Recent studies have indicated that primary autoimmune targets in NMO can be astrocytes, which abundantly express AQP4 in the end foot processes [6C8]. the total B-cells. Peripheral blood mononuclear cells (PBMC) and cerebrospinal fluid (CSF) were obtained from neuromyelitis optica (NMO) and multiple sclerosis (MS) patients. The proportions (%) of PB cells among the total B cells (CD19+) are reported. The Mann-Whitney test provided the statistical p values (**p < 0.01; *p < 0.05). The bars represent the median interquartile range (IQR).(TIF) pone.0083036.s003.tif (305K) GUID:?D38C0337-4386-4430-A8AA-D8409CB6E722 Figure S4: The number of somatic hypermutations in plasmablast (PB) clones. VH and VKappa regions of the IgG gene were evaluated in a total of 38 PB clones derived from a patient with neuromyelitis optica NMO (Pt1) during relapse. There were 17.4 1.3 [mean standard error of the mean (SEM)] in the VH regions and 10.5 1.5 mutations in the V kappa regions.(TIF) pone.0083036.s004.tif (204K) GUID:?8A40C3AF-7A7E-479D-BBB6-DFAF9069D2A5 Figure S5: Plasmablast (PB) cells are diversified by somatic hypermutations. The mutation frequencies in the framework regions (FR) and in complementarity-determining regions (CDR) of the VH and VKappa regions of the IgG genes were analyzed in PB clones from patient 1 (Pt1). The ratio of replacement (R, black bars) to silent (S, white bars) changes are shown at the bottom (R/S ratio).(TIF) Mestranol pone.0083036.s005.tif (408K) GUID:?F3A2FCE5-A817-4111-9508-8760432B2885 Figure S6: Comparison of Mestranol the somatic hypermutations in peripheral blood mononuclear cells (PBMC)- and cerebrospinal fluid (CSF)-derived PB clones. Here, we compare the plasmablast (PB) clones derived from the peripheral blood (N = 14) and from CSF (N = 24) with the number Mestranol of mutations in the VH and VKappa regions of the IgG genes. The statistic p values were obtained by Mann-Whitney test. The data represent the median interquartile range (IQR).(TIF) pone.0083036.s006.tif (351K) GUID:?D8B768F0-5A71-4756-9E3A-C354F28EFA47 Abstract Neuromyelitis optica (NMO) is an inflammatory disease characterized by recurrent attacks of optic neuritis and myelitis. It is generally accepted that autoantibodies against aquaporin 4 water channel protein play a pathogenic role in neuromyelitis optica. We have recently reported that plasmablasts are increased in the Mestranol peripheral blood of this autoimmune disease, and are capable of producing autoantibodies against ARVD aquaporin 4. Here, we demonstrate that CD138+HLA-DR+ plasmablasts, a subset of IgG-producing cells, are increased in the peripheral blood and are enriched among the cerebrospinal fluid (CSF) lymphocytes during the relapse of neuromyelitis optica. Notably, these CD138+HLA-DR+ plasmablasts overexpress CXCR3, whose ligands are present in the cerebrospinal fluid during the relapse of neuromyelitis optica. These results led us to speculate that plasmablasts producing anti-aquaporin 4 autoantibodies might traffic toward the central nervous system (CNS). Furthermore, we performed single-cell sorting of plasmablasts from peripheral blood and CSF samples from NMO and sequenced the complementarity-determining regions (CDRs) of the IgG heavy chain expressed by the sorted plasmablast clones. There were high frequencies of mutations in the CDRs compared with framework regions, indicating that these plasmablast clones would represent a post-germinal center B-cell lineage. Consistent with the preceding results, the plasmablast clones from the peripheral blood shared the same CDR sequences with the clones from the CSF. These results indicate that IgG-producing plasmablasts, which are guided by helper T-cells, may migrate from the peripheral blood preferentially to the CSF. Since migratory plasmablasts could be involved in the inflammatory pathology of NMO, the B-cell subset and their migration might be an attractive therapeutic target. Introduction Neuromyelitis optica (NMO) is a rare inflammatory disease primarily affecting Mestranol the optic nerve and spinal cord, with relatively sparing brain white matter [1]. NMO exhibits a relapsingCremitting course reminiscent of multiple sclerosis (MS) and was previously thought to be a variant of MS. However, NMO is now considered to have a unique pathogenesis characterized by the elevation of autoantibodies against aquaporin 4 (AQP4) [2,3]. NMO is more often accompanied by the elevation of serum autoantibodies including anti-nuclear, anti-SSA, and anti-SSB antibodies than MS. Notably, the relapses of NMO are not prevented but rather triggered by disease-modifying agents prescribed for MS, including interferon-beta[4,5]. Recent studies have indicated that primary autoimmune targets in NMO can.