CD62E

CD62E, commonly known as E-selectin, is a cell adhesion molecule expressed primarily on activated endothelial cells. It plays a central role in the inflammatory response by mediating the initial capture and rolling of leukocytes along the vascular endothelium, a prerequisite for leukocyte extravasation into tissues.

E-selectin binds to carbohydrate ligands on leukocytes, most notably sialyl Lewis X, to generate transient, low-affinity interactions that slow circulatory cells. This rolling allows integrins on leukocytes to switch to a high-affinity state and promote firm adhesion and subsequent transmigration. E-selectin is part of the selectin family, which also includes L-selectin on leukocytes and P-selectin on platelets and endothelium. Expression of E-selectin is not constitutive; it is rapidly upregulated on endothelial cells in response to inflammatory stimuli such as interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-α), and endotoxins.

Structurally, E-selectin is a type I transmembrane glycoprotein containing an N-terminal lectin domain, an epidermal growth factor–like domain, and a mucin-like stalk with multiple repeats that project the lectin domain from the cell surface. Ligands for E-selectin include sialylated carbohydrates such as sialyl Lewis X and, in some contexts, ESL-1 and CD44.

Clinically, soluble E-selectin can be measured in blood and serves as a biomarker of endothelial activation and inflammation; elevated levels are reported in sepsis, cardiovascular disease, and autoimmune conditions. Therapeutic strategies targeting E-selectin have been explored but face challenges due to redundant adhesion pathways. Research uses ELISA to detect soluble E-selectin and flow cytometry or immunohistochemistry to assess surface expression.