Multiple Glycoproteins Research Articles

CXCL13 promotes broad immune responses induced by circular RNA vaccines.

Antibody responses induced by current vaccines for influenza and SARS-CoV-2 often lack robust cross-reactivity. As hubs where diverse immune cells converge and interact, the alterations in the immune microenvironment within lymph nodes (LNs) are intricately linked to immune responses. Herein, we designed a lipid nanoparticle (LNP) loaded with circular RNA (circRNA) and targeted to LNs, in which CXCL13 was directly integrated into antigen-encoding circRNA strands. We demonstrated that CXCL13 alters the transcriptomic profiles of LNs, especially the upregulation of IL-21 and IL-4. Meanwhile, CXCL13 promotes the formation of germinal center and elicits robust antigen-specific T cell responses. With the codelivery of CXCL13 and the antigen, CXCL13 enhances cross-reactive antibodies against influenza virus and SARS-CoV-2, achieving protection against both homologous and heterologous influenza virus challenges in a mouse model. Notably, the targeted modification of LNP surfaces with antibodies helps address some of the challenges associated with lyophilized LNP vaccines, which is crucial for the long-term storage of LNP-circRNA vaccines. Overall, the circRNA-based antigen-CXCL13 coexpression system developed herein provides a simple and robust platform that enhances the magnitude and breadth of antibody responses against multiple viral glycoproteins, highlighting the potential utility of CXCL13 in inducing broad immune responses.

Antiviral mechanisms of guanylate-binding protein 5: versatile inhibition of multiple viral glycoproteins.

Guanylate-binding proteins (GBPs) are interferon-inducible cellular factors known to inhibit a wide variety of pathogens. Humans encode seven GBPs that have functionally diversified to provide broad protection against a variety of bacteria, protozoa, and viruses. Here, we discuss recent data on the mechanisms underlying the broad antiviral activity of GBP5 (H. Veler, C. M. Lun, A. A. Waheed, and E. O. Freed, mBio e02086-24, 2024, https://doi.org/10.1128/mbio.02086-24) and place them in the context of previous studies on the ability of this antiviral factor to impair the function of numerous viral envelope (Env) glycoproteins. We focus on the effects of GBP5 on the glycosylation, proteolytic processing, and anterograde transport of Env and discuss mechanistic interdependencies of these maturation steps. Understanding the induction and action of broadly acting immune factors, such as GBP5, may help develop effective immune-based strategies against numerous pathogens.

Improved influenza vaccine responses after expression of multiple viral glycoproteins from a single mRNA.

Influenza viruses cause substantial morbidity and mortality every year despite seasonal vaccination. mRNA-based vaccines have the potential to elicit more protective immune responses, but for maximal breadth and durability, it is desirable to deliver both the viral hemagglutinin and neuraminidase glycoproteins. Delivering multiple antigens individually, however, complicates manufacturingand increases cost, thus it would be beneficial to express both proteins from a single mRNA. Here, we develop an mRNA genetic configuration that allows the simultaneous expression of unmodified, full-length NA and HA proteins from a single open reading frame. We apply this approach to glycoproteins from contemporary influenza A and B viruses and, after vaccination, observe high levels of functional antibodies and protection from disease in female mouse and male ferret challenge models. This approach may further efforts to utilize mRNA technology to improve seasonal vaccine efficacy by efficiently delivering multiple viral antigens simultaneously and in their native state.

Academic outcomes before and after clinical onset of acquired demyelinating syndromes in children: a matched cohort data linkage study.

It is unknown if cognition is impaired before clinical onset of paediatric acquired demyelinating syndromes. We conducted a matched cohort study using prospectively collected educational data in multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) patients (n = 60) and controls (pooled n = 449,553). Academic performance at ages 10-11 was impaired in MOGAD (-1.27 adjusted z-score [95% CI: -1.81 to -0.73], P < 0.001) and preclinical MS (-0.40 [-0.80 to -0.0003], P = 0.0498). Moderate/high-efficacy MS treatment was associated with better final academic performance (0.92 [0.28-1.57], P = 0.005). After clinical onset MS patients missed 8.7% of school (controls 2.9%, P < 0.001) and MOGAD patients 11.9% (controls 2.0%, P < 0.001).

Relapsing tumefactive demyelination lesions: A unique, distinct inflammatory brain pathology.

We report the case of a patient suffering from biopsy-proven relapsing tumefactive demyelinating lesions (TDLs) of the central nervous system who had five relapses in 16 years. No signs/symptoms suggestive of alternative pathologies emerged during the follow-up. A limited benefit was observed with intravenous (IV) high-dose steroids, while both plasma exchange and IV immunoglobulin G (IgG) administration were ineffective. A long-lasting (9 years) but transient clinical stabilization was obtained with cyclophosphamide. Our case supports the view that recurrent TDL is a relapsing brain inflammation not belonging to multiple sclerosis (MS) or myelin oligodendrocyte glycoprotein (MOG)-/AQP4-associated disorders. TDL concept and clinical features should be revised.

GP-Marker facilitates the analysis of intact glycopeptide quantitative data at different levels.

Protein glycosylation is a highly heterogeneous post-translational modification that has been demonstrated to exhibit significant variations in various diseases. Due to the differential patterns observed in disease and healthy populations, the glycosylated proteins hold promise as early indicators for multiple diseases. With the continuous development of liquid chromatography-mass spectrometry (LC-MS) technology and spectrum analysis software, the sensitivity for the decipher of the tandem mass spectra of the glycopeptides carrying intact glycans, i.e., intact glycopeptides, enzymatic hydrolyzed from glycoproteins has been significantly improved. From quantified intact glycopeptides, the difference of protein glycosylation at multiple levels, e.g., glycoprotein, glycan, glycosite, and site-specific glycans, could be obtained for different samples. However, the manual analysis of the intact glycopeptide quantitative data at multiple levels is tedious and time consuming. In this study, we have developed a software tool named "GP-Marker" to facilitate large-scale data mining of spectra dataset of intact N-glycopeptide at multiple levels. This software provides a user-friendly and interactive interface, offering operational tools for machine learning to researchers without programming backgrounds. It includes a range of visualization plots displaying differential glycosylation and provides the ability to extract multi-level data analysis from intact glycopeptide data quantified by Glyco-Decipher.

Pearls & Oy-sters: Optic Neuritis as First Demyelinating Event During Pregnancy in 2 Young Hispanic Women: MS vs MOGAD.

Optic neuritis (ON) can present as the first demyelinating attack in both multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD), which may require different treatment depending on the final diagnosis. We present 2 young Hispanic women who presented with ON during pregnancy, one of whom was diagnosed with MS and the other with MOGAD. We describe key clinical features to help differentiate between MS and MOGAD including ON features, brain and spinal MRI, CSF profiles, and serum MOG and aquaporin-4 (AQP-4) antibodies, which all can help guide clinicians to an ultimate diagnosis. Pregnancy is usually considered an immunotolerant state because complex immunologic shifts arising to support tolerance of the developing fetus seem to decrease the risk of relapses. However, relapses may still occur during pregnancy, and relapse rates increase immediately postpartum. Our cases raise the possibility that young Hispanic patients may face increased risk of demyelinating disease activity even during the relatively immunotolerant state of pregnancy. A high index of suspicion for demyelinating disease should be maintained to accelerate diagnosis and prevent disability.

Prevalence of anti-myelin oligodendrocyte glycoprotein antibodies across neuroinflammatory and neurodegenerative diseases

Inflammatory central nervous system (CNS) diseases, such as multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD), are characterized by humoral immune abnormalities. Anti-MOG antibodies are not specific to MOGAD, with their presence described in MS. Autoantibodies may also be present and play a role in various neurodegenerative diseases. Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease driven by motor neuron dysfunction. While immune involvement in ALS has been recognized, the presence of antibodies targeting CNS myelin antigens has not been established. We aimed to establish a live cell-based assay for quantification of serum anti-MOG IgG1 in patients with CNS diseases, including MS and ALS. In total, 771 serum samples from the John L. Trotter MS Center and the Northeast ALS Consortium were examined using a live cell-based assay for detection of anti-MOG IgG1. Samples from three cohorts were tested in blinded fashion: healthy control (HC) subjects, patients with clinically diagnosed MOGAD, and an experimental group of ALS and MS patients. All samples from established MOGAD cases were positive for anti-MOG antibodies, while all HC samples were negative. Anti-MOG IgG1 was detected in 65 of 658 samples (9.9%) from MS subjects and 4 of 108 (3.7%) samples from ALS subjects. The presence of serum anti-MOG IgG1 in MS and ALS patients raises questions about the contribution of these antibodies to disease pathophysiology as well as accuracy of diagnostic approaches for CNS inflammatory diseases.

Multivalent MVA-vectored vaccine elicits EBV neutralizing antibodies in rhesus macaques that reduce EBV infection in humanized mice.

Epstein-Barr virus (EBV) is an oncogenic human herpesvirus associated with ~350,000 cases of lymphoid and epithelial malignancies every year, and is etiologically linked to infectious mononucleosis and multiple sclerosis. Despite four decades of research, no EBV vaccine candidate has yet reached licensure. Most previous vaccine attempts focused on a single viral entry glycoprotein, gp350, but recent data from clinical and pre-clinical studies, and the elucidation of viral entry mechanisms, support the inclusion of multiple entry glycoproteins in EBV vaccine design. Here we generated a modified vaccinia Ankara (MVA)-vectored EBV vaccine, MVA-EBV5-2, that targets five EBV entry glycoproteins, gp350, gB, and the gp42gHgL complex. We characterized the genetic and translational stability of the vaccine, followed by immunogenicity assessment in BALB/c mice and rhesus lymphocryptovirus-negative rhesus macaques as compared to a gp350-based MVA vaccine. Finally, we assessed the efficacy of MVA-EBV5-2-immune rhesus serum at preventing EBV infection in human CD34+ hematopoietic stem cell-reconstituted NSG mice, under two EBV challenge doses. The MVA-EBV5-2 vaccine was genetically and translationally stable over 10 viral passages as shown by genetic and protein expression analysis, and when administered to female and male BALB/c mice, elicited serum EBV-specific IgG of both IgG1 and IgG2a subtypes with neutralizing activity in vitro. In Raji B cells, this neutralizing activity outperformed that of serum from mice immunized with a monovalent MVA-vectored gp350 vaccine. Similarly, MVA-EBV5-2 elicited EBV-specific IgG in rhesus macaques that were detected in both serum and saliva of immunized animals, with serum antibodies demonstrating neutralizing activity in vitro that outperformed serum from MVA-gp350-immunized macaques. Finally, pre-treatment with serum from MVA-EBV5-2-immunized macaques resulted in fewer EBV-infected mice in the two challenge experiments than pretreatment with serum from pre-immune macaques or macaques immunized with the monovalent gp350-based vaccine. These results support the inclusion of multiple entry glycoproteins in EBV vaccine design and position our vaccine as a strong candidate for clinical translation.

Chemical Synthesis Creates Single Glycoforms of the Ectodomain of Herpes Simplex Virus-1 Glycoprotein D.

Herpes simplex virus-1 (HSV-1) utilizes multiple viral surface glycoproteins to trigger virus entry and fusion. Among these glycoproteins, glycoprotein D (gD) functions as a receptor-binding protein, which makes it an attractive target for the development of vaccines against HSV-1 infection. Several recombinant gD subunit vaccines have been investigated in both preclinical and clinical phases with varying degrees of success. It is fundamentally critical to explore the functions of gD glycans. In light of this, we report an efficient synthetic platform to construct glycosylated gDs bearing homogeneous glycans at N94 and N121. The oligosaccharides were prepared by enzymatic synthesis and conjugated to peptidyl sectors. The glycoproteins were constructed via a combination of 7-(piperazin-1-yl)-2-(methyl)quinolinyl (PPZQ)-assisted expressed protein ligation and β-mercapto amino acid-assisted-desulfurization strategies. Biological studies showed that synthetic gDs exhibited potent in vivo activity in mice.

Non-overlapping epitopes on the gHgL-gp42 complex for the rational design of a triple-antibody cocktail against EBV infection

Epstein-Barr virus (EBV) is closely associated with cancer, multiple sclerosis, and post-acute coronavirus disease 2019 (COVID-19) sequelae. There are currently no approved therapeutics or vaccines against EBV. It is noteworthy that combining multiple EBV glycoproteins can elicit potent neutralizing antibodies (nAbs) against viral infection, suggesting possible synergistic effects. Here, we characterize three nAbs (anti-gp42 5E3, anti-gHgL 6H2, and anti-gHgL 10E4) targeting different glycoproteins of the gHgL-gp42 complex. Two antibody cocktails synergistically neutralize infection in B cells (5E3+6H2+10E4) and epithelial cells (6H2+10E4) invitro. Moreover, 5E3 alone and the 5E3+6H2+10E4 cocktail confer potent invivo protection against lethal EBV challenge in humanized mice. The cryo-EM structure of a heptatomic gHgL-gp42 immune complex reveals non-overlapping epitopes of 5E3, 6H2, and 10E4 on the gHgL-gp42 complex. Structural and functional analyses highlight different neutralization mechanisms for each of the three nAbs. In summary, our results provide insight for the rational design of therapeutics or vaccines against EBV infection.

N-acetylglucosamine inhibits inflammation and neurodegeneration markers in multiple sclerosis: a mechanistic trial

BackgroundIn the demyelinating disease multiple sclerosis (MS), chronic-active brain inflammation, remyelination failure and neurodegeneration remain major issues despite immunotherapy. While B cell depletion and blockade/sequestration of T and B cells potently reduces episodic relapses, they act peripherally to allow persistence of chronic-active brain inflammation and progressive neurological dysfunction. N-acetyglucosamine (GlcNAc) is a triple modulator of inflammation, myelination and neurodegeneration. GlcNAc promotes biosynthesis of Asn (N)-linked-glycans, which interact with galectins to co-regulate the clustering/signaling/endocytosis of multiple glycoproteins simultaneously. In mice, GlcNAc crosses the blood brain barrier to raise N-glycan branching, suppress inflammatory demyelination by T and B cells and trigger stem/progenitor cell mediated myelin repair. MS clinical severity, demyelination lesion size and neurodegeneration inversely associate with a marker of endogenous GlcNAc, while in healthy humans, age-associated increases in endogenous GlcNAc promote T cell senescence.Objectives and methodsAn open label dose-escalation mechanistic trial of oral GlcNAc at 6 g (n = 18) and 12 g (n = 16) for 4 weeks was performed in MS patients on glatiramer acetate and not in relapse from March 2016 to December 2019 to assess changes in serum GlcNAc, lymphocyte N-glycosylation and inflammatory markers. Post-hoc analysis examined changes in serum neurofilament light chain (sNfL) as well as neurological disability via the Expanded Disability Status Scale (EDSS).ResultsPrior to GlcNAc therapy, high serum levels of the inflammatory cytokines IFNγ, IL-17 and IL-6 associated with reduced baseline levels of a marker of endogenous serum GlcNAc. Oral GlcNAc therapy was safe, raised serum levels and modulated N-glycan branching in lymphocytes. Glatiramer acetate reduces TH1, TH17 and B cell activity as well as sNfL, yet the addition of oral GlcNAc dose-dependently lowered serum IFNγ, IL-17, IL-6 and NfL. Oral GlcANc also dose-dependently reduced serum levels of the anti-inflammatory cytokine IL-10, which is increased in the brain of MS patients. 30% of treated patients displayed confirmed improvement in neurological disability, with an average EDSS score decrease of 0.52 points.ConclusionsOral GlcNAc inhibits inflammation and neurodegeneration markers in MS patients despite concurrent immunomodulation by glatiramer acetate. Blinded studies are required to investigate GlcNAc’s potential to control residual brain inflammation, myelin repair and neurodegeneration in MS.

Targeting herpesvirus entry complex and fusogen glycoproteins with prophylactic and therapeutic agents.

Herpesviruses are among the most successful viruses found in human populations. They establish lifelong latent infections, which are punctuated by recurrent reactivations. The entry process of herpesviruses into specific target cells requires a well-orchestrated teamwork involving multiple envelope glycoproteins. The conserved glycoprotein B (gB) is the membrane fusogen, of which conformational changes are induced by an entry complex (EC) consisting of at least gH and gL. Despite the high prevalence and heavy disease burdens associated with human herpesviruses (HHVs), vaccines against these pathogens are still lacking, except for varicella zoster virus (VZV). Recent advances in understanding the coordinated mechanisms of action of the key EC glycoproteins and fusogen will help to improve approaches for effective vaccine development and neutralizing antibody (nAb) screening.

Fusogenic structural changes in arenavirus glycoproteins are associated with viroporin activity.

Many enveloped viruses enter host cells by fusing with acidic endosomes. The fusion activity of multiple viral envelope glycoproteins does not generally affect viral membrane permeability. However, fusion induced by the Lassa virus (LASV) glycoprotein complex (GPc) is always preceded by an increase in viral membrane permeability and the ensuing acidification of the virion interior. Here, systematic investigation of this LASV fusion phenotype using single pseudovirus tracking in live cells reveals that the change in membrane barrier function is associated with the fusogenic conformational reorganization of GPc. We show that a small-molecule fusion inhibitor or mutations that impair viral fusion by interfering with GPc refolding into the post-fusion structure prevent the increase in membrane permeability. We find that the increase in virion membrane permeability occurs early during endosomal maturation and is facilitated by virus-cell contact. This increase is observed using diverse arenavirus glycoproteins, whether presented on lentivirus-based pseudoviruses or arenavirus-like particles, and in multiple different cell types. Collectively, these results suggest that conformational changes in GPc triggered by low pH and cell factor binding are responsible for virion membrane permeabilization and acidification of the virion core prior to fusion. We propose that this viroporin-like activity may augment viral fusion and/or post-fusion steps of infection, including ribonucleoprotein release into the cytoplasm.

Effects of Tolerant Nanoparticles Loaded with Various Regulatory Molecules on the Development of Experimental Autoimmune Encephalomyelitis

This research investigated the effects of tolerating nanoparticles (tNPs) loaded with multiple regulatory molecules on progression of experimental autoimmune encephalomyelitis (EAE). The polylactic acid-glycolic acid copolymer (PLGA), multiple regulatory molecular fragments (Fc) (programmed death receptor ligand 1-Fc (PD-L1-Fc), CD47-Fc), transforming growth factor (TGF-β1), and multiple oligodendrocyte glycoprotein (MOG) antigen peptides (p-MOG) were selected to prepare the tNPs (MRM-tNPs) loaded with various regulatory molecules. Then, the MRM-tNPs were applied in MOG35-55 polypeptide-induced EAE mouse model. According to the treatment methods, the mice were rolled into a group A (BS therapeutic agent), a group B (no-load-NPs), a group C (MOG-tNPs), and a group D (MRM-tNPs). The therapeutic effects were evaluated by the inflammatory infiltration degree (IID), demyelination loss degree (DLD), and apoptosis rate (AR) of CD4+ and CD8+ T cells. The Results showed that the encapsulation rate (ER) of TGF-β1 was 87.65%, and its cumulative release rate (RR) was 58.22%. There were obvious fluorescence signals on MRM-tNPs, MRM-tNPs without PD-L1, and MRM-tNPs without CD47. The neurological function (NF) score in the group D after MRM-tNPs treatment was less than 2 points (P &lt;0.05). The scores of IID and DLD in the brain and spinal cord (SC) of EAE mice in the group D were much lower to those in groups A, B, and C, and the ARs of CD4+ and CD8+ T cells were higher (P &lt;0.05). In conclusion, the tNPs loaded with various regulatory molecules can promote the apoptosis of antigen-specific T cells (AST) and reduce the infiltration and demyelination of inflammatory cells, thus alleviating the EAE.

MRI to differentiate multiple sclerosis, neuromyelitis optica, and myelin oligodendrocyte glycoprotein antibody disease.

Differentiating multiple sclerosis (MS) from other relapsing inflammatory autoimmune diseases of the central nervous system such as neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is crucial in clinical practice. The differential diagnosis may be challenging but making the correct ultimate diagnosis is critical, since prognosis and treatments differ, and inappropriate therapy may promote disability. In the last two decades, significant advances have been made in MS, NMOSD, and MOGAD including new diagnostic criteria with better characterization of typical clinical symptoms and suggestive imaging (magnetic resonance imaging [MRI]) lesions. MRI is invaluable in making the ultimate diagnosis. An increasing amount of new evidence with respect to the specificity of observed lesions as well as the associated dynamic changes in the acute and follow-up phase in each condition has been reported in distinct studies recently published. Additionally, differences in brain (including the optic nerve) and spinal cord lesion patterns between MS, aquaporin4-antibody-positive NMOSD, and MOGAD have been described. We therefore present a narrative review on the most relevant findings in brain, spinal cord, and optic nerve lesions on conventional MRI for distinguishing adult patients with MS from NMOSD and MOGAD in clinical practice. In this context, cortical and central vein sign lesions, brain and spinal cord lesions characteristic of MS, NMOSD, and MOGAD, optic nerve involvement, role of MRI at follow-up, and new proposed diagnostic criteria to differentiate MS from NMOSD and MOGAD were discussed.

The Role of Microorganisms in the Etiopathogenesis of Demyelinating Diseases.

Multiple sclerosis (MS), neuromyelitis optica (NMO) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) are inflammatory diseases of the central nervous system (CNS) with a multifactorial aetiology. Environmental factors are important for their development and microorganisms could play a determining role. They can directly damage the CNS, but their interaction with the immune system is even more important. The possible mechanisms involved include molecular mimicry, epitope spreading, bystander activation and the dual cell receptor theory. The role of Epstein-Barr virus (EBV) in MS has been definitely established, since being seropositive is a necessary condition for the onset of MS. EBV interacts with genetic and environmental factors, such as low levels of vitamin D and human endogenous retrovirus (HERV), another microorganism implicated in the disease. Many cases of onset or exacerbation of neuromyelitis optica spectrum disorder (NMOSD) have been described after infection with Mycobacterium tuberculosis, EBV and human immunodeficiency virus; however, no definite association with a virus has been found. A possible role has been suggested for Helicobacter pylori, in particular in individuals with aquaporin 4 antibodies. The onset of MOGAD could occur after an infection, mainly in the monophasic course of the disease. A role for the HERV in MOGAD has been hypothesized. In this review, we examined the current understanding of the involvement of infectious factors in MS, NMO and MOGAD. Our objective was to elucidate the roles of each microorganism in initiating the diseases and influencing their clinical progression. We aimed to discuss both the infectious factors that have a well-established role and those that have yielded conflicting results across various studies.

Central Vein Sign in Pediatric Multiple Sclerosis and Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

BackgroundThe central vein sign (CVS) on brain magnetic resonance imaging (MRI) is a promising diagnostic marker for distinguishing adult multiple sclerosis (MS) from other demyelinating conditions, but its prevalence is not well-established in pediatric-onset multiple sclerosis (POMS) versus myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). MOGAD can mimic MS radiologically. This study seeks to determine the utility of CVS, together with other radiological findings, in distinguishing POMS from MOGAD in children. MethodsChildren with POMS or MOGAD were identified in a pediatric demyelinating database. Two reviewers, blinded to diagnosis, fused fluid-attenuated inversion recovery sequences and susceptibility-weighted imaging from clinical imaging to identify CVS. Agreement in CVS number was reported using intraclass correlation coefficients (ICC). We performed topographic analyses as well as characterization of the clinical information and lesions on brain, spinal cord, and orbital MRI when available. ResultsTwenty children, 10 with POMS and 10 with MOGAD, were assessed. The median lesion percentage of CVS was higher in POMS versus MOGAD for both raters (rater 1: 80% vs 9.8%; rater 2: 22.7% vs 7.5%). Inter-rater reliability for identifying total white matter lesions was strong (ICC 0.94 [95% confidence interval [CI] 0.84, 0.97]); however, it was poor for detecting CVS lesions (ICC −0.17 [95% CI: −0.37, 0.58]). ConclusionThe CVS can be a useful diagnostic tool for differentiating POMS from MOGAD. However, advanced clinical imaging tools that can better detect CVS are needed to increase inter-rater reliability before clinical application.

Germline C1GALT1C1 mutation causes a multisystem chaperonopathy

Mutations in genes encoding molecular chaperones can lead to chaperonopathies, but none have so far been identified causing congenital disorders of glycosylation. Here we identified two maternal half-brothers with a novel chaperonopathy, causing impaired protein O-glycosylation. The patients have a decreased activity of T-synthase (C1GALT1), an enzyme that exclusively synthesizes the T-antigen, a ubiquitous O-glycan core structure and precursor for all extended O-glycans. The T-synthase function is dependent on its specific molecular chaperone Cosmc, which is encoded by X-chromosomal C1GALT1C1. Both patients carry the hemizygous variant c.59C>A (p.Ala20Asp; A20D-Cosmc) in C1GALT1C1. They exhibit developmental delay, immunodeficiency, short stature, thrombocytopenia, and acute kidney injury (AKI) resembling atypical hemolytic uremic syndrome. Their heterozygous mother and maternal grandmother show an attenuated phenotype with skewed X-inactivation in blood. AKI in the male patients proved fully responsive to treatment with the complement inhibitor Eculizumab. This germline variant occurs within the transmembrane domain of Cosmc, resulting in dramatically reduced expression of the Cosmc protein. Although A20D-Cosmc is functional, its decreased expression, though in a cell or tissue-specific manner, causes a large reduction of T-synthase protein and activity, which accordingly leads to expression of varied amounts of pathological Tn-antigen (GalNAcα1-O-Ser/Thr/Tyr) on multiple glycoproteins. Transient transfection of patient lymphoblastoid cells with wild-type C1GALT1C1 partially rescued the T-synthase and glycosylation defect. Interestingly, all four affected individuals have high levels of galactose-deficient IgA1 in sera. These results demonstrate that the A20D-Cosmc mutation defines a novel O-glycan chaperonopathy and causes the altered O-glycosylation status in these patients.

Neutrophil to lymphocyte ratio may be a useful marker in distinguishing MOGAD and MS and platelet to lymphocyte ratio associated with MOGAD activity.

Clinical overlap is observed between multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein immunoglobulin-G (MOG-IgG) associated disease (MOGAD) and the difficulty in distinguishing between the two diseases. Here, we measured and compared the readily available neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and monocyte to lymphocyte ratio (MLR) to determine whether these three biomarkers can help to distinguish MOGAD and MS at disease onset. The impact of these three biomarkers on MOGAD and MS relapse also needs to be explored. In this retrospective analysis, we obtained clinical and paraclinical data from the first attacks of MOGAD (N=31) and MS (N=50). Electronic medical records were used to collect demographic data (gender, age at onset), clinical symptoms, EDSS at onset, and medical treatments. The primary outcome was relapse within one year of onset. Four hematological parameters were recorded, including neutrophil count, platelet count, lymphocyte count, and monocyte count. NLR, PLR, and MLR were calculated and compared between MOGAD, MS, and HC. Receiver operator curve (ROC) analysis was performed to assess the ability of NLR, PLR, and MLR to distinguish between MOGAD and MS, MOGAD and HC, respectively. A logistic regression analysis was performed to determine the impact of NLR/PLR/MLR on MOGAD/MS relapse within one year of onset. Compared to HC, NLR is significantly higher in MOGAD and MS (p<0.001, p=0.04, respectively). The PLR and MLR are elevated in MOGAD compared to HC (p<0.001, p<0.001, respectively), and MLR in MS are also statistically higher than in HC (p=0.023). It is worth noting that NLR and PLR were much higher in MOGAD compared to MS (p<0.001, p=0.001, respectively), but a significant difference regarding MLR has not been found between MOGAD and MS. Based on ROC curve analyses, we found that using NLR, PLR, and MLR to discriminate between MOGAD and MS yielded a ROC-plot area under the curve (AUC) value of 0.794, 0.727, and 0.681, respectively. Meanwhile, the AUC of NLR, PLR, and MLR to discriminate between MOGAD and HC were 0.926, 0.772, and 0.786. Furthermore, the logistics analysis revealed a significant positive association between PLR and MOGAD relapse. NLR helps differentiate MOGAD and MS in disease onset, and higher PLR was related to MOGAD relapse.