Background and Objectives To analyze (1) the effect of immunoglobulin G (IgG) from patients with anti–myelin oligodendrocyte glycoprotein antibody (MOG-Ab)–associated disorder on the blood-brain barrier (BBB) endothelial cells and (2) the positivity of glucose-regulated protein 78 (GRP78) antibodies in MOG-Ab–associated disorders. Methods IgG was purified from sera with patients with MOG-Ab–associated disorder in the acute phase (acute MOG, n = 15), in the stable stage (stable MOG, n = 14), healthy controls (HCs, n = 9), and disease controls (DCs, n = 27). Human brain microvascular endothelial cells (BMECs) were incubated with IgG, and the number of nuclear NF-κB p65-positive cells in BMECs using high-content imaging system and the quantitative messenger RNA change in gene expression over the whole transcriptome using RNA-seq were analyzed. GRP78 antibodies from patient IgGs were detected by Western blotting. Results IgG in the acute MOG group significantly induced the nuclear translocation of NF-κB and increased the vascular cell adhesion molecule 1/intercellular adhesion molecule 1 expression/permeability of 10-kDa dextran compared with that from the stable MOG and HC/DC groups. RNA-seq and pathway analysis revealed that NF-κB signaling and oxidative stress (NQO1) play key roles. The NQO1 and Nrf2 protein amounts were significantly decreased after exposure to IgG in the acute MOG group. The rate of GRP78 antibody positivity in the acute MOG group (10/15, 67% [95% confidence interval, 38%–88%]) was significantly higher than that in the stable MOG group (5/14, 36% [13%–65%]), multiple sclerosis group (4/29, 14% [4%–32%]), the DCs (3/27, 11% [2%–29%]), or HCs (0/9, 0%). Removal of GRP78 antibodies from MOG-IgG reduced the effect on NF-κB nuclear translocation and increased permeability. Discussion GRP78 antibodies may be associated with BBB dysfunction in MOG-Ab–associated disorder.

Breakdown of the blood-nerve barrier (BNB) is observed in patients with Guillain-Barré syndrome (GBS); however, the molecular mechanism underlying this phenomenon remains unclear.The aim of this study was to identify antibodies against the BNB-endothelial cells that initiate BNB breakdown in patients with GBS. We purified IgGs from the serum samples of patients with GBS (n = 77) during the acute phase, disease controls ([DCs], n = 51), and healthy controls ([HCs], n = 24). Human peripheral nerve microvascular endothelial cells (PnMECs) were incubated with IgG. Molecular changes in PnMECs after GBS-IgG exposure were evaluated using RNA-seq and a high-content imaging system. U1-small nuclear ribonucleoprotein (U1-snRNP) autoantibodies were detected using an ELISA. The clinical information of U1-snRNP antibody-positive GBS patients was verified. GBS-IgGs significantly increased NF-κB nuclear translocation and permeability of the 10-kDa dextran in PnMECs compared with DC-IgGs or HC-IgGs. RNA-seq analyses of PnMECs demonstrated that NF-κB p65 in the center of the network analysis, snRNPs as upstream genes of NF-κB p65, and CXCR5 as downstream genes of NF-κB p65 were important molecules after GBS-IgG exposure. The protein level of claudin-5 and U1-snRNP was significantly reduced while that of CXCR5 was significantly increased after incubation with IgG from patients with GBS, compared with that from HCs. The rate of U1-snRNP antibody positivity was 36% (28 of 77) in patients with GBS, 7% (2 of 28) in DCs, and 0% (0 of 16) in HCs. The serum titer of snRNP antibody decreased after treatment. Both cerebral spinal fluid protein and albumin quotient (QALB)/QALBLIM were higher in snRNP antibody-positive GBS patients than in snRNP antibody-negative GBS patients. IgG from U1-snRNP antibody-positive GBS patients decreased the barrier function and claudin-5 expression more than that from HCs in an in vitro BNB coculture model. The reduction in U1-snRNP antibody decreased the biological effect of IgG from GBS patients with U1-snRNP antibody on the increased permeability of PnMECs. U1-snRNP autoantibodies are associated with the breakdown of BNB in GBS, through the reduction of U1-snRNP and claudin-5 and the induction of NF-κB activation in BNB-endothelial cells. A temporary autoantibody response against snRNP may be boosted by the periodic response to infection in GBS.

Purpose: The role of intestinal flora in carcinogenesis and chemotherapy efficacy has been increasingly studied; however, comparisons between oral and intestinal flora remain limited. Given the oral microbiome’s role in systemic inflammation and immune modulation, it may significantly influence cancer progression and response to immunotherapy. This study aimed to identify the microbial changes in urothelial carcinoma (UC) by analyzing oral saliva and stool samples from healthy individuals and UC patients. We also examined the association between microbial composition and immune checkpoint inhibitor (ICI) response. Methods: A total of 20 healthy individuals and 38 patients with UC were analyzed. Among them, 27 patients with UC underwent ICI treatment. Oral saliva and stool samples were analyzed for 16S rRNA sequences to assess bacterial composition. Operational taxonomic units were generated, and phylogenetic analysis was performed using the Illumina BaseSpace. Results: Patients with UC showed higher Veillonellaceae and Prevotellaceae levels in saliva and stool, with lower levels of these bacteria associated with more prolonged overall survival and progression-free survival, particularly Veillonellaceae in stool. A higher neutrophil-to-lymphocyte ratio correlated with increased levels of these bacteria. Conclusion: Veillonellaceae and Prevotellaceae are potential microbial biomarkers of survival outcomes and ICI efficacy in patients with UC. Non-invasive oral microbial sampling may facilitate personalized cancer treatment strategies.

Impairment of the blood–nerve barrier (BNB) is associated with the pathogenesis of chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). This research analyzes the molecular mechanisms of immunoglobulin (Ig) G in patients with typical CIDP, CIDP variants (multifocal CIDP), and multifocal motor neuropathy in BNB-endothelial cells. IgG was purified from the sera of patients with typical CIDP (n = 15), multifocal CIDP (n = 14), multifocal motor neuropathy (MMN; n = 12), and healthy controls (HCs; n = 14). Molecular changes in the RNA-seq/high-content imaging system and permeability were evaluated after the incubation of human peripheral nerve microvascular endothelial cells (PnMECs) with IgG. RNA-seq and a pathway analysis using PnMECs showed that TNF-α, CCL20 (MIP-3α), and ICAM-1 were the centers of the upregulated gene pathways in patients with typical CIDP. TNF-α, VCAM-1, NF-κB, and CSF2 (GM-CSF) are important molecules in patients with multifocal CIDP. The high-content imaging system demonstrated that MIP-3, GM-CSF, and VCAM-1 increased after exposure to typical CIDP-IgG, claudin-5 decreased after exposure to IgG from patients with multifocal CIDP, and TNF-α and VCAM-1 increased after exposure to IgG from patients with MMN. The 10 kDa dextran permeability using coculture with PnMECs and pericytes increased after exposure to IgG from patients with typical CIDP and multifocal CIDP. This effect was reversed after incubation with GM-CSF neutralizing antibodies. Upregulation of MIP-3, GM-CSF, and VCAM-1 may contribute to the infiltration of leukocytes/lymphocytes/monocytes across the BNB into the PNS in typical CIDP. IgG from typical CIDP and multifocal CIDP may decrease barrier properties through autocrine GM-CSF from PnMECs. VCAM-1 upregulation through autocrine TNF secretion in PnMECs may induce lymphocyte entry across the BNB in MMN.