Biology subjects

Liu, Q.

Publications and source records attributed to Liu, Q..

At least 19 recordsLinked to original sources

bioRxiv2018

Bacteriophages dynamically modulate the gut microbiota and metabolome

The human gut microbiome is comprised of densely colonizing micro-organisms in dynamic interaction with each other and the host. While the bacterial component of the microbiome is under intense investigation, far less is known about how bacteriophages impact bacterial communities in the gut. We investigated the dynamic effects of phages on a model microbiome using gnotobiotic mice colonized by commensal bacteria that colonize the human infant gut, and found that phage predation not only directly impacts susceptible bacteria but also leads to cascading effects on other bacterial species via inter-bacterial interactions. Using metabolomic profiling, we also found that the shifts in the microbiome caused by phage predation have a direct consequence on the gut metabolome. Our work provides insight into the ecological importance of phages as modulators of bacterial colonization, and additionally suggests the potential impact of gut phages on the host with implications for the use of phages as therapeutic tools to rationally and precisely modulate the microbiome.

microbiology↗

bioRxiv2018

Bacterial T6SS Effector EvpP Inhibits Neutrophil Recruitment via Jnk-Caspy Inflammasome Signaling In vivo

The type VI secretion system (T6SS) comprises dynamic complex bacterial contractile nanomachines and is used by many bacteria to inhibit or kill other prokaryotic or eukaryotic cells. Previous studies have revealed that T6SS is constitutively active in response to various stimuli, or fires effectors into host cells during infection. It has been proposed that the T6SS effector EvpP in Edwardsiella piscicida can inhibit NLRP3 inflammasome activation via the Ca2+-dependent JNK pathways. Here, we developed an in vivo infection model by microinjecting bacteria into the tail vein muscle of 3-day-post-fertilized zebrafish larvae, and found that both macrophages and neutrophils are essential for bacterial clearance. Further study revealed that EvpP plays a critical role in promoting the pathogenesis of E. piscicida via inhibiting the phosphorylation of Jnk signaling to reduce the expression of cxcl8a, mmp13 and IL-1{beta} in vivo. Subsequently, by utilizing Tg (mpo:eGFP+/+) zebrafish larvae for E. piscicida infection, we found that the EvpP-inhibited Jnk-caspy inflammasome signaling axis significantly suppressed the recruitment of neutrophils to infection sites, and the caspy- or IL-1{beta}-MO knockdown larvae were more susceptible to infection and failed to restrict bacterial colonization in vivo.\n\nIMPORTANCEInnate immunity is regulated by phagocytic cells and is critical for host control of bacterial infection. In many bacteria, T6SSs can affect bacterial virulence in certain environments, but little is known about the mechanisms underlying T6SS regulation of innate immune responses during infection in vivo. Here, we investigated the role of an E. piscicida T6SS effector EvpP in manipulating the reaction of neutrophils in vivo. We show that EvpP inhibits the activation of Jnk-caspy inflammasome pathway in zebrafish larvae, and reveal that macrophages are essential for neutrophil recruitment in vivo. This interaction improves our understanding about the complex and contextual role of a bacterial T6SS effector in modulating the action of myeloid cells during infection, and offers new insights into the warfare between bacterial weapons and host immunological surveillance.

microbiology↗

bioRxiv2018

AIM-SNPtag: a computationally efficient approach for developing ancestry-informative SNP panels

Inferring an individuals ancestry or group membership using a small set of highly informative genetic markers is very useful in forensic and medical genetics. However, given the huge amount of SNP data available from a diverse of populations, it is challenging to develop informative panels by exhaustively searching for all possible SNP combination. In this study, we formulate it as an algorithm problem of selecting an optimal set of SNPs that maximizes the inference accuracy while minimizes the set size. Built on this conception, we develop a computational approach that is capable of constructing ancestry informative panels from multi-population genome-wide SNP data efficiently. We evaluate the performance of the method by comparing the panel size and membership inference accuracy of the constructed SNP panels to panels selected through empirical procedures in former studies. For the membership inference of population groups including Asian, European, African, East Asian and Southeast Asian, a 36-SNP panel developed by our approach has an overall accuracy of 99.07%, and a 21-SNP subset of the panel has an overall accuracy of 95.36%. In comparison, the existing panel requires 74 SNPs to achieve an accuracy of 94.14% on the same set of population groups. We further apply the method to four subpopulations within Europe (Finnish, British, Spain and Italia); a 175-SNP panel can discriminate individuals of those European subpopulations with an accuracy of 99.36%, of which a 68-SNP subset can achieve an accuracy of 95.07%. We expect our method to be a useful tool for constructing ancestry informative markers in forensic genetics.

bioinformatics↗

bioRxiv2018

Red and black: A β-carotene-binding protein carrying a red pigment regulates body-color transition in locusts

Changes of body color have important effects for animals in adapting to variable environments. The migratory locust exhibits body color polyphenism between solitary and gregarious individuals, with the former displaying a uniform green coloration and the latter having a prominent pattern of black dorsal and brown ventral surface. However, the molecular mechanism underlying the density-dependent body color changes of conspecific locusts remain largely unknown. Here, we found that up regulation of {beta}-carotene-binding protein promotes the accumulation of red pigment, which added to the green color palette present in solitary locusts changes it from green to black, and that down regulation of this protein led to the reverse, changing the color of gregarious locusts from black to green. Our results provide insight that color changes of locusts are dependent on variation in the red {beta}-carotene pigment binding to {beta}CBP. This finding of animal coloration corresponds with trichromatic theory of color vision.

evolutionary biology↗

bioRxiv2018

Microbial Cells Harboring a Mitochondrial Gene Are Capable of CO2 Capture

Global warming is escalating with increased temperatures reported worldwide. Given the enormous land mass on the planet, biological capture of CO2 remains a viable approach to mitigate the crisis as it is economical and easy to implement. In this study, a gene capable of CO2 capture was identified via selection in minimal media. This mitochondrial gene named as OG1 encodes the OK/SW-CL.16 protein and shares homology with cytochrome oxidase subunit III of various species and PII uridylyl-transferase from Loktanella vestfoldensis SKA53. CO2 capture experiments indicate that {delta}13C was substantially higher in the cells harboring the gene OG1 than the control in the nutrition-poor media. This study suggests that CO2 capture using engineered microorganisms in barren land can be exploited to address the soaring CO2 level in the atmosphere, opening up vast land resources to cope with global warming.\n\nIMPORTANCEGlobal warming crisis is deteriorating with increased CO2 levels in the atmosphere each year. Action must be taken before catastrophic consequences occur in the not-so-distant future. Biological capture of CO2 is a feasible approach to alleviate the current crisis. We have identified a mitochondrial gene which demonstrated CO2 utilization capability. Data presented in this study suggest that CO2 capture using engineered microorganisms can be harnessed to address the ever-rising CO2 level in the atmosphere.

bioengineering↗

bioRxiv2018

A novel maize gene, glossy6 involved in epicuticular wax deposition and drought tolerance

Epicuticular waxes, long-chain hydrocarbon compounds, form the outermost layer of plant surfaces in most terrestrial plants. The presence of epicuticular waxes protects plants from water loss and other environmental stresses. Cloning and characterization of genes involved in the regulation, biosynthesis, and extracellular transport of epicuticular waxes on to the surface of epidermal cells have revealed the molecular basis of epicuticular wax accumulation. However, intracellular trafficking of synthesized waxes to the plasma membrane for cellular secretion is poorly understood. Here, we characterized a maize glossy (gl6) mutant that exhibited decreased epicuticular wax load, increased cuticle permeability, and reduced seedling drought tolerance relative to wild type. We combined an RNA-sequencing based mapping approach (BSR-Seq) and chromosome walking to identify the gl6 candidate gene, which was confirmed via the analysis of multiple independent mutant alleles. The gl6 gene represents a novel maize glossy gene containing a conserved, but uncharacterized domain. Functional characterization suggests that the GL6 protein may be involved in the intracellular trafficking of epicuticular waxes, opening a door to elucidating the poorly understood process by which epicuticular wax is transported from its site of biosynthesis to the plasma membrane.\n\nSIGNIFICANCE STATEMENTPlant surface waxes provide an essential protective barrier for terrestrial plants. Understanding the composition and physiological functions of surface waxes, as well as the molecular basis underlying wax accumulation on plant surfaces provides opportunities for the genetic optimization of this protective layer. Genetic studies have identified genes involved in wax biosynthesis, extracellular transport, as well as spatial and temporal regulation of wax accumulation. In this study, a maize mutant, gl6 was characterized that exhibited reduced wax load on plant surfaces, increased water losses, and reduced seedling drought tolerance compared to wild type controls. The gl6 gene is a novel gene harboring a conserved domain with an unknown function. Quantification and microscopic observation of wax accumulation as well as subcellular localization of the GL6 protein provided evidence that gl6 may be involved in the intracellular trafficking of waxes, opening a door for studying this necessary yet poorly understood process for wax loading on plant surfaces.

plant biology↗

bioRxiv2018

Evaluation of the antifibrotic potency by knocking down SPARC, CCR2 and SMAD3

The genes of SPARC, CCR2, and SMAD3 are implicated in orchestrating inflammation and fibrosis in scleroderma and other fibrotic disorders. Aim of the studies was to examine synergistic effect of inhibition of these genes in treating fibrosis. The peptide nanoparticles were used to deliver the siRNAs in bleomycin-induced fibrotic mice. Triple combination of siRNAs targeting on Sparc, Ccr2 and Smad3 achieved favorable anti-inflammatory and anti-fibrotic effects. Inhibition of inflammation was evidenced by reduced inflammatory cells and proinflammatory cytokines in the BALF and/or the tissues. Activation of fibroblasts was suppressed in mouse tissues in which -Sma and collagens were significantly reduced. Aberrant expression of the genes in fibroblasts, monocytes/macrophage, endothelial and epithelial cells were reinstalled after the treatment. In addition, transcriptome profiles indicated that some bleomycin-induced alterations of multiple biological pathways were recovered to varying degrees by the treatment. The results indicated that the triple combination of siRNAs systemically reinstated multiple biopathways, probably through controlling on different cell types including fibroblasts, monocytes/macrophages, endothelial cells and others. The multi-target-combined therapeutic approach examined herein may represent a novel and effective therapy for fibrosis.

molecular biology↗

bioRxiv2018

A different state of mind: neural activity related to volitionally up- versus downregulating cortical excitability

To date there exists no reliable method to non-invasively upregulate or downregulate the state of the resting motor system over a large dynamic range. Here we show that an operant conditioning paradigm which provides neurofeedback of the size of motor evoked potentials (MEPs) in response to transcranial magnetic stimulation (TMS), enables participants to self-modulate their own brain state. Following training, participants were able to robustly increase (by 83.8%) and decrease (by 30.6%) their MEP amplitudes. This volitional up-versus down-regulation of corticomotor excitability caused an increase of late-cortical disinhibition (LCD), a TMS derived read-out of presynaptic GABAB disinhibition, which was accompanied by an increase of gamma and a decrease of alpha oscillations in the trained hemisphere. This approach paves the way for future investigations into how altered brain state influences motor neurophysiology and recovery of function in a neurorehabilitation context.

neuroscience↗

bioRxiv2018

Identifying Lineage-specific Targets of Darwinian Selection by a Bayesian Analysis of Genomic Polymorphisms and Divergence from Multiple Species

We present a method that jointly analyzes the polymorphism and divergence sites in genomic sequences of multiple species to identify the genes under positive or negative selection and pinpoints the occurrence time of selection to a specific lineage of the species phylogeny. This method integrates population genetics models using the Bayesian Poisson random field framework and combines information over all gene loci to boost the power to detect selection. The method provides posterior distributions of the fitness effects of each gene along with parameters associated with the evolutionary history, including the species divergence times and effective population sizes of external species. A simulation is performed, and the results demonstrate that our method provides accurate estimates of these population genetic parameters.\n\nThe proposed method is applied to genomic sequences of humans, chimpanzees, gorillas and orangutans, and a spatial and temporal map is constructed of the natural selection that occurred during the evolutionary history of the four Hominidae species. In addition to FOXP2 and other known genes, we identify a new list of lineage-specific targets of Darwinian selection. The positively selected genes in the human lineage are enriched in pathways of gene expression regulation, immune system, metabolism etc. Interestingly, some pathways, such as gene expression, are significantly enriched with positively selected genes, whereas other pathways, such as metabolism, are enriched with both positively and negatively selected genes. Our analysis provides insights into Darwinian evolution in the coding regions of humans and great apes and thus serves as a basis for further molecular and functional studies.

genomics↗

bioRxiv2018

The C. elegans AWA Olfactory Neuron Fires Calcium-Mediated All-or-None Action Potentials

We find, unexpectedly, that C. elegans neurons can encode information through regenerative all-or-none action potentials. In a survey of current-voltage relationships in C. elegans neurons, we discovered that AWA olfactory neurons generate membrane potential spikes with defining characteristics of action potentials. Ion substitution experiments, pharmacology, and mutant analysis identified a voltage-gated CaV1 calcium channel and a Shaker-type potassium channel that underlie action potential dynamics in AWA. Simultaneous patch-clamp recording and calcium imaging in AWA revealed spike-associated calcium signals that were also observed after odor stimulation of intact animals, suggesting that natural odor stimuli induce AWA action potentials. The stimulus regimes that elicited action potentials match AWAs proposed specialized function in climbing odor gradients. Our results provide evidence that C. elegans can use digital as well as analog coding schemes, expand the computational repertoire of its nervous system, and inform future modeling of its neural coding and network dynamics.

neuroscience↗

bioRxiv2018

Insight into relationship between micro-consortia, nitrogen source and petroleum degradation at low temperature anaerobic condition

Biostimulation by addition nutrients has been proved to be an effective bioremediation strategies. Revealing response law of nitrogen source and structure characteristics of anaerobic petroleum degrading microorganisms microbial population will help us optimize nutrient to promote oil degradation. Anaerobic micro-consortia characteristics in the enrichment marine sediment samples with different nitrogen source, combining with analysis of the oil degradation rates were studied in this paper, as well as functional genes involved in petroleum degradation were also analyzed. On the basis of optimizing the best inorganic nitrogen sources and organic nitrogen sources, an effective medium was designed by response surface methodology that used for enriching petroleum degradation micro-consortia. Amplicon sequencing analysis showed that the population of microorganisms migrated obviously when enriched with different nitrogen sources. With the increase of oil degradation rate, the microbial diversity was significantly decreased, and concentrated on a limited number of genera. The reasonable proportions of GammaProteobacteria, Bacteroidetes and Fusobacteria made the greatest contribution to petroleum degradation. Metagenomic analysis unveiled the mixed nitrogen source promoted the expression of functional genes related to petroleum degradation such as the transfer of succinyl-CoA, synthesis of acetyl CoA and {beta}-oxidation cycle, and was beneficial to degradation of petroleum at low temperature anaerobic condition.\n\nOriginality Significance StatementAddition of nutrients can promote growth of indigenous petroleum degradation-related bacteria and be helpful to the rapid degradation of petroleum. Previous studies accurately characterized aerobic microorganisms on petroleum degradation. However, we still known little about anaerobic microorganisms in marine environment. Most biostimulation methods use inorganic salt as the main nutritional supplement to improve the efficiency of petroleum degradation, but effects of different nitrogen sources on diversity of microorganisms and distribution of functional genes related to petroleum degradation at anaerobic conditions are still unknown. In this research, the effects of nitrogen on petroleum biodegradation, anaerobic microconsortium structure and distribution of genes related to petroleum degradation were unveiled by using amplicon sequencing and metagenomic analysis.

microbiology↗

bioRxiv2018

Subjugation of TGFβ Signaling by Human Papilloma Virus in Head and Neck Squamous Cell Carcinoma Shifts DNA Repair from Homologous Recombination to Alternative End-Joining

Purpose: Following cytotoxic therapy, 70% of patients with human papillomavirus (HPV) positive oropharyngeal head and neck squamous cell carcinoma (HNSCC) are alive at 5 years compared to 30% of those with similar HPV-negative cancer, which is thought to be due to dysregulation of DNA repair. Loss of transforming growth factor {beta} (TGF{beta}) signaling is a poorly studied consequence of HPV that could contribute to this phenotype.\n\nExperimental Design: Human HNSCC cell lines (n=9), patient-derived xenografts (n=9), tissue microarray (n=194), TCGA expression data and primary tumor specimens (n=10) were used to define the relationship between TGF{beta} competency, response to DNA damage, and type of DNA repair.\n\nResults: Analysis of HNSCC specimens in situ and in vitro showed that HPV associates with loss of TGF{beta} signaling that increases the response to radiation or cisplatin. TGF{beta} suppressed miR-182 that inhibited both BRCA1, necessary for homologous recombination repair, and FOXO3, which is required for ATM kinase activity. TGF{beta} signaling blockade by either HPV or inhibitors released this control, compromised HRR and increased response to PARP inhibition. Antagonizing miR-182 rescued the homologous recombination deficit in HPV+ cells. Loss of TGF{beta} signaling unexpectedly increased error-prone, alternative end-joining repair.\n\nConclusions: HPV-positive HNSCC cells are unresponsive to TGF{beta}. Abrogated TGF{beta} signaling compromises homologous recombination and shifts reliance on alt-EJ repair that provides a mechanistic basis for sensitivity to PARP inhibitors. The effect of HPV in HNSCC provides critical validation of TGF{beta}s role in DNA repair proficiency and further raises the translational potential of TGF{beta} inhibitors in cancer therapy.

cancer biology↗

bioRxiv2018

Mammalian CST averts replication failure by preventing G-quadruplex accumulation

Human CST (CTC1-STN1-TEN1) is an RPA-like complex that associates with G-rich single-strand DNA and helps resolve replication problems both at telomeres and genome-wide. We previously showed that CST binds and disrupts G-quadruplex (G4) DNA in vitro, suggesting that CST may prevent in vivo blocks to replication by resolving G4 structures. Here, we demonstrate that CST binds and unfolds G4 with similar efficiency to RPA. In cells, CST is recruited to telomeric and non-telomeric chromatin upon G4 stabilization. STN1 depletion increases G4 accumulation and slows bulk genomic DNA replication. At telomeres, combined STN1 depletion and G4 stabilization causes multi-telomere FISH signals and telomere loss, hallmarks of deficient telomere duplex replication. Strand-specific telomere FISH indicates preferential loss of C-strand DNA while analysis of BrdU uptake during leading and lagging-strand telomere replication shows preferential under-replication of lagging telomeres. Together these results indicate a block to Okazaki fragment synthesis. Overall, our findings indicate a novel role for CST in maintaining genome integrity through resolution of G4 structures both ahead of the replication fork and on the lagging strand template.

molecular biology↗

bioRxiv2018

Reliable Multiplex Sequencing with Rare Index Mis-Assignment on DNB-Based NGS Platform

BackgroundMassively-parallel-sequencing, coupled with sample multiplexing, has made genetic tests broadly affordable. However, intractable index mis-assignments (commonly exceeds 1%) were repeatedly reported on some widely used sequencing platforms.\n\nResultsHere, we investigated this quality issue on BGI sequencers using three library preparation methods: whole genome sequencing (WGS) with PCR, PCR-free WGS, and two-step targeted PCR. BGIs sequencers utilize a unique DNB technology which uses rolling circle replication for DNA-nanoball preparation; this linear amplification is PCR free and can avoid error accumulation. We demonstrated that single index mis-assignment from free indexed oligos occurs at a rate of one in 36 million reads, suggesting virtually no index hopping during DNB creation and arraying. Furthermore, the DNB-based NGS libraries have achieved an unprecedentedly low sample-to-sample mis-assignment rate of 0.0001% to 0.0004% under recommended procedures.\n\nConclusionsSingle indexing with DNB technology provides a simple but effective method for sensitive genetic assays with large sample numbers.

genomics↗

bioRxiv2018

The probiotic effectiveness in experimental colitis is correlated with gut microbiome and host genetic features

Current evidence to support extensive use of probiotics in inflammatory bowel disease is limited and factors contribute to the inconsistent effectiveness of clinical probiotic therapy are not completely known. Here, as a proof-of-concept, we utilized Bifidobacterium longum JDM 301, a widely used commercial probiotic strain in China, to study potential factors that may influence the beneficial effect of probiotics in experimental colitis. We found that the probiotic therapeutic effect was varied across individual mouse even with the same genetic background and consuming the same type of food. The different probiotic efficacy was highly correlated with different microbiome features in each mouse. Consumption of a diet rich in fat can change the host sensitivity to mucosal injury-induced colitis but did not change the host responsiveness to probiotic therapy. Finally, the host genetic factor TLR2 was required for a therapeutic effect of B. longum JDM 301. Together, our results suggest that personalized microbiome and genetic features may modify the probiotic therapeutic effect.

microbiology↗

bioRxiv2018

Quantitative assessment of cell population diversity in single-cell landscapes

Single-cell RNA-sequencing (scRNA-seq) has become a powerful tool for the systematic investigation of cellular diversity. As a number of computational tools have been developed to identify and visualize cell populations within a single scRNA-seq dataset, there is a need for methods to quantitatively and statistically define proportional shifts in cell population structures across datasets, such expansion or shrinkage, or emergence or disappearance of cell populations. Here we present sc-UniFrac, a framework to statistically quantify compositional diversity in cell populations between single-cell transcriptome landscapes. sc-UniFrac enables sensitive and robust quantification in simulated and experimental datasets in terms of both population identity and quantity. We have demonstrated the utility of sc-UniFrac in multiple applications, including assessment of biological and technical replicates, classification of tissue phenotypes, identification and definition of altered cell populations, and benchmarking batch correction tools. sc-UniFrac provides a framework for quantifying diversity or alterations in cell populations across conditions, and has broad utility for gaining insight on how cell populations respond to perturbations.

bioinformatics↗

bioRxiv2018

Cycloserine for Treatment of Multidrug-Resistant Tuberculosis in China: A Retrospective Observational Study

ObjectivesCycloserine is crucial in multidrug-resistant tuberculosis (MDR-TB) treatment. Although extensive research has been carried out on MDR-TB, most researchers have not treated cycloserine in much detail. Therefore, we evaluate the efficacy and safety of cycloserine and seek to clarify the role of cycloserine for treatment of simple MDR-TB, pre-extensively drug-resistant tuberculosis (pre-XDR-TB), and extensively drug-resistant tuberculosis (XDR-TB).\n\nPatients and methodsA retrospective observational study was performed in China. We determined the treatment outcome as the primary outcome for 144 cycloserine-treated and 181 cycloserine-nontreated patients according to the definitions of WHO. The proportion of patients with sputum-culture conversion and the frequency of adverse drug reactions related to cycloserine were assessed as well.\n\nResultsAmong 325 MDR-TB patients, 144 were treated with cycloserine and 100 (69.4%) out of 144 successfully completed treatment. Compared with patients in non-cycloserine group, the hazard ratio of any unfavorable treatment outcome was 0.53 (95%CI: 0.35-0.81, P=0.003). Culture conversion rate at the intensive phase was similar whether cycloserine was administered or not (P=0.703). Of the 144 patients treated with cycloserine, a total of 16 (11.1%) patients experienced side-effects related to cycloserine, including 7 patients who discontinued cycloserine permanently.\n\nConclusionsCycloserine could be an attractive agent to treat MDR-TB. Its safety profile warrants use in the most of MDR-TB cases. Cycloserine significantly improved the chance of favorable outcome for patients with simple MDR-TB but not pre-XDR-TB and XDR-TB. More aggressive regimens might be required for pre-XDR-TB or XDR-TB patients.

microbiology↗

bioRxiv2018

Hemolysin liberates bacterial outer membrane vesicles for cytosolic lipopolysaccharide sensing

Inflammatory caspase-11/4/5 recognize cytosolic LPS from invading Gram-negative bacteria and induce pyroptosis and cytokine release, forming rapid innate antibacterial defenses. Since extracellular or vacuole-constrained bacteria are thought to rarely access the cytoplasm, how their LPS are exposed to the cytosolic sensors is a critical event for pathogen recognition. Hemolysin is a pore-forming bacterial toxin, which was generally accepted to rupture cell membrane, leading to cell lysis. Whether and how hemolysin participates in non-canonical inflammasome signaling remains uncovered. Here, we show that hemolysin-overexpressed enterobacteria triggered significantly increased caspase-4 activation in human intestinal epithelial cells (IECs). Hemolysin promoted LPS cytosolic delivery from extracellular bacteria through dynamin-dependent endocytosis. Further, we revealed that hemolysin was largely associated with bacterial outer membrane vesicles (OMVs) and induced rupture of OMV-containing vacuoles, subsequently increasing LPS exposure to the cytosolic sensor. Accordingly, overexpression of hemolysin promoted caspase-11 dependent IL-18 secretion, gut inflammation, and enterocyte pyroptosis in orally-infected mice, which was associated with restricting bacterial colonization in vivo. Together, our work reveals a concept that hemolysin promotes noncanonical inflammasome activation via liberating OMVs for cytosolic LPS sensing, which offers insights into innate immune surveillance of dysregulated hemolysin via caspase-11/4 in intestinal antibacterial defenses.\n\nSignificanceSensing of lipopolysaccharide (LPS) in the cytosol triggers non-canonical inflammasome-mediated innate responses. Recent work revealed that bacterial outer membrane vesicles (OMVs) enables LPS to access the cytosol for extracellular bacteria. However, since intracellular OMVs are generally constrained in endosomes, how OMV-derived LPS gain access to the cytosol remains unknown. Here, we reported that hemolysin largely bound with OMVs and entered cells through dynamin-dependent endocytosis. Intracellular hemolysin significantly impaired OMVs-constrained vacuole integrity and increased OMV-derived LPS exposure to the cytosolic sensor, which promoted non-canonical inflammasome activation and restricted bacterial gut infections. This work reveals the role of hemolysin in promoting non-canonical inflammasome activation and alerting host immune recognition, which provides insights into the more sophisticated biological functions of hemolysin upon infection.

immunology↗