomyocytes, are the principal responders to leptin in the heart, redefining how this major endocrine pathway influences cardiac remodeling and disease.

cell biology↗

bioRxiv2025

Lead optimization against drug-resistant Leishmania donovani infection: Semi-synthetic derivatives of ethyl linoleate isolated from Indian edible mushroom Meripilus giganteus.

Visceral leishmaniasis, the most severe form, affects thousands of people annually. Current drugs in practice fail to provide an absolute cure. Globally, treatment relies on a single dose of liposomal amphotericin B, which requires a costly setup and cold chain to maintain. Natural molecules remain the vital sources of therapeutic ingredients in modern medicine. Meripilus giganteus is traditionally consumed by the people of the North-eastern regions of the Himalayas, India. In this study, we planned for the stepwise bioactivity-guided isolation of natural molecules from M. giganteus and to synthesize more potential therapeutic derivatives against the drug-resistant Leishmania infection. HPLC chromatogram of ethyl acetate extract obtained from M. giganteus revealed the presence of ethyl linoleate as the most active anti-leishmanial molecule. Several derivatives of ethyl linoleate were synthesized and evaluated against Leishmania promastigotes. Among them, a single epoxygenated variant of ethyl linoleate, ethyl (Z)-8-(3-(oct-2-en-1-yl) oxiran-2-yl) octanoate (EL3), showed promising anti-leishmanial activity against both drug-sensitive and drug-resistant Leishmania donovani. The lead derivative disrupts the biosynthesis of trypanothione from glutathione and spermidine, making the parasite vulnerable to the oxidative burst inside the host. Interestingly, the lead derivative was found to be more efficient against the drug-resistant L. donovani, in vivo. Besides this, it has almost no toxicity towards host cells. Considering the urgency for new drug development, we propose this novel semi-synthetic derivative as a potent therapeutic lead.

immunology↗

bioRxiv2025

IL-17A potentiates malignant T-cell viability via electron transport chain complex I in cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is a rare malignancy of skin-resident T cells characterized by an aberrant cytokine profile, notably elevated Interleukin-17A (IL-17A) levels. However, the functional importance of IL-17A dysregulation in the CTCL pathogenesis remains poorly understood. Our analysis revealed increased IL-17A receptor (IL-17RA) expression in CTCL patient samples, supporting the importance of IL-17A signaling in CTCL progression. Proteomic and metabolomic profiling of IL-17A-treated malignant T cells revealed mitochondrial electron transport chain (ETC) complex I as a key downstream target of IL-17A signaling. Furthermore, we confirmed the elevated expression of ETC complex I in CTCL patient samples compared to healthy control T cells, hence highlighting the clinical relevance of the IL-17A signaling-ETC complex 1 axis. Altogether, our data unveil the function of IL-17A signaling in the metabolic axis in CTCL progression, which could be useful for developing advanced therapeutic strategies. Significance statement: We uncover an IL-17A-induced electron transport chain (ETC) complex I pro-tumorigenic circuit and provide proof of concept evidence that ETC complex I can be targeted to combat the challenges posed by Cutaneous T-cell Lymphoma aggressiveness.

cancer biology↗

bioRxiv2025

Intracellular formate is a critical mediator of the antimicrobial fate of Salmonella Typhimurium Against meropenem and ciprofloxacin

Salmonella enterica serovar Typhimurium (STM) employs various strategies to endure antibiotic stress, but the contribution of central metabolites to resistance remains insufficiently characterized. In this work, we identify intracellular formate, produced by pyruvate-formate lyase (PflB), as a key determinant of STM susceptibility to meropenem and ciprofloxacin. Deletion of pflB disrupts cellular pH homeostasis, impairing efflux pump function, increasing reactive oxygen species, and causing membrane depolarization, collectively heightening sensitivity to antibiotics. Supplementing extracellular formate reverses these phenotypes. Mechanistically, pH imbalance activates the RpoE-csrB regulatory pathway, leading to reduced expression of efflux pump genes acrB and tolC, while extracellular formate engages the BarA/SirA two-component system to further influence the CsrA/csrB network. Disrupting the formate pool interferes with efflux-dependent resistance, revealing a previously unrecognized signalling function for intracellular metabolites. Overall, our results position formate as a metabolic driver of antibiotic outcomes in STM and highlight it as a potential target for mitigating resistance.

microbiology↗

bioRxiv2025

Undecaprenyl Pyrophosphate Phosphatase (UppP) is a pivotal element in Salmonella Intramacrophage Survival

To establish infection, Salmonella confronts a dynamic barrage of host-induced stresses. The peptidoglycan layer, essential for maintaining cell integrity and counteracting environmental stress, relies on the lipid carrier undecaprenyl phosphate, generated by Undecaprenyl pyrophosphate phosphatase (UppP). While UppP is linked to virulence in other pathogens, its role in Salmonella remains unclear. We show that an uppP mutant in S. Typhimurium exhibits altered cell morphology, reduced stiffness, and impaired survival in RAW 264.7 macrophages. The mutant is also attenuated in systemic infection in C57BL/6 mice. These defects are associated with increased sensitivity to nitrosative stress. Notably, iNOS inhibition or deficiency restores intracellular survival of the uppP mutant in both RAW 264.7 macrophages and the mouse model, implicating UppP in resistance to nitrosative stress. Our findings reveal a critical role for UppP in promoting Salmonella survival within macrophages and contributing to systemic pathogenesis.

microbiology↗

bioRxiv2025

Computational Modeling Of Immersed Non-spherical Bodies In Viscous Flows To Study Embolus Hemodynamics Interactions For Large Vessel Occlusion Stroke.

Interactions of particles with unsteady non-linear viscous flows has widespread implications in physiological and biomedical systems. One key application where this plays a fundamental role is in the mechanism and etiology of embolic strokes. Specifically, there is a need to better understand how large occlusive emboli traverse complex vascular geometries, and block a vessel disrupting blood supply. Existing modeling approaches resort to key simplifications in terms of embolic particle shape, size, and their coupling to fluid flow. Here, we devise a novel computational model for resolving embolus-hemodynamics interactions for large non-spherical emboli approaching near occlusive regimes in anatomically real vascular segment. The formulation relies on extending an immersed finite element approach, coupled with a six degree-of-freedom particle dynamics model. The geometric complexities and their manifestation in embolus-flow and embolus-wall interactions are handles using a parametric shape representation, and projection of vessel signed distance fields on the particle boundaries. We illustrate our methodology and algorithmic details, as well as present examples of benchmark cases and convergence of our technique. Thereafter, we demonstrate a parametric study of large emboli for LVO strokes, showing that our methodology can capture the non-linear tumbling dynamics of emboli originating form their interactions with the flow and vessel walls; and resolve near-occlusive scenarios involving lubrication effects around the embolus and flow re-routing to non-occludes branches. This is a key methodological advancement in stroke modeling, as to the best of our knowledge this is the first modeling framework for LVO stroke and occlusion biofluid mechanics. Finally, even though we present our framework from the perspective of LVO strokes, the methodology as developed is broadly generalizable to two-way coupled fluid-particle interaction in unsteady viscous flows for a wide range of applications.

bioengineering↗

bioRxiv2025

Predicting High-Resolution Spatial and Spectral Features in Mass Spectrometry Imaging with Machine Learning and Multimodal Data Fusion

Recent advancements in molecular Mass Spectrometry Imaging (MSI) have sparked interest in integrating high spatial resolution methods with molecular mass-spectrometry-based chemical imaging. Fusion-based algorithms have proven effective in generating high spatial-resolution molecular mass spectra. However, a significant challenge stems from the differing physical mechanisms underlying image generation and data upsampling techniques, potentially leading to discrepancies in integrated information channels. Integrating physical constraints into data processing workflows is essential to tackle this issue. In this study, we propose an innovative approach that merges data from Fourier transform ion cyclotron resonance (FTICR), time- of-flight matrix-assisted laser desorption/ionization (MALDI-ToF), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging techniques. By leveraging FT-ICRs unparalleled spectral resolution and ToF-SIMSs exceptional spatial resolution, we achieve submicron spatial resolution, enabling the observation of intact molecular species with remarkable spectral precision. Canonical correlation analysis is employed to incorporate physical constraints. Through sophisticated image processing and machine learning techniques, the results of this fusion hold significant promise for advancing our comprehension of complex systems and unveiling concealed molecular intricacies.

neuroscience↗

bioRxiv2025

Neutrophil KLF2 regulates inflammasome-dependent neonatal mortality from endotoxemia

Preterm neonates die at a significantly higher rate from sepsis than full-term neonates, attributable to their dysregulated immune response. In addition to tissue destruction caused directly by bacterial invasion, an overwhelming cytokine response by the immune cells to bacterial antigens also results in collateral damage. Sepsis leads to decreased gene expression of a critical transcription factor, Kruppel-like factor-2 (KLF2), a tonic repressor of myeloid cell activation. Using a murine model of myeloid-Klf2 deletion, we show that loss of KLF2 is associated with decreased survival after endotoxemia in a developmentally dependent manner, with increased mortality at postnatal day 4 (P4) compared to P12 pups. This survival is significantly increased by neutrophil depletion. P4 knockout pups have increased pro-inflammatory cytokine levels after endotoxemia compared to P4 controls or P12 pups, with significantly increased levels of IL-1{beta}, a product of the activation of the NLRP3 inflammasome complex. Loss of myeloid-KLF2 at an earlier postnatal age leads to a greater increase in NLRP3 priming and activation and greater IL-1{beta} release by BMNs. Inhibition of NLRP3 inflammasome activation by MCC950 significantly increased survival after endotoxemia in P4 pups. Transcriptomic analysis of bone marrow neutrophils showed that loss of myeloid-KLF2 is associated with gene enrichment of pro-inflammatory pathways in a developmentally dependent manner. These data suggest that targeting KLF2 could be a novel strategy to decrease the pro-inflammatory cytokine storm in neonatal sepsis and improve survival in neonates with sepsis. Summary sentenceKLF2 regulates the developmental response to endotoxin in neonatal mice through the NLRP3 inflammasome signaling pathway.

immunology↗