IgG1 memory B cells keep the memory of IgE responses

Area of Science:

• Immunology
• Molecular Biology
• Cellular Biology

Background:

• Immunoglobulin E (IgE) plays a dual role in immunity and allergic reactions.
• The mechanisms for generating high-affinity IgE in memory responses remain unclear.
• IgE-producing cells, including plasma cells, exhibit unique differentiation pathways.

Purpose of the Study:

• To investigate the function of IgG1 memory B cell subsets in IgE production.
• To elucidate the cellular origins and clonal selection processes for high-affinity IgE.
• To understand the mechanisms underlying IgE memory and antibody production.

Main Methods:

• Analysis of IgG1 memory B cell subsets (CD80+CD73+ and CD80-CD73-) involved in IgE production.
• Repertoire analysis to trace the differentiation of high-affinity IgE and IgG1 plasma cells.
• Investigating IgE generation via class-switch recombination in IgG1 memory B cells.

Main Results:

• Two IgG1 memory B cell subsets, CD80+CD73+ and CD80-CD73-, differentially contribute to pathogenic and non-pathogenic IgE repertoires.
• High-affinity IgE and IgG1 plasma cells originate from rare CD80+CD73+ memory clones without further mutagenesis.
• IgE can be generated from IgG1 memory B cells through class-switch recombination, bypassing additional somatic hypermutation.

Conclusions:

• Identified the cellular origin of high-affinity IgE and the clonal selection into plasma cell fate.
• Provided fundamental insights into allergy pathogenesis and antibody production in memory B cell responses.
• Demonstrated IgE generation from IgG1 memory B cells via class-switch recombination without additional somatic hypermutation.