Lung nonresponsiveness produced in guinea pigs by aerosolized antigen. I. Nonresponsiveness is not antigen specific

Nonresponsiveness to aerosolized antigen induced by repeated exposure of guinea pigs to either bovine serum albumin (BSA) or ragweed (RW) aerosols was not antigen specific, since induction of lung sensitization with the same, as well as heterologous antigen, was prevented. However, prior lung sensitization to an antigen was maintained in spite of subsequent treatment with aerosolized antigen. In this case treatment with aerosolized antigen could abrogate sensitization of the lung to all subsequent antigens. Chopped lung pieces could not be passively sensitized by antisera to homologous or heterologous antigens unless they were previously treated at low pH. High levels of conventional and homocytotropic antibody were demonstrated in nonresponder animals. Nonresponsiveness induced by fed antigen, however, was antigen specific, and elevated homocytotropic antibody levels were not present. Aerosol-induced nonresponsiveness appears to be a local phenomenon which involves a blocking of the pulmonary mast cells by immune complexes or other blocking factors so that they can no longer respond to antigen challenge.