Murine cell surface transferrin receptor: Studies with an anti‐receptor monoclonal antibody

Abstract

A rat monoclonal antibody against the murine transferrin receptor has been identified. The receptor is a 95,000 molecular weight species that exists in the cell membrane as a disulphide‐bonded dimer. Whereas 29 of 29 murine hematopoietic tumor cell lines express detectable numbers of transferrin receptors, less than 1% of adult thymocytes or spleen cells and only 5% of bone marrow cells are positive. However, fetal liver and neonatal spleen contain substantial numbers of transferrin receptor‐positive cells. Induction of Friend cells in vitro with dimethyl‐sulphoxide leads to an overall increase in the expression of transferrin receptors on the cell surface. The anti‐transferin receptor antibody we have obtained partially blocks iron uptake from ⁵⁹Fe‐transferrin by a variety of murine cell lines and inhibits the growth of a murine myeloma cell line in vitro.