[2] These diverse tissue-specific adhesion molecules on lymphocytes (homing receptors) and on endothelial cells (vascular addressins) contribute to the development of specialized immune responses.
[3] The process of lymphocyte homing is deliberate, mediated by lymphocyte-endothelial recognition mechanisms that enable antigen-specific immune responses.
[2] Recently, lymphocyte homing has become a topic of interest for investigation of treatments for multiple sclerosis, type 1 diabetes mellitus, leukemia, and psoriasis.
[2] Lymphocyte homing occurs in four steps leading to extravasation into target tissue; Rolling, activation, activation-dependent “arrest”, and diapedesis.
[5] Mediated by lymphocyte receptors and vascular ligand interactions, “tethering” is a reversible linkage that leads to either rolling along the vessel wall or transient immediate arrest.
L-selectin, for example, is also able to be cleaved by an enzyme, ensuring proper binding of lymphocytes and allowing release of non-target cells.