B cells establish, but do not maintain, long-lived murine anti-peanut IgE^a

Background Peanut allergy (PNA) has been reported to be transferred to tolerant recipients through organ and bone marrow (BM) transplantation. The roles T and B cells play in establishing, and the roles B cell subsets play in maintaining lifelong anti-peanut IgE levels are unknown. Objectives: To determine the cellular requirements for the transfer of murine PNA and to determine the role CD20⁺ cells play in maintaining long-lived anti-peanut IgE levels. Methods: We developed a novel adoptive transfer model to investigate the cellular requirements for transferring murine PNA. We also treated peanut-allergic (PA) mice with anti-CD20 antibody and measured IgE levels throughout treatment. Results: Purified B220⁺ cells from PA splenocytes and purified CD4⁺ cells from naïve (NA) splenocytes are the minimal requirements for the adoptive transfer of PNA. Prolonged treatment of allergic mice with anti-CD20 antibody results in significant depletion of B cell subsets but does not affect anti-peanut IgE levels, symptoms, or numbers of IgE antibody secreting cells (ASCs) in the BM. Adoptive transfer of BM and spleen cells from allergic donors treated with anti-CD20 antibody does not result in the transfer of PNA in NA recipients, demonstrating that anti-CD20 antibody treatment depletes B cells capable of differentiating into peanut-specific IgE ASCs. Conclusions and Clinical Relevance: Peanut allergy can be established in a NA hosts with B220⁺ cells from PA donors and CD4⁺ cells from peanut-NA donors. However, long-term depletion of B220⁺ cells with anti-CD20 antibody does not affect anti-peanut IgE levels. These results highlight a novel role for B cells in the development of PNA and provide evidence that long-lived anti-peanut IgE levels may be maintained by long-lived ASCs.