Specific complement-fixing antigens in polyoma tumors and transformed cells

Abstract

One or more new specific antigens are present in “virus-free” polyoma tumors, as demonstrated by their complement fixation reaction with serum from animals carrying transplantable tumors. These antigens cannot be found in normal animal tissues or in tumors induced by other viruses or by methylcholanthrene. Mouse and hamster cell tissue cultures after exposure to polyoma virus are positive for the antigen and corresponding control cultures are negative. The presence of the antigen in these tissue culture cells is not related to the presence or absence of infectious virus in a carrier culture relationship or to the ability of the culture cells to produce tumors in isologous animals. Sera from tumor-bearing animals having high titers of CF antibody against tumor antigen are negative for antiviral antibody activity. Some sera from virus immunized animals are negative against the tumor antigen but have high anti-viral antibody titers. The presence of demonstrable anti-tumor CF antibodies is not necessary for virus-immunized animals to resist challenge with an isologous polyoma tumor.