Establishment of novel cell lines that maintain the features of B cells derived from patients with neuromyelitis optica spectrum disorder.

B cells that produce anti-aquaporin-4 (AQP4) antibodies play a crucial role in neuromyelitis optica spectrum disorder (NMOSD) pathogenesis. We previously reported that naïve B (NB) cells from patients with NMOSD, unlike those from healthy controls, exhibit transcriptional changes suggesting the adoption of an antibody-secreting cell (ASCs) phenotype. CD25⁺ NB cells, whose numbers are increased in NMOSD patients, have a greater capacity to differentiate into ASCs than do CD25^- NB cells. Here, we attempted to establish novel B cell subset cell lines from patients with NMOSD to enable molecular analysis of their abnormalities. We generated Epstein-Barr virus-immortalized lymphoblastoid cell lines (LCLs) from CD25⁺ NB, CD25^- NB, and switched memory B (SMB) cells. All LCLs largely maintained the features of the original cell type in terms of cell surface marker expression and could differentiate into ASCs. Notably, CD25⁺ NB-LCLs derived from patients with NMOSD exhibited a greater capacity to differentiate into SMB-LCLs than did CD25^- NB-LCLs derived from patients with NMOSD, suggesting that the established LCLs maintained the characteristics of cells isolated from patients. The LCLs established in this study are likely to be useful for elucidating the mechanism by which cells that produce anti-AQP4 antibodies develop in NMOSD.