Type Ⅰ Interferon Pathway In NMOSD B Cell

Objective: Neuromyelitis optica spectrum disorder(NMOSD)is a severely disabled autoimmune central nervous system demyelinating disease.IFN-β is widely used in multiple sclerosis,and has been proven to reduce the annual relapse rate,while the clinical course could be aggravated with administration of IFN-β in patients with NMOSD.Recent case reports suggest that IFN-α might induce NMO,while the pathogenesis is unclear.The purpose of this study was to explore how the type I interferon pathway changes in NMOSD patients,what are the differences between the type I interferon signature in NMOSD patients and MS patients,and what role of type I interferons play in the pathogenesis and development of NMOSD disease.Methods: 1.B cells in Cerebrospinal fluid,bone marrow and blood of NMOSD patients in acute phase were sorted by flow cytometry.The expression characteristics and differences of interferon pathway gene profiles were compared by 10 × Genomics scRNA-seq platform.2.B cells were isolated from NMOSD patients,MS patients and healthy controls by magnetic-activated cell sorting(MACS),and qPCR was performed to evaluate the relative expression level of type I interferon pathway related genes(IRF4,IFI44,IFI44 L,IF16,MX1);3.Using MACS to obtain peripheral blood B cells from NMOSD patients,and stimulated with recombinant human IFN-α in vitro B cell culture.We evaluate the effect of type I interferon on B cell activation,apoptosis and differentiation.AQP4-IgG in cell culture supernatant was detected using CBA and flow cytometry.In addition,IFNAR inhibitor was used to verify that blocking IFNAR can reverse the effect of IFN-α on B cells.Results: 1.By GO pathway analysis,we found that over-activated interferon-related signaling pathways appear in the CSF and peripheral blood B cells of NMOSD patients suffering relapse phase,especially in CSF B cells including interferon-gamma-mediated signaling pathway,type I interferon signaling pathway,response to type I interferon,response to interteron-beta and defense response to virus.2.Compared with MS patients and healthy adults,peripheral blood B cells in NMOSD patients will have increased expression of genes related to type I interferon pathway.3.IFN-α can promote the activation of B cells in a dosage dependent manner,especially in transitional B cells;IFN-α can significantly protect transitional B cell from apoptosis;IFN-α combined with other cytokines can promote B cells differentiate into mature B cells,such as memory B cells and antibody-secreting plasma cells,and promote the production of AQP4-IgG;in addition,blocking IFNAR can reverse the effects of IFN-α on the promotion of B cells.Conclusions: In our study,scRNA-seq was used for the first time to detect the presence of significantly abnormally activated type I interferon-related pathways in NMOSD patients.the relative expression level of type I interferon pathway-related genes in NMOSD peripheral blood B cells was upregulated,and it was clear that there was difference in type I interferon pathway genes between NMOSD and MS.The effects of type I interferon on B cells in patients with NMOSD,especially the effects of transitional B cells,have been explored,providing a new direction for future research.It is also clear that type I interferon can promote the production of AQP4-IgG in vitro B cell culture.Partly explains the different treatment responses of NMOSD and MS to IFN-β.In addition,we also found that blocking IFNAR may be a potential therapeutic target for NMOSD disease in the future.