Tumour Specificity and Immunological Suppression

Abstract

ANTISERA toxic for tumours but innocuous for normal tissues have been sought with meagre or questionable success since the early days of immunology. The outcome of most experiments has emphasized the antigenic similarities rather than the disparities between normal and tumour cells so that the existence of tumour-specific antigens has remained entirely hypothetical. Indeed, it would seem rather hopeless to resume the search for tumour-specific antigens were it not for two circumstances. The first of these is the work of Zil'ber^1,2 and others in the U.S.S.R. who by means of anaphylactic reactions in the guinea pig have provided strong evidence for the existence of tumour-specific antigens. The second is the phenomenon of immunological suppression, including acquired tolerance for homologous transplants³ and suppression of specific antibody response⁴ by the introduction of tissues or simple antigens into embryonic or early post-natal mammals. The present experiments were based on the assumption that if one could suppress antibody formation against normal tissues, as suggested by the work of Feldman and Yaffee⁵, it might be possible to produce antibodies directed exclusively against the specific antigens of tumours—providing such antigens exist. Our results thus far encourage the conclusion that the immunologically suppressed animal provides the long-sought means of producing antisera capable of discriminating between tumours and normal tissues.