| Popis: |
Monocytes and macrophages play an essential role in the thymus-dependent immune response by taking up an antigen and presenting it to the T-cell. They phagocyte and kill infectious agents during secondary immune response. Furthermore, macrophages secrete a wide range of biologically active molecules which influence the development of the immune-responsive lymphocytes and even play a role in the control of hemopoiesis. Proliferation and differentiation of hemopoietic precursor cells in vitro require specific growth factors such as colony-stimulating factor (CSF) for granulopoiesis and erythropoietin (Epo) for erythropoiesis. In the presence of these glycoproteins committed hemopoietic stem cells form distinct granulocytic-monocytic cell aggregates (colony-forming unit in culture, CFU-c) or erythroid colonies (colony-forming unit — erythroid, CFU-e), when incubated in semisolid culture medium. CSF is ubiquitously distributed in rodent and human tissues [3–5,10,14,17,18,26,28] and monocytes and macrophages are of the major sources of it [6,12,13,17]. The role of macrophages in controlling erythropoiesis was until very recently only suggestive. |
