Figure 2From: Soluble adhesion molecules as markers for sepsis and the potential pathophysiological discrepancy in neonates, children and adultsShedding of selectin and immunoglobulin superfamily adhesion molecules and its functional implications. For simplification, only one example receptor ligand pair (very late antigen-4 (VLA-4)/vascular cell adhesion molecule-1 (VCAM-1)) is illustrated. (A) Interactions of cell surface integrin VLA-4, present on leukocytes, with endothelial cell surface VCAM-1 during different steps in the leukocyte adhesion cascade. (B) Ectodomain shedding of cell surface VCAM-1 (thereby generating the soluble isoform sVCAM-1) by sheddases might reduce leukocyte adhesion to the endothelium on two complementary levels: reduction of cell surface density of adhesion molecules (for example, decreased endothelial cell surface VCAM-1, in this example); and binding of the resulting soluble isoforms to cell surface ligands (that is, binding of sVCAM-1 to leukocyte cell surface VLA-4 in this example), thereby serving as competitive antagonists (or decoy ligands) for the remaining cell-surface adhesion receptors. See [10] and the text for more details on functional implications of shedding.Back to article page