Expression of Heterophil Forssman Antigen as Glycoprotein on Transformed Rat Cell Lines: Shedding of the Antigen From the Cells<xref ref-type="fn" rid="FN2">2</xref>

Abstract

Monoclonal Forssman (F) antibodies of the IgM class were obtained by hybridization of spleen cells from an immunized F344 rat with murine myeloma cells. By means of the indirect immunofluorescence test with monoclonal F-antibodies, F-antigen was demonstrated on rat cell lines derived from a normal cell line that was transformed by transfection with whole adenovirus type 12 DNA or a fragment (E1a + E1b) of adenovirus type 12 DNA. These transformed cells were shown to shed the F-antigen into the culture supernatant, depending on their degree of malignancy. The F-antigen was demonstrated in a glycoprotein, but not in a glycolipid fraction of the supernatants. The glycoprotein purified by affinity chromatography was subjected to gel electrophoresis and subsequent Western blotting. The F-active molecules were identified as three distinct bands of approximately 130,000, 60,000, and 27,000.