Search

CD8+ T cells are the dominant lymphocyte population in multiple sclerosis (MS) lesions where they are highly clonally expanded. The clonal identity, function, and antigen specificity of CD8+ T cells in MS are not well understood. Here we report a comprehensive single-cell RNA-seq and T cell receptor (TCR)-seq analysis of the cerebrospinal fluid (CSF) and blood from a cohort of treatment-naïve MS patients and control participants. A small subset of highly expanded and activated CD8+ T cells were enriched in the CSF in MS that displayed high activation, cytotoxicity and tissue-homing transcriptional profiles. Using a combination of unbiased and targeted antigen discovery approaches, MS-derived CD8+ T cell clonotypes recognizing Epstein-Barr virus (EBV) antigens and multiple novel mimotopes were identified. These findings shed vital insight into the role of CD8+ T cells in MS and pave the way towards disease biomarkers and therapeutic targets.

Multiple sclerosis is an autoimmune disease of the CNS in which both genetic and environmental factors are involved. Genome-wide association studies revealed more than 200 risk loci, most of which harbour genes primarily expressed in immune cells. However, whether genetic differences are translated into cell-specific gene expression profiles and to what extent these are altered in patients with multiple sclerosis are still open questions in the field. To assess cell type-specific gene expression in a large cohort of patients with multiple sclerosis, we sequenced the whole transcriptome of fluorescence-activated cell sorted T cells (CD4+ and CD8+) and CD14+ monocytes from treatment-naive patients with multiple sclerosis (n = 106) and healthy subjects (n = 22). We identified 479 differentially expressed genes in CD4+ T cells, 435 in monocytes, and 54 in CD8+ T cells. Importantly, in CD4+ T cells, we discovered upregulated transcripts from the NAE1 gene, a critical subunit of the NEDD8 activating enzyme, which activates the neddylation pathway, a post-translational modification analogous to ubiquitination. Finally, we demonstrated that inhibition of NEDD8 activating enzyme using the specific inhibitor pevonedistat (MLN4924) significantly ameliorated disease severity in murine experimental autoimmune encephalomyelitis. Our findings provide novel insights into multiple sclerosis-associated gene regulation unravelling neddylation as a crucial pathway in multiple sclerosis pathogenesis with implications for the development of tailored disease-modifying agents., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Central nervous system B cells have several potential roles in multiple sclerosis (MS): secretors of proinflammatory cytokines and chemokines, presenters of autoantigens to T cells, producers of pathogenic antibodies, and reservoirs for viruses that trigger demyelination. To interrogate these roles, single-cell RNA sequencing (scRNA-Seq) was performed on paired cerebrospinal fluid (CSF) and blood from subjects with relapsing-remitting MS (RRMS; n = 12), other neurologic diseases (ONDs; n = 1), and healthy controls (HCs; n = 3). Single-cell immunoglobulin sequencing (scIg-Seq) was performed on a subset of these subjects and additional RRMS ( n = 4), clinically isolated syndrome ( n = 2), and OND ( n = 2) subjects. Further, paired CSF and blood B cell subsets (RRMS; n = 7) were isolated using fluorescence activated cell sorting for bulk RNA sequencing (RNA-Seq). Independent analyses across technologies demonstrated that nuclear factor kappa B (NF-κB) and cholesterol biosynthesis pathways were activated, and specific cytokine and chemokine receptors were up-regulated in CSF memory B cells. Further, SMAD/TGF-β1 signaling was down-regulated in CSF plasmablasts/plasma cells. Clonally expanded, somatically hypermutated IgM+ and IgG1+ CSF B cells were associated with inflammation, blood-brain barrier breakdown, and intrathecal Ig synthesis. While we identified memory B cells and plasmablast/plasma cells with highly similar Ig heavy-chain sequences across MS subjects, similarities were also identified with ONDs and HCs. No viral transcripts, including from Epstein-Barr virus, were detected. Our findings support the hypothesis that in MS, CSF B cells are driven to an inflammatory and clonally expanded memory and plasmablast/plasma cell phenotype., Competing Interests: Competing interest statement: R.D.S. served on an advisory board for Sanofi Genzyme and is currently an employee of Asceneuron SA. A.J.G. reports personal fees from Inception Sciences and Mylan Pharmaceuticals and has reported serving on an end point adjudication committee for Biogen and Medimmune. He has served on trial steering committees for Novartis and serves on the Scientific Advisory Board for Bionure. R.M.B. has received personal compensation for medical legal consulting and for consulting or serving on the advisory boards of F. Hoffmann-La Roche Ltd., Sanofi-Genzyme, and Novartis. J.M.G. has received research support to University of California, San Francisco from Genentech, personal compensation for consulting for Biogen and Alexion, and personal compensation for medical legal consulting; he has also received honoraria from Dynamed Plus for editorial work. B.A.C.C. receives personal compensation for consulting from Abbvie, Biogen, EMD Serono, GeNeuro, Novartis, and Sanofi Genzyme. S.S.Z. is Deputy Editor of Neurology, Neuroimmunology and Neuroinflammation and is an Associate Editor for Frontiers in Immunology and Frontiers in Neurology. He serves on the Advisory Committee for the American Congress on Treatment and Research in Multiple Sclerosis and on the grant review committee for the National Multiple Sclerosis Society (NMSS). Previously, he has served on the Editorial Board of the Journal of Clinical Investigation, The Journal of Immunology, and The Journal of Neurological Sciences and has been a charter member of the grant review committee for the NIH Clinical Neuroimmunology and Brain Tumors. He has served as a consultant and received honoraria from Biogen-Idec, EMD-Serono, Genzyme, Novartis, Roche/Genentech, and Teva Pharmaceuticals, Inc. and has served on Data Safety Monitoring Boards for Lilly, BioMS, Teva, and Opexa Therapeutics. Currently, S.S.Z. receives research grant support from the NIH, NMSS, Weill Institute, Race to Erase MS, and the Maisin Foundation. S.L.H. currently serves on the Scientific Advisory Board of Alector, Annexon, Bionure, and Molecular Stethoscope and on the Board of Trustees of Neurona. S.L.H. also has received travel reimbursement and writing assistance from F. Hoffmann-La Roche Ltd. and Novartis for CD20-related meetings and presentations. M.R.W. received research funding from Roche/Genentech., (Copyright © 2020 the Author(s). Published by PNAS.)

Giardia lamblia , a widespread parasitic protozoan, attaches to the host gastrointestinal epithelium by using the ventral disc, a complex microtubule (MT) organelle. The 'cup-like' disc is formed by a spiral MT array that scaffolds numerous disc-associated proteins (DAPs) and higher-order protein complexes. In interphase, the disc is hyperstable and has limited MT dynamics; however, it remains unclear how DAPs confer these properties. To investigate mechanisms of hyperstability, we confirmed the disc-specific localization of over 50 new DAPs identified by using both a disc proteome and an ongoing GFP localization screen. DAPs localize to specific disc regions and many lack similarity to known proteins. By screening 14 CRISPRi-mediated DAP knockdown (KD) strains for defects in hyperstability and MT dynamics, we identified two strains - DAP5188KD and DAP6751KD -with discs that dissociate following high-salt fractionation. Discs in the DAP5188KD strain were also sensitive to treatment with the MT-polymerization inhibitor nocodazole. Thus, we confirm here that at least two of the 87 known DAPs confer hyperstable properties to the disc MTs, and we anticipate that other DAPs contribute to disc MT stability, nucleation and assembly., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2020. Published by The Company of Biologists Ltd.)

Appropriate physician compensation is essential if affiliations between physicians and healthcare organizations are to be successful. A physician's compensation should be based on market-specific data about compensation for his or her specialty, as well as on data about each physician's productivity. Healthcare organizations also must have a process for adjusting compensation based on performance and market changes and a process for ensuring equity between newly hired physicians and currently employed physicians. A systematic, data-driven approach to establishing physician compensation can help build a foundation for successful physician recruiting and relations.

Managed care and systems integration are having a major impact on physician compensation, says a new survey by the Hay Group. The survey of physician compensation across hospital, group practice and managed care settings shows a slowing in pay growth, a shift in emphasis toward primary care, and increased emphasis on variable compensation strategies. At the same time, demand for physician executives is rising dramatically.