Macrophage Activation Mechanisms in Human Monocytic Cell Line-derived Macrophages.

BACKGROUND Although the mechanisms of macrophage activation are important for cancer immunotherapy, they are poorly understood. Recently, easy and robust assay systems for assessing the macrophage-activating factor (MAF) using monocytic cell line-derived macrophages were established. MATERIALS AND METHODS Gene-expression profiles of U937- and THP-1-derived macrophages were compared using gene expression microarray analysis and their responses against several MAFs were examined by in vitro experiments. RESULTS Activated states of these macrophages could not be assigned to a specific sub-type but showed, however, different unique characteristics. CONCLUSION The unique of monocytic cell line-derived macrophages could provide clues to understand the activation mechanism of macrophages and, therefore, help to develop effective cancer immunotherapy with MAFs.