THE EFFECTS OF RHGM-CSF ON MACROPHAGE FUNCTION

Markers of monocyte/macrophage activity are numerous, and offer an insight on the potential effects of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF). These include anti-microbial effects, anti-tumour effects, inflammation and wound healing enhancing effects, antigen presenting effects and effects on the haematopoietic microenvironment. The actions of rhGM-CSF on monocytes/macrophages relevant to enhanced antimicrobial activity include increased phagocytosis, increased oxidative metabolism, increased numbers of Fc receptors, release of chemotactic factors and stimulation of mechanisms for killing intracellular viruses, fungi, bacteria and protozoa. Markers of macrophage anti-tumour activities can be divided into two types: those associated with antitumour antibodies, antibody-dependent cell cytotoxicity (ADCC) and those associated with synthesis and secretion of cytolytic substances by activated macrophages. In addition, rhGM-CSF has actions on fibroblasts and kerotinocytes consistent with an important role in wound healing. Moreover, the clinical use of rhGM-CSF to enhance antibody responses in conditions of inadequate immunisation is currently being investigated. Furthermore, rhGM-CSF appears to have a role in stimulating haemopoietic recovery following cytotoxic chemotherapy or radiation damage to bone marrow tissue.