Resident memory B cells are enriched in chronic rhinosinusitis with nasal polyps

Abstract

BackgroundChronic rhinosinusitis with nasal polyps (CRSwNPs) is a chronic nasal and sinonasal inflammatory disease. Recently, resident memory B cells (BRMs) have been identified in the lungs, although not in the sinonasal mucosa. ObjectiveTo characterize memory B cell phenotypes with regards to patients with CRSwNPs and to identify BRMs in both normal sinonosal mucosa and CRSwNPs. MethodsCD19+ B cells were isolated from patients with CRSwNPs and analyzed using flow cytometry and immunohistochemistry. ResultsAlthough BRMs were found in the normal sinonasal mucosa, their numbers and frequencies tended to be limited. These findings were confirmed based on immunohistochemical analyses indicating an upregulation of CD69/CD45RB in tissue sections from CRSwNPs, although not in normal sinonasal mucosa. Accordingly, BRMs were established to be enriched in the nasal polyps isolated from patients with CRSwNPs. ConclusionOur findings in this study reveal that BRMs can be detected in normal sinonasal mucosa, although are significantly enriched in nasal polyps derived from patients with CRSwNP. These findings can contribute to gaining a more comprehensive understanding of the immune reactions associated with CRSwNP and facilitate the identification of potential therapeutic targets, such as anti-B cell therapy.