IgE plasma cells are transcriptionally and functionally distinct from other isotypes.

Understanding the phenotypic and transcriptional signature of immunoglobulin E (IgE)-producing cells is fundamental to plasma cell (PC) biology and development of therapeutic interventions for allergy. Here, using a mouse model of intranasal house dust mite (HDM) exposure, we showed that short-lived IgE PCs emerge in lung draining lymph nodes (dLNs) during early exposure (<3 weeks) and long-lived IgE PCs accumulate in the bone marrow (BM) with prolonged exposure (>7 weeks). IgE PCs had distinct surface and gene expression profiles in these different tissues compared with other Ig isotypes.

TRAPnSeq allows high-throughput profiling of antigen-specific antibody-secreting cells.

Following activation by cognate antigen, B cells undergo fine-tuning of their antigen receptors and may ultimately differentiate into antibody-secreting cells (ASCs). While antigen-specific B cells that express surface receptors (B cell receptors [BCRs]) can be readily cloned and sequenced following flow sorting, antigen-specific ASCs that lack surface BCRs cannot be easily profiled. Here, we report an approach, TRAPnSeq (antigen specificity mapping through immunoglobulin [Ig] secretion TRAP and Sequencing), that allows capture of secreted antibodies on the surface of ASCs, which in turn enables high-throughput screening of single ASCs against large antigen panels.