Endothelial leukocyte interaction during inflammation is mediated by
**Core Concept**
The interaction between endothelial cells and leukocytes during inflammation is a complex process that involves the coordinated action of various adhesion molecules and signaling pathways. This process is crucial for the recruitment of leukocytes to sites of inflammation, where they can participate in the immune response.
**Why the Correct Answer is Right**
The primary adhesion molecules involved in endothelial leukocyte interaction are selectins, integrins, and members of the immunoglobulin superfamily, such as ICAM-1 and VCAM-1. During inflammation, the expression of these adhesion molecules is upregulated on the surface of endothelial cells, allowing them to bind to their ligands on leukocytes. This binding is a critical step in the process of leukocyte recruitment, as it enables the leukocytes to roll along the endothelial surface and eventually adhere to it, facilitating their migration into the inflamed tissue.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because while it is true that endothelial cells play a crucial role in inflammation, they are not the primary site of action for the interaction between leukocytes and the immune system.
* **Option B:** This option is incorrect because while integrins are involved in the interaction between endothelial cells and leukocytes, they are not the only adhesion molecules involved in this process.
* **Option C:** This option is incorrect because while selectins are involved in the rolling of leukocytes along the endothelial surface, they are not the primary adhesion molecules involved in the interaction between endothelial cells and leukocytes.
**Clinical Pearl / High-Yield Fact**
The expression of adhesion molecules on the surface of endothelial cells is a critical step in the process of leukocyte recruitment during inflammation. Understanding the role of these adhesion molecules is essential for the development of effective therapies for inflammatory diseases.
**Correct Answer:** D.