Functional macrophages and gastrointestinal disorders

Figure 1 Receptors or molecules of resident and inflammatory macrophages. MΦ express opsonic (FcR and C3bR) or nonopsonic receptors, such as CKRs, MRs, SRs, fMLP and TLRs, as well as express high levels of MHC II. However, there are some differences between resident MΦ and inflammatory MΦ. Resident MΦ (left side) do not express high levels of costimulatory molecules such as CD40, CD80 and CD86, and present hyporesponsiveness to TLRs to suppress inflammation. However, inflammatory MΦ (right side) show the opposite trend. The PAMPs lead to inflammation by connecting with hyperresponsive TLRs. CKR: Cytokine receptor; fMLP: Formyl-methionine-leucyl-phenylalanine; MR: Mannose receptor; MΦ: Macrophages; PAMP: Pathogen-associated molecular pattern; SR: Scavenger receptor; TLR: Toll-like receptor.