Clone GHI/75 reacts with CD85j (ILT2), an inhibitory immunoreceptor of the immunoglobulin-like transcript (ILT) family. CD85j is a type I transmembrane protein with four extracellular Ig-like domains and four cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs) in its cytoplasmic tail. The inhibitory signal is transmitted by recruiting SH2-containing protein tyrosine phosphatase-1 that dephosphorylates and inactivates downstream tyrosine kinases. Expression of CD85j is found on B cells, monocytes, dendritic cells, and subsets of natural killer (NK) and T cells. CD85j is known to bind classical and non-classical MHC class I molecules, human cytomegalovirus UL18 protein, and some HLA-C alleles, as ligands. Crosslinking of CD85j prevents activation of B cells, T cells, NK cells, macrophages, and downregulation of effector mechanisms, such as NK and T cells cytolytic functions.
