IgG antibodies in food allergy influence allergen-antibody complex formation and binding to B cells: a role for complement receptors.

Abstract

Allergen-IgE complexes are more efficiently internalized and presented by B cells than allergens alone. It has been suggested that IgG Abs induced by immunotherapy inhibit these processes. Food-allergic patients have high allergen-specific IgG levels. However, the role of these Abs in complex formation and binding to B cells is unknown. To investigate this, we incubated sera of peanut- or cow's milk-allergic patients with their major allergens to form complexes and added them to EBV-transformed or peripheral blood B cells (PBBCs). Samples of birch pollen-allergic patients were used as control. Complex binding to B cells in presence or absence of blocking Abs to CD23, CD32, complement receptor 1 (CR1, CD35), and/or CR2 (CD21) was determined by flow cytometry. Furthermore, intact and IgG-depleted sera were compared. These experiments showed that allergen-Ab complexes formed in birch pollen, as well as food allergy, contained IgE, IgG1, and IgG4 Abs and bound to B cells. Binding of these complexes to EBV-transformed B cells was completely mediated by CD23, whereas binding to PBBCs was dependent on both CD23 and CR2. This reflected differential receptor expression. Upon IgG depletion, allergen-Ab complexes bound to PBBCs exclusively via CD23. These data indicated that IgG Abs are involved in complex formation. The presence of IgG in allergen-IgE complexes results in binding to B cells via CR2 in addition to CD23. The binding to both CR2 and CD23 may affect Ag processing and presentation, and (may) thereby influence the allergic response.

• Authors: Laura A P M Meulenbroek, Renske J de Jong, Constance F den Hartog Jager, Hanneke N Monsuur, Diana Wouters, Alma J Nauta, Léon M J Knippels, R J Joost van Neerven, Bert Ruiter, Jeanette H W Leusen, C Erik Hack, Carla A F M Bruijnzeel-Koomen, André C Knulst, Johan Garssen, Els van Hoffen
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 191 Issue 7 Pg. 3526-33 (Oct 01 2013) ISSN: 1550-6606 [Electronic] United States
• PMID: 23997216 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Allergens
• Antigen-Antibody Complex
• Immunoglobulin G
• Receptors, Complement
• Receptors, Complement 3b
• Receptors, Complement 3d
• Receptors, IgG
• Immunoglobulin E

Topics

• Adolescent
• Adult
• Aged
• Allergens (immunology)
• Animals
• Antigen-Antibody Complex (immunology, metabolism)
• B-Lymphocytes (immunology, metabolism)
• Betula (immunology)
• Cell Line
• Complement Activation (immunology)
• Food Hypersensitivity (immunology, metabolism)
• Humans
• Immunoglobulin E (blood, immunology)
• Immunoglobulin G (blood, immunology)
• Mice
• Middle Aged
• Pollen (immunology)
• Protein Binding (immunology)
• Receptors, Complement (immunology, metabolism)
• Receptors, Complement 3b (immunology, metabolism)
• Receptors, Complement 3d (immunology, metabolism)
• Receptors, IgG (immunology, metabolism)
• Rhinitis, Allergic, Seasonal (immunology, metabolism)
• Young Adult