MECHANISM OF ALLERGIC CROSS-REACTIONS

The incidence of cross-stimulations by natural allergens was investiga ted using RBL-2H3 cells sensitized with five different mouse monoclona l anti-DNP IgEs and four mercury-induced rat monoclonal IgEs. Cells se nsitized with 3 of the 5 monoclonal anti-DNP IgEs (clones SPE-7, SRT-1 , LB4) responded by serotonin release upon stimulation by natural alle rgens such as Dermatophagoides, pterornyssinus, horse dander and mugwo rt extracts. Serotonin release could be inhibited by monovalent DNP-ly sine, indicating the involvement of DNP-binding sites of IgEs. Two of the clones (LO-DNP-30 and LA2) were negative on all tests with allerge ns. All but one (Hg32) of the mercury-induced rat IgE monoclonal antib odies tested positive with DNP-B SA, and with at least one of the six allergen extracts. IgE clone Hg12 mediated serotonin release with 5 of the 6 allergens tested.