scholarly journals Insufficient Acidification of Autophagosomes Facilitates Group A Streptococcus Survival and Growth in Endothelial Cells

mBio ◽  
2015 ◽  
Vol 6 (5) ◽  
Author(s):  
Shiou-Ling Lu ◽  
Chih-Feng Kuo ◽  
Hao-Wen Chen ◽  
Yi-Shuan Yang ◽  
Ching-Chuan Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Epithelial Cells ◽  
Bacterial Growth ◽  
Group A Streptococcus ◽  
Multiorgan Failure ◽  
Specific Inhibitor ◽  
Low Ph ◽  
Bafilomycin A1 ◽  
Group A

ABSTRACTGroup A streptococcus (GAS) is an important human pathogen, and its invasion via blood vessels is critically important in serious events such as bacteremia or multiorgan failure. Although GAS was identified as an extracellular bacterium, the internalization of GAS into nonphagocytic cells may provide a strategy to escape from immune surveillance and antibiotic killing. However, GAS has also been reported to induce autophagy and is efficiently killed within lysosome-fused autophagosomes in epithelial cells. In this study, we show that GAS can replicate in endothelial cells and that streptolysin O is required for GAS growth. Bacterial replication can be suppressed by altering GAS gene expression in an acidic medium before internalization into endothelial cells. The inhibitory effect on GAS replication can be reversed by treatment with bafilomycin A1, a specific inhibitor of vacuolar-type H+-ATPase. Compared with epithelial cells in which acidification causes autophagy-mediated clearance of GAS, there was a defect in acidification of GAS-containing vesicles in endothelial cells. Consequently, endothelial cells fail to maintain low pH in GAS-containing autophagosomes, thereby permitting GAS replication inside LAMP-1- and LC3-positive vesicles. Furthermore, treatment of epithelial cells with bafilomycin A1 resulted in defective GAS clearance by autophagy, with subsequent bacterial growth intracellularly. Therefore, low pH is a key factor for autophagy-mediated suppression of GAS growth inside epithelial cells, while defective acidification of GAS-containing vesicles results in bacterial growth in endothelial cells.IMPORTANCEPrevious reports showed that GAS can induce autophagy and is efficiently killed within lysosome-fused autophagosomes in epithelial cells. In endothelial cells, in contrast, induction of autophagy is not sufficient for GAS killing. In this study, we provide the first evidence that low pH is required to prevent intracellular growth of GAS in epithelial cells and that this mechanism is defective in endothelial cells. Treatment of GAS with low pH altered GAS growth rate and gene expression of virulence factors and resulted in enhanced susceptibility of GAS to intracellular lysosomal killing. Our findings reveal the existence of different mechanisms of host defense against GAS invasion between epithelial and endothelial cells.

scholarly journals Galectin-3 Inhibits Galectin-8/Parkin-Mediated Ubiquitination of Group A Streptococcus

mBio ◽  
2017 ◽  
Vol 8 (4) ◽  
Author(s):  
Yi-Lin Cheng ◽  
Yan-Wei Wu ◽  
Chih-Feng Kuo ◽  
Shiou-Ling Lu ◽  
Fu-Tong Liu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Epithelial Cells ◽  
Animal Studies ◽  
Defense Mechanism ◽  
Group A Streptococcus ◽  
Immune Surveillance ◽  
E3 Ligase ◽  
Skin Damage ◽  
Galectin 3 ◽  
Group A

ABSTRACTGroup A streptococcus (GAS) is an important human pathogen that causes a wide variety of cutaneous and systemic infections. Although originally thought to be an extracellular bacterium, numerous studies have demonstrated that GAS can trigger internalization into nonimmune cells to escape from immune surveillance or antibiotic-mediated killing. Epithelial cells possess a defense mechanism involving autophagy-mediated targeting and killing of GAS within lysosome-fused autophagosomes. In endothelial cells, in contrast, we previously showed that autophagy is not sufficient for GAS killing. In the present study, we showed higher galectin-3 (Gal-3) expression and lower Gal-8 expression in endothelial cells than in epithelial cells. The recruitment of Gal-3 to GAS is higher and the recruitment of Gal-8 to GAS is lower in endothelial cells than in epithelial cells. We further showed that Gal-3 promotes GAS replication and diminishes the recruitment of Gal-8 and ubiquitin, the latter of which is a critical protein for autophagy sequestration. After knockdown of Gal-3 in endothelial cells, the colocalization of Gal-8, parkin, and ubiquitin-decorated GAS is significantly increased, as is the interaction of Gal-8 and parkin, an E3 ligase. Furthermore, inhibition of Gal-8 in epithelial cells attenuates recruitment of parkin; both Gal-8 and parkin contribute to ubiquitin recruitment and GAS elimination. Animal studies confirmed that Gal-3-knockout mice develop less-severe skin damage and that GAS replication can be detected only in the air pouch and not in organs and endothelial cells. These results demonstrate that Gal-3 inhibits ubiquitin recruitment by blocking Gal-8 and parkin recruitment, resulting in GAS replication in endothelial cells.IMPORTANCEIn epithelial cells, GAS can be efficiently killed within the lysosome-fused autophaosome compartment. However, we previously showed that, in spite of LC-3 recruitment, the autophagic machinery is not sufficient for GAS killing in endothelial cells. In this report, we provide the first evidence that Gal-3, highly expressed in endothelial cells, blocks the tagging of ubiquitin to GAS by inhibiting recruitment of Gal-8 and parkin, leading to an enhancement of GAS replication. We also provide the first demonstration that Gal-8 can interact with parkin, the critical E3 ligase, for resistance to intracellular bacteria by facilitating the decoration of bacteria with ubiquitin chains. Our findings reveal that differential levels of Gal-3 and Gal-8 expression and recruitment to GAS between epithelial cells and endothelial cells may contribute to the different outcomes of GAS elimination or survival and growth of GAS in these two types of cells.

scholarly journals Biochemical and biological activity of arginine deiminase from Streptococcus pyogenes M22

2016 ◽  
Vol 94 (2) ◽  
pp. 129-137 ◽  
Author(s):  
Eleonora A. Starikova ◽  
Alexey V. Sokolov ◽  
Anna Yu. Vlasenko ◽  
Larisa A. Burova ◽  
Irina S. Freidlin ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Streptococcus Pyogenes ◽  
Group A Streptococcus ◽  
Bacterial Pathogen ◽  
Arginine Deiminase ◽  
Dependent Manner ◽  
Group A ◽  
Micro Organisms ◽  
Dose Dependent

Streptococcus pyogenes (group A Streptococcus; GAS) is an important gram-positive extracellular bacterial pathogen responsible for a number of suppurative infections. This micro-organism has developed complex virulence mechanisms to avoid the host’s defenses. We have previously reported that SDSC from GAS type M22 causes endothelial-cell dysfunction, and inhibits cell adhesion, migration, metabolism, and proliferation in a dose-dependent manner, without affecting cell viability. This work aimed to isolate and characterize a component from GAS type M22 supernatant that suppresses the proliferation of endothelial cells (EA.hy926). In the process of isolating a protein possessing antiproliferative activity we identified arginine deiminase (AD). Further study showed that this enzyme is most active at pH 6.8. Calculating Km and Vmax gave the values of 0.67 mmol·L–1 and 42 s−1, respectively. A distinctive feature of AD purified from GAS type M22 is that its optimum activity and the maximal rate of the catalytic process is close to neutral pH by comparison with enzymes from other micro-organisms. AD from GAS type M22 suppressed the proliferative activity of endothelial cells in a dose-dependent mode. At the same time, in the presence of AD, the proportion of cells in G0/G1 phase increased. When l-Arg was added at increasing concentrations to the culture medium containing AD (3 μg·mL–1), the enzyme’s capacity to inhibit cell proliferation became partially depressed. The proportion of cells in phases S/G2 increased concomitantly, although the cells did not fully recover their proliferation activity. This suggests that AD from GAS type M22 has potential for the suppression of excessive cell proliferation.

scholarly journals M1 Protein Triggers a Phosphoinositide Cascade for Group A Streptococcus Invasion of Epithelial Cells

2003 ◽  
Vol 71 (10) ◽  
pp. 5823-5830 ◽  
Author(s):  
Sai Sudha Purushothaman ◽  
Beinan Wang ◽  
P. Patrick Cleary
Keyword(s):  
Epithelial Cells ◽  
Group A Streptococcus ◽  
Dominant Negative ◽  
M Protein ◽  
Lipid Kinase ◽  
Cytoskeletal Rearrangement ◽  
M1 Protein ◽  
Serovar Typhimurium ◽  
Group A

ABSTRACT Invasion of nonphagocytic cells by bacteria provides a favorable niche for persistence and evasion of host defenses and antibiotics. M protein is a major virulence factor because it promotes high-frequency invasion of epithelial cells by group A Streptococcus (GAS) and also renders the bacterium resistant to phagocytosis. In this study, we investigated the role of M1 protein from serotype M1 strain 90-226 in regulating mammalian signal transduction and cytoskeletal rearrangement for bacterial entry. LY294002 and wortmannin, which are inhibitors of phosphatidylinositol 3-kinase (PI 3-K) blocked invasion of epithelial cells by GAS by 75 and 80%, respectively, but failed to inhibit invasion by Salmonella enterica serovar Typhimurium. Also, epithelial cells transiently transfected with dominant negative p85 and p110 genes, the regulatory and catalytic subunits of PI 3-K, respectively, were less able to be invaded by GAS. To separate the influence of other streptococcal virulence factors from M protein, Lactococcus lactis was engineered to express M1 protein on its surface. L. lactis(pLM1) invaded epithelial cells efficiently in vitro, and PI 3-K inhibitors blocked 90% of this invasion. Purified soluble M1 protein stimulated the formation of stress fibers and actin tuffs on epithelial cells. LY294002 and wortmannin inhibited these cellular changes. A phosphoinositide analogue also inhibited the invasion of epithelial cells by GAS. Therefore, M1 protein, either directly or via bound fibronectin, initiates signals that depend on the lipid kinase PI 3-K pathway, which paves the way for cytoskeletal rearrangement that internalize the bacterium.

scholarly journals Global differential gene expression in response to growth temperature alteration in group A Streptococcus

2001 ◽  
Vol 98 (18) ◽  
pp. 10416-10421 ◽  
Author(s):  
L. M. Smoot ◽  
J. C. Smoot ◽  
M. R. Graham ◽  
G. A. Somerville ◽  
D. E. Sturdevant ◽  
...  
Keyword(s):  
Gene Expression ◽  
Differential Gene Expression ◽  
Growth Temperature ◽  
Group A Streptococcus ◽  
Group A ◽  
Differential Gene

scholarly journals Ischemia-Reperfusion Injury in a Simulated Lung Transplant Setting Differentially Regulates Transcriptomic Profiles between Human Lung Endothelial and Epithelial Cells

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2713
Author(s):  
Gaowa Saren ◽  
Aaron Wong ◽  
Yun-Bi Lu ◽  
Cristina Baciu ◽  
Wenyong Zhou ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Human Lung ◽  
Ischemia Reperfusion Injury ◽  
Protein Biosynthesis ◽  
Ischemia Reperfusion ◽  
Gene Clusters ◽  
Related Gene

Current understanding of mechanisms of ischemia-reperfusion-induced lung injury during lung preservation and transplantation is mainly based on clinical observations and animal studies. Herein, we used cell and systems biology approaches to explore these mechanisms at transcriptomics levels, especially by focusing on the differences between human lung endothelial and epithelial cells, which are crucial for maintaining essential lung structure and function. Human pulmonary microvascular endothelial cells and human lung epithelial cells were cultured to confluent, subjected to different cold ischemic times (CIT) to mimic static cold storage with preservation solution, and then subjected to warm reperfusion with a serum containing culture medium to simulate lung transplantation. Cell morphology, viability, and transcriptomic profiles were studied. Ischemia-reperfusion injury induced a CIT time-dependent cell death, which was associated with dramatic changes in gene expression. Under normal control conditions, endothelial cells showed gene clusters enriched in the vascular process and inflammation, while epithelial cells showed gene clusters enriched in protein biosynthesis and metabolism. CIT 6 h alone or after reperfusion had little effect on these phenotypic characteristics. After CIT 18 h, protein-biosynthesis-related gene clusters disappeared in epithelial cells; after reperfusion, metabolism-related gene clusters in epithelial cells and multiple gene clusters in the endothelial cells also disappeared. Human pulmonary endothelial and epithelial cells have distinct phenotypic transcriptomic signatures. Severe cellular injury reduces these gene expression signatures in a cell-type-dependent manner. Therapeutics that preserve these transcriptomic signatures may represent new treatment to prevent acute lung injury during lung transplantation.

scholarly journals Regulation of capsule gene expression by group A Streptococcus during pharyngeal colonization and invasive infection

2008 ◽  
Vol 42 (1) ◽  
pp. 61-74 ◽  
Author(s):  
Ioannis Gryllos ◽  
Colette Cywes ◽  
Michael H. Shearer ◽  
Max Cary ◽  
Ronald C. Kennedy ◽  
...  
Keyword(s):  
Gene Expression ◽  
Group A Streptococcus ◽  
Invasive Infection ◽  
Group A

scholarly journals Inhibitor of streptokinase gene expression improves survival after group A streptococcus infection in mice

2012 ◽  
Vol 109 (9) ◽  
pp. 3469-3474 ◽  
Author(s):  
H. Sun ◽  
Y. Xu ◽  
I. Sitkiewicz ◽  
Y. Ma ◽  
X. Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Group A Streptococcus ◽  
Group A

scholarly journals Group A Streptococcus Adheres to Pharyngeal Epithelial Cells with Salivary Proline-rich Proteins via GrpE Chaperone Protein

2012 ◽  
Vol 287 (26) ◽  
pp. 22266-22275 ◽  
Author(s):  
Jumpei Murakami ◽  
Yutaka Terao ◽  
Ichijiro Morisaki ◽  
Shigeyuki Hamada ◽  
Shigetada Kawabata
Keyword(s):  
Epithelial Cells ◽  
Group A Streptococcus ◽  
Chaperone Protein ◽  
Group A

scholarly journals Unraveling the Regulatory Network in Streptococcus pyogenes: the Global Response Regulator CovR Represses rivR Directly

2006 ◽  
Vol 189 (4) ◽  
pp. 1459-1463 ◽  
Author(s):  
Samantha A. Roberts ◽  
Gordon G. Churchward ◽  
June R. Scott
Keyword(s):  
Gene Expression ◽  
Rna Polymerase ◽  
Streptococcus Pyogenes ◽  
Regulatory Network ◽  
Group A Streptococcus ◽  
Response Regulator ◽  
Master Regulator ◽  
Global Response ◽  
Conserved Sequences ◽  
Group A

ABSTRACT The response regulator CovR acts as a master regulator of virulence in Streptococcus pyogenes by repressing transcription of approximately 15% of the group A streptococcus genome directly or indirectly. We demonstrate that phosphorylated CovR represses transcription of rivR directly by binding to conserved sequences located downstream from the promoter to block procession of RNA polymerase. This establishes the first link in a regulatory network where CovR interacts directly with other proteins that modulate gene expression.

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