DIFFERENTIATION OF MONOCYTES IN-VITRO - INFLUENCE OF DIFFERENT TYPES OF SUBSTANCES

The monocyte is one of the cell types activated in inflammatory proces ses to leave the blood and to enter the site of tissue inflammation th rough the endothelium as part of the cellular infiltrate. In tissue, m onocytes differentiate to macrophages. This process is characterized b y the expression of differentiation antigens, which can be monitored b y monoclonal antibodies. A set of monoclonal antibodies has been used to design a test to analyse the ability of substances to influence the pattern of antigen expression during macrophage differentiation. Irri tant substances stimulate the enhanced expression of an 'acute marker' , which indicates the infiltration of macrophages into acutely inflame d tissues. Anti-inflammatory substances stimulate the enhanced express ion of a 'middle marker' associated with the down-regulatory phase of macrophages. The stimulation of the 'acute marker' is positively corre lated with the potential of substances and products to induce or elici t adverse skin reactions.