Transfer Agent of Immunity

V. Antibody Formation of Cultured Macrophages Treated with an Immune Ribonucleic Acid Preparation

Abstract

An almost pure population of mononuclear phagocytes (macrophages) was obtained by repeated replacement of the culture medium. When treated in vitro with an immune ribonucleic acid (RNA) preparation extracted from the spleens of mice immunized with horse red blood cells (H-RBC) the rosette forming cells against H-RBC were demonstrated in some of the cultured macrophages but not against calf red blood cells. According to both microscopic observations and phagocytic activity, almost all of the rosette formers in this population were found to be large mononuclear phagocytes. These results support our view that large mononuclear phagocytes of mesenchymal origin constitute another cell line responsible for antibody formation in addition to the plasma and lymphocytic cell lines.