Target Cells of Human Ragweed-Binding Antibodies in Monkey Skin

To determine the immunoglobulin nature of the allergen-binding antibodies which fix to monkey mast cells, sections from biopsies preincubated with sera of ragweed atopic or normal human individuals were stained by immunofluorescence techniques using antisera specific for human immunoglobulins. Evidence was obtained that one of the antibodies fixed to the mast cells was of the reaginic IgE type. By immunofluorescence and column chromatographic studies it was shown that non-reaginic ragweed-binding antibodies other than IgG, IgA, IgM or IgD present in the sera of hyposensitized individuals also fix to the monkey skin mast cells. The ability of both types of antibodies to render the mast cells fluorescent was lost after heating at 56°C for 4 hours.