A 28-year-old man develops an abscess after a splinter injury on his finger. What adhesion molecule is primarily involved in the inflammation process?

• A. Cadherins
• B. Selectins
• C. Proteoglycans
• D. Integrins

Answer: (B)

In the context of inflammation, selectins play a crucial role during the initial stages of leukocyte recruitment to sites of injury or infection. After a splinter injury, the body responds with an inflammatory process that involves the movement of white blood cells from the bloodstream into the damaged tissue.

Selectins are adhesion molecules that mediate the rolling of leukocytes along the endothelial surface of blood vessels. They bind to specific carbohydrates on the surface of leukocytes, allowing these immune cells to slow down, roll, and eventually adhere to the endothelium. This is a critical step before the leukocytes can migrate through the vessel wall into the tissues where they can help combat infection and clear debris.

The other adhesion molecules mentioned do have roles in cell adhesion and immune responses, but they function at different stages or in different contexts. Cadherins are primarily involved in cell-cell adhesion within tissues, integrins facilitate tight adhesion and signaling between cells and the extracellular matrix, and proteoglycans are important for structural integrity and signaling in tissues rather than direct leukocyte adhesion. Therefore, selectins are specifically important for the acute inflammatory response associated with leukocyte rolling and initial adhesion during the inflammatory process.