Risk-Benefit Evaluation of Immunostimulants

Abstract

For the purposes of this essay we pay tribute to the centenary of von Behring’s discovery of antibodies at the Koch Institute in Berlin, to the recognition by Koch himself of tuberculous allergy, as well as to the ‘jubilee’ of lymphoid-cell transfer of delayed hypersensitivity by Landsteiner and Chase. Yet our desire to manipulate the immune response predictably for individual human benefit remains as prevalent and as elusive as it was in the 1890’s or even the 1940’s. Quite simply, we insist that the normal immune system must recognise and respond with fine molecular specificity to foreign chemical or biological antigens whilst maintaining an indifferent stance to self-components. Moreover the normal immune response should be able to rid the foreign (microbial) agent from any part of the body and to remember that it did so: for subsequent encounters of the same foreign agent must be dealt with more efficiently than first ones. In the late 1990’s we now speak of the molecular immunological specificity with which T-cell receptor molecules, free or cell-bound antibody, or B-cell antibody receptors recognise immunodominant and cryptogenic components of complex antigens, of the cellular basis of immunological memory, and of mechanisms by which normal immunoregulation is effected through two-way cooperation between adaptive (lymphocytic) and innate (e.g. phagocytic) elements of the immune system.