Adhesion molecules

Proteins found on the cell membrane of almost all body cells that establish targeted contact between cells according to the receptor-ligand principle and thus enable communication (see cell contacts or gap junctions below). The cell-cell contact induces a variety of subsequent reactions, such as the formation of regulatory T cells (Treg), the intracellular activation of cytokines with consecutive events, remodeling and control of the cytoskeleton or cluster formation of surface proteins in the cell-cell contact area. Adhesion molecules (CAM) are preferentially located in vesicles within the cell and are only released into the cell's environment by exocytosis following an external signal. This rapidly increases the concentration of adhesion molecules on the cell surface. This leads to a temporary strengthening of the cell-cell contact. The process of cell adhesion plays a role in the immune system, but also in tumor diseases.

The adhesion molecules (CAM) include:

• integrins
• selectins
• cadherins
• Members of the immunoglobulin gene superfamily: The immunoglobulin superfamily is so named because the individual members have structural similarities to immunoglobulins. They are expressed by the vascular endothelium and bind to integrins on the cell surface of leukocytes. These include:
  • ICAM (Intercellular Cell Adhesion Molecule)
  • VCAM (Vascular Cell Adhesion Molecule)
  • PECAM (Platelet-Endothelial Cell Adhesion Molecule).

1. Carlos TM et al (1994) Leukocyte-Endothelial Adhesion Molecules. Blood 84: 2068-2101
2. Springer TA (1995) Traffic signals on endothelium for lymphocyte recirculation and leukocyte emigration. Ann Rev Physiol 57: 827-872
3. Trzpis M et al(2007) Epithelial cell adhesion molecule: more than a carcinoma marker and adhesion molecule. At J cathode 171: 386-95