scholarly journals Klebsiella pneumoniae reduces SUMOylation to limit host defence responses

2020 ◽  
Author(s):  
Joana Sá-Pessoa ◽  
Kornelia Przybyszewska ◽  
Filipe Nuno Vasconcelos ◽  
Amy Dumigan ◽  
Christian G. Frank ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Klebsiella Pneumoniae ◽  
Inflammatory Responses ◽  
Treatment Options ◽  
Multidrug Resistant ◽  
Cellular Level ◽  
Lung Epithelial Cells ◽  
Type I ◽  
Dependent Manner ◽  
Medical Needs

ABSTRACTKlebsiella pneumoniae is an important cause of multidrug resistant infections worldwide. Understanding the virulence mechanisms of K. pneumoniae is a priority and timely to design new therapeutics. Here we demonstrate that K. pneumoniae limits the SUMOylation of host proteins in epithelial cells and macrophages (mouse and human) to subvert cell innate immunity. Mechanistically, in lung epithelial cells Klebsiella increases the levels of the deSUMOylase SENP2 in the cytosol by affecting its K48-ubiquitylation and its subsequent degradation by the ubiquitin proteasome. This is dependent on Klebsiella preventing the NEDDylation of the Cullin-1 subunit of the ubiquitin ligase complex E3-SCFβ-TrCP by exploiting the CSN5 deNEDDylase. Klebsiella induces the expression of CSN5 in an EGFR-PI3K-AKT-ERK-GSK3β signalling pathway dependent manner. In macrophages, TLR4-TRAM-TRIF induced type-I IFN via IFNAR1-controlled signalling mediates Klebsiella-triggered decrease in the levels of SUMOylation via let-7 miRNAs. Our results revealed the crucial role played by Klebsiella polysaccharides, the capsule and the LPS O-polysaccharide, to decrease the levels of SUMO-conjugated proteins in epithelial cells and macrophages. Klebsiella-induced decrease in SUMOylation promotes infection by limiting the activation of inflammatory responses and increasing intracellular survival in macrophages.IMPORTANCEKlebsiella pneumoniae has been singled out as an urgent threat to human health due to the increasing isolation of strains resistant to “last line” antimicrobials, narrowing the treatment options against Klebsiella infections. Unfortunately, at present, we cannot identify candidate compounds in late-stage development for treatment of multidrug Klebsiella infections; this pathogen is exemplary of the mismatch between unmet medical needs and the current antimicrobial research and development pipeline. Furthermore, there is still limited evidence on K. pneumoniae pathogenesis at the molecular and cellular level in the context of the interactions between bacterial pathogens and their hosts. In this research, we have uncovered a sophisticated strategy employed by Klebsiella to subvert the activation of immune defences by controlling the modification of proteins. Our research may open opportunities to develop new therapeutics based on counteracting this Klebsiella-controlled immune evasion strategy.

scholarly journals Klebsiella pneumoniae Reduces SUMOylation To Limit Host Defense Responses

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Joana Sá-Pessoa ◽  
Kornelia Przybyszewska ◽  
Filipe Nuno Vasconcelos ◽  
Amy Dumigan ◽  
Christian G. Frank ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Klebsiella Pneumoniae ◽  
Glycogen Synthase ◽  
Defense Responses ◽  
Multidrug Resistant ◽  
Lung Epithelial Cells ◽  
Type I ◽  
Dependent Manner ◽  
Content Type ◽  
Medical Needs

ABSTRACT Klebsiella pneumoniae is an important cause of multidrug-resistant infections worldwide. Understanding the virulence mechanisms of K. pneumoniae is a priority and timely to design new therapeutics. Here, we demonstrate that K. pneumoniae limits the SUMOylation of host proteins in epithelial cells and macrophages (mouse and human) to subvert cell innate immunity. Mechanistically, in lung epithelial cells, Klebsiella increases the levels of the deSUMOylase SENP2 in the cytosol by affecting its K48 ubiquitylation and its subsequent degradation by the ubiquitin proteasome. This is dependent on Klebsiella preventing the NEDDylation of the Cullin-1 subunit of the ubiquitin ligase complex E3-SCF-βTrCP by exploiting the CSN5 deNEDDylase. Klebsiella induces the expression of CSN5 in an epidermal growth factor receptor (EGFR)-phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT)-extracellular signal-regulated kinase (ERK)-glycogen synthase kinase 3 beta (GSK3β) signaling pathway-dependent manner. In macrophages, Toll-like receptor 4 (TLR4)-TRAM-TRIF-induced type I interferon (IFN) via IFN receptor 1 (IFNAR1)-controlled signaling mediates Klebsiella-triggered decrease in the levels of SUMOylation via let-7 microRNAs (miRNAs). Our results revealed the crucial role played by Klebsiella polysaccharides, the capsule, and the lipopolysaccharide (LPS) O-polysaccharide, to decrease the levels of SUMO-conjugated proteins in epithelial cells and macrophages. A Klebsiella-induced decrease in SUMOylation promotes infection by limiting the activation of inflammatory responses and increasing intracellular survival in macrophages. IMPORTANCE Klebsiella pneumoniae has been singled out as an urgent threat to human health due to the increasing isolation of strains resistant to “last-line” antimicrobials, narrowing the treatment options against Klebsiella infections. Unfortunately, at present, we cannot identify candidate compounds in late-stage development for treatment of multidrug-resistant Klebsiella infections; this pathogen is exemplary of the mismatch between unmet medical needs and the current antimicrobial research and development pipeline. Furthermore, there is still limited evidence on K. pneumoniae pathogenesis at the molecular and cellular levels in the context of the interactions between bacterial pathogens and their hosts. In this research, we have uncovered a sophisticated strategy employed by Klebsiella to subvert the activation of immune defenses by controlling the modification of proteins. Our research may open opportunities to develop new therapeutics based on counteracting this Klebsiella-controlled immune evasion strategy.

Nitric oxide increases IL-8 gene transcription and mRNA stability to enhance IL-8 gene expression in lung epithelial cells

2004 ◽  
Vol 287 (4) ◽  
pp. L764-L773 ◽  
Author(s):  
Loretta Sparkman ◽  
Vijayakumar Boggaram
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Protein Kinase ◽  
Epithelial Cells ◽  
Gene Transcription ◽  
Mrna Stability ◽  
Inflammatory Responses ◽  
Lung Epithelial Cells ◽  
Mrna Levels ◽  
Lung Epithelial

Interleukin (IL)-8, a C-X-C chemokine, is a potent chemoattractant and an activator for neutrophils, T cells, and other immune cells. The airway and respiratory epithelia play important roles in the initiation and modulation of inflammatory responses via production of cytokines and surfactant. The association between elevated levels of nitric oxide (NO) and IL-8 in acute lung injury associated with sepsis, acute respiratory distress syndrome, respiratory syncytial virus infection in infants, and other inflammatory diseases suggested that NO may play important roles in the control of IL-8 gene expression in the lung. We investigated the role of NO in the control of IL-8 gene expression in H441 lung epithelial cells. We found that a variety of NO donors significantly induced IL-8 mRNA levels, and the increase in IL-8 mRNA was associated with an increase in IL-8 protein. NO induction of IL-8 mRNA was due to increases in IL-8 gene transcription and mRNA stability. NO induction of IL-8 mRNA levels was not inhibited by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one and KT-5823, inhibitors of soluble guanylate cyclase and protein kinase G, respectively, and 8-bromo-cGMP did not increase IL-8 mRNA levels. This indicated that NO induces IL-8 mRNA levels independently of changes in the intracellular cGMP levels. NO induction of IL-8 mRNA was significantly reduced by inhibitors of extracellular regulated kinase and protein kinase C. IL-8 induction by NO was also reduced by hydroxyl radical scavengers such as dimethyl sulfoxide and dimethylthiourea, indicating the involvement of hydroxyl radicals in the induction process. NO induction of IL-8 gene expression could be a significant contributing factor in the initiation and induction of inflammatory response in the respiratory epithelium.

scholarly journals EphB6 Regulates TFEB-Lysosomal Pathway and Survival of Disseminated Indolent Breast Cancer Cells

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1079
Author(s):  
Manuela Zangrossi ◽  
Patrizia Romani ◽  
Probir Chakravarty ◽  
Colin D.H. Ratcliffe ◽  
Steven Hooper ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Epithelial Cells ◽  
Cancer Cells ◽  
Lung Epithelial Cells ◽  
Late Relapse ◽  
Alveolar Type ◽  
Type I ◽  
Extrinsic Factors ◽  
Lung Epithelial

Late relapse of disseminated cancer cells is a common feature of breast and prostate tumors. Several intrinsic and extrinsic factors have been shown to affect quiescence and reawakening of disseminated dormant cancer cells (DDCCs); however, the signals and processes sustaining the survival of DDCCs in a foreign environment are still poorly understood. We have recently shown that crosstalk with lung epithelial cells promotes survival of DDCCs of estrogen receptor-positive (ER+) breast tumors. By using a lung organotypic system and in vivo dissemination assays, here we show that the TFEB-lysosomal axis is activated in DDCCs and that it is modulated by the pro-survival ephrin receptor EphB6. TFEB lysosomal direct targets are enriched in DDCCs in vivo and correlate with relapse in ER+ breast cancer patients. Direct coculture of DDCCs with alveolar type I-like lung epithelial cells and dissemination in the lung drive lysosomal accumulation and EphB6 induction. EphB6 contributes to survival, TFEB transcriptional activity, and lysosome formation in DDCCs in vitro and in vivo. Furthermore, signaling from EphB6 promotes the proliferation of surrounding lung parenchymal cells in vivo. Our data provide evidence that EphB6 is a key factor in the crosstalk between disseminated dormant cancer cells and the lung parenchyma and that the TFEB-lysosomal pathway plays an important role in the persistence of DDCCs.

scholarly journals Lung Epithelial Regulation of BCL2 Related Protein A1 (BCL2A1) by Coronaviruses (SARS-CoV) and Type I Interferon Signaling

2021 ◽  
Author(s):  
Ramana Chilakamarti
Keyword(s):  
Epithelial Cells ◽  
Human Lung ◽  
Type I Interferon ◽  
Respiratory Viruses ◽  
Lung Epithelial Cells ◽  
Type I ◽  
Related Protein ◽  
Interferon Signaling ◽  
Lung Epithelial ◽  
Human Lung Epithelial Cells

Highly pathogenic respiratory viruses such as 1918 influenza (HIN1) and coronavirus (SARS-CoV-2) induce significant lung injury with diffuse alveolar damage, capillary leak, and extensive cell death resulting in acute respiratory distress syndrome (ARDS). Direct effects of the virus, as well as host immune response such as proinflammatory cytokine production, contribute to programmed cell death or apoptosis. Alveolar lung epithelial type II (AT2) cells play a major role in the clearance of respiratory viruses, secretion of surfactant proteins and antimicrobial substances into the bronchoalveolar fluid as well as repair of lung injury. Gene expression in AT2 cells is regulated in a tissue and cell-specific manner and in a temporal fashion. The availability of tissue and cell-specific RNA datasets in Human Protein Atlas led to the identification of localized expression patterns of BCL-2 family members such as BCL2 related protein A1 (BCL2A1) in AT2 cells and immune cells of the lung. BCL2A1 expression was regulated by multiple stimuli including Toll-like receptor (TLR) ligands, interferons (IFNs), inflammatory cytokines, and inhibited by the steroid dexamethasone. In this study, regulation of BCL2A1 gene expression in human lung epithelial cells by several respiratory viruses and type I interferon signaling was investigated. SARS-CoV-2 infection significantly induced BCL2A1 expression in human lung epithelial cells within 24 hours that required the expression of Angiotensin-converting enzyme 2 (ACE2). BCL2A1 mRNA induction by SARS-CoV-2 was correlated with the induced expression of IFN-β and IFN-regulated transcription factor mRNA. BCL2A1 was induced by IFN-β treatment or by infection with influenza virus lacking the non-structural protein1(NS1) in NHBE cells. Furthermore, bioinformatics revealed that a subset of BCL-2 family members involved in the control of apoptosis and transcription such as BCL2A1, BCL2L14, BCL3, and BCL6 were regulated in the lung epithelial cells by coronaviruses and in the lung tissue samples of COVID-19 patients. Transcriptomic data also suggested that these genes were differentially regulated by the steroid drug dexamethasone.

scholarly journals Transcriptional Response of Multidrug-Resistant Klebsiella pneumoniae Clinical Isolates to Ciprofloxacin Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Roman Farooq Alvi ◽  
Bilal Aslam ◽  
Muhammad Hidayat Rasool ◽  
Saima Muzammil ◽  
Abu Baker Siddique ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Stress Responses ◽  
Genetic Resistance ◽  
Transcriptional Response ◽  
Multidrug Resistant ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Isolation And Identification ◽  
Concentration Dependent Manner ◽  
High Level

Background. The term “persisters” refers to a small bacterial population that persists during treatment with high antibiotic concentration or dose in the absence of genetic resistance. The present study was designed to investigate the transcriptional response in indigenous Klebsiella pneumoniae under the ciprofloxacin stress. Methods. Isolation and identification of K. pneumoniae were carried out through standard microbiological protocols. The characterization of quinolone resistance was performed by estimating the quinolone susceptibility testing, MIC estimation, and detecting the QRDR and PMQR. Transcriptional response of the isolates to ciprofloxacin was determined using qPCR. Results. Among 34 isolates, 23 (67%) were resistant to ciprofloxacin. Both QRDR (gyrA and gyrB) and PMQR (qnrA, qnrB, and qnrS) were detected in the isolates, and all were found resistant to ciprofloxacin. The mRNA levels of both mutS and euTu under the influence of ciprofloxacin were significantly increased. On ciprofloxacin exposure, the mRNA levels of the DNA damage response element (mutS) were raised in a time-dependent fashion. K. pneumoniae showed high-level resistance to ciprofloxacin in the presence of mutations in QRDR and PMQR genes. Conclusion. The transcriptional response revealed the upregulation of DNA repair and protein folding elements (mutS and euTu) in ciprofloxacin stress and delayed cell division. The ciprofloxacin was found to trigger various stress responses in a time- and concentration-dependent manner.

scholarly journals Genomic evolution and local epidemiology of Klebsiella pneumoniae from a major hospital in Beijing, China, over a 15 year period: dissemination of known and novel high-risk clones

2021 ◽  
Author(s):  
Mattia Palmieri ◽  
Kelly L. Wyres ◽  
Caroline Mirande ◽  
Zhao Qiang ◽  
Ye Liyan ◽  
...  
Keyword(s):  
High Risk ◽  
Klebsiella Pneumoniae ◽  
Type Species ◽  
Treatment Options ◽  
Multidrug Resistant ◽  
Virulence Plasmid ◽  
Content Type ◽  
Origin And Evolution ◽  
Link Type ◽  
Beijing China

Klebsiella pneumoniae is a frequent cause of nosocomial and severe community-acquired infections. Multidrug-resistant (MDR) and hypervirulent (hv) strains represent major threats, and tracking their emergence, evolution and the emerging convergence of MDR and hv traits is of major importance. We employed whole-genome sequencing (WGS) to study the evolution and epidemiology of a large longitudinal collection of clinical K. pneumoniae isolates from the H301 hospital in Beijing, China. Overall, the population was highly diverse, although some clones were predominant. Strains belonging to clonal group (CG) 258 were dominant, and represented the majority of carbapenemase-producers. While CG258 strains showed high diversity, one clone, ST11-KL47, represented the majority of isolates, and was highly associated with the KPC-2 carbapenemase and several virulence factors, including a virulence plasmid. The second dominant clone was CG23, which is the major hv clone globally. While it is usually susceptible to multiple antibiotics, we found some isolates harbouring MDR plasmids encoding for ESBLs and carbapenemases. We also reported the local emergence of a recently described high-risk clone, ST383. Conversely to strains belonging to CG258, which are usually associated to KPC-2, ST383 strains seem to readily acquire carbapenemases of different types. Moreover, we found several ST383 strains carrying the hypervirulence plasmid. Overall, we detected about 5 % of simultaneous carriage of AMR genes (ESBLs or carbapenemases) and hypervirulence genes. Tracking the emergence and evolution of such strains, causing severe infections with limited treatment options, is fundamental in order to understand their origin and evolution and to limit their spread. This article contains data hosted by Microreact.

scholarly journals Epigenomics, genomics, resistome, mobilome, virulome and evolutionary phylogenomics of carbapenem-resistant Klebsiella pneumoniae clinical strains

2020 ◽  
Vol 6 (12) ◽  
Author(s):  
Katlego Kopotsa ◽  
Nontombi M. Mbelle ◽  
John Osei Sekyere
Keyword(s):  
Klebsiella Pneumoniae ◽  
Multidrug Resistant ◽  
Type I ◽  
Bacteriophage Therapy ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Plasmid Replicon ◽  
Size Number ◽  
Plasmid Size ◽  
Epidemiological Trends

Carbapenem-resistant Klebsiella pneumoniae (CRKP) remains a major clinical pathogen and public health threat with few therapeutic options. The mobilome, resistome, methylome, virulome and phylogeography of CRKP in South Africa and globally were characterized. CRKP collected in 2018 were subjected to antimicrobial susceptibility testing, screening by multiplex PCR, genotyping by repetitive element palindromic (REP)-PCR, plasmid size, number, incompatibility and mobility analyses, and PacBio’s SMRT sequencing (n=6). There were 56 multidrug-resistant CRKP, having bla OXA-48-like and bla NDM-1/7 carbapenemases on self-transmissible IncF, A/C, IncL/M and IncX3 plasmids endowed with prophages, traT, resistance islands, and type I and II restriction modification systems (RMS). Plasmids and clades detected in this study were respectively related to globally established/disseminated plasmids clades/clones, evincing transboundary horizontal and vertical dissemination. Reduced susceptibility to colistin occurred in 23 strains. Common clones included ST307, ST607, ST17, ST39 and ST3559. IncFIIk virulent plasmid replicon was present in 56 strains. Whole-genome sequencing of six strains revealed least 41 virulence genes, extensive ompK36 mutations, and four different K- and O-loci types: KL2, KL25, KL27, KL102, O1, O2, O4 and O5. Types I, II and III RMS, conferring m6A (G A TC, G A TGNNNNNNTTG, CA A NNNNNNCATC motifs) and m4C (C C WGG) modifications on chromosomes and plasmids, were found. The nature of plasmid-mediated, clonal and multi-clonal dissemination of blaOXA-48-like and blaNDM-1 mirrors epidemiological trends observed for closely related plasmids and sequence types internationally. Worryingly, the presence of both bla OXA-48 and bla NDM-1 in the same isolates was observed. Plasmid-mediated transmission of RMS, virulome and prophages influence bacterial evolution, epidemiology, pathogenicity and resistance, threatening infection treatment. The influence of RMS on antimicrobial and bacteriophage therapy needs urgent investigation.

scholarly journals Epithelial transglutaminase 2 is needed for T cell interleukin-17 production and subsequent pulmonary inflammation and fibrosis in bleomycin-treated mice

2011 ◽  
Vol 208 (8) ◽  
pp. 1707-1719 ◽  
Author(s):  
Keunhee Oh ◽  
Hyung-Bae Park ◽  
Ok-Jin Byoun ◽  
Dong-Myung Shin ◽  
Eui Man Jeong ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Epithelial Cells ◽  
Transforming Growth Factor ◽  
Inflammatory Responses ◽  
Tissue Injury ◽  
Marrow Cell ◽  
Transglutaminase 2 ◽  
Cell Phenotype ◽  
Interleukin 17 ◽  
Dependent Manner

Pulmonary fibrosis is a potentially life-threatening disease that may be caused by overt or asymptomatic inflammatory responses. However, the precise mechanisms by which tissue injury is translated into inflammation and consequent fibrosis remain to be established. Here, we show that in a lung injury model, bleomycin induced the secretion of IL-6 by epithelial cells in a transglutaminase 2 (TG2)–dependent manner. This response represents a key step in the differentiation of IL-17–producing T cells and subsequent inflammatory amplification in the lung. The essential role of epithelial cells, but not inflammatory cells, TG2 was confirmed in bone marrow chimeras; chimeras made in TG2-deficient recipients showed reduced inflammation and fibrosis, compared with those in wild-type mice, regardless of the bone marrow cell phenotype. Epithelial TG2 thus appears to be a critical inducer of inflammation after noninfectious pulmonary injury. We further demonstrated that fibroblast-derived TG2, acting downstream of transforming growth factor-β, is also important in the effector phase of fibrogenesis. Therefore, TG2 represents an interesting potential target for therapeutic intervention.

scholarly journals Cytotoxic Effects of Air Freshener Biocides in Lung Epithelial Cells

2013 ◽  
Vol 8 (9) ◽  
pp. 1934578X1300800
Author(s):  
Jung-Taek Kwon ◽  
Mimi Lee ◽  
Gun-Baek Seo ◽  
Hyun-Mi Kim ◽  
Ilseob Shim ◽  
...  
Keyword(s):  
Dna Damage ◽  
Epithelial Cells ◽  
Cell Viability ◽  
Lung Epithelial Cells ◽  
Ros Generation ◽  
Dependent Manner ◽  
Cytotoxic Effects ◽  
Lung Epithelial ◽  
Dose Dependent ◽  
A549 Lung

This study evaluated the cytotoxicity of mixtures of citral (CTR) and either benzisothiazolinone (BIT, Mix-CTR-BIT) or triclosan (TCS, Mix-CTR-TCS) in human A549 lung epithelial cells. We investigated the effects of various mix ratios of these common air freshener ingredients on cell viability, cell proliferation, reactive oxygen species (ROS) generation, and DNA damage. Mix-CTR-BIT and Mix-CTR-TCS significantly decreased the viability of lung epithelial cells and inhibited cell growth in a dose-dependent manner. In addition, both mixtures increased ROS generation, compared to that observed in control cells. In particular, cell viability, growth, and morphology were affected upon increase in the proportion of BIT or TCS in the mixture. However, comet analysis showed that treatment of cells with Mix-CTR-BIT or Mix-CTR-TCS did not increase DNA damage. Taken together, these data suggested that increasing the content of biocides in air fresheners might induce cytotoxicity, and that screening these compounds using lung epithelial cells may contribute to hazard assessment.

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