RELATIONSHIP BETWEEN T-ANTIGEN AND TUMOR-SPECIFIC TRANSPLANTATION ANTIGEN IN SIMIAN-VIRUS 40-TRANSFORMED CELLS

The SV40 tumor antigen (T-antigen) and tumor-specific transplantation antigen (TSTA) were partially purified and studied to clarify their relationship. The T-antigen and the TSTA were partially purified from nuclei of SV AL/N cells, an SV40-transformed mouse embryo fibroblast line, by precipitation with (NH4)2SO4 and chromatography on DEAE- and DNA-cellulose. The T-antigen was assayed by complement fixation, and the TSTA was assayed by its ability to immunize mice against SV40-containing ascites tumor cells. When T-antigen- and TSTA-containing preparations were sedimented through sucrose gradients, each antigen had a major peak of activity at a sedimentation coefficient of 6.7 and minor peaks in other regions. Antiserum against T-antigen (from tumor-bearing hamsters) immunoprecipitated the TSTA activity. A preparation of T-antigen from human SV80 cells, which exhibited only 1 protein band after sodium dodecyl sulfate-polyacrylamide gel electrophoresis, had TSTA activity when as little as 0.6 .mu.g of protein/mouse was used for immunization. The T-antigen, the product of the SV40 early A gene, is capable of inducing specific immunity against transplantation of SV40-transformed tumor cells in mice.