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Wade-Vallance, A. K.

Publications and source records attributed to Wade-Vallance, A. K..

2 recordsLinked to original sources

Sequential Switching Through IgG1 is Redundant for Allergic Reactivity and Memory to Allergens

Allergic reactions to foods are driven by allergen-binding immunoglobulin (Ig)E antibodies. IgE- expressing cells can be generated through a sequential class switching pathway where activated B cells first switch to an intermediary isotype, most frequently IgG1, and then to IgE. It has been proposed that sequential class switch recombination is important in generating high affinity IgE, augmenting anaphylactic reactions, and in holding the memory of IgE responses. Here, we observed surprising redundancy of sequential switching through IgG1 for the functional affinity of the IgE repertoire against multiple food allergens as well as for the ability of IgE to elicit anaphylaxis. We further found that sequential switching via IgG1 was irrelevant for allergic memory. These results indicate that allergen-specific IgG1 B cells are redundant in sensitization, anaphylaxis, and food allergy persistence, thereby implicating other switching pathways as important considerations in the development of therapeutics for allergic diseases.

immunology↗

B cell receptor stimulation induces IgE plasma cell apoptosis

The proper regulation of IgE production safeguards against allergic disease, highlighting the importance of mechanisms that restrict IgE plasma cell (PC) survival. IgE PCs have unusually high surface B cell receptor (BCR) expression, yet the functional consequences of ligating this receptor are unknown. Here, we found that BCR ligation induced BCR signaling in IgE PCs followed by their elimination. In cell culture, exposure of IgE PCs to cognate antigen or anti-BCR antibodies induced apoptosis. IgE PC depletion correlated with the affinity, avidity, amount, and duration of antigen exposure and required the BCR signalosome components Syk, BLNK, and PLC{gamma}2. In mice with a PC-specific impairment of BCR signaling, the abundance of IgE PCs was selectively increased. Conversely, BCR ligation by injection of cognate antigen or anti-IgE depleted IgE PCs. These findings establish a mechanism for the elimination of IgE PCs through BCR ligation. This has important implications for allergen tolerance and immunotherapy as well as anti-IgE monoclonal antibody treatments.

immunology↗