Discrimination of Human Macrophages and Dendritic Cells by Means of Monoclonal Antibodies

Abstract

Two monoclonal antibodies (MoAb), RFD1 and RFD7, have been used to investigate whether human macrophages and dendritic cells represent phenotypically distinct cell types. RFD7 recognizes a 77 kd antigen, and is specific for acid phosphatase positive tissue macrophages, while RFD1 recognizes a unique Class II antigen, which is associated with dendritic cells. With immunohistological/cytological methods it was found that neither of these reagents reacted with granulocytes, monocytes, or lymphocytes, with the exception that a small proportion (−, RFD7⁻) were matured in vitro, two distinct populations of RFD1⁺ RFD7⁻ and RFD7⁺ RFD1⁻ cells emerged. It is concluded that in normal tissues these two reagents identify phenotypic differences between macrophages and dendritic cells that may have functional significance.