Development of a Specific Antibody Marker for Circulating Human Monocytes and Tissue Macrophages

Publisher Summary The development of specific hetero-antibody markers for human thymus and bone marrow-derived lymphocyte suggests that specific antigens are present on the membrane of hematopoietic-derived cells, which allow them to be distinguished. The chapter describes an experiment for the development of a specific antibody marker for human macrophages. In this experiment, peritoneal exudate cells were derived from patients receiving intraperitoneal BCG as a part of an immunotherapy protocol. Rabbits were immunized intravenously and subcutaneously on two occasions and bled within 10 days after the last immunization. After absorption with buffy coat depleted human erythrocytes and two absorptions with a tonsil lymphocyte suspension, an antibody was derived that was specific by fluorescence for human macrophages and for peripheral blood monocytes. These cells did not show the characteristics of T & B cells, but they stained with pararosaniline and were peroxidase positive. The absorption of the antiserum, by either adherent or non-adherent pararosaniline staining mononuclear cells, significantly decreased the fluorescent activity of the antibody. This suggests that the macrophage and the human equivalent of the K cell share the same membrane antigens and the antiserum reacts with both.