Diapedesis

Diapedesis is a process in which white blood cells move through the blood vessel walls to reach the site of an infection or inflammation. This process is crucial for the immune response and is facilitated by the interaction between white blood cells and the endothelial cells that line the blood vessels.

Process

The process of diapedesis involves several steps. First, the white blood cells adhere to the endothelial cells in a process known as margination. This is facilitated by the interaction between selectins on the endothelial cells and integrins on the white blood cells.

Next, the white blood cells roll along the endothelial cells, a process known as rolling adhesion. This is facilitated by the interaction between P-selectin on the endothelial cells and PSGL-1 on the white blood cells.

Following rolling adhesion, the white blood cells become firmly adhered to the endothelial cells in a process known as firm adhesion. This is facilitated by the interaction between ICAM-1 on the endothelial cells and LFA-1 on the white blood cells.

Finally, the white blood cells move through the endothelial cells and the underlying basement membrane in a process known as transmigration. This is facilitated by the interaction between PECAM-1 on the endothelial cells and the white blood cells.

Role in Immune Response

Diapedesis plays a crucial role in the immune response. By moving through the blood vessel walls, white blood cells are able to reach the site of an infection or inflammation. This allows them to directly attack and destroy pathogens, as well as to recruit other immune cells to the site.

Clinical Significance

Abnormalities in the process of diapedesis can lead to a variety of medical conditions. For example, defects in the adhesion molecules that facilitate diapedesis can lead to leukocyte adhesion deficiency, a rare genetic disorder that results in recurrent infections. On the other hand, excessive diapedesis can contribute to the development of chronic inflammation and related conditions such as rheumatoid arthritis and atherosclerosis.

Diapedesis Resources
Latest articles Most recent articles Ongoing trials	Wikipedia