Life-Threatening MOG Antibody-Associated Hemorrhagic ADEM With Elevated CSF IL-6.

Acute disseminated encephalomyelitis (ADEM) is one characteristic manifestation of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). A previously healthy man presented with retro-orbital headache and urinary retention 14 days after Tdap vaccination. Brain and spine MRI suggested a CNS demyelinating process. Despite treatment with IV steroids, he deteriorated, manifesting hemiparesis and later impaired consciousness, requiring intubation. A repeat brain MRI demonstrated new bilateral supratentorial lesions associated with venous sinus thrombosis, hemorrhage, and midline shift. Anti-MOG antibody was present at a high titer. CSF IL-6 protein was >2,000 times above the upper limits of normal. He improved after plasma exchange, then began monthly treatment alone with anti-IL-6 receptor antibody, tocilizumab, and has remained stable. This case highlights how adult-onset MOGAD, like childhood ADEM, can rapidly become life-threatening. The markedly elevated CSF IL-6 observed here supports consideration for evaluating CSF cytokines more broadly in patients with acute MOGAD.

Differentiated pattern of complement system activation between MOG-IgG-associated disease and AQP4-IgG-positive neuromyelitis optica spectrum disorder.

Background: Myelin oligodendrocyte glycoprotein antibody (MOG) immunoglobulin G (IgG)-associated disease (MOGAD) has clinical and pathophysiological features that are similar to but distinct from those of aquaporin-4 antibody (AQP4-IgG)-positive neuromyelitis optica spectrum disorders (AQP4-NMOSD). MOG-IgG and AQP4-IgG, mostly of the IgG1 subtype, can both activate the complement system. Therefore, we investigated whether the levels of serum complement components, regulators, and activation products differ between MOGAD and AQP4-NMOSD, and if complement analytes can be utilized to differentiate between these diseases. Methods: The sera of patients with MOGAD (from during an attack and remission; N=19 and N=9, respectively) and AQP4-NMOSD (N=35 and N=17), and healthy controls (N=38) were analyzed for C1q-binding circulating immune complex (CIC-C1q), C1 inhibitor (C1-INH), factor H (FH), C3, iC3b, and soluble terminal complement complex (sC5b-9). Results: In attack samples, the levels of C1-INH, FH, and iC3b were higher in the MOGAD group than in the NMOSD group (all, p<0.001), while the level of sC5b-9 was increased only in the NMOSD group. In MOGAD, there were no differences in the concentrations of complement analytes based on disease status. However, within AQP4-NMOSD, remission samples indicated a higher C1-INH level than attack samples (p=0.003). Notably, AQP4-NMOSD patients on medications during attack showed lower levels of iC3b (p<0.001) and higher levels of C3 (p=0.008), C1-INH (p=0.004), and sC5b-9 (p<0.001) compared to those not on medication. Among patients not on medication at the time of attack sampling, serum MOG-IgG cell-based assay (CBA) score had a positive correlation with iC3b and C1-INH levels (rho=0.764 and p=0.010, and rho=0.629 and p=0.049, respectively), and AQP4-IgG CBA score had a positive correlation with C1-INH level (rho=0.836, p=0.003). Conclusions: This study indicates a higher prominence of complement pathway activation and subsequent C3 degradation in MOGAD compared to AQP4-NMOSD. On the other hand, the production of terminal complement complexes (TCC) was found to be more substantial in AQP4-NMOSD than in MOGAD. These findings suggest a strong regulation of the complement system, implying its potential involvement in the pathogenesis of MOGAD through mechanisms that extend beyond TCC formation.

Autoantibodies-Abzymes with Phosphatase Activity in Experimental Autoimmune Encephalomyelitis Mice.

The exact mechanisms of MS (multiple sclerosis) evolution are still unknown. However, the development of EAE (experimental autoimmune encephalomyelitis simulating human MS) in C57BL/6 mice occurs due to the violation of bone marrow hematopoietic stem cell differentiation profiles, leading to the production of toxic for human autoantibody splitting MBP (myelin basic protein), MOG (mouse oligodendrocyte glycoprotein), five histones, DNA, and RNA. Here, we first analyzed the changes in the relative phosphatase activity of IgGs from C57BL/6 mice blood over time, corresponding to three stages of EAE: onset, acute, and remission. Antibodies have been shown to catalyze the hydrolysis of p-nitrophenyl phosphate at several optimal pH values, mainly in the range of 6.5-7.0 and 8.5-9.5. During the spontaneous development of EAE, the most optimal value is pH 6.5. At 50 days after the birth of mice, the phosphatase activity of IgGs at pH 8.8 is 1.6-fold higher than at pH 6.5. During spontaneous development of EAE from 50 to 100 days, an increase in phosphatase activity is observed at pH 6.5 but a decrease at pH 8.8. After mice were immunized with DNA-histone complex by 20 and 60 days, phosphatase activity increased respectively by 65.3 and 109.5 fold (pH 6.5) and 128.4 and 233.6 fold (pH 8.8). Treatment of mice with MOG at the acute phase of EAE development (20 days) leads to a maximal increase in the phosphatase activity of 117.6 fold (pH 6.5) and 494.7 fold (pH 8.8). The acceleration of EAE development after mice treatment with MOG and DNA-histone complex results in increased production of lymphocytes synthesizing antibodies with phosphatase activity. All data show that IgG phosphatase activity could be essential in EAE pathogenesis.

Myelin oligodendrocyte glycoprotein antibody-associated disease with clinical presentation as multiple episodes of isolated meningeal involvement: a case report.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) constitutes a group of autoimmune neuroinflammatory conditions that are characterized by positive serum MOG-immunoglobulin G antibodies. The relationship between MOGAD and immune factors remains unclear. Herein, we report a man in his early 30s who initially presented symptoms of headache and low-grade fever persisting for 20 days. The patient experienced isolated meningitis onset and had recurrent meningitis as the primary clinical feature, which manifested as low-grade fever, headache, and neck rigidity. Although cranial magnetic resonance imaging showed no abnormalities, immunotherapy was promptly administered upon diagnosing MOGAD through positive MOG-specific antibody testing of cerebrospinal and serum fluids. Notably, the patient's symptoms exhibited rapid improvement following treatment. Although meningitis is traditionally associated with infectious diseases, it can also occur in antibody-related autoimmune diseases that affect the central nervous system. Consequently, MOGAD should be considered in cases of aseptic meningitis with an unknown etiology, to facilitate definitive diagnosis and enhance patient prognosis.

Neuromyelitis Optica Spectrum Disorders and Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease.

For over two centuries, clinicians have been aware of various conditions affecting white matter which had come to be grouped under the umbrella term multiple sclerosis. Within the last 20 years, specific scientific advances have occurred leading to more accurate diagnosis and differentiation of several of these conditions including, neuromyelitis optica spectrum disorders and myelin oligodendrocyte glycoprotein antibody disease. This new understanding has been coupled with advances in disease-modifying therapies which must be accurately applied for maximum safety and efficacy.

Administration methods and dosage of poly(lactic acid)-glycol intervention to myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalitis mice.

BACKGROUND: Myelin oligodendrocyte glycoprotein-associated disorders (MOGAD) is an autoimmune central nervous system disease. Antigen-specific immune tolerance using nanoparticles such as Polylactic-co-glycolic acid (PLGA) have recently been used as a new therapeutic tolerization approach for CNS autoimmune diseases. We examined whether MOG1-125 conjugated with PLGA could induce MOG-specific immune tolerance in an experimental autoimmune encephalitis (EAE) mouse model. EAE was induced in sixty C57BL/6 J wild-type mice using MOG1-125 peptide with complete Freund's Adjuvant. The mice were divided into 12 groups (n = 5 each) to test the ability of MOG1-125 conjugated PLGA intervention to mitigate the severity or improve the outcomes from EAE with and without rapamycin compared to antigen alone or PLGA alone. EAE score and serum MOG-IgG titers were compared among the interventions.Kindly check and confirm the processed Affiliation “4” is appropriate.I confirmed the Aff 4.Affiliation: Corresponding author information have been changed to present affiliation. Kindly check and confirm.I checked and confirmed the Corresponding author's information. RESULTS: Mice with EAE that were injected intraperitoneally with MOG1-125 conjugated PLGA + rapamycin complex showed dose-dependent mitigation of EAE score. Intraperitoneal and intravenous administration resulted in similar clinical outcomes, whereas 80% of mice treated with subcutaneous injection had a recurrence of clinical score worsening after approximately 1 week. Although there was no significant difference in EAE scores between unconjugated-PLGA and MOG-conjugated PLGA, serum MOG-IgG tended to decrease in the MOG-conjugated PLGA group compared to controls. CONCLUSION: Intraperitoneal administration of PLGA resulted in dose-dependent and longer-lasting immune tolerance than subcutaneous administration. The induction of immune tolerance using PLGA may represent a future therapeutic option for patients with MOGAD.

Scoring Central Nervous System Inflammation, Demyelination, and Axon Injury in Experimental Autoimmune Encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE) is a common immune-based model of multiple sclerosis (MS). This disease can be induced in rodents by active immunization with protein components of the myelin sheath and Complete Freund's adjuvant (CFA) or by the transfer of myelin-specific T effector cells from rodents primed with myelin protein/CFA into naïve rodents. The severity of EAE is typically scored on a 5-point clinical scale that measures the degree of ascending paralysis, but this scale is not optimal for assessing the extent of recovery from EAE. For example, clinical scores remain high in some EAE models (e.g., myelin oligodendrocyte glycoprotein [MOG] peptide-induced model of EAE) despite the resolution of inflammation. Thus, it is important to complement clinical scoring with histological scoring of EAE, which also provides a means to study the underlying mechanisms of cellular injury in the central nervous system (CNS). Here, a simple protocol is presented to prepare and stain spinal cord and brain sections from mice and to score inflammation, demyelination, and axonal injury in the spinal cord. The method for scoring leukocyte infiltration in the spinal cord can also be applied to score brain inflammation in EAE. A protocol for measuring soluble neurofilament light (sNF-L) in the serum of mice using a Small Molecule Assay (SIMOA) assay is also described, which provides feedback on the extent of overall CNS injury in live mice.

Trans-Synaptic Degeneration in the Visual Pathway in Patients With Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease.

BACKGROUND AND OBJECTIVES: We aimed to assess the presence of retinal neurodegeneration independent of optic neuritis (ON) in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and to investigate the development of trans-synaptic anterograde degeneration in these patients after ON. METHODS: Cross-sectional, retrospective study of 34 adult patients with MOGAD and 23 healthy controls (HC). Clinical, optical coherence tomography (OCT), and MRI data were collected. Peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell inner plexiform layer (GCIPL) were obtained using Heidelberg Spectralis. FreeSurfer7 was used to obtain the lateral geniculate nucleus (LGN), occipital volume fractions (to total estimated intracranial volume), and occipital cortical thickness. For the anterior visual pathway, the analysis was conducted using eyes, classified based on the history of ON (Eye-ON and Eye-NON) and compared with Eye-HC. The analysis of OCT and brain volumetric measures was conducted comparing MOGAD-ON, MOGAD-NON, and HC groups. The analysis of covariance with a Bonferroni-adjusted post hoc test was used to test differences between groups and linear regression analysis to evaluate OCT/MRI associations; age and sex were considered as covariates. RESULTS: 24 (70.5%) patients had a prior ON. Median pRNFL and GCIPL thickness (um) was significantly reduced in Eye-ON vs EyeNON and HC (pRNFL: 69.4 (17.3), 89.6 (13.7), 98.2 (11.7), p < 0.001; GCIPL: 55.8 (8.7), 67.39 (8.7), 72.6 (4.5), p < 0.001). pRNFL and GCIPL thickness had a negative correlation with the number of ON episodes (p = 0.025 and p = 0.031, respectively). LGN volume fraction was significantly lower in patients with MOGAD-ON than in HC (0.33 (0.05) vs 0.39 (0.04), p = 0.002). The occipital cortical thickness was lower in MOGAD-ON compared with MOGAD-NON and HC (p = 0.010). In patients with MOGAD-ON, pRNFL correlated with LGN volume (p = 0.006), occipital thickness (p = 0.002), and the medial occipital cortex (p = 0.002), but not the lateral occipital lobe. DISCUSSION: Compared with HC, MOGAD-ON exhibits reduced retinal thickness, primarily influenced by the presence and the number of prior ON episodes. Moreover, MOGAD-ON demonstrates significant atrophy in the retinal, subcortical, and cortical regions of the visual pathway, distinguishing them from MOGAD-NON and HC. These findings suggest that in patients with MOGAD neurodegeneration is tightly correlated with damage to the involved pathway.

Cell-Based Assay to Detect the Autoantibody Serostatus in Patients with Neuromyelitis Optica Spectrum Disorder (NMOSD).

Cell-based assay (CBA) is an immunofluorescence assay that is extensively used for the confirmatory diagnosis of inflammatory demyelinating diseases of the central nervous system, like neuromyelitis optica spectrum disorder (NMOSD). Detecting the type of autoantibody present in the sera of the patients is the primary goal. CBA is the most sensitive and recommended detection method among all similar tools. Briefly, serum autoantibody is screened by transfecting specific cells seeded on cover glasses with full-length specific antigen fused with green fluorescent protein (GFP), followed by treating them with the patient serum used here as the source of primary antibody. The autoantibody-treated cells are further labeled with a rhodamine-conjugated secondary antibody. The co-localization of GFP and rhodamine is visualized by confocal microscopy, and the intensity of fluorescence is evaluated to determine the presence of autoantibody. A detailed protocol to screen antibodies against AQP4 and MOG in human sera using this method is described.

Sustained effects on immune cell subsets and autoreactivity in multiple sclerosis patients treated with oral cladribine.

Introduction: Cladribine tablet therapy is an efficacious treatment for multiple sclerosis (MS). Recently, we showed that one year after the initiation of cladribine treatment, T and B cell crosstalk was impaired, reducing potentially pathogenic effector functions along with a specific reduction of autoreactivity to RAS guanyl releasing protein 2 (RASGRP2). In the present study we conducted a longitudinal analysis of the effect of cladribine treatment in patients with RRMS, focusing on the extent to which the effects observed on T and B cell subsets and autoreactivity after one year of treatment are maintained, modulated, or amplified during the second year of treatment. Methods: In this case-control exploratory study, frequencies and absolute counts of peripheral T and B cell subsets and B cell cytokine production from untreated patients with relapsing-remitting MS (RRMS) and patients treated with cladribine for 52 (W52), 60 (W60), 72 (W72) and 96 (W96) weeks, were measured using flow cytometry. Autoreactivity was assessed using a FluoroSpot assay. Results: We found a substantial reduction in circulating memory B cells and proinflammatory B cell responses. Furthermore, we observed reduced T cell responses to autoantigens possibly presented by B cells (RASGRP2 and a-B crystallin (CRYAB)) at W52 and W96 and a further reduction in responses to the myelin antigens myelin basic protein (MBP) and myelin oligodendrocyte glycoprotein (MOG) after 96 weeks. Conclusion: We conclude that the effects of cladribine observed after year one are maintained and, for some effects, even increased two years after the initiation of a full course of treatment with cladribine tablets.

Milk and multiple sclerosis: A possible link?

Despite having been formally defined over 150 years ago, the etiology of multiple sclerosis (MS) is still relatively unknown. However, it is now recognized as a multifactorial disease in which genetics, infection, immune function, and environment play a role. We propose an additional piece to the puzzle: milk. In this review, milk is highlighted as a potential risk factor for MS. We examine the overall correlation between bovine milk consumption and the incidence of MS. We then discuss possible mechanisms that may explain the positive association between milk consumption and the development of MS. For instance, butyrophilin (BTN), a milk glycoprotein, can provide molecular mimicry of myelin oligodendrocyte glycoprotein and induce an autoinflammatory response against myelin. Other milk components such as casein, gangliosides, xanthine oxidase, and saturated fats are also analyzed for their potential involvement in the pathophysiology of MS. Finally, we fit milk alongside other well known risk factors of MS: vitamin D levels, Epstein Barr virus infection, and gut dysbiosis. In conclusion, this review summarizes potential mechanisms linking milk as an underappreciated potential risk factor for the development of MS.

Myelin oligodendrocyte glycoprotein (MOG) associated optic neuritis in a patient with idiopathic intracranial hypertension (IIH) and compressive optic neuropathy case report.

BACKGROUND: Myelin oligodendrocyte glycoprotein-associated disease (MOGAD) has a wide phenotypic expression and should be considered in a differential diagnosis of patients with optic disc edema and increased intracranial pressure because MOGAD can mimic IIH and compressive optic neuropathy. CASE PRESENTATION: A 53-year-old woman with a history of presumed idiopathic intracranial hypertension ("IIH") presented with new headache and visual loss. She had a BMI of 35.44 kg/m2 and a past medical history significant for depression, hepatitis C, hyperlipidemia, and uterine cancer post-hysterectomy. She had undergone multiple lumboperitoneal shunts for presumed IIH and had a prior pituitary adenoma resection. Her visual acuity was no light perception OD and counting fingers OS. After neuro-ophthalmic consultation, a repeat cranial MRI showed symmetric thin peripheral optic nerve sheath enhancement of the intra-orbital optic nerves OU. Serum MOG antibody was positive at 1:100 and she was treated with intravenous steroids followed by plasma exchange and rituximab. CONCLUSIONS: This case highlights the importance of considering MOGAD in the differential diagnosis of optic neuropathy. Although likely multifactorial, we believe that the lack of improvement in our case from presumed IIH and despite adequate neurosurgical decompression of a pituitary adenoma with compression of the optic apparatus reflected underlying unrecognized MOGAD. Clinicians should consider repeat imaging of the orbit (in addition to the head) in cases of atypical IIH or compressive optic neuropathy especially when the clinical course or response to therapy is poor or progressive.

Predictors of relapsing disease course following index event in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

BACKGROUND: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an autoimmune disease that can present as a monophasic or relapsing disease course. Here, we investigate the predictors of developing relapsing disease with a focus on the index event. METHODS: MOGAD patients followed at Massachusetts General Hospital and Brigham and Women's Hospital were included. Data on demographic, clinical, and laboratory features were collected. Time-to-event survival analysis was performed using a Cox proportional hazards model. Univariate and multivariate regression analyses were performed. RESULTS: We included 124 patients with a diagnosis of MOGAD of which 62.1% (n = 77) were female. The median (IQR) onset age and follow-up time were 31 (16, 45), and 4.08 (2.2, 7.9) years respectively. In total, 40.3% (n = 50) of patients remained monophasic and, 59.7% (n = 74) developed a relapsing course. The median (IQR) time between the index event and the second attack was 3(2, 13.7) months. Starting maintenance therapy following the index event was associated with decreased risk of relapsing disease (HR:0.26; 95%CI: 0.12, 0.54; P < 0.001). Maintenance therapy with intravenous immunoglobulin (HR:0.1; 95% CI:0.01, 0.78, P = 0.02), rituximab (HR: 0.21; 95%CI: 0.08, 0.55; P = 0.001), and mycophenolate mofetil (HR: 0.27; 95%CI: 0.09, 0.77; P = 0.01) was associated with a decreased risk of relapsing disease course. A polyphasic first attack (HR:2.4; 95%CI:1.31, 4.4; P = 0.004) and high CSF protein (HR:2.06; 95%CI: 1.01, 4.16; P = 0.04) were associated with a relapsing course. CONCLUSIONS: In MOGAD patients, starting maintenance therapy following the index event reduces the risk of relapsing disease regardless of age, sex, and onset phenotype, while polyphasic first attack, and elevated CSF protein predict relapsing disease course.

Epstein-Barr Virus Strongly Associates With Pediatric Multiple Sclerosis, But Not Myelin Oligodendrocyte Glycoprotein-Antibody-Associated Disease.

Reported rates of Epstein-Barr virus (EBV) seropositivity in children meeting multiple sclerosis (MS) diagnostic criteria are considerably lower than those reported in adult-onset MS, putting in question a requisite role for EBV in MS development. As prior work preceded recognition of myelin oligodendrocyte glycoprotein-associated disease (MOGAD), we assessed viral serologies in 251 children with incident demyelination and prospectively ascertained diagnoses. When MOGAD was serologically accounted for, the prevalence of EBV infection among MS children exceeded 90%, whereas remote EBV infection was not associated with MOGAD risk. Together, these findings substantiate EBV's role across the MS spectrum, and support distinct pathobiological mechanisms in MS versus MOGAD. ANN NEUROL 2024;95:700-705.

Leptomeningeal Enhancement in Pediatric Anti-Myelin Oligodendrocyte Glycoprotein Antibody Disease, Multiple Sclerosis, and Neuromyelitis Optica Spectrum Disorder.

BACKGROUND: Anti-myelin oligodendrocyte glycoprotein (MOG) antibody disease (MOGAD) is a type of acquired demyelinating disease that is distinct from multiple sclerosis (MS) and aquaporin-4 antibody neuromyelitis optica spectrum disorder (AQP4-NMOSD). Leptomeningeal enhancement (LME) has been reported in children and adults with MOGAD, and in adults with MS and AQP4-NMOSD, but less is known about LME in pediatric-onset MS (POMS) and pediatric AQP4-NMOSD. Here we compare the rates of LME in children with MOGAD, POMS, and AQP4-NMOSD. METHODS: A retrospective chart review was performed in patients with MOGAD, POMS, and AQP4-NMOSD who presented to our institution. Clinical characteristics, imaging features, and relapsing data were included. Descriptive statistics were used, including chi-square or Fischer exact test, to compare proportions. The Benjamini-Hochberg procedure was used to correct for multiple comparisons. RESULTS: A total of 42 children were included: 16 with POMS, six with AQP4-NMOSD, and 20 with MOGAD. Brain LME was only observed in the MOGAD group (six of 20 = 30%) when compared with zero (0%) POMS and AQP4-NMOSD (P = 0.012). Relapsing disease occurred in nine of 20 (45%), but LME did not associate with relapse. CONCLUSIONS: LME is only observed in pediatric MOGAD and not in POMS or pediatric AQP4-NMOSD. LME did not predict relapses in MOGAD. Further work is needed to determine the clinical significance of LME in pediatric MOGAD.

Effectiveness of immunotherapies in relapsing myelin oligodendrocyte glycoprotein antibody-associated disease.

BACKGROUND: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) can cause optic neuritis, transverse myelitis, or acute disseminated encephalomyelitis (ADEM). Immunotherapy is often used for relapsing disease, but there is variability in treatment decisions. OBJECTIVE: The objective was to determine the annualized relapse rates (ARRs) and incidence rate ratios (IRRs) compared to pre-treatment and relapse-freedom probabilities among patients receiving steroids, B-cell depletion (BCD), intravenous immunoglobulin (IVIG), and mycophenolate mofetil (MMF). METHODS: Retrospective cohort study of patients with relapsing MOGAD treated at Mass General Brigham. ARRs and IRRs compared to pre-treatment, and relapse-freedom probability and odds ratio for relapse-freedom compared to prednisone were calculated. RESULTS: A total of 88 patients met the inclusion criteria. The ARR on IVIG was 0.13 (95% confidence interval (CI) = 0.06-0.27) and the relapse-freedom probability after at least 6 months of therapy was 72%. The ARR on BCD was 0.51 (95% CI = 0.34-0.77), and the relapse-freedom probability was 33%. The ARR on MMF was 0.32 (95% CI = 0.19-0.53) and the relapse-freedom probability was 49%. In pediatric-onset disease, MMF had the lowest ARRs (0.15, 95% CI = 0.07-0.33). CONCLUSION: IVIG had the lowest ARRs and IRRs compared to pre-treatment and the highest relapse-freedom odds ratio compared to prednisone, while BCD had the lowest. In pediatric-onset MOGAD, MMF had the lowest ARRs.

Role of CD4 T Cell in Relapsing-Remitting Experimental Autoimmune Encephalomyelitis.

Multiple sclerosis (MS) is an autoimmune disease characterized by the infiltration of immune cells and demyelination in the central nervous system (CNS). Experimental autoimmune encephalomyelitis (EAE) serves as a prototypic animal model for studying MS. In this study, we aimed to investigate the role of CD4 T cells in the initiation and relapse of EAE, focusing on the activation phase and immune response. To create the EAE mice model, female mice were immunized with myelin oligodendrocyte glycoprotein (MOG)35-55 emulsified with complete Freund's adjuvant (CFA). Clinical scores were assessed daily, and results demonstrated that mice in the EAE group exhibited a classic relapsing-remitting pattern. Hematoxylin-eosin (H&E) and luxol fast blue (LFB) staining analysis revealed significant infiltration of inflammatory cells in the CNS and demyelination in EAE mice. Regarding the activation phase, both CD4+CD69+ effector T (Teff) cells and CD4+CD44+CD62L- effector memory T (Tem) cells may contribute to the initiation of EAE, however, the relapse stage was probably dominated by CD4+CD44+CD62L- Tem cells. Additionally, in terms of immune function, helper T (Th)1 cells are primarily involved in initiating the EAE. However, both Th1 and Th17 cells contribute to the relapse stage, and the immunosuppressive function of regulatory T (Treg) cells was inhibited during the EAE pathological process.

Development of an in vitro peptide-stimulated T cell assay to evaluate immune effects by cannabinoid compounds.

Previous studies demonstrated that cannabinoids exhibit immunosuppressive effects in experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS). To ask questions about treatment timing and investigate mechanisms for immune suppression by the plant-derived cannabinoids, cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), an in vitro peptide stimulation of naive splenocytes (SPLC) was developed to mimic T cell activation in EAE. The peptide was derived from the myelin oligodendrocyte glycoprotein (MOG) protein, which is one component of the myelin sheath. MOG peptide is typically used with an immune adjuvant to trigger MOG-reactive T cells that attack MOG-containing tissues, causing demyelination and clinical disease in EAE. To develop the in vitro model, naïve SPLC were stimulated with MOG peptide on day 0 and restimulated on day 4. Cytokine analyses revealed that CBD and THC suppressed MOG peptide-stimulated cytokine production. Flow cytometric analysis showed that intracellular cytokines could be detected in CD4+ and CD8+ T cells. To determine if intracellular calcium was altered in the cultures, cells were stimulated for 4 days to assess the state of the cells at the time of MOG peptide restimulation. Both cannabinoid-treated cultures had a smaller population of the calcium-positive population as compared to vehicle-treated cells. These results demonstrate the establishment of an in vitro model that can be used to mimic MOG-reactive T cell stimulation in vivo.