Human Monocytes: Distinct Receptor Sites for the Third Component of Complement and for Immunoglobulin G

• Published in: Science (American Association for the Advancement of Science) Vol. 162; no. 3859; pp. 1281 - 1283
• Main Authors: Huber, Heinz, Polley, Margaret J., Linscott, William D., Fudenberg, H. Hugh, Müller-Eberhard, Hans J.
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 13.12.1968
• Subjects: Antibodies; Antiserum; Beta-Globulins; Complement System Proteins; Erythrocytes; Erythrocytes - immunology; gamma-Globulins; Humans; Immunoglobulins; Ingestion; Molecules; Monocytes; Monocytes - immunology; Phagocytosis; Receptors; Receptors, Drug
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.162.3859.1281

Human monocytes contain two distinct receptor sites, one specific for the third component of complement (C′3), the other for immunoglobulin G (γG). The two receptors may function either independently or cooperatively in the induction of phagocytosis. Ingestion of erythrocytes coated with immunoglobulin M antibody requires a relatively large number of bound C′3 molecules per cell. Ingestion of erythrocytes sensitized with γG antibody is independent of complement; however, the reaction is inhibited by concentrations of γ G far below those in normal serum. Inhibition by γG-globulin is overcome by a relatively small number of bound C′3 molecules per cell. The two monocyte receptors exert a cooperative effect on ingestion by monocytes of erythrocytes coated with γG antibody in the presence of inhibitory amounts of free ′G.