What are the important endothelial adhesion molecules involved in the influx of neutrophils and mononuclear cells into a damaged or infected tissue?
The important endothelial adhesion molecules involved in the influx of neutrophils and mononuclear cells into a damaged or infected tissue are given in the below table.
Important Endothelial Adhesion Molecules Involved in the Influx of Neutrophils and Monocytes into Damaged or Infected Tissue
| Time to Activation | Leukocyte | Activated Endothelium |
|---|---|---|
| <2 hours | L-selectin PSGL-1 (inactivated neutrophils/monos) | CD34, GlyCAM-1, MADCAM-1 (integrin α4β7), P-selectin |
| <4 hours | ESL-1 | E-selectin (ELAM-1) |
| <12 hours | LFA-1 (CD11a/CD18) (activated neutrophils/monos) | ICAM-1 (CD54) |
| <24 hours | Mac-1 (CD11b/CD18) (activated neutrophils/monos) PECAM1 | ICAM-1 Endothelial PECAM1 |
| <48 hours | VLA-4 (CD49d/CD29) (lymphs, monos) | VCAM-1 (CD106) |
The time to adhesion molecule activation explains why neutrophils and monocytes/macrophages enter inflammatory site first (acute inflammation), whereas lymphocytes enter later (chronic inflammation).
Targeting of adhesion molecules using monoclonal antibody therapeutics has been successful in the treatment of some inflammatory conditions. For example, vedolizumab targets MADCAM-1 (integrin α4β7) and prevents leukocyte recruitment to the intestines for the treatment of Crohn’s disease.
