ENVIRONMENTAL ANTIGENS AND ATOPIC DISEASE - UNDERLYING MECHANISMS ANDPROSPECTS FOR THERAPY AND PROPHYLAXIS

Natural exposure to non-pathogenic antigens, the so-called 'environmen tal antigens', experimentally elicits a characteristic pattern of T-ce ll immunity, involving selective suppression of the T-cell-dependent I gE responses that trigger allergic reactions. This 'immune deviation' results in the generation of long-lived T-cell memory, which confers a ctive protection against allergic sensitization. Corresponding primary immune responses to environmental antigens in humans occur most frequ ently during infancy, and the development of allergic sensitization ca n be viewed as a failure of this natural immune-deviation process. In this article, potential strategies for primary prevention of allergic disease in infants involving, in particular, the exploitation of oral and mucosal tolerance to stimulate protective CD8(+) T-cell-mediated i mmune deviation, are discussed.