Alternate Changes of Surface Antigen(s) in Adenovirus Type 12-Transformed and Tumor Cells

抄録

Alternate changes of specific surface antigen(s) (S antigen) were examined in transformed and tumor cells induced by human adenovirus type 12. All of the hamster and mouse cells transformed in vitro showed ring-form membrane fluorescence staining by anti-S antigen rabbit sera, whereas tumor cells, either induced by the virus in vivo or produced by inoculation with the S(+)-transformed cells, did not show any fluorescence. When the S(-) tumor cells were serially subcultured in vitro, all of them converted to S(+) cells, although more than ten subcultures were necessary. For the S(+) cells to form tumors in hamsters about ten times as many cells were necessary as the S(-) cells. This difference became greater when tumor formation was tested in preimmunized hamsters, while little, if any, when tested in X-irradiated hamsters. In addition, immunogenicity of the S(+) cells was sug-gested to be higher than that of the S(-) cells. These findings indicate that the S(+) cells are more immunosensitive and immunogenic than the S(-) cells, and that in vivo conversion from S(+) to S(-) may be due to selection of S(-)-mutant cells. In vitro conversion from S(-) to S(+) was also suggested to be due to the appearance of S(+)-mutant cells.