Measurement of murine IgE antibody responses to dust mite allergens by in vitro assay

In an analysis of murine immune responses to the dust mite allergen Der p 1 , treatment with purified allergen induced a significant increase in the le vel of circulating IgE immunoglobulin (from less than 100 ng/ml in normal m ice to 1,350 ng/ml in mice receiving the allergen). Even so, specific IgE a ntibodies binding to purified Der p 1 were not detected in a conventional E LISA, and the major response appeared to be the induction of high titre IgG antibodies. Specific circulating murine IgE antibodies were however detect ed using the following assay format: murine IgE was captured to anti-murine IgE antibody coated wells; Der p 1 was added and bound by immobilized anti -Der p 1 IgE antibodies; the captured Der p 1 was then detected by the addi tion of monoclonal IgG antibodies against Der p 1 and these antibodies were measured by the addition of anti-murine IgG antibody-enzyme conjugate with which colour development is produced after substrate addition. This assay establishes a procedure to measure circulating anti-Der p 1 IgE antibodies which are present together with competing high titre IgG anti-Der p 1 antib odies.