Adhesion receptors of the immune system are important in regulating the mechanism of cell adhesion. In vivo, adhesion molecules guide cell interactions. The size and shape of adhesion molecules involved with the immune system have been determined by electron microscopy or X-ray crystallography. Lymphocyte adhesion receptors regulate lymphocyte antigen-specific interactions and also transmit information that affects cellular differentiation and responsiveness and interactions with the environment. There are important interactions between adhesion molecules and antigen receptors involving signaling and induction of gene expression.
Adhesive interactions take place when lymphocytes have been activated by foreign antigen.
These interactions will direct their localization and migration before receptors determine lymphocyte homing to different lymphoid organs and neutrophil localization in inflammation.