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Human blood basophils do not act as antigen‐presenting cells for the major birch pollen allergen B et v 1
Author(s) -
Kitzmüller C.,
Nagl B.,
Deifl S.,
Walterskirchen C.,
JahnSchmid B.,
Zlabinger G. J.,
Bohle B.
Publication year - 2012
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1111/j.1398-9995.2011.02764.x
Subject(s) - immunology , cd80 , allergen , immunoglobulin e , antigen presentation , cd86 , immune system , biology , microbiology and biotechnology , allergy , t cell , antibody , cd40 , biochemistry , in vitro , cytotoxic t cell
Background: Several studies in mice have recently shown that basophils can act as antigen‐presenting cells ( APC ) inducing T h2‐mediated immune responses against parasites or protease allergens. The aim of this study was to investigate whether human basophils function as APC for the major birch pollen allergen B et v 1. Methods: Fluorescently labeled B et v 1 was used to assess surface binding and internalization of allergen by basophils and different types of APC from birch pollen‐allergic and nonallergic individuals. Sorted basophils were analyzed in terms of up‐regulation of MHC class II and co‐stimulatory molecules in the absence and presence of IL ‐3 and IFN ‐γ by flow cytometry. Expression of proteins crucial for antigen presentation, namely cathepsin S and invariant chain, was determined. Basophils were used as APC in co‐culture experiments with B et v 1‐specific T ‐cell clones ( TCC s). Results: Basophils from birch pollen‐allergic donors very efficiently bound B et v 1 through I g E / F cε RI complexes on their surface. In contrast to professional APC , basophils did not internalize allergen and expressed marginal levels of cathepsin S and invariant chain. HLA ‐ DP , HLA ‐ DQ , CD 80/ CD 86, and CD 40 were absent from purified basophils even when stimulated with IL ‐3 plus IFN ‐γ. IL ‐3/ IFN ‐γ marginally up‐regulated HLA ‐ DR . B et v 1‐pulsed basophils failed to induce proliferative and cytokine responses in B et v 1‐specific, HLA ‐ DR ‐restricted TCC s. Conclusion: Human basophils neither internalize, process nor present B et v 1. Because B et v 1 is a highly relevant allergen, we conclude that basophils play no role as APC in I g E ‐mediated allergy in humans.