Video Experimental Relacionado
Updated: Jun 22, 2026
09:14
Static Adhesion Assay for the Study of Integrin Activation in T Lymphocytes
Published on: June 13, 2014
Las bacterias secuestran la quinasa ligada a la integrina para estabilizar las adherencias focales y bloquear el
Minsoo Kim1, Michinaga Ogawa, Yukihiro Fujita
1Department of Infectious Disease Control, International Research Center for Infectious Diseases, University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
Nature
|June 3, 2009
Resumen
Las bacterias Shigella usan la proteína OspE para mejorar la adhesión de las células huésped, previniendo el desprendimiento de las células epiteliales durante la infección. Esta interacción con la quinasa ligada a la integrina (ILK) ayuda a las bacterias a mantener su posición infecciosa.
Área de la Ciencia:
- Microbiología Microbiología.
- Biología celular Biología celular.
- Enfermedades infecciosas Enfermedades infecciosas.
Sus antecedentes:
- Las células epiteliales mucosas se desprenden naturalmente para prevenir la infección bacteriana.
- Las bacterias patógenas como la Shigella pueden superar esta defensa para colonizar el epitelio.
- Comprender las estrategias bacterianas para la adherencia de las células huésped es crucial para combatir las infecciones.
Objetivo del estudio:
- Investigar el mecanismo por el cual el efector de Shigella flexneri OspE promueve la colonización bacteriana.
- Para dilucidar el papel de la interacción entre OspE y la proteína de la célula huésped integrin-linked kinase (ILK) en la adhesión bacteriana y la supervivencia.
Principales métodos:
- Investigó la interacción entre Shigella flexneri OspE y la quinasa ligada a la integrina del huésped (ILK).
- Se analizaron los cambios en las adherencias focales, los niveles de integrina y la fosforilación de la cinasa de adhesión focal y la paxilina.
- Se utilizaron ensayos de lavado de nocodazol para evaluar el desmontaje de la adhesión focal.
- Comparación del desprendimiento celular en células epiteliales polarizadas infectadas con Shigella de tipo salvaje y un mutante ospE.
- Colones de conejillos de indias infectados con Shigella para evaluar el papel in vivo de la interacción OspE-ILK.
Principales resultados:
- Shigella OspE se une al ILK huésped, aumentando las adherencias focales y el ILK ligado a la membrana.
- La interacción OspE-ILK eleva la integrina 1 de la superficie celular y reduce la rotación de la adhesión focal.
- El OspE bloquea el desmontaje de la adhesión focal inducido por el lavado de nocodazol.
- Los mutantes de Shigella ospE exhiben un mayor desprendimiento de células epiteliales en comparación con el tipo salvaje.
- In vivo, la interacción OspE-ILK suprime el desprendimiento epitelial, mejora la propagación bacteriana y promueve la colonización.
Conclusiones:
- Shigella utiliza el efector OspE para unirse a ILK, reforzando la adherencia de las células huésped y evitando el desprendimiento de las células epiteliales.
- Este mecanismo permite a Shigella mantener un punto de apoyo infeccioso estable y promover la colonización.
- La interacción OspE-ILK es un factor de virulencia clave para Shigella en la supresión de las defensas del huésped.
Videos de Conceptos Relacionados
01:17Intracellular Signaling Affects Focal Adhesions
Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Some...
01:24Adherens Junctions
Strong contact points between adjacent cells anchor them to each other, forming tissues. Such anchoring junctions are of two types – adherens junctions and desmosomes. Adherens junctions are abundant in tissues such as epithelium and endothelium, forming a continuous zone of adhesion called the adhesion belt. In other tissues, such as heart muscle, they appear as clusters, linking the cells to produce coordinated heart muscle contraction.
Adherens Junctions are Dynamic
The endothelial cells...
Adherens Junctions are Dynamic
The endothelial cells...
01:15Activation of Integrins
Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling."
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
01:03Anchoring Junctions
Anchoring junctions are multiprotein complexes that help cells connect to other cells and the extracellular matrix. Anchoring junctions are present on the lateral and basal surfaces of cells, providing strong and flexible connections. Focal adhesions are often formed due to cell interactions with the ECM substrata, which initiate signal transduction via kinase cascades and other mechanisms. Together, they provide stability and tissue integrity. There are three types of anchoring junctions:...
01:10Integrins
Animal and protozoan cells do not have cell walls to help maintain shape and provide structural stability. Instead, these eukaryotic cells secrete a sticky mass of carbohydrates and proteins into the spaces between adjacent cells. This network of proteins and molecules is called an extracellular matrix or ECM.
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
01:39Mechanism of Filopodia Formation
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...