Multiple independent IgE epitopes on the highly allergenic grass pollen allergen Phl p 5. Issue 11 (November 2014)

• Record Type: Journal Article
• Authors: Levin, M.; Rotthus, S.; Wendel, S.; Najafi, N.; Källström, E.; Focke‐Tejkl, M.; Valenta, R.; Flicker, S.; Ohlin, M.
• Is Part Of: Clinical & experimental allergy. Volume 44:Issue 11(2014:Nov.)
• Page Start: 1409
• Page End: 1419
• Publication Date: 2014-11
• Subjects: Allergy -- Periodicals; Immunology -- Periodicals; 616.97
• DOI: 10.1111/cea.12423
• Languages: English
• ISSNs: 0954-7894

Abstract

<abstract abstract-type="main" id="cea12423-abs-0001"> <title>Summary</title> <sec id="cea12423-sec-0001" sec-type="section"> <title>Background</title> <p>Group 5 allergens are small proteins that consist of two domains. They belong to the most potent respiratory allergens.</p> </sec> <sec id="cea12423-sec-0002" sec-type="section"> <title>Objective</title> <p>To determine the binding sites and to study allergic patients' IgE recognition of the group 5 allergen (Phl p 5) from timothy grass pollen using human monoclonal IgE antibodies that have been isolated from grass pollen allergic patients.</p> </sec> <sec id="cea12423-sec-0003" sec-type="section"> <title>Methods</title> <p>Using recombinant isoallergens, fragments, mutants and synthetic peptides of Phl p 5, as well as peptide‐specific antibodies, the interaction of recombinant human monoclonal IgE and Phl p 5 was studied using direct binding and blocking assays. Cross‐reactivity of monoclonal IgE with group 5 allergens in several grasses was studied and inhibition experiments with patients' polyclonal IgE were performed.</p> </sec> <sec id="cea12423-sec-0004" sec-type="section"> <title>Results</title> <p>Monoclonal human IgE showed extensive cross‐reactivity with group 5 allergens in several grasses. Despite its small size of 29 kDa, four independent epitope clusters on isoallergen Phl p 5.0101, two in each domain, were recognized by human IgE. Isoallergen Phl p 5.0201 carried two of these epitopes. Inhibition studies with allergic patients' polyclonal IgE suggest the presence of additional IgE epitopes on Phl p 5.</p> </sec> <sec id="cea12423-sec-0005" sec-type="section"> <title>Conclusions & Clinical Relevance</title> <p>Our results reveal the presence of a large number of independent IgE epitopes on the Phl p 5 allergen explaining the high allergenic activity of this protein and its ability to induce severe allergic symptoms. High‐density IgE recognition may be a general feature of many potent allergens and form a basis for the development of improved diagnostic and therapeutic procedures in allergic disease.</p> </sec> </abstract>