An epitope of the transferrin receptor is exposed on the cell surface of
high-grade but not low-grade human lymphomas
L Esserman, S Takahashi, V Rojas, R Warnke and R Levy
Department of Surgery, Stanford University Medical Center, CA 94305.
In attempting to identify antigens that are differentially expressed on
tumor cells following transformation from follicular small cleaved cell
lymphoma (FSC) to immunoblastic lymphoma (IL), we identified a unique
epitope of the transferrin receptor (TfR). The epitope is available for
binding in aggressive lymphomas but not in indolent lymphomas or normal
cells. An immunoglobulin G2a (IgG2a) antibody that binds this epitope,
Trump, was produced by screening on tumor cells from a patient who
initially had a low-grade lymphoma which subsequently converted to a
high-grade lymphoma. Immunoprecipitation and comodulation studies show that
Trump binds to the TfR, but blocking studies and immunostaining reveal that
the TfR epitope seen by Trump is distinct from the OKT9 and anti-TfR
binding sites. The ability of Trump to discriminate a separate population
of more highly malignant cells suggests that the expression of the Trump
epitope is determined by the state of activation or degree of malignancy of
the cell. In addition, it may be possible to use the Trump antibody
diagnostically or therapeutically in the management of lymphomas.
Volume 74,
Issue 8,
pp. 2718-2729,
12/01/1989
Copyright © 1989 by The American Society of Hematology
