Abstract
Thirty‐one different long‐term established human carcinoma culture cell lines were examined for the presence or absence of receptors for the Fc portion of immunoglobulin G (IgG) (“Fc receptors”), the third component of complement (C3 receptors), sheep erythrocytes and mouse erythrocytes. Included in the catalogue of lines tested were adeno‐carcinoma of the adrenal cortex, colon, rectum, lung, liver, breast and kidney, and carcinomas of the uterine cervix, bladder and vulva. All lines were found to be consistently Fc receptor‐negative, as assayed by rosette formation with sheep erythrocytes coated with subhemagglutinating amounts of anti‐sheep erythrocyte antibodies, or bovine erythrocytes heavily coated with non‐hemagglutinating anti‐bovine erythrocyte antibodies. This is similar to results obtained with murine tumors: carcinomas are consistently Fc receptor‐negative, while those lines which are Fc receptor‐positive are invariably lymphoreticular in nature. The human carcinoma cell lines were also negative for complement (C3) receptors and spontaneous T and B rosette markers. It is proposed that, in most cases, rosette‐forming cells found in primary human carcinomas are, as in the mouse or rat, representative of infiltrating non‐malignant lympho‐reticular cells.