Receptors for Immunoglobulin and Complement on Mouse Leukemias and Lymphomas

Abstract

Abstract Bone marrow-derived B lymphocytes bear a receptor for antigen-antibody-complement complexes (EAC). Monocytes and macrophages also bear a receptor for EAC, but require the Mg++ ion for the attachment of EAC. A receptor for red cell IgG complexes (EA) is found on monocytes, but not on lymphocytes. Twenty-one mouse leukemias and lymphomas were examined for the presence of these receptors. None of the tumors studied bore the lymphocyte EAC receptor. One tumor bore both the monocyte EAC and EA receptors; two of the tumors bore the monocyte EA receptor alone. The binding of the IgG EA complex to both these tumor cells and to normal monocytes could be inhibited only by mouse myeloma proteins of the γF (γ1) and γH (γ2b) subclasses of mouse IgG.