Affinity purified immunoglobulin G transfers immediate hypersensitivity to guinea pig colonic epithelium in vitro

Our aim was to establish whether the epithelial type 1 hypersensitivity reaction in response to a dietary antigen, as we have previously described, had an immunologic basis. Using serum from guinea pigs fed with milk proteins we examined the passive transfer of sensitivity to beta-lactoglobulin. Biophysical methods were used to measure electrogenic chloride secretion across colonic epithelia. This response has been shown previously to be the cellular function that is altered after antigen challenge. Affinity column chromatography was used to separate immune serum into immunoglobulin G-(IgG)-rich and immunoglobulin G-depleted fractions and the purity of these fractions was established. Passive transfer of sensitivity was possible with the immunoglobulin G-rich, but not the immunoglobulin G-depleted, fraction. We have proven, therefore, that the reaction is mediated, at least in part, by immunoglobulins of the G class. This finding may have implications for the study of phenomena of food allergy.