Research article

An investigation into IgE-facilitated allergen recognition and presentation by human dendritic cells

Inas K Sharquie, Abeer Al-Ghouleh, Patricia Fitton, Mike R Clark, Kathryn L Armour, Herb F Sewell, Farouk Shakib and Amir M Ghaemmaghami

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BMC Immunology 2013, 14:54  doi:10.1186/1471-2172-14-54

Published: 13 December 2013

Abstract (provisional)

Background

Allergen recognition by dendritic cells (DCs) is a key event in the allergic cascade leading to production of IgE antibodies. C-type lectins, such as the mannose receptor and DC-SIGN, were recently shown to play an important role in the uptake of the house dust mite glycoallergen Der p 1 by DCs. In addition to mannose receptor (MR) and DC-SIGN the high and low affinity IgE receptors, namely FcepsilonRI and FcepsilonRII (CD23), respectively, have been shown to be involved in allergen uptake and presentation by DCs.

Objectives

This study aims at understanding the extent to which IgE- and IgG-facilitated Der p 1 uptake by DCs influence T cell polarisation and in particular potential bias in favour of Th2. We have addressed this issue by using two chimaeric monoclonal antibodies produced in our laboratory and directed against a previously defined epitope on Der p 1, namely human IgE 2C7 and IgG1 2C7.

Results

Flow cytometry was used to establish the expression patterns of IgE (FcepsilonRI and FcepsilonRII) and IgG (FcgammaRI) receptors in relation to MR on DCs. The impact of FcepsilonRI, FcepsilonRII, FcgammaRI and mannose receptor mediated allergen uptake on Th1/Th2 cell differentiation was investigated using DC/T cell co-culture experiments. Myeloid DCs showed high levels of FcepsilonRI and FcgammaRI expression, but low levels of CD23 and MR, and this has therefore enabled us to assess the role of IgE and IgG-facilitated allergen presentation in T cell polarisation with minimal interference by CD23 and MR. Our data demonstrate that DCs that have taken up Der p 1 via surface IgE support a Th2 response. However, no such effect was demonstrable via surface IgG.

Conclusions

IgE bound to its high affinity receptor plays an important role in Der p 1 uptake and processing by peripheral blood DCs and in Th2 polarisation of T cells.

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