Autophagy Eliminates Group A Streptococcus Invading Host Cells

2006 ◽  
pp. 139-150
Author(s):  
Atsuo Amano ◽  
Tamotsu Yoshimori
Keyword(s):  
Group A Streptococcus ◽  
Host Cells ◽  
Group A

scholarly journals SpyAD, a Moonlighting Protein of Group A Streptococcus Contributing to Bacterial Division and Host Cell Adhesion

2014 ◽  
Vol 82 (7) ◽  
pp. 2890-2901 ◽  
Author(s):  
Marilena Gallotta ◽  
Giovanni Gancitano ◽  
Giampiero Pietrocola ◽  
Marirosa Mora ◽  
Alfredo Pezzicoli ◽  
...  
Keyword(s):  
Cell Division ◽  
Mammalian Cells ◽  
Group A Streptococcus ◽  
Host Cells ◽  
Knockout Mutant ◽  
Content Type ◽  
Moonlighting Protein ◽  
Group A

ABSTRACTGroup A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of thespy0269gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interactin vitrowith the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cellsin vitroand thatLactococcus lactisexpressing Spy0269 on its cell surface could adhere to mammalian cellsin vitroand to mice nasal mucosain vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (StreptococcuspyogenesAdhesion andDivision protein).

Assays to Analyze Adhesion of Group A Streptococcus to Host Cells

2020 ◽  
pp. 271-278
Author(s):  
Adrina H. J. Khemlani ◽  
Thomas Proft ◽  
Jacelyn M. S. Loh
Keyword(s):  
Group A Streptococcus ◽  
Host Cells ◽  
Group A

scholarly journals Streptococcus pyogenes prtFII, but not sfbI, sfbII or fbp54, is represented more frequently among invasive-disease isolates of tropical Australia

2002 ◽  
Vol 128 (3) ◽  
pp. 391-396 ◽  
Author(s):  
A. DELVECCHIO ◽  
B. J. CURRIE ◽  
J. D. McARTHUR ◽  
M. J. WALKER ◽  
K. S. SRIPRAKASH
Keyword(s):  
Streptococcus Pyogenes ◽  
Group A Streptococcus ◽  
Invasive Disease ◽  
Host Cells ◽  
Non Invasive ◽  
Invasive Diseases ◽  
Genetic Endowment ◽  
Group A ◽  
Tropical Australia

Streptococcus pyogenes (group A streptococcus) strains may express several distinct fibronectin-binding proteins (FBPs) which are considered as major streptococcal adhesins. Of the FBPs, SfbI was shown in vitro to promote internalization of the bacterium into host cells and has been implicated in persistence. In the tropical Northern Territory, where group A streptococcal infection is common, multiple genotypes of the organism were found among isolates from invasive disease cases and no dominant strains were observed. To determine whether any FBPs is associated with invasive disease propensity of S. pyogenes, we have screened streptococcal isolates from bacteraemic and necrotizing fasciitis patients and isolates from uncomplicated infections for genetic endowment of 4 FBPs. No difference was observed in the distribution of sfbII, fbp54 and sfbI between the blood isolates and isolates from uncomplicated infection. We conclude that the presence of sfbI does not appear to promote invasive diseases, despite its association with persistence. We also show a higher proportion of group A streptococcus strains isolated from invasive disease cases possess prtFII when compared to strains isolated from non-invasive disease cases. We suggest that S. pyogenes may recruit different FBPs for different purposes.

scholarly journals Streptolysin O Inhibits Clathrin-Dependent Internalization of Group A Streptococcus

mBio ◽  
2011 ◽  
Vol 2 (1) ◽  
Author(s):  
Lauren K. Logsdon ◽  
Anders P. Håkansson ◽  
Guadalupe Cortés ◽  
Michael R. Wessels
Keyword(s):  
Epithelial Cells ◽  
Group A Streptococcus ◽  
Bacterial Species ◽  
Expression System ◽  
Human Keratinocytes ◽  
Host Cells ◽  
Local Perturbation ◽  
Lysosomal Degradation ◽  
Streptolysin O ◽  
Group A

ABSTRACTGroup AStreptococcus(GAS) can be internalized by epithelial cells, including keratinocytes from human skin or pharyngeal epithelium. Internalization of GAS by epithelial cells has been postulated both to play a role in host defense and to provide a sanctuary site for GAS survival. The cholesterol-binding cytolysin streptolysin O (SLO) appears to enhance virulence in part by inhibiting GAS internalization by human keratinocytes and by disrupting the lysosomal degradation of internalized GAS. We now report that low-level production of SLO by an inducible expression system reduced GAS internalization by keratinocytes. Induced SLO expression also prevented lysosomal colocalization with intracellular bacteria and acidification of GAS-containing vacuoles. Exogenous recombinant SLO mimicked the inhibitory effect of SLO secretion on GAS entry but not that on colocalization with the lysosomal marker LAMP-1, implying that disruption of lysosomal degradation requires intracellular secretion of SLO. The internalization of SLO-negative GAS was blocked by the depletion of host cell cholesterol and by the inhibition or knocking down of the expression of clathrin or dynamin. SLO also inhibited the cellular uptake of other cargos that are internalized by clathrin-mediated uptake or by macropinocytosis. We conclude that SLO interferes with the internalization of GAS through local perturbation of the keratinocyte cell membrane and disruption of a clathrin-dependent uptake pathway.IMPORTANCEStreptolysin O (SLO) is a member of a family of pore-forming toxins, the cholesterol-dependent cytolysins, that are produced by many Gram-positive bacterial pathogens. While SLO can lyse host cells at high doses, much smaller amounts appear to contribute to pathogenesis by inhibiting the internalization of group AStreptococcus(GAS) by pharyngeal keratinocytes and by preventing efficient intracellular killing by lysosomal fusion. This study provides evidence that SLO blocks a clathrin-dependent pathway for the internalization of GAS through effects on the cell surface, whereas inhibition of lysosomal fusion depends on the intracellular production of SLO. These observations may have broader implications for understanding the pathogenesis of multiple bacterial species that produce cholesterol-dependent cytolysins.

scholarly journals The N-terminal domain of the R28 protein promotes emm28 group A Streptococcus adhesion to host cells via direct binding to three integrins

2018 ◽  
Vol 293 (41) ◽  
pp. 16006-16018 ◽  
Author(s):  
Antonin Weckel ◽  
Dorian Ahamada ◽  
Samuel Bellais ◽  
Céline Méhats ◽  
Céline Plainvert ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Group A Streptococcus ◽  
Divalent Cations ◽  
Surface Protein ◽  
Host Cells ◽  
Endometrial Stromal Cells ◽  
Terminal Domain ◽  
Wide Range ◽  
Invasive Infections ◽  
Group A

Group A Streptococcus (GAS) is a human-specific pathogen responsible for a wide range of diseases, ranging from superficial to life-threatening invasive infections, including endometritis, and autoimmune sequelae. GAS strains express a vast repertoire of virulence factors that varies depending on the strain genotype, and many adhesin proteins that enable GAS to adhere to host cells are restricted to some genotypes. GAS emm28 is the third most prevalent genotype in invasive infections in France and is associated with gyneco-obstetrical infections. emm28 strains harbor R28, a cell wall–anchored surface protein that has previously been reported to promote adhesion to cervical epithelial cells. Here, using cellular and biochemical approaches, we sought to determine whether R28 supports adhesion also to other cells and to characterize its cognate receptor. We show that through its N-terminal domain, R28Nt, R28 promotes bacterial adhesion to both endometrial–epithelial and endometrial–stromal cells. R28Nt was further subdivided into two domains, and we found that both are involved in cell binding. R28Nt and both subdomains interacted directly with the laminin-binding α3β1, α6β1, and α6β4 integrins; interestingly, these bindings events did not require divalent cations. R28 is the first GAS adhesin reported to bind directly to integrins that are expressed in most epithelial cells. Finally, R28Nt also promoted binding to keratinocytes and pulmonary epithelial cells, suggesting that it may be involved in supporting the prevalence in invasive infections of the emm28 genotype.

scholarly journals Identification and Characterization of Serotype-Specific Variation in Group A Streptococcus Pilus Expression

2017 ◽  
Vol 86 (2) ◽  
Author(s):  
Gregory Calfee ◽  
Jessica L. Danger ◽  
Ira Jain ◽  
Eric W. Miller ◽  
Poulomee Sarkar ◽  
...  
Keyword(s):  
Human Blood ◽  
Vaccine Development ◽  
Group A Streptococcus ◽  
Bacterial Pathogen ◽  
Host Cells ◽  
Dependent Manner ◽  
Content Type ◽  
Low Level ◽  
Invasive Infections ◽  
Group A

ABSTRACTIsolates of a given bacterial pathogen often display phenotypic variation, and this can negatively impact public health, for example, by reducing the efficacy of preventative measures. Here, we identify that the human pathogen group AStreptococcus(GAS;Streptococcus pyogenes) expresses pili on its cell surface in a serotype-specific manner. Specifically, we show that serotype M3 GAS isolates, which are nonrandomly associated with causing particularly severe and lethal invasive infections, produce negligible amounts of pili relative to serotype M1 and M49 isolates. Performance of an interserotype transcriptome comparison (serotype M1 versus serotype M3) was instrumental in this discovery. We also identified that the transcriptional regulator Nra positively regulates pilus expression in M3 GAS isolates and that the low level of pilus expression of these isolates correlates with a low level ofnratranscription. Finally, we discovered that the phenotypic consequences of low levels of pilus expression by M3 GAS isolates are a reduced ability to adhere to host cells and an increased ability to survive and proliferate in human blood. We propose that an enhanced ability to survive in human blood, in part due to reduced pilus expression, is a contributing factor in the association of serotype M3 isolates with highly invasive infections. In conclusion, our data show that GAS isolates express pili in a serotype-dependent manner and may inform vaccine development, given that pilus proteins are being discussed as possible GAS vaccine antigens.

scholarly journals The IL-8 protease SpyCEP is detrimental for Group A Streptococcus host-cells interaction and biofilm formation

2014 ◽  
Vol 5 ◽  
Author(s):  
Federica Andreoni ◽  
Taiji Ogawa ◽  
Mariko Ogawa ◽  
Jerzy Madon ◽  
Satoshi Uchiyama ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Group A Streptococcus ◽  
Host Cells ◽  
Group A

Etiology, clinical presentation, laboratory diagnostics, pathogenesis of impetigo and treatment methods

2020 ◽  
pp. 64-70
Author(s):  
Anastasiya Laknitskaya
Keyword(s):  
Streptococcus Pyogenes ◽  
Skin Diseases ◽  
Group A Streptococcus ◽  
Antibiotic Sensitivity ◽  
Antioxidant Defense System ◽  
Laboratory Diagnostics ◽  
Treatment Methods ◽  
Group A ◽  
The Individual

Currently, one of the priority medical and social problems is the optimization of treatment methods for pyoderma associated with Streptococcus pyogenes — group A streptococcus (GAS). To date, the proportion of pyoderma, the etiological factor of which is Streptococcus pyogenes, is about 6 % of all skin diseases and is in the range from 17.9 to 43.9 % of all dermatoses. Role of the bacterial factor in the development of streptococcal pyoderma is obvious. Traditional treatment complex includes antibacterial drugs selected individually, taking into account the antibiotic sensitivity of pathognomonic bacteria, and it is not always effective. Currently implemented immunocorrection methods often do not take into account specific immunological features of the disease, the individual, and the fact that the skin performs the function of not only a mechanical barrier, but it is also an immunocompetent organ. Such an approach makes it necessary to conduct additional studies clarifying the role of factors of innate and adaptive immunity, intercellular mediators and antioxidant defense system, that allow to optimize the treatment of this pathology.

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