scholarly journals Pleiotropic Enhancement of Bacterial Pathogenesis Resulting from the Constitutive Activation of the Listeria monocytogenes Regulatory Factor PrfA

2005 ◽  
Vol 73 (4) ◽  
pp. 1917-1926 ◽  
Author(s):  
Kimberly J. Mueller ◽  
Nancy E. Freitag
Keyword(s):  
Plasma Membrane ◽  
Listeria Monocytogenes ◽  
Epithelial Cells ◽  
Host Cell ◽  
Cell Lines ◽  
Surface Proteins ◽  
Broth Culture ◽  
Bacterial Invasion ◽  
Gene Products ◽  
Constitutive Activation

ABSTRACT Listeria monocytogenes is a facultative intracellular bacterial pathogen that causes serious disease in immunocompromised individuals, pregnant women, and neonates. Bacterial virulence is mediated by the expression of specific gene products that facilitate entry into host cells and enable bacterial replication; the majority of these gene products are regulated by a transcriptional activator known as PrfA. L. monocytogenes strains containing prfA E77K or prfA G155S mutations exhibit increased expression of virulence genes in broth culture and are hypervirulent in mice. To define the scope of the influences of the prfA E77K and prfA G155S mutations on L. monocytogenes pathogenesis, multiple aspects of bacterial invasion and intracellular growth were examined. Enhanced bacterial invasion of host epithelial cells was dependent on the expression of a number of surface proteins previously associated with invasion, including InlA, InlB, and ActA. In addition to these surface proteins, increased production of the hly-encoded secreted hemolysin listeriolysin O (LLO) was also found to significantly enhance bacterial invasion into epithelial cell lines for both prfA mutant strains. Although prfA E77K and prfA G155S strains were similar in their invasive phenotypes, the infection of epithelial cells with prfA E77K strains resulted in host cell plasma membrane damage, whereas prfA G155S strains did not alter plasma membrane integrity. Bacterial infection of human epithelial cells, in which the production of LLO is not required for bacterial entry into the cytosol, indicated that prfA E77K cytotoxic effects were mediated via LLO. Both prfA E77K and prfA G155S strains were more efficient than wild-type bacteria in gaining access to the host cell cytosol and in initiating the polymerization of host cell actin, and both were capable of mediating LLO-independent lysis of host cell vacuoles in cell lines for which L. monocytogenes vacuole disruption normally requires LLO activity. These experiments illuminate the diverse facets of L. monocytogenes pathogenesis that are significantly enhanced by the constitutive activation of PrfA via prfA mutations and underscore the critical role of this protein in promoting L. monocytogenes virulence.

scholarly journals Requirement of the Listeria monocytogenes Broad-Range Phospholipase PC-PLC during Infection of Human Epithelial Cells

2003 ◽  
Vol 185 (21) ◽  
pp. 6295-6307 ◽  
Author(s):  
Angelika Gründling ◽  
Mark D. Gonzalez ◽  
Darren E. Higgins
Keyword(s):  
Listeria Monocytogenes ◽  
Epithelial Cells ◽  
Host Cell ◽  
Phospholipase C ◽  
Expression System ◽  
Broth Culture ◽  
Listeriolysin O ◽  
Proteolytic Activation ◽  
Human Epithelial Cells ◽  
Cell Spread

ABSTRACT In this study, we investigated the requirement of the Listeria monocytogenes broad-range phospholipase C (PC-PLC) during infection of human epithelial cells. L. monocytogenes is a facultative intracellular bacterial pathogen of humans and a variety of animal species. After entering a host cell, L. monocytogenes is initially surrounded by a membrane-bound vacuole. Bacteria promote their escape from this vacuole, grow within the host cell cytosol, and spread from cell to cell via actin-based motility. Most infection studies with L. monocytogenes have been performed with mouse cells or an in vivo mouse model of infection. In all mouse-derived cells tested, the pore-forming cytolysin listeriolysin O (LLO) is absolutely required for lysis of primary vacuoles formed during host cell entry. However, L. monocytogenes can escape from primary vacuoles in the absence of LLO during infection of human epithelial cell lines Henle 407, HEp-2, and HeLa. Previous studies have shown that the broad-range phospholipase C, PC-PLC, promotes lysis of Henle 407 cell primary vacuoles in the absence of LLO. Here, we have shown that PC-PLC is also required for lysis of HEp-2 and HeLa cell primary vacuoles in the absence of LLO expression. Furthermore, our results indicated that the amount of PC-PLC activity is critical for the efficiency of vacuolar lysis. In an LLO-negative derivative of L. monocytogenes strain 10403S, expression of PC-PLC has to increase before or upon entry into human epithelial cells, compared to expression in broth culture, to allow bacterial escape from primary vacuoles. Using a system for inducible PC-PLC expression in L. monocytogenes, we provide evidence that phospholipase activity can be increased by elevated expression of PC-PLC or Mpl, the enzyme required for proteolytic activation of PC-PLC. Lastly, by using the inducible PC-PLC expression system, we demonstrate that, in the absence of LLO, PC-PLC activity is not only required for lysis of primary vacuoles in human epithelial cells but is also necessary for efficient cell-to-cell spread. We speculate that the additional requirement for PC-PLC activity is for lysis of secondary double-membrane vacuoles formed during cell-to-cell spread.

scholarly journals Adhesion to the host cell surface is sufficient to mediateListeria monocytogenesentry into epithelial cells

2017 ◽  
Vol 28 (22) ◽  
pp. 2945-2957 ◽  
Author(s):  
Fabian E. Ortega ◽  
Michelle Rengarajan ◽  
Natalie Chavez ◽  
Prathima Radhakrishnan ◽  
Martijn Gloerich ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Epithelial Cells ◽  
Cell Surface ◽  
Host Cell ◽  
Cell Junctions ◽  
Bacterial Invasion ◽  
Filamentous Actin ◽  
Host Cell Surface ◽  
E Cadherin

The intestinal epithelium is the first physiological barrier breached by the Gram-positive facultative pathogen Listeria monocytogenes during an in vivo infection. Listeria monocytogenes binds to the epithelial host cell receptor E-cadherin, which mediates a physical link between the bacterium and filamentous actin (F-actin). However, the importance of anchoring the bacterium to F-actin through E-cadherin for bacterial invasion has not been tested directly in epithelial cells. Here we demonstrate that depleting αE-catenin, which indirectly links E-cadherin to F-actin, did not decrease L. monocytogenes invasion of epithelial cells in tissue culture. Instead, invasion increased due to increased bacterial adhesion to epithelial monolayers with compromised cell–cell junctions. Furthermore, expression of a mutant E-cadherin lacking the intracellular domain was sufficient for efficient L. monocytogenes invasion of epithelial cells. Importantly, direct biotin-mediated binding of bacteria to surface lipids in the plasma membrane of host epithelial cells was sufficient for uptake. Our results indicate that the only requirement for L. monocytogenes invasion of epithelial cells is adhesion to the host cell surface, and that E-cadherin–mediated coupling of the bacterium to F-actin is not required.

scholarly journals The Gb3-enriched CD59/flotillin plasma membrane domain regulates host cell invasion by Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Annette Brandel ◽  
Sahaja Aigal ◽  
Simon Lagies ◽  
Manuel Schlimpert ◽  
Ana Valeria Meléndez ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Plasma Membrane ◽  
Host Cell ◽  
Acyl Chain ◽  
Mass Spectrometry Analysis ◽  
Bacterial Invasion ◽  
Fatty Acyl Chain ◽  
Membrane Domain ◽  
Host Cell Membrane ◽  
Plasma Membrane Domain

AbstractThe opportunistic pathogen Pseudomonas aeruginosa has gained precedence over the years due to its ability to develop resistance to existing antibiotics, thereby necessitating alternative strategies to understand and combat the bacterium. Our previous work identified the interaction between the bacterial lectin LecA and its host cell glycosphingolipid receptor globotriaosylceramide (Gb3) as a crucial step for the engulfment of P. aeruginosa via the lipid zipper mechanism. In this study, we define the LecA-associated host cell membrane domain by pull-down and mass spectrometry analysis. We unraveled a predilection of LecA for binding to saturated, long fatty acyl chain-containing Gb3 species in the extracellular membrane leaflet and an induction of dynamic phosphatidylinositol (3,4,5)-trisphosphate (PIP3) clusters at the intracellular leaflet co-localizing with sites of LecA binding. We found flotillins and the GPI-anchored protein CD59 not only to be an integral part of the LecA-interacting membrane domain, but also majorly influencing bacterial invasion as depletion of either of these host cell proteins resulted in about 50% reduced invasiveness of the P. aeruginosa strain PAO1. In summary, we report that the LecA-Gb3 interaction at the extracellular leaflet induces the formation of a plasma membrane domain enriched in saturated Gb3 species, CD59, PIP3 and flotillin thereby facilitating efficient uptake of PAO1.

scholarly journals Internalization of prolactin receptor and prolactin in transfected cells does not involve nuclear translocation

1997 ◽  
Vol 110 (9) ◽  
pp. 1123-1132 ◽  
Author(s):  
M. Perrot-Applanat ◽  
O. Gualillo ◽  
H. Buteau ◽  
M. Edery ◽  
P.A. Kelly
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Cell Lines ◽  
Map Kinases ◽  
Nuclear Translocation ◽  
Short Form ◽  
Confocal Laser Microscopy ◽  
Confocal Laser ◽  
Laser Microscopy ◽  
Transfected Cells

Prolactin (PRL) interacts with a specific, well characterized plasma membrane receptor (PRLR) that is coupled to signal transduction pathways involving Jak2, Fyn, and MAP kinases, and signal transducers and activators of transcription (STAT). Although a few previous studies have indicated nuclear translocation of PRL in IL-2 stimulated T lymphocytes, PRL-dependent Nb2 lymphoma cell lines and 235–1 lactotrophs, the mechanisms of nuclear targeting remain unknown and conflicting results have been reported concerning the putative nuclear translocation of the PRLR. We therefore decided to investigate nuclear translocation of PRLR and PRL in various cell lines transfected with an expression plasmid encoding PRLR, using confocal laser microscopy. We have constructed various cDNAs of the long and short forms of the rat PRLR containing an oligonucleotide encoding a Flag epitope inserted either just before the N-terminal amino acid or in the C-terminal end of the mature receptor (named N-terminal or C-terminal Flag-tagged PRLR). The corresponding receptors function as the PRLR in transfected cells: they are expressed at the plasma membrane and in compartments of the secretory pathway, they bind PRL with normal affinity (Kd= 4x10(−10) M) and have the same capacity to stimulate the transcriptional activity of a milk protein (beta-casein) gene as wild-type PRLR. In addition, the tagged receptors are much more efficiently immunodetected using anti-Flag antibodies, as compared to anti-PRL antibodies (U5 or U6). Immunofluorescence combined with detailed confocal laser microscopy showed that addition of PRL (0 to 12 hours) to COS-7, CHO and NIH-3T3 transfected fibroblasts induces rapid internalization of the receptor (long form), without any translocation to the nucleus. Using PRL-R tagged both in the N-terminal or C-terminal regions of the mature receptor excludes the possibility of a cleaved fragment which could have been subsequently imported into the nucleus. An absence of nuclear translocation of PRLR was also observed in a 293 cell line stably expressing the receptor, and in physiological targets for PRL, i.e. in Nb2 lymphoma cells expressing the Nb2 form of the receptor or in BGME mammary gland epithelial cells upon overexpression of a Flag-tagged PRLR. Similarly, the short form of the PRLR was not detected in nuclei of transfected COS cells upon PRL treatment. Clearly, our results provide evidence that internalization of the plasma membrane PRLR does not lead to nuclear translocation of the receptor, or part of it, in most fibroblasts and epithelial cells at physiological concentrations of PRL. Also, in co-localization experiments, PRL was internalized without nuclear translocation. Activation of STATs transcription factors and MAP kinases, as well as translocation of these proteins to the nucleus following their phosphorylation, probably remains the intracellular mechanism coupling stimulation to nuclear events.

scholarly journals Salmonella typhimurium induces selective aggregation and internalization of host cell surface proteins during invasion of epithelial cells

1994 ◽  
Vol 107 (7) ◽  
pp. 2005-2020 ◽  
Author(s):  
F. Garcia-del Portillo ◽  
M.G. Pucciarelli ◽  
W.A. Jefferies ◽  
B.B. Finlay
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Epithelial Cells ◽  
Cell Surface ◽  
Heavy Chain ◽  
Surface Proteins ◽  
Class I ◽  
Plasma Membrane Proteins ◽  
Class I Mhc ◽  
Host Plasma Membrane

Salmonella interact with eucaryotic membranes to trigger internalization into non-phagocytic cells. In this study we examined the distribution of host plasma membrane proteins during S. typhimurium invasion of epithelial cells. Entry of S. typhimurium into HeLa epithelial cells produced extensive aggregation of cell surface class I MHC heavy chain, beta 2-microglobulin, fibronectin-receptor (alpha 5 beta 1 integrin), and hyaluronate receptor (CD-44). Other cell surface proteins such as transferrin-receptor or Thy-1 were aggregated by S. typhimurium to a much lesser extent. Capping of these plasma membrane proteins was observed in membrane ruffles localized to invading S. typhimurium and in the area surrounding these structures. In contrast, membrane ruffling induced by epidermal growth factor only produced minor aggregations of surface proteins, localized exclusively in the membrane ruffle. This result suggests that extensive redistribution of these proteins requires a signal related to bacterial invasion. This bacteria-induced process was associated with rearrangement of polymerized actin but not microtubules, since preincubation of epithelial cells with cytochalasin D blocked aggregation of these proteins while nocodazole treatment did not. Of the host surface proteins aggregated by S. typhimurium, only class I MHC heavy chain was predominantly present in the bacteria-containing vacuoles. No extensive aggregation of host plasma membrane proteins was detected when HeLa epithelial cells were infected with invasive bacteria that do not induce membrane ruffling, including Yersinia enterocolitica, a bacterium that triggers internalization via binding to beta 1 integrin, and a S. typhimurium invasion mutant that utilizes the Yersinia-internalization route. In contrast to the situation with S. typhimurium, class I MHC heavy chain was not selectively internalized into vacuoles containing these other bacteria. Extensive aggregation of host plasma membrane proteins was also not observed when other S. typhimurium mutants that are defective for invasion were used. The amount of internalized host plasma membrane proteins in the bacteria-containing vacuoles decreased over time with all invasive bacteria examined, indicating that modification of the composition of these vacuoles occurs. Therefore, our data show that S. typhimurium induces selective aggregation and internalization of host plasma membrane proteins, processes associated with the specific invasion strategy used by this bacterium to enter into epithelial cells.

scholarly journals Secretion Chaperones PrsA2 and HtrA Are Required for Listeria monocytogenes Replication following Intracellular Induction of Virulence Factor Secretion

2016 ◽  
Vol 84 (10) ◽  
pp. 3034-3046 ◽  
Author(s):  
Jana K. Ahmed ◽  
Nancy E. Freitag
Keyword(s):  
Listeria Monocytogenes ◽  
Virulence Factor ◽  
Bacterial Growth ◽  
Cell Types ◽  
Broth Culture ◽  
Bacterial Invasion ◽  
Bacterial Membrane ◽  
Content Type ◽  
Factor Secretion

The Gram-positive bacteriumListeria monocytogenestransitions from an environmental organism to an intracellular pathogen following its ingestion by susceptible mammalian hosts. Bacterial replication within the cytosol of infected cells requires activation of the central virulence regulator PrfA followed by a PrfA-dependent induction of secreted virulence factors. The PrfA-induced secreted chaperone PrsA2 and the chaperone/protease HtrA contribute to the folding and stability of select proteins translocated across the bacterial membrane.L. monocytogenesstrains that lack bothprsA2andhtrAexhibit near-normal patterns of growth in broth culture but are severely attenuatedin vivo. We hypothesized that, in the absence of PrsA2 and HtrA, the increase in PrfA-dependent protein secretion that occurs following bacterial entry into the cytosol results in misfolded proteins accumulating at the bacterial membrane with a subsequent reduction in intracellular bacterial viability. Consistent with this hypothesis, the introduction of a constitutively activated allele ofprfA(prfA*) into ΔprsA2ΔhtrAstrains was found to essentially inhibit bacterial growth at 37°C in broth culture. ΔprsA2ΔhtrAstrains were additionally found to be defective for cell invasion and vacuole escape in selected cell types, steps that precede full PrfA activation. These data establish the essential requirement for PrsA2 and HtrA in maintaining bacterial growth under conditions of PrfA activation. In addition, chaperone function is required for efficient bacterial invasion and rapid vacuole lysis within select host cell types, indicating roles for PrsA2/HtrA prior to cytosolic PrfA activation and the subsequent induction of virulence factor secretion.

scholarly journals Models of Invasion of Enteric and Periodontal Pathogens Into Epithelial Cells: A Comparative Analysis

1997 ◽  
Vol 8 (4) ◽  
pp. 389-409 ◽  
Author(s):  
D.H. Meyer ◽  
K.P. Mintz ◽  
P.M. Fives-Taylor
Keyword(s):  
Epithelial Cells ◽  
Host Cell ◽  
Cell Function ◽  
Shigella Flexneri ◽  
Host Cells ◽  
Bacterial Invasion ◽  
Periodontal Pathogens ◽  
Chronic Infections ◽  
Enteropathogenic Bacteria ◽  
Bacteroides Gingivalis

Bacterial invasion of epithelial cells is associated with the initiation of infection by many bacteria. To carry out this action, bacteria have developed remarkable processes and mechanisms that co-opt host cell function and stimulate their own uptake and adaptation to the environment of the host cell. Two general types of invasion processes have been observed. In one type, the pathogens (e.g., Salmonella and Yersinia spp.) remain in the vacuole in which they are internalized and replicate within the vacuole. In the other type, the organism (e.g., Actinobacillus actinomycetemcomitans, Shigella flexneri, and Listeria monocytogenes) is able to escape from the vacuole, replicate in the host cell cytoplasm, and spread to adjacent host cells. The much-studied enteropathogenic bacteria usurp primarily host cell microfilaments for entry. Those organisms which can escape from the vacuole do so by means of hemolytic factors and C type phospholipases. The cell-to-cell spread of these organisms is mediated by microfilaments. The investigation of invasion by periodontopathogens is in its infancy in comparison with that of the enteric pathogens However, studies to date on two invasive periodontopathogens, A. actinomycetemcomitans and Porphyromonas (Bacteroides) gingivalis, reveal that these bacteria have developed invasion strategies and mechanisms similar to those of the enteropathogens. Entry of A. actinomycetemcomitans is mediated by microfilaments, whereas entry of P. gingivalis is mediated by both microfilaments and microtubules. A. actinomycetemcomitans, like Shigella and Listeria, can escape from the vacuole and spread to adjacent cells. However, the spread of A. actinomycetemcomitans is linked to host cell microtubules, not microfilaments. The paradigms presented establish that bacteria which cause chronic infections, such as periodontitis, and bacteria which cause acute diseases, such as dysentery, have developed similar invasion strategies.

scholarly journals A diarrheal pathogen, enteropathogenic Escherichia coli (EPEC), triggers a flux of inositol phosphates in infected epithelial cells.

1994 ◽  
Vol 179 (3) ◽  
pp. 993-998 ◽  
Author(s):  
V Foubister ◽  
I Rosenshine ◽  
B B Finlay
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Host Cell ◽  
Tyrosine Phosphorylation ◽  
Inositol Phosphates ◽  
Protein Kinase Inhibitors ◽  
Cell Protein ◽  
Bacterial Invasion ◽  
Enteropathogenic Escherichia Coli ◽  
Cytoskeletal Rearrangement

Enteropathogenic Escherichia coli (EPEC) is a bacterial pathogen that causes diarrhea in infants by adhering to intestinal epithelial cells. EPEC induces host cell protein phosphorylation and increases intracellular calcium levels that may function to initiate cytoskeletal rearrangement. We found that EPEC triggers the release of inositol phosphates (IPs) after adherence of bacteria to cultured epithelial cells. We also demonstrated that the EPEC-induced flux of IPs precedes actin rearrangement and bacterial invasion. EPEC mutants and tyrosine protein kinase inhibitors were used to establish that formation of IPs is dependent on tyrosine phosphorylation of a 90-kD HeLa protein. Collectively these results suggest that EPEC-induced tyrosine phosphorylation of a host cell substrate(s) leads to release of IPs, which may then trigger cytoskeletal rearrangement.

scholarly journals In situ expression and localization of Neisseria gonorrhoeae opacity proteins in infected epithelial cells: apparent role of Opa proteins in cellular invasion.

1991 ◽  
Vol 173 (6) ◽  
pp. 1395-1405 ◽  
Author(s):  
J F Weel ◽  
C T Hopman ◽  
J P van Putten
Keyword(s):  
Epithelial Cells ◽  
Host Cell ◽  
Natural Infection ◽  
Phase Variation ◽  
Functional Adaptation ◽  
Host Cells ◽  
Bacterial Invasion ◽  
Rapid Phase ◽  
Immunomorphological Study ◽  
Opacity Proteins

During natural infection, gonococcal opacity proteins (Opa) undergo rapid phase variation, but how this phenomenon contributes to the virulence of the bacteria is not well understood. In the present immunomorphological study we examined the actual Opa status of individual gonococci during various stages of gonococcal infection of Chang epithelial cells, by probing ultrathin sections of infected specimens with Opa-specific monoclonal antibodies. Our results demonstrate a heterogeneous Opa expression during the initial interaction of the bacteria, but an almost 100% expression of one of the probed Opas during their secondary attachment and entry into the host cells, suggesting a role for distinct Opas in cellular penetration. The association between Opa expression, tight attachment, and bacterial invasion into the host cells could be confirmed with isogenic variants that expressed different Opa proteins. Once inside the epithelial cells, both morphologically intact, Opa positive and morphologically disintegrated, Opa negative bacteria were observed. The loss of Opa immunoreactivity in intracellular gonococci could not be related to the presence of a particular Opa protein, but could be mimicked by incubating the organisms with extracts of sonicated uninfected epithelial cells, suggesting that it was caused by host cell proteolytic activity. Taken together, our data suggest that Opa phase transitions confer a functional adaptation of the bacteria enabling host cell penetration.

scholarly journals Lipoxin A4prevents tight junction disruption and delays the colonization of cystic fibrosis bronchial epithelial cells byPseudomonas aeruginosa

2016 ◽  
Vol 310 (11) ◽  
pp. L1053-L1061 ◽  
Author(s):  
Gerard Higgins ◽  
Coral Fustero Torre ◽  
Jean Tyrrell ◽  
Paul McNally ◽  
Brian J. Harvey ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Tight Junction ◽  
Cell Lines ◽  
Bronchial Epithelial Cell ◽  
Bacterial Invasion ◽  
Airway Epithelial ◽  
Bronchial Epithelial ◽  
Tight Junction Disruption

The specialized proresolution lipid mediator lipoxin A4(LXA4) is abnormally produced in cystic fibrosis (CF) airways. LXA4increases the CF airway surface liquid height and stimulates airway epithelial repair and tight junction formation. We report here a protective effect of LXA4(1 nM) against tight junction disruption caused by Pseudomonas aeruginosa bacterial challenge together with a delaying action against bacterial invasion in CF airway epithelial cells from patients with CF and immortalized cell lines. Bacterial invasion and tight junction integrity were measured by gentamicin exclusion assays and confocal fluorescence microscopy in non-CF (NuLi-1) and CF (CuFi-1) bronchial epithelial cell lines and in primary CF cultures, grown under an air/liquid interface, exposed to either a clinical or laboratory strains of P. aeruginosa. LXA4delayed P. aeruginosa invasion and transepithelial migration in CF and normal bronchial epithelial cell cultures. These protective effects of LXA4were inhibited by the ALX/FPR2 lipoxin receptor antagonist BOC-2. LXA4prevented the reduction in mRNA biosynthesis and protein abundance of the tight junction protein ZO-1 and reduced tight junction disruption induced by P. aeruginsosa inoculation. In conclusion, LXA4plays a protective role in bronchial epithelium by stimulating tight junction repair and by delaying and reducing the invasion of CF bronchial epithelial cells by P. aeruginsosa.

Sign in / Sign up

Export Citation Format

Share Document