[The role of myeloid differential protein-2 in innate immunity].
As typical PRRs (pattern-recognition receptors), TLRs (Toll-like receptors) play an important role during innate immunity recognition. MD-2 (myeloid differential protein-2) may contain distinct functional domains that can separately and simultaneously bind TLRs (TLR4 or TLR2) and TLR ligands, such as lipopolysaccharide (LPS). The special structure of MD-2 may result in its three main functions: (1) An association with TLR4 that amplifies TLR4 responsiveness to ligands, especially LPS. (2) Enabling TLR2-mediated responses to LPS and enhancing TLR2-mediated responses to bacteria and their cell wall components. (3) Increasing the expression of TLR2 and TLR4 and possibly influencing the correct intracellular distribution of TLR4. Importantly, while MD-2 regulation of TLR expression and distribution is well established, determining whether the interaction is direct or not will require further study. Thus, MD-2 is not only an assistant molecule of TLR4 but is also a key regulatory molecule in innate immunity, and may play important roles during infection, inflammation, immune responses and many other pathologic and physiologic processes.
Xu
Fa-Liang
FL
Research Institute of Surgery, Third Military Medical University, Chongqing 400042.
Li
Lei
L
D000818:Animals; D000954:Antigens, Surface / Q000502:physiology*; D002352:Carrier Proteins / Q000502:physiology*; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology*; D008070:Lipopolysaccharides / Q000378:metabolism; D051218:Lymphocyte Antigen 96; D008562:Membrane Glycoproteins / Q000502:physiology*; D018375:Neutrophil Activation / Q000502:physiology; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D011956:Receptors, Cell Surface / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors
D000954:Antigens, Surface; D002352:Carrier Proteins; C495377:LY96 protein, human; D008070:Lipopolysaccharides; D051218:Lymphocyte Antigen 96; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors