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Inamm. Res. (2017) 66:209216DOI 10.1007/s00011-016-0995-1 Inammation Research
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Web End = The biological function and signicance of CD74 in immune diseases
Huiting Su1,2 Ning Na3 Xiaodong Zhang4 Yong Zhao1,2
Received: 18 August 2016 / Accepted: 30 September 2016 / Published online: 17 October 2016 Springer International Publishing 2016
Abstract CD74 (MHC class II invariant chain, Ii) is a non-polymorphic type II transmembrane glycoprotein. It is clear that, in addition to be an MHC class II chaperone, CD74 has a diversity of biological functions in physiological and pathological situations. CD74 also participates in other non-MHC II protein trafcking, such as angiotensin II type I receptor. In addition, CD74 is a cell membrane high-afnity receptor for macrophage migration inhibitory factor (MIF), D-dopachrome tautomerase (DDT/MIF-2) and bacterial proteins. CD74 also regulates T-cell and B-cell developments, dendritic cell (DC) motility, macrophage inammation, and thymic selection. The activation of receptor complex CD74/CD44 may lead to multiple intracellular signal pathways, such as the activation of the extracellular signal regulated kinase (ERK) 1 and 2, the PI3K-Akt signal transduction cascade, NFjB, and the AMP-activated protein kinase (AMPK) pathway.
CD74 plays important roles in many inammatory diseases, such as liver brosis, type I diabetes, systemic lupus erythematosus, and Alzheimer disease. In this study, we will focus on the immunological functions of CD74 molecules and its roles in immune-relevant disorders.
Keywords CD74 MIF Inammation Innate immunity
Introduction
CD74 (MHC class II invariant chain, Ii) is a non-polymorphic type II transmembrane glycoprotein. It was initially identied to act mainly as an MHC class II chaperone. However, it is clear that CD74 has a much wide range of biological functions in physiological and pathological situations in addition to its regulatory roles on cell surface MHC II expression [1, 2]. CD74 also participates in other non-MHC II protein trafcking. Importantly, CD74 molecule is a cell membrane high-afnity receptor for macrophage migration inhibitory factor (MIF), D-dopa-chrome tautomerase (D-DT/MIF-2), and bacterial proteins that also behave as an accessory signaling molecule, which undergoes regulated intramembrane proteolysis (RIP) upon its ligand binding [1, 36]. In this study, we will focus on the immunological functions of CD74 molecule and its roles in immune disorders.
The expression of CD74 in immune cells
Mouse CD74 molecule has a short...