title: 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.affiliation: Department of Dermatology and Allergology, University Medical Center Utrecht, 3508 GA Utrecht, The Netherlands;
authors.forename: Laura A P M
authors.initials: LA
authors.lastname: Meulenbroek
authors.forename: Renske J
authors.initials: RJ
authors.lastname: de Jong
authors.forename: Constance F
authors.initials: CF
authors.lastname: den Hartog Jager
authors.forename: Hanneke N
authors.initials: HN
authors.lastname: Monsuur
authors.forename: Diana
authors.initials: D
authors.lastname: Wouters
authors.forename: Alma J
authors.initials: AJ
authors.lastname: Nauta
authors.forename: Léon M J
authors.initials: LM
authors.lastname: Knippels
authors.forename: R J Joost
authors.initials: RJ
authors.lastname: van Neerven
authors.forename: Bert
authors.initials: B
authors.lastname: Ruiter
authors.forename: Jeanette H W
authors.initials: JH
authors.lastname: Leusen
authors.forename: C Erik
authors.initials: CE
authors.lastname: Hack
authors.forename: Carla A F M
authors.initials: CA
authors.lastname: Bruijnzeel-Koomen
authors.forename: André C
authors.initials: AC
authors.lastname: Knulst
authors.forename: Johan
authors.initials: J
authors.lastname: Garssen
authors.forename: Els
authors.initials: E
authors.lastname: van Hoffen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000276:immunology; D000818:Animals; D000936:Antigen-Antibody Complex / Q000276:immunology* / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D029662:Betula / Q000276:immunology; D002460:Cell Line; D003167:Complement Activation / Q000276:immunology; D005512:Food Hypersensitivity / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D051379:Mice; D008875:Middle Aged; D011058:Pollen / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D011951:Receptors, Complement / Q000276:immunology / Q000378:metabolism; D017463:Receptors, Complement 3b / Q000276:immunology / Q000378:metabolism; D017464:Receptors, Complement 3d / Q000276:immunology / Q000378:metabolism; D017452:Receptors, IgG / Q000276:immunology / Q000378:metabolism; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology / Q000378:metabolism; D055815:Young Adult
chemical_list: D000485:Allergens; D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D011951:Receptors, Complement; D017463:Receptors, Complement 3b; D017464:Receptors, Complement 3d; D017452:Receptors, IgG; D007073:Immunoglobulin E