Allergen specificity of IgG(4)-expressing B cells in patients with grass pollen allergy undergoing immunotherapy

TY - JOUR

T1 - Allergen specificity of IgG(4)-expressing B cells in patients with grass pollen allergy undergoing immunotherapy

AU - James, Louisa K.

AU - Bowen, Holly

AU - Calvert, Rosaleen A.

AU - Dodev, Tihomir S.

AU - Shamji, Mohamed H.

AU - Beavil, Andrew J.

AU - McDonnell, James M.

AU - Durham, Stephen R.

AU - Gould, Hannah J.

PY - 2012/9

Y1 - 2012/9

N2 - Background: Serum IgG(4) responses to allergen immunotherapy are well documented as blocking allergen binding to receptor-bound IgE on antigen-presenting cells and effector cells, but the molecular characteristics of treatment-induced IgG(4), particularly in relation to expressed antibody, are poorly defined. Objectives: We aimed to clone and express recombinant IgG(4) from patients receiving grass pollen immunotherapy using single B cells to obtain matched heavy-and light-chain pairs. Methods: IgG(4)(+) B cells were enriched from blood samples taken from 5 patients receiving grass pollen immunotherapy. Matched heavy-and light-chain variable-region sequences were amplified from single IgG(4)(+) B cells. Variable regions were cloned and expressed as recombinant IgG(4). Binding analysis of grass pollen-specific IgG(4) was performed by using surface plasmon resonance. Functional assays were used to determine IgE blocking activity. In a separate experiment grass pollen-specific antibodies were depleted from serum samples to determine the proportion of grass pollen-specific IgG(4) within total IgG(4). Results: Depletion of grass pollen-specific antibodies from serum led to a modest reduction in total IgG(4) levels. Matched heavy-and light-chain sequences were cloned from single IgG(4)(+) B cells and expressed as recombinant IgG(4). We identified an IgG(4) that binds with extremely high affinity to the grass pollen allergen Phl p 7. Furthermore, we found that a single specific mAb can block IgE-mediated facilitated allergen presentation, as well as IgE-mediated basophil activation. Conclusion: Although increases in IgG(4) levels cannot be wholly accounted for within the allergen-specific fraction, allergen immunotherapy might result in the production of high-affinity allergen-specific blocking IgG(4). (J Allergy Clin Immunol 2012;130:663-70.)

AB - Background: Serum IgG(4) responses to allergen immunotherapy are well documented as blocking allergen binding to receptor-bound IgE on antigen-presenting cells and effector cells, but the molecular characteristics of treatment-induced IgG(4), particularly in relation to expressed antibody, are poorly defined. Objectives: We aimed to clone and express recombinant IgG(4) from patients receiving grass pollen immunotherapy using single B cells to obtain matched heavy-and light-chain pairs. Methods: IgG(4)(+) B cells were enriched from blood samples taken from 5 patients receiving grass pollen immunotherapy. Matched heavy-and light-chain variable-region sequences were amplified from single IgG(4)(+) B cells. Variable regions were cloned and expressed as recombinant IgG(4). Binding analysis of grass pollen-specific IgG(4) was performed by using surface plasmon resonance. Functional assays were used to determine IgE blocking activity. In a separate experiment grass pollen-specific antibodies were depleted from serum samples to determine the proportion of grass pollen-specific IgG(4) within total IgG(4). Results: Depletion of grass pollen-specific antibodies from serum led to a modest reduction in total IgG(4) levels. Matched heavy-and light-chain sequences were cloned from single IgG(4)(+) B cells and expressed as recombinant IgG(4). We identified an IgG(4) that binds with extremely high affinity to the grass pollen allergen Phl p 7. Furthermore, we found that a single specific mAb can block IgE-mediated facilitated allergen presentation, as well as IgE-mediated basophil activation. Conclusion: Although increases in IgG(4) levels cannot be wholly accounted for within the allergen-specific fraction, allergen immunotherapy might result in the production of high-affinity allergen-specific blocking IgG(4). (J Allergy Clin Immunol 2012;130:663-70.)

U2 - 10.1016/j.jaci.2012.04.006

DO - 10.1016/j.jaci.2012.04.006

M3 - Article

SN - 0091-6749

VL - 130

SP - 663-670.e3

JO - Journal of Allergy and Clinical Immunology

JF - Journal of Allergy and Clinical Immunology

IS - 3

ER -