| Figure 3-31 |
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| Recognition of bacterial lipopolysaccharide by innate immune cells | |
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| Lipopolysaccharide (LPS) monomers are extracted from bacterial membranes by the serum protein LPS-binding protein (LBP) which transfers the LPS monomer to a lipid-binding site on CD14 in the membrane of phagocytes. CD14 promotes the binding of LPS to the TLR4–MD-2 complex, which signals to the cell interior. In the absence of CD14, TLR4–MD-2 can still function with some forms of LPS or with much higher LPS concentrations. |