Adhesion molecules and central nervous system inflammation

From the ever-changing acronyms and the increased grouping of molecules with different acronyms into single units, it is apparent that a general consensus on the classification of adhesion molecules has yet to be achieved. This state of flux notwithstanding, three major groups (superfamilies) of adhesion molecules exist (the immunoglobulin, integrin and selectin superfamilies), with several less well-defined groups (e.g. addressins and cadherins) waiting in the wings, not yet granted superfamily status. Just as many of the immune system-related molecules play crucial roles in leukocyte traffic within lymphoid organs, it is now apparent that the same molecules are involved in immune system cell traffic and immune-mediated damage within non-lymphoid tissues like the central nervous system (CNS). For example, inflammation is the key in lesion development in some CNS diseases and data are presented here which strongly implicate adhesion molecules in immune cell trafficking to the CNS. Although a CNS-specific homing molecule or ligand has not yet been found, some of the vascular addressins constitutive for lymphoid tissues seem to display some site-specificity during the CNS autoimmune condition experimental allergic encephalomyelitis. Understanding the molecular mechanisms underlying CNS inflammation might lead to new therapeutic strategies, e.g. treatment with anti-adhesion molecule antibodies and antibodies against soluble mediators, such as cytokines, that modulate adhesion-molecule expression. Such strategies should have broad-ranging applicability.