ISSN:
1365-3083
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Medizin
Notizen:
Alternatively activated macrophages (Mφ2) are induced by Th2 cytokines and by glucocorticoids (GC), and can be distinguished from classically activated effector macrophages (Mφ1) on the basis of their anti-inflammatory properties. In addition, Mφ2 are involved in Th2/Th1 skewing, enhance antigen uptake and processing and support tissue remodelling and healing. In order to elucidate the heterogeneity of Mφ2 population systematically, we analysed a number of genes involved in extracellular matrix (ECM) remodelling, inflammation and phagocytosis in Mφ2 populations generated with interleukin-4 (IL-4) or GC. Using real-time polymerase chain reaction, we demonstrated that the ECM component, tenascin-C, is stimulated by IL-4, whereas it is suppressed by dexamethasone. The ECM remodelling enzymes – MMP-1 and MMP-12 – and tissue transglutaminase (TG) showed a similar regulation pattern. FXIIIa, another putative Mφ2-associated TG, was synergistically regulated by IL-4 and GC. Enzyme-linked immunosorbent assay analysis revealed that the production of Mφ2-associated chemokines, AMAC-1, MCP-4 or TARC, was induced by IL-4 and was modulated by GC. Phagocytosis of opsonized and non-opsonized particles was stimulated by GC, whereas IL-4 had only a modulatory effect, what may be partially explained by the expression pattern of hMARCO, a scavenger receptor for non-opsonized particles, that was strongly and selectively induced by GC. In conclusion, stimulation of Mφ with IL-4 and GC regulate antagonistically the expression of ECM remodelling-related molecules and phagocytosis of opsonized and non-opsonized particles.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.0300-9475.2005.01524.x
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