The Rab1 in host cells modulates Brucella intracellular survival and binds to Brucella DnaK protein

2016 ◽  
Vol 198 (9) ◽  
pp. 923-931 ◽  
Author(s):  
Ning Liu ◽  
Changjiang Sun ◽  
Guimei Cui ◽  
Pan Wei ◽  
Li Yang ◽  
...  
Keyword(s):  
Intracellular Survival ◽  
Host Cells ◽  
Dnak Protein

scholarly journals Intracellular Gene Expression Profile of Listeria monocytogenes

2006 ◽  
Vol 74 (2) ◽  
pp. 1323-1338 ◽  
Author(s):  
Som Subhra Chatterjee ◽  
Hamid Hossain ◽  
Sonja Otten ◽  
Carsten Kuenne ◽  
Katja Kuchmina ◽  
...  
Keyword(s):  
Gene Expression ◽  
Listeria Monocytogenes ◽  
Host Cell ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
Intracellular Survival ◽  
Host Cells ◽  
Wall Structure ◽  
Glucose Limitation ◽  
Serotype 4B

ABSTRACT Listeria monocytogenes is a gram-positive, food-borne microorganism responsible for invasive infections with a high overall mortality. L. monocytogenes is among the very few microorganisms that can induce uptake into the host cell and subsequently enter the host cell cytosol by breaching the vacuolar membrane. We infected the murine macrophage cell line P388D1 with L. monocytogenes strain EGD-e and examined the gene expression profile of L. monocytogenes inside the vacuolar and cytosolic environments of the host cell by using whole-genome microarray and mutant analyses. We found that ∼17% of the total genome was mobilized to enable adaptation for intracellular growth. Intracellularly expressed genes showed responses typical of glucose limitation within bacteria, with a decrease in the amount of mRNA encoding enzymes in the central metabolism and a temporal induction of genes involved in alternative-carbon-source utilization pathways and their regulation. Adaptive intracellular gene expression involved genes that are associated with virulence, the general stress response, cell division, and changes in cell wall structure and included many genes with unknown functions. A total of 41 genes were species specific, being absent from the genome of the nonpathogenic Listeria innocua CLIP 11262 strain. We also detected 25 genes that were strain specific, i.e., absent from the genome of the previously sequenced L. monocytogenes F2365 serotype 4b strain, suggesting heterogeneity in the gene pool required for intracellular survival of L. monocytogenes in host cells. Overall, our study provides crucial insights into the strategy of intracellular survival and measures taken by L. monocytogenes to escape the host cell responses.

scholarly journals Intracellular Survival of Leishmania major in Neutrophil Granulocytes after Uptake in the Absence of Heat-Labile Serum Factors

2002 ◽  
Vol 70 (2) ◽  
pp. 826-835 ◽  
Author(s):  
Helmut Laufs ◽  
Kerstin Müller ◽  
Jens Fleischer ◽  
Norbert Reiling ◽  
Nicole Jahnke ◽  
...  
Keyword(s):  
Leishmania Major ◽  
Intracellular Survival ◽  
Host Cells ◽  
Polymorphonuclear Neutrophil ◽  
Heat Inactivation ◽  
Neutrophil Granulocytes ◽  
Complement Components ◽  
Serum Factors

ABSTRACT The role of polymorphonuclear neutrophil granulocytes (PMN) in defense against the intracellular parasite Leishmania is poorly understood. In the present study, the interaction of human PMN with Leishmania major promastigotes was investigated in vitro. In the presence of fresh human serum, about 50% of PMN phagocytosed the parasites within 10 min and the parasite uptake led to PMN activation, resulting in the killing of most ingested parasites. Heat inactivation of the serum markedly reduced the rate of early parasite phagocytosis, suggesting a role of complement components in the early uptake of Leishmania. However, over 50% of PMN were able to ingest parasites in the presence of heat-inactivated serum if the coincubation was extended to 3 h. After 3 h, 10% of the PMN were found to internalize Leishmania even under serum-free conditions. These findings indicate that PMN possess mechanisms for both opsonin/complement-dependent and -independent uptake of Leishmania. Both pathways of uptake could be partially blocked by anti-CR3 antibody. Mannan-binding lectin was found not to be involved in this process. When phagocytosed in the absence of opsonin, the majority of Leishmania parasites survived intracellularly in PMN for at least 1 day. These data suggest a dual role of PMN in the early response to L. major infection. On the one hand, PMN can rapidly eliminate the intracellular parasites, and on the other hand, Leishmania can survive intracellularly in PMN. These data, together with the finding that intact parasites were seen in PMN isolated from the skin of infected mice, suggest that PMN can serve as host cells for the intracellular survival of Leishmania within the first hours or days after infection.

scholarly journals Targeting Salmonella Typhimurium Invasion and Intracellular Survival Using Pyrogallol

2021 ◽  
Vol 12 ◽  
Author(s):  
Biruk Tesfaye Birhanu ◽  
Eon-Bee Lee ◽  
Seung-Jin Lee ◽  
Seung-Chun Park
Keyword(s):  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Efflux Pump ◽  
Intracellular Survival ◽  
Host Cells ◽  
Intracellular Bacteria ◽  
Intracellular Pathogen ◽  
Intracellular Accumulation ◽  
Protection Assay ◽  
Serovar Typhimurium

Salmonella enterica serovar Typhimurium, an intracellular pathogen, evades the host immune response mechanisms to cause gastroenteritis in animals and humans. After invading the host cells, the bacteria proliferate in Salmonella-containing vacuole (SCV) and escapes from antimicrobial therapy. Moreover, Salmonella Typhimurium develops resistance to various antimicrobials including, fluoroquinolones. Treating intracellular bacteria and combating drug resistance is essential to limit the infection rate. One way of overcoming these challenges is through combination therapy. In this study, Pyrogallol (PG), a polyphenol, is combined with marbofloxacin (MAR) to investigate its effect on Salmonella Typhimurium invasion and intracellular survival inhibition. The Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PG against Salmonella Typhimurium were 128 and 256 μg/mL, respectively. The lowest fractional inhibitory concentration (FIC) index for a combination of PG and MAR was 0.5. The gentamycin protection assay revealed that PG (30 μg/mL) alone and in combination with sub-MIC of MAR inhibited 72.75 and 76.18% of the invading bacteria in Caco-2 cells, respectively. Besides, the intracellular survival of Salmonella Typhimurium was reduced by 7.69 and 74.36% in treatment with PG alone and combined with sub-MIC of MAR, respectively, which was visualized by the confocal microscopy. PG has also shown to increase the intracellular accumulation of fluoroquinolone by 15.2 and 34.9% at 30 and 100 μg/mL concentration, respectively. Quantitative real-time PCR demonstrated PG suppressed the genetic expression of hilA, invF, sipB, and acrA by 14.6, 15.4, 13.6, and 36%, respectively. However, the downregulation of hilA, invF, sipB, and acrA increased to 80, 74.6, 78, and 70.1%, in combination with sub-MIC of MAR, respectively. Similarly, PG combined with MAR inhibited the expression of sdiA, srgE, and rck genes by 78.6, 62.8, and 61.8%, respectively. In conclusion, PG has shown antimicrobial activity against Salmonella Typhimurium alone and in combination with MAR. It also inhibited invasion and intracellular survival of the bacteria through downregulation of quorum sensing, invading virulence, and efflux pump genes. Hence, PG could be a potential antimicrobial candidate which could limit the intracellular survival and replication of Salmonella Typhimurium.

scholarly journals Intracellular Survival of Brucellaspp. in Human Monocytes Involves Conventional Uptake but Special Phagosomes

2001 ◽  
Vol 69 (6) ◽  
pp. 3995-4006 ◽  
Author(s):  
Michael G. Rittig ◽  
Maria-Teresa Alvarez-Martinez ◽  
Françoise Porte ◽  
Jean-Pierre Liautard ◽  
Bruno Rouot
Keyword(s):  
Close Contact ◽  
Intracellular Survival ◽  
Reproductive Organs ◽  
Host Cells ◽  
Human Monocytes ◽  
Blood Monocytes ◽  
Free Medium ◽  
Peripheral Blood Monocytes ◽  
Specific Antibodies ◽  
Intracellular Parasites

ABSTRACT Brucella spp. are facultative intracellular parasites of various mammals, including humans, typically infecting lymphoid as well as reproductive organs. We have investigated howB. suis and B. melitensis enter human monocytes and in which compartment they survive. Peripheral blood monocytes readily internalized nonopsonized brucellae and killed most of them within 12 to 18 h. The presence ofBrucella-specific antibodies (but not complement) increased the uptake of bacteria without increasing their intracellular survival, whereas adherence of the monocytes or incubation in Ca2+- and Mg2+-free medium reduced the uptake. Engulfment of all Brucella organisms (regardless of bacterial viability or virulence) initially resulted in phagosomes with tightly apposed walls (TP). Most TP were fully fusiogenic and matured to spacious phagolysosomes containing degraded bacteria, whereas some TP (more in monocyte-derived macrophages, HeLa cells, and CHO cells than in monocytes) remained tightly apposed to intact bacteria. Immediate treatment of infected host cells with the lysosomotropic base ammonium chloride caused a swelling of all phagosomes and a rise in the intraphagosomal pH, abolishing the intracellular survival of Brucella. These results indicate that (i) human monocytes readily internalizeBrucella in a conventional way using various phagocytosis-promoting receptors, (ii) the maturation of someBrucella phagosomes is passively arrested between the steps of acidification and phagosome-lysosome fusion, (iii) brucellae are killed in maturing but not in arrested phagosomes, and (iv) survival of internalized Brucella depends on an acidic intraphagosomal pH and/or close contact with the phagosomal wall.

scholarly journals ClpC affects the intracellular survival capacity of Staphylococcus aureus in non-professional phagocytic cells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Gubesh Gunaratnam ◽  
Lorena Tuchscherr ◽  
Mohamed I. Elhawy ◽  
Ralph Bertram ◽  
Janina Eisenbeis ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Protein A ◽  
Intracellular Survival ◽  
Host Cells ◽  
Virulence Determinants ◽  
Phagocytic Cells ◽  
Survival Capacity ◽  
Shock Proteins ◽  
Mutant Cells

Abstract Invasion and persistence of bacteria within host cells requires that they adapt to life in an intracellular environment. This adaptation induces bacterial stress through events such as phagocytosis and enhanced nutrient-restriction. During stress, bacteria synthesize a family of proteins known as heat shock proteins (HSPs) to facilitate adaptation and survival. Previously, we determined the Staphylococcus aureus HSP ClpC temporally alters bacterial metabolism and persistence. This led us to hypothesize that ClpC might alter intracellular survival. Inactivation of clpC in S. aureus strain DSM20231 significantly enhanced long-term intracellular survival in human epithelial (HaCaT) and endothelial (EA.hy926) cell lines, without markedly affecting adhesion or invasion. This phenotype was similar across a genetically diverse collection of S. aureus isolates, and was influenced by the toxin/antitoxin encoding locus mazEF. Importantly, MazEF alters mRNA synthesis and/or stability of S. aureus virulence determinants, indicating ClpC may act through the mRNA modulatory activity of MazEF. Transcriptional analyses of total RNAs isolated from intracellular DSM20231 and isogenic clpC mutant cells identified alterations in transcription of α-toxin (hla), protein A (spa), and RNAIII, consistent with the hypothesis that ClpC negatively affects the intracellular survival of S. aureus in non-professional phagocytic cells, via modulation of MazEF and Agr.

scholarly journals Intracellular Staphylococcus aureusEscapes the Endosome and Induces Apoptosis in Epithelial Cells

1998 ◽  
Vol 66 (1) ◽  
pp. 336-342 ◽  
Author(s):  
Kenneth W. Bayles ◽  
Carla A. Wesson ◽  
Linda E. Liou ◽  
Lawrence K. Fox ◽  
Gregory A. Bohach ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nuclear Dna ◽  
Electron Microscopic Examination ◽  
Intracellular Survival ◽  
Host Cells ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Epithelial Cell Line ◽  
Electron Microscopic ◽  
Endosomal Membrane

ABSTRACT We examined the invasion of an established bovine mammary epithelial cell line (MAC-T) by a Staphylococcus aureusmastitis isolate to study the potential role of intracellular survival in the persistence of staphylococcal infections. S. aureuscells displayed dose-dependent invasion of MAC-T cells and intracellular survival. An electron microscopic examination of infected cells indicated that the bacteria induced internalization via a mechanism involving membrane pseudopod formation and then escaped into the cytoplasm following lysis of the endosomal membrane. Two hours after the internalization of S. aureus, MAC-T cells exhibited detachment from the matrix, rounding, a mottled cell membrane, and vacuolization of the cytoplasm, all of which are indicative of cells undergoing programmed cell death (apoptosis). By 18 h, the majority of the MAC-T cell population exhibited an apoptotic morphology. Other evidence for apoptosis was the generation of MAC-T cell DNA fragments differing in size by increments of approximately 180 bp and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling of the fragmented nuclear DNA of the infected host cells. These results demonstrate that after internalizationS. aureus escapes the endosome and induces apoptosis in nonprofessional phagocytes.

scholarly journals Lon Protease Activity Causes Down-Regulation of Salmonella Pathogenicity Island 1 Invasion Gene Expression after Infection of Epithelial Cells

2004 ◽  
Vol 72 (4) ◽  
pp. 2002-2013 ◽  
Author(s):  
Jennifer D. Boddicker ◽  
Bradley D. Jones
Keyword(s):  
Gene Expression ◽  
Small Intestine ◽  
Epithelial Cells ◽  
Pathogenicity Island ◽  
Intracellular Survival ◽  
Host Cells ◽  
Bacterial Invasion ◽  
Lon Protease ◽  
Negative Regulators ◽  
Down Regulation

ABSTRACT Salmonella enterica serovar Typhimurium causes self-limiting gastroenteritis in humans and a typhoid-like disease in mice that serves as a model for typhoid infections in humans. A critical step in Salmonella pathogenesis is the invasion of enterocytes and M cells of the small intestine via expression of a type III secretion system, encoded on Salmonella pathogenicity island 1 (SPI-1), that secretes effector proteins into host cells, leading to engulfment of the bacteria within large membrane ruffles. The in vitro regulation of invasion genes has been the subject of much scientific investigation. Transcription of the hilA gene, which encodes an OmpR/ToxR-type transcriptional activator of downstream invasion genes, is increased during growth under high-osmolarity and low-oxygen conditions, which presumably mimic the environment found within the small intestine. Several negative regulators of invasion gene expression have been identified, including HilE, Hha, and Lon protease. Mutations within the respective genes increase the expression of hilA when the bacteria are grown under environmental conditions that are not favorable for hilA expression and invasion. In this study, the intracellular expression of invasion genes was examined, after bacterial invasion of HEp-2 epithelial cells, using Salmonella strains containing plasmid-encoded short-half-life green fluorescent protein reporters of hilA, hilD, hilC, or sicA expression. Interestingly, the expression of SPI-1 genes was down-regulated after invasion, and this was important for the intracellular survival of the bacteria. In addition, the effects of mutations in genes encoding negative regulators of invasion on intracellular hilA expression were examined. Our results indicate that Lon protease is important for down-regulation of hilA expression and intracellular survival after the invasion of epithelial cells.

scholarly journals Inhibitory concentrations of ciprofloxacin induce an adaptive response promoting the intracellular survival of Salmonella Typhimurium

2021 ◽  
Author(s):  
Sushmita Sridhar ◽  
Sally Forrest ◽  
Derek Pickard ◽  
Claire Cormie ◽  
Emily Lees ◽  
...  
Keyword(s):  
Bacterial Growth ◽  
Adaptive Response ◽  
Intracellular Survival ◽  
Host Cells ◽  
Health Crisis ◽  
Cellular Survival ◽  
Salmonella Infections ◽  
Collateral Effects ◽  
The Impact

Antimicrobial resistance (AMR) is a pressing global health crisis, which has been fuelled by the sustained use of certain classes of antimicrobials, including fluoroquinolones. While the genetic mutations responsible for decreased fluoroquinolone (ciprofloxacin) susceptibility are known, the implications of ciprofloxacin exposure on bacterial growth, survival, and interactions with host cells are not well described. Aiming to understand the influence of inhibitory concentrations of ciprofloxacin in vitro, we subjected three clinical isolates of S. Typhimurium to differing concentrations of ciprofloxacin, dependent on their minimum inhibitory concentrations (MIC), and assessed the impact on bacterial growth, morphology, and transcription. We further investigated the differential morphology and transcription that occurred following ciprofloxacin exposure and measured the ability of ciprofloxacin-treated bacteria to invade and replicate in host cells. We found that ciprofloxacin-exposed S. Typhimurium are able to recover from inhibitory concentrations of ciprofloxacin, and that the drug induces specific morphological and transcriptional signatures associated with the bacterial SOS response, DNA repair, and intracellular survival. In addition, ciprofloxacin-treated S. Typhimurium have increased capacity for intracellular replication in comparison to untreated organisms. These data suggest that S. Typhimurium undergoes an adaptive response under ciprofloxacin perturbation that promotes cellular survival, a consequence that may justify more measured use of ciprofloxacin for Salmonella infections. The combination of multiple experimental approaches provides new insights into the collateral effects that ciprofloxacin and other antimicrobials have on invasive bacterial pathogens.

scholarly journals YshB Promotes Intracellular Replication and Is Required for Salmonella Virulence

2019 ◽  
Vol 201 (17) ◽  
Author(s):  
Rajdeep Bomjan ◽  
Mei Zhang ◽  
Daoguo Zhou
Keyword(s):  
Small Rnas ◽  
Intracellular Survival ◽  
The Body ◽  
Host Cells ◽  
Bacterial Survival ◽  
Body Of Knowledge ◽  
Common Causes ◽  
Salmonella Virulence ◽  
Mouse Model Of Infection

ABSTRACT Salmonella virulence requires the initial invasion of host cells, followed by modulation of the intracellular environment for survival and replication. In an effort to characterize the role of small RNAs in Salmonella pathogenesis, we inadvertently identified a 5-kDa protein named YshB that is involved in the intracellular survival of Salmonella. We show here that yshB expression is upregulated upon entry into macrophages. When yshB expression is upregulated before bacterial entry, invasion efficiency is inhibited. Lack of YshB resulted in reduced bacterial survival within the macrophages and led to reduced virulence in a mouse model of infection. IMPORTANCE Salmonella gastroenteritis is one of the most common causes of foodborne disease, possibly affecting millions of people globally each year. Here we characterize the role of a novel small protein, YshB, in mediating Salmonella intracellular survival. This elucidation adds to the body of knowledge regarding how this bacterium achieves intracellular survival.

scholarly journals Entry, Intracellular Survival, and Multinucleated-Giant-Cell-Forming Activity of Burkholderia pseudomallei in Human Primary Phagocytic and Nonphagocytic Cells

2017 ◽  
Vol 85 (10) ◽  
Author(s):  
Liam Whiteley ◽  
Teresa Meffert ◽  
Maria Haug ◽  
Christopher Weidenmaier ◽  
Verena Hopf ◽  
...  
Keyword(s):  
Host Cell ◽  
Burkholderia Pseudomallei ◽  
Cell Types ◽  
Giant Cells ◽  
Intracellular Survival ◽  
Host Cells ◽  
Dependent Manner ◽  
Type Vi Secretion System ◽  
Content Type ◽  
Raw264.7 Macrophages

ABSTRACT The human pathogen Burkholderia pseudomallei and the related species Burkholderia thailandensis are facultative intracellular bacteria characterized by the ability to escape into the cytosol of the host cell and to stimulate the formation of multinucleated giant cells (MNGCs). MNGC formation is induced via an unknown mechanism by bacterial type VI secretion system 5 (T6SS-5), which is an essential virulence factor in both species. Despite the vital role of the intracellular life cycle in the pathogenesis of the bacteria, the range of host cell types permissive for initiation and completion of the intracellular cycle is poorly defined. In the present study, we used several different types of human primary cells to evaluate bacterial entry, intracellular survival, and MNGC formation. We report the capacity of B. pseudomallei to enter, efficiently replicate in, and mediate MNGC formation of vein endothelial and bronchial epithelial cells, indicating that the T6SS-5 is important in the host-pathogen interaction in these cells. Furthermore, we show that B. pseudomallei invades fibroblasts and keratinocytes and survives inside these cells as well as in monocyte-derived macrophages and neutrophils for at least 17 h postinfection; however, MNGC formation is not induced in these cells. In contrast, infection of mixed neutrophils and RAW264.7 macrophages with B. thailandensis stimulated the formation of heterotypic MNGCs in a T6SS-5-dependent manner. In summary, the ability of the bacteria to enter and survive as well as induce MNGC formation in certain host cells may contribute to the pathogenesis observed in B. pseudomallei infection.

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