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Translocación mediada por citolisina (CMT): un equivalente funcional de la secreción de tipo III en las bacterias

J C Madden¹, N Ruiz, M Caparon

¹Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA.

|February 13, 2001

Resumen

Las bacterias Gram-positivas como Streptococcus pyogenes utilizan una nueva vía que involucra a la estreptolisina O (SLO) para inyectar proteínas efectoras. Este mecanismo de translocación mediada por citolisina (CMT) es clave para la virulencia del patógeno.

Área de la Ciencia:

Microbiología Microbiología.
La patogénesis bacteriana es la patogénesis bacteriana.
Biología Molecular Biología Molecular

Sus antecedentes:

Los sistemas de secreción de tipo III son cruciales para la virulencia bacteriana Gram-positiva, pero sus mecanismos siguen siendo poco conocidos.
Streptococcus pyogenes es un importante patógeno Gram-positivo responsable de varias enfermedades humanas.

Objetivo del estudio:

Para aclarar el mecanismo de la inyección de proteínas efectoras por el patógeno Gram-positivo Streptococcus pyogenes.
Para investigar el papel de la estreptolisina O (SLO) en la mediación de la translocación de proteínas en las células huésped.
Para establecer un nuevo paradigma para la secreción de bacterias Gram-positivas.

Principales métodos:

Investigó la interacción entre el SLO y las proteínas efectoras.
Utilizó ensayos basados en células para demostrar la translocación de proteínas.
Se analizó la citotoxicidad sinérgica de SLO y el efector SPN.

Principales resultados:

Describió una nueva vía de inyección para las bacterias Gram-positivas utilizando SLO, una citolisina dependiente del colesterol.
Se demostró que el efector SPN (S. pyogenes NAD-glucohidrolasa) se transloca a través del poro SLO a través de un proceso polarizado.
Se demostró que SLO y SPN actúan sinérgicamente para inducir citotoxicidad, con SPN produciendo ADP-ribosa cíclica.

Conclusiones:

La translocación mediada por citolisina (CMT) representa un nuevo mecanismo para la entrega de efectores por patógenos Gram-positivos.
La translocación mediada por SLO proporciona un equivalente funcional a la secreción de tipo III para las bacterias Gram-positivas.
Este descubrimiento ofrece nuevos conocimientos sobre la función de las citolisinas dependientes del colesterol y su papel en la patogénesis bacteriana.

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