Dendritic Cell ITIM/ITAM Immunoreceptors

ITIMs (immunoreceptor tyrosine-based inhibition motif) and ITAMs (immunoreceptor tyrosine-based activation motif) are phosphorylation motifs found in a large number of receptors or adaptor proteins. Phosphorylated ITIMs recruit tyrosine phosphatases, whereas phosphorylated ITAMs serve as docking sites for tandem SH2 domains of Syk family kinases. Signaling through ITAM-bearing receptors usually results in cell activation, while engagement of ITIM-bearing receptors is usually inhibitory, although exceptions have been described.