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The following is a summary of “Staphylococcus aureus lysate induces an IgE response via memory B cells in nasal polyps,” published in the March 2024 issue of Allergy & Immunology by Du, et al.

Locally increased IgE levels are pathological in chronic rhinosinusitis with nasal polyps (CRSwNP). For a study, researchers sought to investigate whether Staphylococcus aureus could induce aberrant IgE synthesis in CRSwNP and the potential mechanisms involved.

ELISA was used to assess total IgE, IL-4, IL-5, and IL-13 concentrations in the supernatants of cultures stimulated with S. aureus lysate. Single-cell RNA sequencing was employed to investigate S. aureus-induced cellular responses. Flow cytometry and quantitative reverse transcription PCR were used to analyze B-cell subsets and stimulated cell ε-germline transcript expression. Immunohistochemistry and immunofluorescence were used to assess IgE-positive B-cell and germinal center localization.

S. aureus lysate induced IgE production in the supernatants of nasal polyp (NP) tissues but not in healthy nasal mucosa. IgE levels increased from days 2 to 4 after stimulation, concomitant with enhanced ε-germline transcript, IL-5, and IL-13 expression. Single-cell RNA sequencing revealed increased IL-5 and IL-13 in group 2 innate lymphoid cells and identified clonal overlap between unstimulated memory B cells and S. aureus-stimulated plasma cells. IgE, mainly produced by IgE-negative memory B cells, was enriched within NPs. Evidence indicated an IgE memory response to S. aureus in the peripheral blood of CRSwNP patients, which was associated with elevated IgE levels in NPs, asthma, and postoperative CRSwNP recurrence.

S. aureus induced an IgE response via IgE-negative memory B cells in CRSwNP patients, potentially contributing to CRSwNP development.

Reference: jacionline.org/article/S0091-6749(23)02405-3/abstract