Chronic inflammation induces the expression of dendritic cell markers not related to functional antigen presentation on peritoneal exudate macrophages.

Phenotypic heterogeneity between macrophages in situ has been reported, using different macrophage-specific monoclonal antibodies. Microenvironmental factors, which may play an important role in inducing this heterogeneity were studied in a local inflammatory response in vivo. Our results show that peritoneal exudate macrophages, formed during Thioglycollate induced chronic inflammation, acquire expression of the dendritic cell markers NLDC-145 and 6D2. In contrast to these phenotypic characteristics, NLDC-145+/6D2+ exudate cells do not function like dendritic cells in an allogeneic-MLR, but are suppressive when compared with steady state peritoneal cells. The expression of these membrane markers on exudate cells is discussed.