{'fraction_non_alphanumeric': 0.026850507982583455, 'fraction_numerical': 0.0, 'mean_word_length': 5.759803921568627, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
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 γ 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.