Leukocyte activation markers and leukocyte–endothelium interaction

Leukocyte activation markers and leukocyte–endothelium interaction refers to the coordinated sequence of molecular events and the specific proteins involved in the recruitment of white blood cells from the circulation into tissues. This process, known as the leukocyte adhesion cascade, involves initial tethering and rolling mediated by selectins (E-, P-, and L-selectin), followed by firm adhesion mediated by leukocyte integrins (such as LFA-1 and VLA-4) binding to endothelial ligands like ICAM-1 and VCAM-1 (Ley et al., 2007, Nature Reviews Immunology). Activation markers, including CD69 and CD25, are upregulated on the leukocyte surface during this process, signaling an enhanced functional state and facilitating extravasation (PubMed, PMID: 15546383). This interaction is critical for normal immune surveillance but becomes pathological in chronic inflammatory conditions, such as rheumatoid arthritis, multiple sclerosis, and atherosclerosis, where excessive leukocyte infiltration causes tissue damage (StatPearls, "Inflammation"). Therapeutic strategies targeting this system include monoclonal antibodies like natalizumab and vedolizumab, which block specific integrins to prevent leukocytes from entering diseased tissues (DrugBank). While effective, these therapies carry risks such as systemic immunosuppression and, in rare cases, progressive multifocal leukoencephalopathy (PML) (FDA Label, Tysabri). Other agents, such as crizanlizumab, target selectins to manage conditions like sickle cell disease by preventing vaso-occlusive crises (PubMed, PMID: 27959701).

Other names

Leukocyte adhesion cascadeLeukocyte-endothelial cell adhesionLeukocyte extravasationCell adhesion molecules (CAMs)Leukocyte-endothelial interaction

Inhibition of leukocyte rolling, adhesion, and transmigration through the antagonism of cell adhesion molecules such as integrins and selectins.