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Una molécula inmunomoduladora de bacterias simbióticas dirige la maduración del sistema inmunológico del huésped
Sarkis K Mazmanian1, Cui Hua Liu, Arthur O Tzianabos
1Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA. smazmanian@rics.bwh.harvard.edu
Cell
|July 13, 2005
Resumen
La bacteria intestinal Bacteroides fragilis utiliza un polisacárido (PSA) para guiar el desarrollo del sistema inmunológico. Esta molécula bacteriana corrige las deficiencias inmunes y promueve la maduración saludable del sistema inmunológico en los animales.
Área de la Ciencia:
- La investigación del microbioma en la investigación del microbioma.
- Inmunología Inmunología.
- Gastroenterología y Gastroenterología.
Sus antecedentes:
- El intestino de los mamíferos alberga un complejo ecosistema bacteriano en equilibrio con el sistema inmunológico del huésped.
- Los mecanismos moleculares que subyacen a esta simbiosis huésped-bacterial no se comprenden completamente.
- La identificación de moléculas bacterianas que median beneficios simbióticos es crucial para comprender la salud intestinal.
Objetivo del estudio:
- Para identificar las moléculas bacterianas de Bacteroides fragilis que median en la simbiosis huésped-bacteriana.
- Investigar el papel del polisacárido bacteriano (PSA) en el desarrollo del sistema inmunológico.
- Para dilucidar la base molecular de la maduración del sistema inmunológico influenciado por la microbiota intestinal.
Principales métodos:
- Colonización de animales con Bacteroides fragilis y una cepa mutante de PSA.
- Comparación del desarrollo del sistema inmunológico en animales colonizados versus animales libres de gérmenes.
- Análisis de las poblaciones de células T, la producción de citoquinas y la organogénesis linfoide.
Principales resultados:
- El polisacárido de Bacteroides fragilis (PSA) dirige la maduración celular y física del sistema inmunológico en desarrollo.
- El PSA corrige las deficiencias sistémicas de células T y los desequilibrios de T (H) 1 / T (H) 2.
- Una mutante de B. fragilis con deficiencia de PSA no pudo restaurar estas funciones inmunológicas, lo que pone de relieve el papel crítico del PSA.
- El PSA presentado por las células dendríticas activa las células T CD4+ y promueve la producción de citoquinas.
Conclusiones:
- El polisacárido bacteriano (PSA) de Bacteroides fragilis es una molécula clave que media en la simbiosis huésped-bacteriana.
- El PSA juega un papel crítico en el desarrollo y maduración del sistema inmunológico de los mamíferos.
- Estos hallazgos proporcionan una explicación molecular de cómo las bacterias comensales dan forma a la inmunidad del huésped.
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