Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1291501 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Transcriptional profiling of mouse gut wall tissue following infection with Salmonella or treatment with Probiotics to see the role of probiotics in preventing salmonella infection through gut mucosal route of mouse.
2018-06-18 | GSE98353 | GEO
Project description:Klebsiella pneumoniae is a major pathogen that causes a variety of human infections, posing a significant public health threat. Understanding its pathogenesis is essential for devising effective treatment strategies. In this study, we aim to identify critical virulence factors in K. pneumoniae through analyzing virulence-associated genes that were identified in three transposon mutagenesis libraries. Two genes, wzi and kvrB, are consistently detected across these libraries, indicating their potential as critical virulence factors. While Wzi has usually been implicated in virulence through CPS, its actual function in K. pneumoniae pathogenicity has rarely been explored. Wzi deficiency reduces CPS production in K. pneumoniae, contrasting with its effect in Escherichia coli. Importantly, Wzi exerts a pivotal role in K. pneumoniae pathogenicity in vitro and in vivo, functioning through both CPS-dependent and -independent pathways. Wzi inhibits the secretion of IFN-γ-related cytokines at early infection stage to promote K. pneumoniae survival in the host. Wzi triggers sustained neutrophil recruitment during infection through the upregulation of CXCL1 expression, resulting in the pulmonary barrier damage and increased K. pneumoniae invasion into the bloodstream. Concurrently, Wzi confers K. pneumoniae to counteract neutrophil-mediated clearance in a CPS-dependent manner. Sequence polymorphisms of wzi significantly affect bacterial resistance to serum killing, with alleles frequently associated with hypervirulent K. pneumoniae exhibiting the highest resistance. Collectively, our findings highlight that the dual role of Wzi as a CPS-dependent and -independent virulence factor that combats host clearance during K. pneumoniae infection, representing a promising target for the development of anti-infective treatment against the bug.
2025-02-25 | GSE286873 | GEO
Project description:Opioids analgesics are frequently prescribed in the United States and worldwide. However, serious side effects such as addiction, immunosuppression and gastrointestinal symptoms limit their use. It has been recently demonstrated that morphine treatment results in significant disruption in gut barrier function leading to increased translocation of gut commensal bacteria. Further study indicated distinct alterations in the gut microbiome and metabolome following morphine treatment, contributing to the negative consequences associated with opioid use. However, it is unclear how opioids modulate gut homeostasis in the context of a hospital acquired bacterial infection. In the current study, a mouse model of C. rodentium infection was used to investigate the role of morphine in the modulation of gut homeostasis in the context of a hospital acquired bacterial infection. Citrobacter rodentium is a natural mouse pathogen that models intestinal infection by enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC) and causes attaching and effacing lesions and colonic hyperplasia. Morphine treatment resulted in 1) the promotion of C. rodentium systemic dissemination, 2) increase in virulence factors expression with C. rodentium colonization in intestinal contents, 3) altered gut microbiome, 4) damaged integrity of gut epithelial barrier function, 5) inhibition of C. rodentium-induced increase in goblet cells, and 6) dysregulated IL-17A immune response. This is the first study to demonstrate that morphine promotes pathogen dissemination in the context of intestinal C. rodentium infection, indicating morphine modulates virulence factor-mediated adhesion of pathogenic bacteria and induces disruption of mucosal host defense during C. rodentium intestinal infection in mice. This study demonstrates and further validates a positive correlation between opioid drug use/abuse and increased risk of infections, suggesting over-prescription of opioids may increase the risk in the emergence of pathogenic strains and should be used cautiously. Therapeutics directed at maintaining gut homeostasis during opioid use may reduce the comorbidities associated with opioid use for pain management.
2020-02-18 | E-MTAB-7503 | biostudies-arrayexpress
Project description:Salmonella enterica serotype Typhimurium cause a localized enteric infection in immunocompetent patients while human immunodeficiency virus (HIV)-infected patients develop a life threatening bacteremia. We used a rhesus macaque ileal loop model to study how simian immunodeficiency virus (SIV) infection triggers defects in mucosal barrier function that enhance S. Typhimurium dissemination. SIV infection resulted in significant depletion of CD4+ T cells in the intestinal mucosa. Gene expression profiling revealed a defective TH17 response (with suppression of IL-17 and IL-22 expression) and impaired homeostasis of the intestinal epithelium in SIV-infected animals during NTS infection. These findings correlated with an impaired ability of lamina propria CD4+ T cells from SIV-infected macaques to produce IL-17 upon ex vivo stimulation, while production of IFNï§ was not affected. This cytokine imbalance in SIV-infected animals was associated with reduced expression of genes required for intestinal epithelial maintenance and repair, increased fluid secretion during NTS infection, epithelial damage and translocation of a non-invasive S. Typhimurium mutant. Although no defects in neutrophil recruitment were noted, the ileum of SIV-infected animals contained lower levels of the enzyme myeloperoxidase, which may indicate defects in neutrophil killing capacity. S. Typhimurium was recovered in markedly increased numbers from the mesenteric lymph nodes of SIV-infected macaques, illustrating the increased potential for systemic dissemination during co-infection. Our data suggest that SIV-infection causes a multi-factorial defect in mucosal barrier function that promotes bacterial dissemination. Keywords: Disease state analysis Comparison of ileal gene expression profiles in SIV infected rhesus macaques in response to Salmonella challange.
2010-05-26 | E-GEOD-10567 | biostudies-arrayexpress
Project description:Background: Emerging evidence suggests that chronic stress compromises blood‒brain barrier (BBB) integrity by disrupting brain microvascular endothelial cells (BMECs), contributing to the development of cognitive impairments. Thus, targeting the BBB is expected to be a promising treatment strategy. The biological function of rutin has been investigated in neurological disorders; however, its regulatory role in stress-induced BBB damage and cognitive decline and the underlying mechanisms remain elusive. Methods: In a chronic unpredictable mild stress (CUMS) mouse model, a fluorescent dye assay and behavioral tests, including a novel object recognition test and Morris water maze, were performed to evaluate the protective effects of rutin on BBB integrity and cognition. The effects of rutin on BMEC function were also investigated in hCMEC/D3 cells (a human brain microvascular endothelial cell line) in vitro. Furthermore, the molecular mechanisms by which rutin restores BBB endothelium dysfunction were explored via RNA-seq, quantitative real-time PCR, western blotting, immunofluorescence and chromatin immunoprecipitation. Finally, biotinylated tumor necrosis factor-α (TNF-α) was employed to test the influence of rutin on the ability of circulating TNF-α to cross the BBB. Results: We identified that rutin attenuated BBB hyperpermeability and cognitive impairment caused by the 8-week CUMS procedure. Moreover, rutin promoted the proliferation, migration and angiogenesis ability of BMECs through positively regulating the expression of genes involved. Furthermore, rutin impeded histone deacetylase 1 (HDAC1) recruitment and stabilized H3K27ac to increase Claudin-5 protein levels. Ultimately, normalization of the hippocampal HDAC1‒Claudin-5 axis by rutin blocked the infiltration of circulating TNF-α into the brain parenchyma and alleviated neuroinflammation. Conclusions: This work establishes a protective role of rutin in regulating BMEC function and BBB integrity and reveals that rutin is a potential drug candidate for curing chronic stress-induced cognitive deficits.
2025-04-09 | GSE288810 | GEO
Project description:The opportunistic pathogen Staphylococcus aureus is carried asymptomatically by about one-third of the human population. Body sites known to be colonized by S. aureus are the skin, nasopharynx and gut. In particular, the mechanisms that allow S. aureus to pass the gut epithelial barrier and to invade the bloodstream are poorly understood. Therefore, our present study was aimed at investigating possible differences between gut-colonizing and bacteremia isolates of S. aureus. To this end, 74 gut-colonizing isolates from healthy individuals and 144 blood-culture isolates were characterized by whole-genome sequencing. Subsequently, the cellular and extracellular proteomes of six representative isolates were examined by mass spectrometry. Lastly, the virulence potential of these isolates was evaluated using infection models based on human gut epithelial cells, blood cells, and a small animal infection model. Intriguingly, our results show that gut-colonizing and bacteremia isolates with the same sequence type (ST1 or ST5) are very similar at the genomic and proteomic levels. Nonetheless, they display differences in virulence, but gut-colonizing isolates may be more virulent than bacteremia isolates and vice versa. Importantly, we show that the main decisive factor preventing infection of gut epithelial cells in vitro is the presence of a tight barrier. Based on our present observations, we propose that the integrity of the gut epithelial layer, rather than the pathogenic potential of a gut-colonizing S. aureus strain, is the main decisive factor that determines whether this colonizer will become an invasive pathogen.
2023-03-11 | PXD030971 | Pride
Project description:Salmonella virulence chiefly relies upon two major pathogenicity islands, SPI-1 and SPI-2, which enable host cell invasion and intracellular survival, respectively. There has been increasing evidence for post-transcriptional control of SPI gene expression by Hfq-dependent small RNAs (sRNAs) such as PinT. This 80-nucleotide sRNA is highly expressed after Salmonella enters host cells and modulates the transition from the SPI-1 to SPI-2 program by targeting different virulence factor mRNAs. It has been elusive, however, how PinT activity could be counteracted when virulence gene suppression were to be relieved. To identify putative inhibitors of PinT, we have mapped the RNA interactome of Salmonella recovered from infected macrophages, using an optimized version of the RIL-seq method. Next to offering an unprecedented view of Hfq-mediated RNA interactions during Salmonella’s intracellular infection stage, RIL-seq uncovered the 3’ end-derived sRNA InvS as a direct negative regulator of PinT. Biochemical and genetic experiments suggest a decoy mechanism whereby InvS lifts the PinT-mediated repression of virulence factors. Additionally, InvS acts as an mRNA repressor of the host cell adhesion protein, MipA, and PinT interaction with InvS relieves mipA repression. Together, our work identifies a unique pair of antagonistic sRNAs in a growing post-transcriptional network of virulence gene regulation.
2025-12-01 | GSE293893 | GEO
Project description:Canonically, the complement system is known for its rapid response to remove microbes in the bloodstream. However, relatively little is known about a functioning complement system on intestinal mucosal surfaces. Herein we report the local synthesis of complement component 3 (C3) in the gut, primarily by stromal cells. C3 is expressed upon commensal colonization, is regulated by the composition of the microbiota in healthy humans and mice, leading to an individual host’s specific luminal C3 levels. The absence of membrane attack complex (MAC) components in the gut ensures that C3 deposition does not result in the lysis of commensals. Pathogen infection triggers the immune system to recruit neutrophils to the infection site for pathogen clearance. Basal C3 levels directly correlate with protection against enteric infection. Our study reveals the gut complement system as a novel innate immune mechanism acting as a vigilant sentinel that combats pathogens and spares commensals.
2024-01-16 | GSE250268 | GEO
Project description:Canonically, the complement system is known for its rapid response to remove microbes in the bloodstream. However, relatively little is known about a functioning complement system on intestinal mucosal surfaces. Herein we report the local synthesis of complement component 3 (C3) in the gut, primarily by stromal cells. C3 is expressed upon commensal colonization, is regulated by the composition of the microbiota in healthy humans and mice, leading to an individual host’s specific luminal C3 levels. The absence of membrane attack complex (MAC) components in the gut ensures that C3 deposition does not result in the lysis of commensals. Pathogen infection triggers the immune system to recruit neutrophils to the infection site for pathogen clearance. Basal C3 levels directly correlate with protection against enteric infection. Our study reveals the gut complement system as a novel innate immune mechanism acting as a vigilant sentinel that combats pathogens and spares commensals.
2023-12-04 | GSE248940 | GEO
Project description:Host-pathogen interactions involve two critical strategies: resistance, whereby hosts clear invading microbes, and tolerance, whereby hosts carry high pathogen burden asymptomatically. Here, we investigate mechanisms by which Salmonella- superspreader hosts (SSP) maintain an asymptomatic state during chronic infection. We found that regulatory T cells (Tregs) are essential for this disease-tolerant state, limiting intestinal immunopathology and enabling SSP hosts to thrive, while facilitating Salmonella transmission. Treg depletion in SSP mice resulted in decreased survival, heightened gut inflammation and impairment of the intestinal barrier, without affecting Salmonella persistence. Colonic Tregs from SSP mice exhibited a unique transcriptomic profile characterized by the upregulation type-1 inflammatory genes, including the transcription factor T-bet. In the absence of Tregs, we observed robust expansion of cytotoxic CD4+ T cells, with CD4+ T cell depletion restoring homeostasis. These results uncover a critical host strategy to establish disease tolerance during chronic enteric infection, providing novel insights into mucosal responses to persistent pathogens and chronic intestinal inflammation.
2025-08-19 | GSE303864 | GEO