Article in Press
Jiun-Bo Chen, PhD
,
Louisa K. James, PhD
,
Anna M. Davies, PhD
,
Y.-C. Wu, PhD
,
Joanne Rimmer, FRCS
,
Valerie J. Lund, MS FRCS
,
Jou-Han Chen, Ms
,
James M. McDonnell, PhD
,
Yih-Chih Chan, PhD
,
George H. Hutchins, BSci
,
Tse Wen Chang, PhD
,
Brian J. Sutton, DPhil
,
Harsha H. Kariyawasam, FRCP PhD
,
Article Info
Abstract
Background
Chronic rhinosinusitis with nasal polyps (CRSwNP) is associated with local immunoglobulin hyperproduction and the presence of IgE antibodies against Staphylococcus aureus enterotoxins (SAEs). Aspirin-exacerbated respiratory disease (AERD) is a severe form of CRSwNP in which nearly all patients express anti-SAEs.
Objectives
We aimed to understand antibodies reactive to SAEs and determine whether they recognize SAEs through their complementarity-determining regions (CDRs) or framework regions (FRs).
Methods
Labeled Staphylococcal enterotoxin A (SEA), SED and SEE were used to isolate single SAE-specific B cells from the nasal polyps of three AERD patients by FACS. Recombinant antibodies with “matched” heavy- and light-chains were cloned as IgG1, and those of high-affinity for specific SAEs, assayed by ELISA and surface plasmon resonance (SPR), were re-cloned as IgE and Fab. The activities of the IgEs were tested in basophil degranulation assays.
Results
Thirty-seven SAE-specific, IgG or IgA-expressing B cells were isolated and yielded six anti-SAE clones, two each for SEA, SED and SEE. Competition binding assays revealed that the anti-SEE antibodies recognize non-overlapping epitopes in SEE. Unexpectedly, each anti-SEE mediated SEE-induced basophil degranulation and IgG1 or Fab of each anti-SEE enhanced degranulation by the other anti-SEE.
Conclusions
SEE may activate basophils by simultaneously binding as antigens in the conventional manner to CDRs and as superantigens to FRs of anti-SEE IgE in anti-SEE IgE-FcεRI complexes. Anti-SEE IgG1s may enhance the activity of anti-SEE IgEs as conventional antibodies via CDRs or simultaneously as conventional antibodies and as “superantibodies” via CDRs and FRs to SEEs in SEE-anti-SEE IgE-FcεRI complexes (Figure 7).
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