PATHOLOGY

Detailed explanation-1: -Lectin-like adhesion glycoproteins, called the selectins, mediate leukocyte rolling, while the firm adhesion and subsequent transendothelial migration of leukocytes are mediated by the interaction of integrins (CD11/CD18, VLA-4) on leukocytes with immunoglobulin-like adhesion molecules on ECs (e.g., ICAM-1, VCAM-1).

Detailed explanation-2: -The selectin family of adhesion molecules is critically involved in mediating leukocyte rolling, a prerequisite for leukocyte adhesion at sites of inflammation. Similarly, the selectins are thought to play a key role in postischemic injury.

Detailed explanation-3: -Leukocyte rolling is a result of rapid, yet balanced formation and dissociation of selectin-ligand bonds in the presence of hydrodynamic shear forces. The hydrodynamic forces acting on the bonds may either increase (catch bonds) or decrease (slip-bonds) their lifetimes.

Detailed explanation-4: -The Ig superfamily of adhesion molecules, including ICAM-1, ICAM-2, ICAM-3, VCAM-1, and MadCAM-1, bind to integrins on leukocytes and mediate their flattening onto the blood vessel wall with their subsequent extravasation into the surrounding tissue.