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Adaptación al huésped de una toxina bacteriana del patógeno humano Salmonella Typhiphi
Lingquan Deng1, Jeongmin Song2, Xiang Gao2
1Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093, USA; Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
Cell
|December 7, 2014
Resumen
La toxina de Salmonella Typhi se dirige a las células humanas al unirse a los glicanos Neu5Ac. Los ratones que expresan Neu5Gc son resistentes, lo que revela la base molecular de la Salmonella Typhi.
Área de la Ciencia:
- Microbiología Microbiología.
- Biología Molecular Biología Molecular
- Biología Estructural Biología estructural.
Sus antecedentes:
- Salmonella Typhi causa fiebre tifoidea, una enfermedad humana importante.
- La toxina tifoidea es un factor de virulencia clave responsable de los síntomas de la enfermedad.
- La actividad de la toxina está mediada por la unión a los glicanos sializados en las superficies celulares.
Objetivo del estudio:
- Para investigar la especificidad de unión de la toxina tifoidea a diferentes glicanos sializados.
- Para dilucidar los mecanismos moleculares subyacentes a la especificidad del huésped de Salmonella Typhi.
- Para identificar posibles objetivos terapéuticos para la fiebre tifoidea.
Principales métodos:
- Análisis de la toxina tifoidea que se une a las células que expresan glicanos humanos (Neu5Ac) y mamíferos (Neu5Gc).
- Evaluación de la toxicidad de las toxinas en modelos de ratones, incluidos los que expresan CMAH.
- Determinación de la estructura atómica de la toxina tifoidea unida a Neu5Ac.
Principales resultados:
- La toxina tifoidea se une preferentemente y es tóxica hacia las células que expresan ácido N-acetilneuramínico (Neu5Ac) terminado glicanos.
- Los ratones que expresan constitutivamente el ácido N-glucolineuraminico (Neu5Gc) son resistentes a la toxina tifoidea.
- La estructura atómica revela las interacciones de unión específicas entre la toxina y Neu5Ac.
Conclusiones:
- La unión diferencial a Neu5Ac frente a Neu5Gc explica la especificidad exclusiva del huésped humano de Salmonella Typhi.
- La comprensión de estas interacciones moleculares proporciona información sobre las interacciones entre patógeno y huésped.
- Estos hallazgos pueden facilitar el desarrollo de nuevas terapias para la fiebre tifoidea.
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