Intercellular adhesion molecule 5 (ICAM5)

Intercellular adhesion molecule 5 (ICAM5), also known as telencephalin, is a type I transmembrane glycoprotein belonging to the immunoglobulin superfamily. It has nine extracellular Ig-like domains and is expressed exclusively in telencephalic neurons of the brain. ICAM5 plays critical roles in neuronal cell adhesion, dendritic growth, and synaptic formation. It mediates both homophilic (neuron-neuron) and heterophilic (neuron-leukocyte via LFA-1) adhesion, facilitating neuron-microglial interactions that are important for brain development and immune regulation. Its developmental regulation is linked with dendritic maturation and synapse plasticity. ICAM5 may help maintain immune privilege in the CNS, suppressing inflammatory responses and limiting neuronal damage. Alterations in ICAM5 expression or function are implicated in neurodevelopmental disorders, and variants in its gene may elevate risk for certain cancers.

Other names

TelencephalinTLCNTLNICAM-5intercellular adhesion molecule 5ICAM5

Not directly targeted by drugs, but mechanistically, ICAM5 functions by binding to LFA-1 (integrin αLβ2) on leukocytes to modulate cell adhesion and immune responses in the CNS