Artículo
α-hemolysin is required for the activation of the autophagic pathway in Staphylococcus aureus-infected cells
Mestre, María Belén; Fader Kaiser, Claudio Marcelo
; Sola, Claudia del Valle
; Colombo, María Isabel
![Icon](/themes/CONICETDigital/images/conicet.png)
![Icon](/themes/CONICETDigital/images/conicet.png)
Fecha de publicación:
01/2010
Editorial:
Landes Bioscience
Revista:
Autophagy
ISSN:
1554-8627
e-ISSN:
1554-8635
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Staphylococcus aureus is a pathogen that causes serious infectious diseases eventually leading to septic and toxic shock. classically S. aureus has been considered an extracellular pathogen, but cumulative evidence indicates that it invades cells and replicates intracellularly leading to staphylococcal persistence and chronic disease. It has been previously shown that this pathogen localizes to LC3-labeled compartments and subverts the autophagy pathway. One of the key features of S. aureus infection is the production of a series of virulence factors, including secreted enzymes and toxins. In the present report we present evidence that the pore-forming toxin α-hemolysin (hla) is a S. aureus secreted factor which participates in the activation of the autophagic pathway. In addition, our results indicate that although the toxin elicits an autophagic response this pathway is dysfunctional as indicated by the accumulation of the LC3-II form in cell lysates obtained from intoxicated cells. In addition, not only the purified hla toxin but also the toxin-secreting pathogen prevented the maturation of autophagosomes. Interestingly, in cells infected with the wild-type strain of S. aureus the bacteria-containing compartments which recruited LC3 onto the limiting membrane did not accumulate the acidotropic probe LysoTracker. In contrast, those phagosomes containing the hla(-) mutant (unable to produce the toxin) localized in an acidic compartment unlabeled by LC3. These results suggest that the LC3 protein is recruited only to those damaged vacuoles (i.e., perforated by the toxin), perhaps as an attempt to protect the cells. Furthermore, we have demonstrated that the toxin-dependent activation of autophagy (although it is regulated by calcium and requires Atg5) is independent of both PI3Kinase activity and Beclin 1 suggesting the involvement of a non-canonical autophagy pathway. © 2010 Landes Bioscience.
Palabras clave:
AUTOPHAGY
,
LC3
,
STAPHYLOCOCCUS AUREUS
,
TOXIN
,
Α-HEMOLYSIN
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Colecciones
Articulos(CIBICI)
Articulos de CENTRO DE INV.EN BIOQUI.CLINICA E INMUNOLOGIA
Articulos de CENTRO DE INV.EN BIOQUI.CLINICA E INMUNOLOGIA
Citación
Mestre, María Belén; Fader Kaiser, Claudio Marcelo; Sola, Claudia del Valle; Colombo, María Isabel; α-hemolysin is required for the activation of the autophagic pathway in Staphylococcus aureus-infected cells; Landes Bioscience; Autophagy; 6; 1; 1-2010; 110-125
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