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Las integrinas forman una barrera de difusión en expansión que coordina la fagocitosis
Spencer A Freeman1, Jesse Goyette2, Wendy Furuya1
1Program in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.
Cell
|January 16, 2016
Resumen
La fagocitosis se basa en la exclusión de la fosfatasa CD45 de los sitios de contacto. Las integrinas forman una barrera atada a la actina que aleja el CD45, lo que permite una absorción eficiente.
Área de la Ciencia:
- Biología celular
- Inmunología
- La biofísica
Sus antecedentes:
- La fagocitosis, un proceso celular crítico, es iniciado por el agrupamiento de receptores y la activación de la familia Src quinasa (SFK).
- La activación de SFK requiere la exclusión de las fosfatasas tirosinas, como la CD45, del sitio de enlace de partículas.
Objetivo del estudio:
- Investigar el mecanismo por el cual la principal fosfatasa CD45 se excluye de los sitios de contacto durante la fagocitosis.
- Para aclarar el papel de los receptores Fcγ e integrinas en la regulación de la movilidad de CD45 y la formación de la copa fagocítica.
Principales métodos:
- Seguimiento de una sola molécula de la movilidad de CD45.
- Micropaternamiento de IgG (ligando del receptor Fcγ) para controlar las zonas de compromiso del receptor.
- Análisis de la señalización del segundo mensajero y la activación de la integrina.
Principales resultados:
- La movilidad de CD45 aumentó significativamente con la activación del receptor Fcγ.
- Una barrera de difusión en expansión, originada más allá de la zona receptor-ligando, desplazó CD45 de la copa fagocítica.
- Las integrinas, activadas por la señalización del receptor Fcγ, formaron una barrera atada a la actina que excluyó a CD45.
Conclusiones:
- Las barreras de actina mediadas por integrina son cruciales para excluir CD45 y facilitar la fagocitosis.
- La onda de integrina en expansión coordina el cierre de la cremallera del receptor Fcγ y el cierre de la copa fagocítica.
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