No abstract

PAbl614, an SV40-speciíic monoclonal antibody of the panel PAbl601-1636 reacts with large and small tumor antigens of SV40, BK and JC virus, and with polyoma virus large and middle tumor antigens, but not with the large tumor antigen of the lymphotropic papova virus. Using immunofluorescence and immunoblot competition assays and ELISA with synthetic peptides, it is shown that the epitope is represented by the SV40 tumor antigen undecapeptide, K39-E49. This peptide comprises the tumor antigen consensus sequence, H42-G47, of the polyoma viruses. However, the epitope of PAbl614 probably does not exactly coincide with this hexapeptide. This explains why some cross-reactions are less strong, or absent, as in the case of the lymphotropic papova virus. Further antibodies of the PAbl601-1636 panel that cross-react with the JC virus large tumor antigen are PAM602,1604,1606,1618,1621,1622,1623, 1624,1626,1629, and 1633.

No abstract

The aim of this study was to quantitate the number of cell membrane-located SV40 large tumor antigen (large T) molecules of SV40-transformed cell lines by cytofluorimetric analysis. Five different SV40-transformed cell lines were labelled by either a biotin-or a fluorescein-conjugated monoclonal antibody, PAb1605, which is specmc for the large T carboxyterminus. The conjugated-antibody fluorescence signals of the stained large T molecules of transformed cells were measured via cytofluorimetry. Comparison of the fluorescence signals of calibrated beads bearing a known number of fluorescein molecules to the signals of conjugated PAb1605 antibodies bound on microbeads to a detbed number of IgG binding sites made it possible to determine the number of antibody-accessible large T molecules per SV40-transformed cell. The numbers ( X lo-*) found per cell were 1.0 (ELONA, hamster), 3.0 (VLM, mouse), 3.5 (mKSA, mouse), 11 (C57SV, mouse), and 5.5 (SVSO, human), respectively. Thus, the technique described allows a precise quantitation of surfaceexposed, antibody-accessible viral antigen expresdoll. 0 1995 WileyLiss, Inc.

No abstract