Immunofluorescent Studies of Adenovirus 12 Tumors and of Cells Transformed or Infected by Adenoviruses

Complement-fixing (CF) antibody-positive sera from hamsters bearing adenovirus type 12 (Ad. 12)-induced tumors revealed specific immunofluorescent stainable antigens in essentially all Ad. 12 hamster tumor cells. The antigens were primarily in the form of cytoplasmic flecks; less frequent staining was seen as nuclear flecks or homogeneous staining of nucleus and cytoplasm of a small proportion of cells. Tumor cells did not stain with rabbit antisera to crude Ad. 12 virus or A and C antigens. The hamster serum also stained cytoplasmic flecks in an Ad. 12-induced BALB/c mouse tumor and Ad. 12-"transformed" hamster embryo tissue culture cells. The hamster serum also stained fleck-shaped antigens in hamster and human cell cultures inoculated with homologous and heterologous adenovirus types, although the hamster cells did not react with the rabbit Ad. 12 antiserum. Attempts to identify the fluorescent-stainable fleck-shaped antigens indicated that they are not previously recognized viral antigens and that the cytoplasmic antigens formed in hamster cell cultures inoculated with Ad. 12 are different from those in tumors and in acutely infected human cell cultures.