通过激活selectin中的白细胞粘附分子-1 (LAM-1) 来调节白细胞迁移
O Spertini1, G S Kansas, J M Munro
1Division of Tumor Immunology, Dana-Farber Cancer Institute, Boston, Massachusetts.
Nature
|February 21, 1991
概括
白细胞粘附分子-1 (LAM-1) 亲和力在激活时增加,在免疫反应期间控制白细胞迁移到组织. 这就解释了不同的白细胞类型是如何具体迁移的.
科学领域:
- 免疫学 免疫学 免疫学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 白细胞迁移到组织中对于宿主防御病原体和炎症至关重要.
- 白细胞粘附分子-1 (LAM-1) 调解白细胞与内皮细胞的结合,引导淋巴细胞到淋巴结,引导中性粒细胞到炎症部位.
- 尽管共享表达,但通过LAM-1控制血统特异性白细胞迁移的机制仍然不清楚.
研究的目的:
- 研究如何控制白细胞迁移的血统特定差异.
- 确定LAM-1亲和度调制在白细胞贩运中的作用.
主要方法:
- 评估了LAM-1对其连接体PPME在激活和非激活的淋巴细胞和中性粒细胞中的亲和力.
- 通过生理刺激激活后,研究了淋巴细胞与高内皮静脉的依赖LAM-1的结合.
主要成果:
- 通过基因特异性刺激激活白细胞显著增加了对碳水化合物配体PPME的LAM-1亲和力.
- 淋巴细胞的激活增强了LAM-1介导的与高内皮静脉的结合.
结论:
- 在白细胞激活后,LAM-1亲和力的暂时变化直接调节白细胞迁移.
- 调节LAM-1亲和力提供了一种机制,用于控制免疫反应期间的血统特异性白细胞贩运.
相关概念视频
Cell Migration
Cell migration, the process by which cells move from one location to another, is essential for the proper development and viability of organisms throughout their life. When cells are not able to migrate properly to their ordained locations, various disorders may occur. For example, disruption in cell migration causes chronic inflammatory diseases such as arthritis.
Cell Migration
Cell migration is a process by which the cells move from one location to another, playing an essential role in embryological development, repair and regeneration, immune response, and metastasis. Cells migrate in response to chemical or mechanical signals generated by specific organs or tissues. The overall mechanism includes three steps - polarization, protrusion, and release. Polarization involves the formation of a distinct cell front and rear, which determines the direction of movement.
Mechanism of Lamellipodia Formation
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
Activation 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.
Intracellular 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...
Selectins
Cell adhesion is an essential aspect of multicellularity. While stable cell interactions usually occur between cells of the same type, transient cell interactions occur between cells of different tissue types, such as between neutrophils and endothelial cells. Selectins are one class of cell adhesion molecules (CAMs) that bind carbohydrate ligands to form transient cell adhesion. They are rod-like proteins with a long extracellular part of variable length ending with the lectin domain, which...


