Murine T-lymphoma 'immunoglobulin' is identical to leukemia virus gp 70.

We have used chicken anti-mouse immunoglobulin antiserum to precipitate molecules from mouse T-lymphoma cells that had been radioiodinated. We analysed the immunoprecipitates by two-dimensional gel electrophoresis and compared the results with immunoprecipitates generated by other antisera. We found that the molecule precipitated by chicken anti-mouse immunoglobulin from T-lymphoma cells was identical to the mouse leukemia virus envelope glycoprotein (gp 70) produced by the T-lymphoma. Mouse IgM myeloma proteins block precipitation of T-lymphoma molecules by chicken anti-mouse immunoglobulin. We conclude that mouse IgM and gp 70 share antigenic determinants. This may lead to erroneous conclusions about the presence of immunoglobulin on T-cells.