Biology of immunoreceptor tyrosine-based inhibition motif-bearing molecules.

摘要: The term “immunoreceptor tyrosine-based inhibition motif” (ITIM) was coined after the activation (ITAM) to designate molecular motifs that antagonize ITAM-dependent cell (Daeron et al. 1995a; D’Ambrosio 1995). concept of ITIM lies on coexpression by single cells “on” and “off” molecules which, when kept in close proximity, transduce intracellular signals interfere with each other. On off receptors can be constitutively associated at membrane, such as B Cell (BCR) CD22 lymphocytes (Law 1996) or high-affinity IgE (FcɛRI) mast cell-associated function antigen (MAFA) (Guthmann 1995); they coaggregated extracellular ligands. Thus, ITIM-bearing low-affinity for IgG (FcγRIIB) ITAM-bearing are antibodies soluble immune complexes (Amigorena 1992; Daeron 1995b; 1995a). Although spatial relationship established between MHC class I-specific killer Ig-like (KIRs) trigger cytotoxicity (Moretta 1997) is unclear, KIRs needed coligated FcɛRI same order inhibit a reconstitution model (Blery 1997). Following aggregation coaggregation receptors, both ITAMs ITIMs tyrosyl phosphorylated src family protein tyrosine kinases and, once phosphorylated, recruit cytoplasmic having SH2 domains (Cambier 1995; Burshtyn Long 1997; Vivier