Semaphorin-4A (mouse):Fc (human) (rec.)

Semaphorin 4A (Sema4A, previously semB) is a Class 4 transmembrane Semaphorin with activity in the immune and nervous systems. Sema4A was first described as a molecule that enhances T cell activation and interacts with TIM2 (T cell immunoglobulin and mucin domain 2). Mice with targeted disruption of Sema4A show defects in dendritic cellmediated T cell priming and Th1 responses. Roles for Sema4A have also been identified in the brain, the endothelium and the eye. It mediates hippocampal neuron growth cone collapse in vitro through interaction of the sema domain with plexinB1. Interaction of Sema4A with endothelial cell plexinD1 causes opposition to the angiogenic, proliferative, chemotactic and integrin mediated adhesive actions of VEGF.