Isolation of Membrane-associated Tumour-specific Antigens from Rat Hepatomas induced by Aminoazo Dye

Abstract

TUMOUR-SPECIFIC antigens (TSTA) have been demonstrated by transplantation methods in tumours induced by carcinogens and an important feature is that each tumour possesses characteristic individual antigens^1–4. Host resistance can be evoked against these tumours after exposure to viable or attenuated tumour cells, whereas isolated tumour fractions have usually been devoid of immunogenic activity^5,6. Tumour-specific antigens with individual specificities similar to those demonstrable by transplantation methods have recently been detected on aminoazo dye induced rat hepatoma cells. An indirect fluorescent antibody test⁸ was used based on that developed by Möller⁹ for the detection of histocompatibility antigens associated with the cell membrane. This in vitro procedure provides a more simple test than tedious transplantation methods for assaying the anti-genicity of subcellular fractions from transplanted rat hepatomas. Particular attention has been paid to plasma membrane fractions prepared by the general method of Davies and his co-workers which was initially devised for the isolation of mouse H-2 isoantigens^10,11 and more recently applied in the extraction of transplantation antigens from human spleen¹².