Paired immunoglobulin-like receptors and their MHC class I recognition.
The immunoglobulin-like receptors provide positive and negative regulation of immune cells upon recognition of various ligands, thus enabling those cells to respond properly to extrinsic stimuli. Murine paired immunoglobulin-like receptor (PIR)-A and PIR-B, a typical receptor pair of the immunoglobulin-like receptor family, are expressed on a wide range of cells in the immune system, such as B cells, mast cells, macrophages and dendritic cells, mostly in a pair-wise fashion. The PIR-A requires the homodimeric Fc receptor common gamma chain for its efficient cell-surface expression and for the delivery of an activation signal. In contrast, PIR-B inhibits receptor-mediated activation signals in vitro upon engagement with other activating-type receptors, such as the antigen receptor on B cells and the high-affinity Fc receptor for immunoglobulin E on mast cells. Recent identification of major histocompatibility complex (MHC) class I molecules as the physiological ligands for PIR has enabled us to attribute various immunological phenotypes observed in PIR-B-deficient mice to the consequences of the absence of a balanced interaction between PIR and MHC class I molecules expressed ubiquitously. Thus, PIR-A and PIR-B constitute a novel and physiologically important MHC class I recognition system.
Takai
Toshiyuki
T
Department of Experimental Immunology and CREST Program of the Japan Science and Technology Agency, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan. tostakai@idac.tohoku.ac.jp
D000818:Animals; D000917:Antibody Formation / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D005260:Female; D015870:Gene Expression / Q000235:genetics / Q000276:immunology; D005799:Genes, Dominant / Q000235:genetics / Q000276:immunology; D005805:Genes, MHC Class I / Q000235:genetics / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008024:Ligands; D008264:Macrophages / Q000276:immunology; D008431:Maternal-Fetal Exchange / Q000235:genetics / Q000276:immunology; D051379:Mice; D009504:Neutrophils / Q000276:immunology; D011247:Pregnancy; D011971:Receptors, Immunologic / Q000235:genetics / Q000276:immunology*; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology
D015395:Histocompatibility Antigens Class I; D008024:Ligands; C105948:Pira1 protein, mouse; C105949:Pirb protein, mouse; D011971:Receptors, Immunologic