Passive sensitization of skin and lung by guinea-pig immunoglobulins.

Guinea-pig γ- and γ-globulins have been purified by preparative electrophoresis followed by chromatography. No γ-globulin was detectable in purified γ-globulin, but purified γ-globulin always contained fast γ-globulin. Normal guinea-pig serum contained much less γ-globulin than immune serum. Antisera prepared against normal guinea-pig serum did not contain useful amounts of antibody specific for γ-globulin. Guinea-pig lung tissue was sensitized by very low concentrations of guinea-pig γ-globulin (of the order of 6×10 molar) but γ-globulin antibodies were almost inactive. No evidence was found that the trace of activity in γ-globulin was not due to very slight contamination with γ-globulin antibodies. The finding that γ-globulin antibodies are far more potent than γ-globulin antibodies in sensitizing skin has been confirmed, but several lines of evidence suggest that γ-globulin antibodies may also have weak activity. Thus quantitative passive cutaneous anaphylaxis (PCA) tests showed that whenever the γ-globulin fraction contained antibody it appeared far more potent relative to γ-globulin than when the same proteins were tested on lung tissue. The PCA activity of moderate amounts of purified γ-globulin antibodies disappeared faster than the skin sensitization produced by small amounts of γ-globulin antibodies, and the γ-globulin preparations did not contain enough γ-globulin impurity to account for their PCA activity. No inhibition of skin responses was observed with the largest doses of antigen tested. The most plausible explanation of these results is that, under the conditions of our experiments, γ-globulin antibody had weak PCA activity. Objections to this hypothesis are discussed. The PCA activity of γ-globulin antibody probably involves a mechanism different from that of the sensitization produced by the highly potent γ-globulin antibody.