Journal of Cell Science, Vol 52, Issue 1 99-120, Copyright © 1981 by Company of Biologists

JOURNAL ARTICLES

Immunological delineation in normal and malignant cells of a membrane protein involved in glucose transport. I. Preparation and properties of the antibody

RD Gingrich, M Wouters, ME Bramwell and H Harris

Partially purified preparations of the 200000 Mr membrane glycoprotein described by Bramwell & Harris were used as antigens to generate monoclonal antibodies. Whether the protein was prepared from human or mouse tumours, the mice immunized with it yielded monoclonal antibodies of broadly similar specificities. All the antibodies obtained were of the immunoglobulin M class, despite a prolonged immunization schedule, and recognized an antigen that was present on the surface of mouse, rat and human cells. One such antibody, M/27, was studied in detail. With the exception of 2 rat kidney cell lines, the antigen detected by M/27 was found on the surface of all cells grown in culture, whether malignant or not. However, in the mouse, the species in which the antibody was generated, M/27 discriminated sharply between malignant tumours and normal tissues excised directly from the animal. In normal adult or embryonic mouse tissues, whether they were composed of multiplying cells or not, the antigen detected by M/27 was present on the cell surface only at the lower limit of detection, if at all. Malignant mouse tumours grown in the animal produced large amounts of the antigen. Explantation of embryonic mouse fibroblasts induced the expression of the antigen, which was not detected on these same cells in their normal habitat in the growing embryo. Conversely, non-malignant cells that express the antigen in vitro cease to do so when they are re-introduced into the animal. The antigenic determinant appeared to be polypeptide in nature rather than polysaccharide.