Fetal Antigen Capable of Inducing Transplantation Immunity against SV40 Hamster Tumor Cells

Abstract

Abstract Hamster, mouse and human cells transformed by simian virus 40 (SV40) share a common antigen capable of stimulating specific transplantation immunity against SV40-induced tumors in hamsters (1, 2). Cursory consideration of this observation might suggest that the viral genome must code for the common tumor-specific antigen in the different cell species. Knowledge acquired recently about the size of the SV40 genome limits the potential informational complement of this virus to seven to eight genes (3). Available data indicate that at least six genes are required for virus synthesis (3, 4), and radiation studies suggest that one or two different genes are required for transformation (5). It is becoming increasingly difficult to adhere to the concept that the virus codes directly for the tumor-specific transplantation antigen (TSTA) which is incorporated into the membrane of transformed cells unless the TSTA is a small protein and is a pleiotropic viral gene product.