Peanut oral immunotherapy transiently expands circulating Ara h 2-specific B cells with a homologous repertoire in unrelated subjects

J Allergy Clin Immunol. 2015 Jul;136(1):125-134.e12. doi: 10.1016/j.jaci.2015.03.026. Epub 2015 May 16.


Background: Peanut oral immunotherapy (PNOIT) induces persistent tolerance to peanut in a subset of patients and induces specific antibodies that might play a role in clinical protection. However, the contribution of induced antibody clones to clinical tolerance in PNOIT is unknown.

Objective: We hypothesized that PNOIT induces a clonal, allergen-specific B-cell response that could serve as a surrogate for clinical outcomes.

Methods: We used a fluorescent Ara h 2 multimer for affinity selection of Ara h 2-specific B cells and subsequent single-cell immunoglobulin amplification. The diversity of related clones was evaluated by means of next-generation sequencing of immunoglobulin heavy chains from circulating memory B cells with 2x250 paired-end sequencing on the Illumina MiSeq platform.

Results: Expression of class-switched antibodies from Ara h 2-positive cells confirms enrichment for Ara h 2 specificity. PNOIT induces an early and transient expansion of circulating Ara h 2-specific memory B cells that peaks at week 7. Ara h 2-specific sequences from memory cells have rates of nonsilent mutations consistent with affinity maturation. The repertoire of Ara h 2-specific antibodies is oligoclonal. Next-generation sequencing-based repertoire analysis of circulating memory B cells reveals evidence for convergent selection of related sequences in 3 unrelated subjects, suggesting the presence of similar Ara h 2-specific B-cell clones.

Conclusions: Using a novel affinity selection approach to identify antigen-specific B cells, we demonstrate that the early PNOIT-induced Ara h 2-specific B-cell receptor repertoire is oligoclonal and somatically hypermutated and shares similar clonal groups among unrelated subjects consistent with convergent selection.

Keywords: Immunotherapy; antibody repertoire; antigen-specific B cells; food allergy; peanut allergy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2S Albumins, Plant / immunology*
  • Administration, Oral
  • Adolescent
  • Antibody Formation
  • Antigens, Plant / immunology*
  • B-Lymphocytes / immunology*
  • Cell Proliferation
  • Cells, Cultured
  • Child
  • Clone Cells
  • Desensitization, Immunologic / methods*
  • Epitopes / immunology
  • Female
  • Glycoproteins / immunology*
  • Humans
  • Immunoglobulin E / immunology
  • Immunologic Memory
  • Lymphocyte Activation
  • Male
  • Peanut Hypersensitivity / immunology
  • Peanut Hypersensitivity / therapy*


  • 2S Albumins, Plant
  • Antigens, Plant
  • Ara h 2 allergen, Arachis hypogaea
  • Epitopes
  • Glycoproteins
  • Immunoglobulin E