An IL-23-STAT4 pathway is required for the proinflammatory function of classical dendritic cells during CNS inflammation.

Although many cytokine pathways are important for dendritic cell (DC) development, it is less clear what cytokine signals promote the function of mature dendritic cells. The signal transducer and activator of transcription 4 (STAT4) promotes protective immunity and autoimmunity downstream of proinflammatory cytokines including IL-12 and IL-23. In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), Stat4-/- mice are resistant to the development of inflammation and paralysis. To define whether STAT4 is required for intrinsic signaling in mature DC function, we used conditional mutant mice in the EAE model. Deficiency of STAT4 in CD11c-expressing cells resulted in decreased T cell priming and inflammation in the central nervous system. EAE susceptibility was recovered following adoptive transfer of wild-type bone marrow-derived DCs to mice with STAT4-deficient DCs, but not adoptive transfer of STAT4- or IL-23R-deficient DCs. Single-cell RNA-sequencing (RNA-seq) identified STAT4-dependent genes in DC subsets that paralleled a signature in MS patient DCs. Together, these data define an IL-23-STAT4 pathway in DCs that is key to DC function during inflammatory disease.

Niacin produces an inconsistent treatment response in the EAE model of multiple sclerosis.

Niacin was found in the lysolecithin model of multiple sclerosis (MS) to promote the phagocytic clearance of debris and enhance remyelination. Lysolecithin lesions have prominent microglia/macrophages but lack lymphocytes that populate plaques of MS or its experimental autoimmune encephalomyelitis (EAE) model. Thus, the current study assessed the efficacy of niacin in EAE. We found that niacin inconsistently affects EAE clinical score, and largely does not ameliorate neuropathology. In culture, niacin enhances phagocytosis by macrophages, but does not reduce T cell proliferation. We suggest that studies of niacin for potential remyelination in MS should include a therapeutic that targets adaptive immunity.

Jung, the Rebirth Motif and Psychedelics I: Documenting Jung's Contact with the British Pioneers.

C. G. Jung wrote very little about psychedelic drugs and he took a sceptical view of them. However, he was sufficiently impressed by Aldous Huxley's 1954 account of taking mescaline, The Doors of Perception, to invite Huxley to visit him in Switzerland. Huxley declined Jung's invitation but Huxley's collaborator Humphry Osmond met Jung instead. This paper documents Jung's contact with the British pioneers of psychedelics research and presents the scant material illuminating his views about these drugs. It also determines the efforts of British psychiatrist Ronald Sandison, who was the first to develop an "explicitly Jungian approach" to psychedelic-assisted psychotherapy (Hill, 2013), and it highlights a connection between Sandison's initiative and the Society of Analytical Psychology (SAP) through the involvement of two SAP members: Margot Cutner, Sandison's colleague, and Michael Fordham, who supervised a trainee working with one of Sandison's former patients. Despite Jung's objections to the use of psychedelics, Sandison and Cutner developed ground-breaking protocols during the 1950s and they were among the first to document the phenomenon of "spiritual rebirth symbolized in the birth experience known to many LSD therapists" (Sandison, 2001). In two companion papers, I consider Jung's treatment of the rebirth motif in his commentary on The Tibetan Book of the Dead, which later became a central text in the psychedelic movement, and I chart the evolution in psychedelics research from an association with schizophrenia during the 1950s to the mystical paradigms of the 1960s and beyond.

C.G. Jung a très peu écrit sur les drogues psychédéliques et il avait à leur égard une attitude sceptique. Cependant il fut suffisamment impressionné par le récit d'Aldous Huxley de son expérience avec la mescaline en 1954, Les Portes de la Perception, pour inviter Huxley à lui rendre visite en Suisse. Huxley déclina l'invitation de Jung mais son collaborateur Humphry Osmond rencontra Jung à sa place. Cet article rend compte des contacts de Jung avec les recherches des pionniers britanniques en matière de drogues psychédéliques. Il présente aussi le peu de matériel qui illustre ses opinions concernant ces drogues. L'article explore les efforts du psychiatre britannique Ronald Sandison ­ qui fut le premier à développer une « approche spécifiquement jungienne ¼ à la psychothérapie assistée par des drogues psychédéliques ­ et il souligne un lien entre l'initiative de Sandison et The Society of Analytical Psychology (SAP) par l'implication de deux de ses membres : Margot Cutner, collègue de Sandison, et Michael Fordham, qui supervisa un candidat sur son travail avec un des anciens patients de Sandison. Malgré les objections de Jung sur l'utilisation des drogues psychédéliques, Sandison et Cutner ont développé des protocoles très innovants durant les années 1950 et furent parmi les premiers à documenter le phénomène de la « renaissance spirituelle symbolisée par l'expérience de naissance, bien connue par la plupart des thérapeutes utilisant le L.S.D. ¼ (Sandison, 2001). Dans deux articles apparentés j'examine la manière dont Jung a traité le motif de la renaissance dans son commentaire sur Le Livre des Morts Tibétain, qui devint par la suite un texte central dans le mouvement psychédélique, et je retrace l'évolution dans la recherche sur les drogues psychédéliques à partir d'une association avec la schizophrénie dans les années 1950 et jusqu'aux paradigmes mystiques des années 1960 et au­delà.

C. G. Jung escribió muy poco sobre las drogas psicodélicas y adoptó una postura escéptica hacia ellas. Sin embargo, quedó lo suficientemente impresionado por el relato, Las Puertas de la Percepción, que Aldous Huxley hizo en 1954 en referencia a su consumo de mescalina, como para invitar a Huxley a visitarle en Suiza. Huxley declinó la invitación, pero en su lugar Jung se reunió con Humphry Osmond, colaborador de Huxley. Este artículo documenta el contacto de Jung con los pioneros británicos en investigación psicodélica y presenta el escaso material que da cuenta de las opiniones de estos, sobre dichas drogas. También determina los esfuerzos del psiquiatra británico Ronald Sandison, que fue el primero en desarrollar un "enfoque explícitamente Junguiano" de la psicoterapia asistida por psicodélicos (Hill, 2013), y destaca una conexión entre la iniciativa de Sandison y la Sociedad de Psicología Analítica (SAP) a través de la participación de dos miembros de la SAP: Margot Cutner, colega de Sandison, y Michael Fordham, quien supervisaba a un candidato a analista que trabajaba con uno de los antiguos pacientes de Sandison. A pesar de las objeciones de Jung al uso de psicodélicos, Sandison y Cutner desarrollaron innovadores protocolos durante la década de 1950 y fueron los primeros en documentar el fenómeno del "renacimiento espiritual simbolizado en la experiencia del nacimiento conocida por muchos terapeutas del LSD" (Sandison, 2001). En dos artículos complementarios, considero el tratamiento que Jung da al motivo del renacimiento en su comentario sobre El Libro Tibetano de los Muertos, que más tarde se convirtió en un texto central del movimiento psicodélico, y trazo la evolución de la investigación sobre psicodélicos desde su asociación con la esquizofrenia durante la década de 1950 hasta los paradigmas místicos de la década de 1960 y posteriores.

Dosage and organic acid residue of MOG35-55 peptide influences immunopathology and development of BCG induced experimental autoimmune encephalomyelitis (EAE).

Experimental autoimmune encephalomyelitis (EAE) serves as a model for studying multiple sclerosis, with immunization strategies utilizing MOG35-55 peptide, emulsified in adjuvant enriched with mycobacterium tuberculosis (Mtb). This study examined the effects of Bacillus Calmette-Guérin (BCG) as an adjuvant, alongside the impact of MOG35-55 peptide doses and their residual counter ions on EAE development. We found that BCG can be effectively used to induce EAE with similar incidence and severity as heat-killed H37Ra, contingent upon the appropriate MOG35-55 peptide dose. Different immunization doses of MOG35-55 peptide significantly affect EAE development, with higher doses leading to a paradoxical reduction in disease activity, probably due to peripheral tolerance mechanisms. Furthermore, doses of MOG35-55 peptides with acetate showed a more pronounced effect on disease development compared to those containing trifluoroacetic acid (TFA), suggesting the potential influence of residual counter ions on EAE activity. We highlighted the feasibility of applying BCG to the establishment of EAE for the first time. Our findings emphasized the importance of MOG peptide dosage and composition in modulating EAE development, offering insights into the mechanisms of autoimmunity and tolerance. This could have implications for autoimmune disease research and the design of therapeutic strategies.

Methylprednisolone Modulates the Tfr/Tfh ratio in EAE-Induced Neuroinflammation through the PI3K/AKT/FoxO1 and PI3K/AKT/mTOR Signalling Pathways.

Methylprednisolone (MP) is a potent glucocorticoid that can effectively inhibit immune system inflammation and brain tissue damage in Multiple sclerosis (MS) patients. T follicular helper (Tfh) cells are a subpopulation of activated CD4 + T cells, while T follicular regulatory (Tfr) cells, a novel subset of Treg cells, possess specialized abilities to suppress the Tfh-GC response and inhibit antibody production. Dysregulation of either Tfh or Tfr cells has been implicated in the pathogenesis of MS. However, the molecular mechanism underlying the anti-inflammatory effects of MP therapy on experimental autoimmune encephalomyelitis (EAE), a representative model for MS, remains unclear. This study aimed to investigate the effects of MP treatment on EAE and elucidate the possible underlying molecular mechanisms involed. We evaluated the effects of MP on disease progression, CNS inflammatory cell infiltration and myelination, microglia and astrocyte activation, as well as Tfr/Tfh ratio and related molecules/inflammatory factors in EAE mice. Additionally, Western blotting was used to assess the expression of proteins associated with the PI3K/AKT pathway. Our findings demonstrated that MP treatment ameliorated clinical symptoms, inflammatory cell infiltration, and myelination. Furthermore, it reduced microglial and astrocytic activation. MP may increase the number of Tfr cells and the levels of cytokine TGF-ß1, while reducing the number of Tfh cells and the levels of cytokine IL-21, as well as regulate the imbalanced Tfr/Tfh ratio in EAE mice. The PI3K/AKT/FoxO1 and PI3K/AKT/mTOR pathways were found to be involved in EAE development. However, MP treatment inhibited their activation. MP reduced neuroinflammation in EAE by regulating the balance between Tfr/Tfh cells via inhibition of the PI3K/AKT/FoxO1 and PI3K/AKT/mTOR signalling pathways.

Electrical stimulation of the vagus nerve ameliorates inflammation and disease activity in a rat EAE model of multiple sclerosis.

Multiple sclerosis (MS) is a demyelinating central nervous system (CNS) disorder that is associated with functional impairment and accruing disability. There are multiple U.S. Food and Drug Administration (FDA)-approved drugs that effectively dampen inflammation and slow disability progression. However, these agents do not work well for all patients and are associated with side effects that may limit their use. The vagus nerve (VN) provides a direct communication conduit between the CNS and the periphery, and modulation of the inflammatory reflex via electrical stimulation of the VN (VNS) shows efficacy in ameliorating pathology in several CNS and autoimmune disorders. We therefore investigated the impact of VNS in a rat experimental autoimmune encephalomyelitis (EAE) model of MS. In this study, VNS-mediated neuroimmune modulation is demonstrated to effectively decrease EAE disease severity and duration, infiltration of neutrophils and pathogenic lymphocytes, myelin damage, blood-brain barrier disruption, fibrinogen deposition, and proinflammatory microglial activation. VNS modulates expression of genes that are implicated in MS pathogenesis, as well as those encoding myelin proteins and transcription factors regulating new myelin synthesis. Together, these data indicate that neuroimmune modulation via VNS may be a promising approach to treat MS, that not only ameliorates symptoms but potentially also promotes myelin repair (remyelination).

Characterization of spinal cord tissue-derived extracellular vesicles in neuroinflammation.

Extracellular vesicles (EVs) are released by all cells, can cross the blood-brain barrier, and have been shown to play an important role in cellular communication, substance shuttling, and immune modulation. In recent years EVs have shifted into focus in multiple sclerosis (MS) research as potential plasma biomarkers and therapeutic vehicles. Yet little is known about the disease-associated changes in EVs in the central nervous system (CNS). To address this gap, we characterized the physical and proteomic changes of mouse spinal cord-derived EVs before and at 16 and 25 days after the induction of experimental autoimmune encephalomyelitis (EAE), a neuroinflammatory model of MS. Using various bioinformatic tools, we found changes in inflammatory, glial, and synaptic proteins and pathways, as well as a shift in the predicted contribution of immune and glial cell types over time. These results show that EVs provide snapshots of crucial disease processes such as CNS-compartmentalized inflammation, re/de-myelination, and synaptic pathology, and might also mediate these processes. Additionally, inflammatory plasma EV biomarkers previously identified in people with MS were also altered in EAE spinal cord EVs, suggesting commonalities of EV-related pathological processes during EAE and MS and overlap of EV proteomic changes between CNS and circulating EVs.

A Camelid-Derived STAT-Specific Nanobody Inhibits Neuroinflammation and Ameliorates Experimental Autoimmune Encephalomyelitis (EAE).

Proinflammatory T-lymphocytes recruited into the brain and spinal cord mediate multiple sclerosis (MS) and currently there is no cure for MS. IFN-γ-producing Th1 cells induce ascending paralysis in the spinal cord while IL-17-producing Th17 cells mediate cerebellar ataxia. STAT1 and STAT3 are required for Th1 and Th17 development, respectively, and the simultaneous targeting of STAT1 and STAT3 pathways is therefore a potential therapeutic strategy for suppressing disease in the spinal cord and brain. However, the pharmacological targeting of STAT1 and STAT3 presents significant challenges because of their intracellular localization. We have developed a STAT-specific single-domain nanobody (SBT-100) derived from camelids that targets conserved residues in Src homolog 2 (SH2) domains of STAT1 and STAT3. This study investigated whether SBT-100 could suppress experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. We show that SBT-100 ameliorates encephalomyelitis through suppressing the expansion of Th17 and Th1 cells in the brain and spinal cord. Adoptive transfer experiments revealed that lymphocytes from SBT-100-treated EAE mice have reduced capacity to induce EAE, indicating that the immunosuppressive effects derived from the direct suppression of encephalitogenic T-cells. The small size of SBT-100 makes this STAT-specific nanobody a promising immunotherapy for CNS autoimmune diseases, including multiple sclerosis.

Pin1 maintains the effector program of pathogenic Th17 cells in autoimmune neuroinflammation.

Th17 cells mediated immune response is the basis of a variety of autoimmune diseases, including multiple sclerosis and its mouse model of immune aspects, experimental autoimmune encephalomyelitis (EAE). The gene network that drives both the development of Th17 and the expression of its effector program is dependent on the transcription factor RORγt. In this report, we showed that Peptidylprolyl Cis/Trans Isomerase, NIMA-Interacting 1 (Pin1) formed a complex with RORγt, and enhanced its transactivation activity, thus sustained the expression of the effector genes as well as RORγt in the EAE-pathogenic Th17 cells. We first found out that PIN1 was highly expressed in the samples from patients of multiple sclerosis, and the expression of Pin1 by the infiltrating lymphocytes in the central nerve system of EAE mice was elevated as well. An array of experiments with transgenic mouse models, cellular and molecular assays was included in the study to elucidate the role of Pin1 in the pathology of EAE. It turned out that Pin1 promoted the activation and maintained the effector program of EAE-pathogenic Th17 cells in the inflammation foci, but had little effect on the priming of Th17 cells in the draining lymph nodes. Mechanistically, Pin1 stabilized the phosphorylation of STAT3 induced by proinflammatory stimuli, and interacted with STAT3 in the nucleus of Th17 cells, which resulted in the increased expression of Rorc. Moreover, Pin1 formed a complex with RORγt, and enhanced the transactivation of RORγt to the +11 kb enhancer of Rorc, which enforced and maintained the expression of both Rorc and the effector program of pathogenic Th17 cells in EAE. Finally, the inhibition of Pin1, by genetic knockdown or by small molecule inhibitor, deceased the population of Th17 cells and the neuroinflammation, and alleviated the symptoms of EAE. These findings suggest that Pin1 is a potential therapeutic target for MS and other autoimmune inflammatory diseases.

Association of enzymatic and optimized ultrasound-assisted aqueous extraction of flavonoid glycosides from dried Hippophae rhamnoides L. (Sea Buckthorn) berries.

The main purpose of the present study was to determine the effect of associating an optimized ultrasound-assisted extraction (UAE) protocol with enzyme-assisted extraction (EAE) in aqueous media, using the dried berries of Hippophae rhamnoides L. (sea buckthorn) as plant material. A specialized software was used for the determination of potential optimal extraction parameters, leading to the development of four optimized extracts with different characteristics (UAE ± EAE). For these extracts, buffered or non-buffered solutions have been used, with the aim to determine the influence of adjustable pH on extractability. As enzymatic solution, a pectinase, cellulase, and hemicellulase mix (2:1:1) has been applied, acting as pre-treatment for the optimized protocol. The highest extractive yields have been identified for non-buffered extracts, and the E-UAE combination obtained extracts with the highest overall in vitro antioxidant activity. The HPLC-MSn analysis demonstrated a rich composition in different types of isorhamnetin-O-glycosides, as well as some quercetin-O-glycosides, showing a high recovery of specific flavonol-type polyphenolic species. Moreover, we have tentatively identified two flavanols (i.e., catechin and epigallocatechin) and one flavone derivative (i.e., luteolin).

Experimental Autoimmune Encephalomyelitis Influences GH-Axis in Female Rats.

Inflammation, demyelination, and axonal damage to the central nervous system (CNS) are the hallmarks of multiple sclerosis (MS) and its representative animal model, experimental autoimmune encephalomyelitis (EAE). There is scientific evidence for the involvement of growth hormone (GH) in autoimmune regulation. Previous data on the relationship between the GH/insulin like growth factor-1 (IGF-1) axis and MS/EAE are inconclusive; therefore, the aim of our study was to investigate the changes in the GH axis during acute monophasic EAE. The results show that the gene expression of Ghrh and Sst in the hypothalamus does not change, except for Npy and Agrp, while at the pituitary level the Gh, Ghrhr and Ghr genes are upregulated. Interestingly, the cell volume of somatotropic cells in the pituitary gland remains unchanged at the peak of the disease. We found elevated serum GH levels in association with low IGF-1 concentration and downregulated Ghr and Igf1r expression in the liver, indicating a condition resembling GH resistance. This is likely due to inadequate nutrient intake at the peak of the disease when inflammation in the CNS is greatest. Considering that GH secretion is finely regulated by numerous central and peripheral signals, the involvement of the GH/IGF-1 axis in MS/EAE should be thoroughly investigated for possible future therapeutic strategies, especially with a view to improving EAE disease.

Amniotic fluid stem cell-derived extracellular vesicles educate type 2 conventional dendritic cells to rescue autoimmune disorders in a multiple sclerosis mouse model.

Dendritic cells (DCs) are essential orchestrators of immune responses and represent potential targets for immunomodulation in autoimmune diseases. Human amniotic fluid secretome is abundant in immunoregulatory factors, with extracellular vesicles (EVs) being a significant component. However, the impact of these EVs on dendritic cells subsets remain unexplored. In this study, we investigated the interaction between highly purified dendritic cell subsets and EVs derived from amniotic fluid stem cell lines (HAFSC-EVs). Our results suggest that HAFSC-EVs are preferentially taken up by conventional dendritic cell type 2 (cDC2) through CD29 receptor-mediated internalization, resulting in a tolerogenic DC phenotype characterized by reduced expression and production of pro-inflammatory mediators. Furthermore, treatment of cDC2 cells with HAFSC-EVs in coculture systems resulted in a higher proportion of T cells expressing the regulatory T cell marker Foxp3 compared to vehicle-treated control cells. Moreover, transfer of HAFSC-EV-treated cDC2s into an EAE mouse model resulted in the suppression of autoimmune responses and clinical improvement. These results suggest that HAFSC-EVs may serve as a promising tool for reprogramming inflammatory cDC2s towards a tolerogenic phenotype and for controlling autoimmune responses in the central nervous system, representing a potential platform for the study of the effects of EVs in DC subsets.

Amelioration of experimental autoimmune encephalomyelitis by gemfibrozil in mice via PPARß/δ: implications for multiple sclerosis.

It is important to describe effective and non-toxic therapies for multiple sclerosis (MS), an autoimmune demyelinating disease. Experimental autoimmune encephalomyelitis (EAE) is an immune-mediated inflammatory disease that serves as a model for MS. Earlier we and others have shown that, gemfibrozil, a lipid-lowering drug, exhibits therapeutic efficacy in EAE. However, the underlying mechanism was poorly understood. Although gemfibrozil is a known ligand of peroxisome proliferator-activated receptor α (PPARα), here, we established that oral administration of gemfibrozil preserved the integrity of blood-brain barrier (BBB) and blood-spinal cord barrier (BSB), decreased the infiltration of mononuclear cells into the CNS and inhibited the disease process of EAE in both wild type and PPARα-/- mice. On the other hand, oral gemfibrozil was found ineffective in maintaining the integrity of BBB/BSB, suppressing inflammatory infiltration and reducing the disease process of EAE in mice lacking PPARß (formerly PPARδ), indicating an important role of PPARß/δ, but not PPARα, in gemfibrozil-mediated preservation of BBB/BSB and protection of EAE. Regulatory T cells (Tregs) play a critical role in the disease process of EAE/MS and we also demonstrated that oral gemfibrozil protected Tregs in WT and PPARα-/- EAE mice, but not PPARß-/- EAE mice. Taken together, our findings suggest that gemfibrozil, a known ligand of PPARα, preserves the integrity of BBB/BSB, enriches Tregs, and inhibits the disease process of EAE via PPARß, but not PPARα.

Intraperitoneal injection of mesenchymal stem cells-conditioned media (MSCS-CM) treated monocyte can potentially alleviate motor defects in experimental autoimmune encephalomyelitis female mice; An original experimental study.

INTRODUCTION: Multiple sclerosis (MS), as a destructive pathology of myelin in central nervous system (CNS), causes physical and mental complications. Experimental autoimmune encephalomyelitis (EAE) is laboratory model of MS widely used for CNS-associated inflammatory researches. Cell therapy using macrophage M2 (MPM2) is a cell type with anti-inflammatory characteristics for all inflammatory-based neuropathies. This experimental study investigated the probable therapeutic anti-inflammatory effects of intraperitoneal (IP) injection of MPM2 on alleviation of motor defect in EAE-affected animals. MATERIALS AND METHODS: 24 C57/BL6 female mice were divided into four groups of EAE, EAE + Dexa, EAE + PBS, and EAE + MP2. EAE was induced through deep cervical injection of spinal homogenate of guinea pigs. MPM2 cells were harvested from bone marrow and injected (106cells/ml) in three days of 10, 13 and 16 post-immunizations (p.i). Clinical score (CS), anti-inflammatory cytokines (IL-4, IL-10), pro-inflammatory gene expression (TNF-α, IL-1ß) and histopathological investigations (HE, Nissl and Luxol Fast Blue) were considered. Data were analyzed using SPSS software (v.19) and p < 0.05 was considered significant level. RESULTS: During EAE induction, the mean animal weight was decreased (p < 0.05); besides, following MPM2 injection, the weight gain was applied (p < 0.05) in EAE + MPM2 groups than control. Increased (p < 0.05) levels of CS was found during EAE induction in days 17-28 in EAE animals; besides, CS was decreased (p < 0.05) in EAE + MPM2 group than EAE animals. Also, in days 25-28 of experiment, the CS was decreased (p < 0.05) in EAE + MPM2 than EAE + Dexa. Histopathological assessments revealed low density of cell nuclei in corpus callosum, microscopically. LFB staining also showed considerable decrease in white matter density of corpus callosum in EAE group. Acceleration of white matter density was found in EAE + MPM2 group following cell therapy procedure. Genes expression of TNF-α, IL-1ß along with IL-4 and IL-10 were decreased (p < 0.05) in EAE + MPM2 group. CONCLUSION: IP injection of MPM2 to EAE-affected female mice can potentially reduce the CNS inflammation, neuronal death and myelin destruction. MPM2 cell therapy can improve animal motor defects.

Follicular CD8+ T cells promote immunoglobulin production and demyelination in multiple sclerosis and a murine model.

Emerging evidence underscores the importance of CD8+ T cells in the pathogenesis of multiple sclerosis (MS), but the precise mechanisms remain ambiguous. This study intends to elucidate the involvement of a novel subset of follicular CD8+ T cells (CD8+CXCR5+ T) in MS and an experimental autoimmune encephalomyelitis (EAE) murine model. The expansion of CD8+CXCR5+ T cells was observed in both MS patients and EAE mice during the acute phase. In relapsing MS patients, higher frequencies of circulating CD8+CXCR5+ T cells were positively correlated with new gadolinium-enhancement lesions in the central nervous system (CNS). In EAE mice, frequencies of CD8+CXCR5+ T cells were also positively correlated with clinical scores. These cells were found to infiltrate into ectopic lymphoid-like structures in the spinal cords during the peak of the disease. Furthermore, CD8+CXCR5+ T cells, exhibiting high expression levels of ICOS, CD40L, IL-21, and IL-6, were shown to facilitate B cell activation and differentiation through a synergistic interaction between CD40L and IL-21. Transferring CD8+CXCR5+ T cells into naïve mice confirmed their ability to enhance the production of anti-MOG35-55 antibodies and contribute to the disease progression. Consequently, CD8+CXCR5+ T cells may play a role in CNS demyelination through heightening humoral immune responses.

Differences in the characteristics and functions of brain and spinal cord regulatory T cells.

T cells play an important role in the acquired immune response, with regulatory T cells (Tregs) serving as key players in immune tolerance. Tregs are found in nonlymphoid and damaged tissues and are referred to as "tissue Tregs". They have tissue-specific characteristics and contribute to immunomodulation, homeostasis, and tissue repair through interactions with tissue cells. However, important determinants of Treg tissue specificity, such as antigen specificity, tissue environment, and pathology, remain unclear. In this study, we analyzed Tregs in the central nervous system of mice with ischemic stroke and experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. The gene expression pattern of brain Tregs in the EAE model was more similar to that of ischemic stroke Tregs in the brain than to that of spinal cord Tregs. In addition, most T-cell receptors (TCRs) with high clonality were present in both the brain and spinal cord. Furthermore, Gata3+ and Rorc+ Tregs expressed TCRs recognizing MOG in the spinal cord, suggesting a tissue environment conducive to Rorc expression. Tissue-specific chemokine/chemokine receptor interactions in the spinal cord and brain influenced Treg localization. Finally, spinal cord- or brain-derived Tregs had greater anti-inflammatory capacities in EAE mice, respectively. Taken together, these findings suggest that the tissue environment, rather than pathogenesis or antigen specificity, is the primary determinant of the tissue-specific properties of Tregs. These findings may contribute to the development of novel therapies to suppress inflammation through tissue-specific Treg regulation.

Hederagenol improves multiple sclerosis by modulating Th17 cell differentiation.

Multiple sclerosis (MS) is a common autoimmune illness that is difficult to treat. The upregulation of Th17 cells is critical in the pathological process of MS. Hederagenol (Hed) has been shown to lower IL-17 levels, although its role in MS pathophysiology is uncertain. In this study, we explore whether Hed could ameliorate MS by modulating Th17 cell differentiation, with the goal of identifying new treatment targets for MS. The experimental autoimmune encephalomyelitis (EAE) mouse model was conducted and Hed was intraperitoneally injected into mice. The weight was recorded and the clinical symptom grade was assessed. Hematoxylin-eosin staining was carried out to determine the extent of inflammation in the spinal cord and liver. The luxol Fast Blue staining was performed to detect the pathological changes in the myelin sheath. Nerve damage was detected using NeuN immunofluorescence staining and terminal deoxynucleotidyl transferase dUTP nick-end labeling staining. Immunohistology approaches were used to study alterations in immune cells in the spinal cord. The proportions of T cell subsets in the spleens were analyzed by flow cytometry. RORγt levels were measured using quantitative real-time PCR or Western blot. The activity of the RORγt promoter was analyzed by Chromatin immunoprecipitation. Hed administration reduced the clinical symptom grade of EAE mice, as well as the inflammatory infiltration, demyelination, and cell disorder of the spinal cord, while having no discernible effect on the mouse weight. In addition, Hed treatment significantly reduced the number of T cells, particularly Th17 cells in the spinal cord and spleen-isolated CD4+ T cells. Hed lowered the RORγt levels in spleens and CD4+ T cells and overexpression of RORγt reversed the inhibitory effect of Hed on Th17 differentiation. Hed decreased nerve injury by modulating Th17 differentiation through the RORγt promoter. Hed regulates Th17 differentiation by reducing RORγt promoter activity, which reduces nerve injury and alleviates EAE.

CD22 blockade aggravates EAE and its role in microglia polarization.

AIMS: Multiple sclerosis (MS) is a neuroinflammatory demyelinating disease. Microglia are reportedly involved in the pathogenesis of MS. However, the key molecules that control the inflammatory activity of microglia in MS have not been identified. METHODS: Experimental autoimmune encephalomyelitis (EAE) mice were randomized into CD22 blockade and control groups. The expression levels of microglial CD22 were measured by flow cytometry, qRT-PCR, and immunofluorescence. The effects of CD22 blockade were examined via in vitro and in vivo studies. RESULTS: We detected increased expression of microglial CD22 in EAE mice. In addition, an in vitro study revealed that lipopolysaccharide upregulated the expression of CD22 in microglia and that CD22 blockade modulated microglial polarization. Moreover, an in vivo study demonstrated that CD22 blockade aggravated EAE in mice and promoted microglial M1 polarization. CONCLUSION: Collectively, our study indicates that CD22 may be protective against EAE and may play a critical role in the maintenance of immune homeostasis in EAE mice.