Leukocyte adhesion and transmigration are regulated largely by the binding of complementary adhesion molecules on the leukocyte and endothelial surfaces, and chemical mediators-chemoattractants and certain cytokines-affect these processes by modulating the surface expression or avidity of such adhesion molecules.

The adhesion receptors involved belong to four molecular families:
 selectins (SELs)
 immunoglobulin superfamily (ICAMs)
 integrins (ITGs)
 mucin-like glycoproteins (like heparan sulfate).

References

 Rhee JS, Santoso S, Herrmann M, Bierhaus A, Kanse SM, May AE, Nawroth PP, Colman RW, Preissner KT, Chavakis T. New aspects of integrin-mediated leukocyte adhesion in inflammation: regulation by haemostatic factors and bacterial products. Curr Mol Med. 2003 Jun;3(4):387-92. PMID: #12776993#