Cell-mediated immunity to carcinoma of the urinary bladder : specificity of the reaction and the nature of the effector cells

The hypothesis that immune mechanisms are a defense system net merely for the eliminatien of microbes, parasites and other foreign material from the body but also for the destruction of aberrant cells of the organism itself was already clearly formulated in 1909 by Paul Ehrlich: 'were it not for the defense mechanism of the organism tumours would appear "in einer geradezu ungeheuerlicher Frekwenz"'. The theory of immunosurveillance, first mooted by Thomas (1959) was refined and presentedinmore detail by Burnet (1970; 1971). He postulated that eliminatien of malignant cells is one of the major functions of the immune system and thought that it may be a very ancient if not the most ancient mechanism. It would have evolved at the time when multicellular organisms first appeared and the need to deal with insubordinate autonorneus cell variants may have been at least as important as a proteetion against foreign substances.