Seeking balance: Potentiation and inhibition of multiple sclerosis autoimmune responses by IL-6 and IL-10

Short and Medium Chain Fatty Acids in a Cohort of Naïve Multiple Sclerosis Patients: Pre- and Post-Interferon Beta Treatment Assessment

Introduction

Alterations in intestinal permeability and microbiota dysregulation have been linked to the development of multiple sclerosis (MS). Short-chain fatty acids (SCFA) and medium-chain fatty acids (MCFA) are products of gut bacteria fermentation which are involved in immune regulation processes. In MS, SCFA have important immunomodulatory properties both in the periphery and the central compartment. Interferon β (IFNβ) was the first disease-modifying therapy approved for the treatment of MS and its effects on the gut microbiota are not fully elucidated.

Patients and Methods

We performed a prospective observational study aimed to assess peripheral levels of SCFA and MCFA in 23 newly diagnosed, treatment-naïve MS patients (nMS) before and after one year of IFNβ treatment and 23 healthy controls (HC). We investigated their associations with inflammation, interleukin-10 (IL-10), and blood-brain barrier permeability, matrix metalloproteinase 9 (MMP9).

Results

No significant differences in SCFA/MCFA levels were observed between baseline and after IFNβ treatment. Caproic acid levels were significantly higher in nMS compared to HC (1.64 vs 1.27 µM, p=0.005). The butyric acid/caproic acid ratio was higher in HC compared to nMS (5.47 vs 2.55, p=0.005). Correlation analysis revealed associations between SCFA/MCFA levels and inflammatory biomarkers.

Conclusion

nMS have a higher gut-inflammatory activity as seen by the caproic acid ratio as opposed to HC. In this cohort, IFNβ does not appear to modify the peripheral SCFA/MCFA levels after one year of treatment. The quantifications of peripheral SCFA/MCFA may prove to be a useful biomarker for gut-brain axis disruption in MS patients.

Immunologic Effects of a Novel Bovine Lactoferrin-Derived Peptide on the Gut and Clinical Perspectives

Bovine lactoferrin is a natural iron-binding glycoprotein known for its antimicrobial, antiviral, antitumor, anti-inflammatory, and immunomodulatory properties. In this study, we artificially recombined a fragment of bovine lactoferrin with immunomodulatory and antimicrobial properties to create a novel peptide named LF-MQL. The primary objective was to investigate the effects of LF-MQL on the intestinal tract and immune cells in animals. First, we assessed the in vitro activation effects of LF-MQL on mouse peritoneal macrophages. The results indicated that LF-MQL enhanced the macrophage phagocytic activity and increased IL-1β mRNA expression without significantly affecting IL-6 mRNA levels. Next, we examined the effects of LF-MQL on mucosal immunity by administering LF-MQL orally at doses of 300 mg/kg, 30 mg/kg, and 3 mg/kg to mice. The results demonstrated that different doses of LF-MQL modulated IL-6 and IL-10 mRNA levels in the small intestine. Low doses enhanced the intestinal immune response, while higher doses reduced the inflammatory response. In conclusion, LF-MQL exerts immunomodulatory effects rather than simply boosting immune activity in animal models.

IL-6 Inhibition as a Therapeutic Target in Aged Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) onset at an advanced age is associated with a higher risk of developing progressive forms and a greater accumulation of disability for which there are currently no effective disease-modifying treatments. Immunosenescence is associated with the production of the senescence-associated secretory phenotype (SASP), with IL-6 being one of the most prominent cytokines. IL-6 is a determinant for the development of autoimmunity and neuroinflammation and is involved in the pathogenesis of MS. Herein, we aimed to preclinically test the therapeutic inhibition of IL-6 signaling in experimental autoimmune encephalomyelitis (EAE) as a potential age-specific treatment for elderly MS patients. Young and aged mice were immunized with myelin oligodendrocyte protein (MOG)35-55 and examined daily for neurological signs. Mice were randomized and treated with anti-IL-6 antibody. Inflammatory infiltration was evaluated in the spinal cord and the peripheral immune response was studied. The blockade of IL-6 signaling did not improve the clinical course of EAE in an aging context. However, IL-6 inhibition was associated with an increase in the peripheral immunosuppressive response as follows: a higher frequency of CD4 T cells producing IL-10, and increased frequency of inhibitory immune check points PD-1 and Tim-3 on CD4+ T cells and Lag-3 and Tim-3 on CD8+ T cells. Our results open the window to further studies aimed to adjust the anti-IL-6 treatment conditions to tailor an effective age-specific therapy for elderly MS patients.

Immune System Dysregulation in the Progression of Multiple Sclerosis: Molecular Insights and Therapeutic Implications

Multiple sclerosis (MS), a prevalent neurological disorder, predominantly affects young adults and is characterized by chronic autoimmune activity. The study explores the immune system dysregulation in MS, highlighting the crucial roles of immune and non-neuronal cells in the disease's progression. This review examines the dual role of cytokines, with some like IL-6, TNF-α, and interferon-gamma (IFN-γ) promoting inflammation and CNS tissue injury, and others such as IL-4, IL-10, IL-37, and TGF-β fostering remyelination and protecting against MS. Elevated chemokine levels in the cerebrospinal fluid (CSF), including CCL2, CCL5, CXCL10, CXCL13, and fractalkine, are analyzed for their role in facilitating immune cell migration across the blood-brain barrier (BBB), worsening inflammation and neurodegeneration. The study also delves into the impact of auto-antibodies targeting myelin components like MOG and AQP4, which activate complement cascades leading to further myelin destruction. The article discusses how compromised BBB integrity allows immune cells and inflammatory mediators to infiltrate the CNS, intensifying MS symptoms. It also examines the involvement of astrocytes, microglia, and oligodendrocytes in the disease's progression. Additionally, the effectiveness of immunomodulatory drugs such as IFN-β and CD20-targeting monoclonal antibodies (e.g., rituximab) in modulating immune responses is reviewed, highlighting their potential to reduce relapse rates and delaying MS progression. These insights emphasize the importance of immune system dysfunction in MS development and progression, guiding the development of new therapeutic strategies. The study underscores recent advancements in understanding MS's molecular pathways, opening avenues for more targeted and effective treatments.

Osteoporosis in a Woman With Multiple Sclerosis: A Case Report

Multiple sclerosis is a systemic autoimmune disease characterized by demyelination of nerves within the central nervous system. The prevalence of the disease is increasing. Cases with varying severity are observed. Multiple sclerosis is accompanied by severe osteoporosis, which may lead to fractures and may compromise patient mobility. The aim was to describe the case of a patient with multiple sclerosis who developed severe osteoporosis with multiple fractures. A female patient was diagnosed with multiple sclerosis at the age of 52. At the age of 63, she presented with a fracture of the right femur. She was treated surgically with total arthroplasty. Osteoporosis was diagnosed and treatment was initiated. Seven months later the patient fell upon the fractured leg and developed a periprosthetic femoral fracture. She was treated with open reduction and internal fixation. Thereafter, bisphosphonates were administered. The patient can now walk with difficulty, independently, without orthotic help. In this case report, we have presented a case of multiple sclerosis who developed severe osteoporosis with multiple fractures.

The Role of Selected Interleukins in the Development and Progression of Multiple Sclerosis-A Systematic Review

Multiple sclerosis is a disabling inflammatory disorder of the central nervous system characterized by demyelination and neurodegeneration. Given that multiple sclerosis remains an incurable disease, the management of MS predominantly focuses on reducing relapses and decelerating the progression of both physical and cognitive decline. The continuous autoimmune process modulated by cytokines seems to be a vital contributing factor to the development and relapse of multiple sclerosis. This review sought to summarize the role of selected interleukins in the pathogenesis and advancement of MS. Patients with MS in the active disease phase seem to exhibit an increased serum level of IL-2, IL-4, IL-6, IL-13, IL-17, IL-21, IL-22 and IL-33 compared to healthy controls and patients in remission, while IL-10 appears to have a beneficial impact in preventing the progression of the disease. Despite being usually associated with proinflammatory activity, several studies have additionally recognized a neuroprotective role of IL-13, IL-22 and IL-33. Moreover, selected gene polymorphisms of IL-2R, IL-4, IL-6, IL-13 and IL-22 were identified as a possible risk factor related to MS development. Treatment strategies of multiple sclerosis that either target or utilize these cytokines seem rather promising, but more comprehensive research is necessary to gain a clearer understanding of how these cytokines precisely affect MS development and progression.

Vitamin D Supplementation: Effect on Cytokine Profile in Multiple Sclerosis

Vitamin D is known for its role in modulating calcium and phosphate homeostasis and is implicated both in bone mineralization and immune system regulation. The immune-modulatory role of vitamin D and its impact on multiple sclerosis (MS) courses are still debated. The aim of this review was to check the effect of vitamin D supplementation on cytokine profile regulation in people with MS. A significant increase in serum concentrations of interleukin (IL)-10 and Transforming growth factor (TGF)-β1 after vitamin D supplementation was demonstrated in most studies, with some of them reporting a reduction in disability scores after vitamin D supplementation and an inverse correlation between IL-10 levels and disability. The effect of vitamin D on the serum levels of IL-17 and IL-6 was controversial; different results across studies could be explained by a variability in the treatment duration, route, and frequency of administration, as well as the dosage of vitamin D supplementation, responses to vitamin D treatment and the serum levels reached with supplementation, including the methods used for cytokine analysis and the different cell types investigated, the MS phenotype, the disease phase (active vs. non-active) and duration, and concomitant treatment with disease-modifying therapies. Nevertheless, the significant increase in the serum concentrations of IL-10 and TGF-β1, demonstrated in most studies, suggests an anti-inflammatory effect of vitamin D supplementation.

The brain cytokine orchestra in multiple sclerosis: from neuroinflammation to synaptopathology

The central nervous system (CNS) is finely protected by the blood-brain barrier (BBB). Immune soluble factors such as cytokines (CKs) are normally produced in the CNS, contributing to physiological immunosurveillance and homeostatic synaptic scaling. CKs are peptide, pleiotropic molecules involved in a broad range of cellular functions, with a pivotal role in resolving the inflammation and promoting tissue healing. However, pro-inflammatory CKs can exert a detrimental effect in pathological conditions, spreading the damage. In the inflamed CNS, CKs recruit immune cells, stimulate the local production of other inflammatory mediators, and promote synaptic dysfunction. Our understanding of neuroinflammation in humans owes much to the study of multiple sclerosis (MS), the most common autoimmune and demyelinating disease, in which autoreactive T cells migrate from the periphery to the CNS after the encounter with a still unknown antigen. CNS-infiltrating T cells produce pro-inflammatory CKs that aggravate local demyelination and neurodegeneration. This review aims to recapitulate the state of the art about CKs role in the healthy and inflamed CNS, with focus on recent advances bridging the study of adaptive immune system and neurophysiology.

Intruders or protectors - the multifaceted role of B cells in CNS disorders

B lymphocytes are immune cells studied predominantly in the context of peripheral humoral immune responses against pathogens. Evidence has been accumulating in recent years on the diversity of immunomodulatory functions that B cells undertake, with particular relevance for pathologies of the central nervous system (CNS). This review summarizes current knowledge on B cell populations, localization, infiltration mechanisms, and function in the CNS and associated tissues. Acute and chronic neurodegenerative pathologies are examined in order to explore the complex, and sometimes conflicting, effects that B cells can have in each context, with implications for disease progression and treatment outcomes. Additional factors such as aging modulate the proportions and function of B cell subpopulations over time and are also discussed in the context of neuroinflammatory response and disease susceptibility. A better understanding of the multifactorial role of B cell populations in the CNS may ultimately lead to innovative therapeutic strategies for a variety of neurological conditions.

Game of microbes: the battle within - gut microbiota and multiple sclerosis

Multiple sclerosis (MS) is a chronic and progressive autoimmune disease of the central nervous system (CNS), with both genetic and environmental factors contributing to the pathobiology of the disease. While human leukocyte antigen (HLA) genes have emerged as the strongest genetic factor, consensus on environmental risk factors are lacking. Recently, trillions of microbes residing in our gut (microbiome) have emerged as a potential environmental factor linked with the pathobiology of MS as PwMS show gut microbial dysbiosis (altered gut microbiome). Thus, there has been a strong emphasis on understanding the factors (host and environmental) regulating the composition of the gut microbiota and the mechanism(s) through which gut microbes contribute to MS disease, especially through immune system modulation. A better understanding of these interactions will help harness the enormous potential of the gut microbiota as a therapeutic approach to treating MS.

Identification of the immune-related biomarkers in Behcet's disease by plasma proteomic analysis

BACKGROUND

This study aimed to investigate the expression profile of immune response-related proteins of Behcet's disease (BD) patients and identify potential biomarkers for this disease.

METHODS

Plasma was collected from BD patients and healthy controls (HC). Immune response-related proteins were measured using the Olink Immune Response Panel. Differentially expressed proteins (DEPs) were used to construct prediction models via five machine learning algorithms: naive Bayes, support vector machine, extreme gradient boosting, random forest, and neural network. The prediction performance of the five models was assessed using the area under the curve (AUC) value, recall (sensitivity), specificity, precision, accuracy, F1 score, and residual distribution. Subtype analysis of BD was performed using the consensus clustering method.

RESULTS

Proteomics results showed 43 DEPs between BD patients and HC (P < 0.05). These DEPs were mainly involved in the Toll-like receptor 9 and NF-κB signaling pathways. Five models were constructed using DEPs [interleukin 10 (IL10), Fc receptor like 3 (FCRL3), Mannan-binding lectin serine peptidase 1 (MASP1), NF2, moesin-ezrin-radixin like (MERLIN) tumor suppressor (NF2), FAM3 metabolism regulating signaling molecule B (FAM3B), and O-6-methylguanine-DNA methyltransferase (MGMT)]. Among these models, the neural network model showed the best performance (AUC = 0.856, recall: 0.692, specificity: 0.857, precision: 0.900, accuracy: 0.750, F1 score: 0.783). BD patients were divided into two subtypes according to the consensus clustering method: one with high disease activity in association with higher expression of tripartite motif-containing 5 (TRIM5), SH2 domain-containing 1A (SH2D1A), phosphoinositide-3-kinase adaptor protein 1 (PIK3AP1), hematopoietic cell-specific Lyn substrate 1 (HCLS1), and DNA fragmentation factor subunit alpha (DFFA) and the other with low disease activity in association with higher expression of C-C motif chemokine ligand 11 (CCL11).

CONCLUSIONS

Our study not only revealed a distinctive immune response-related protein profile for BD but also showed that IL10, FCRL3, MASP1, NF2, FAM3B, and MGMT could serve as potential immune biomarkers for this disease. Additionally, a novel molecular disease classification model was constructed to identify subsets of BD.

IL-10 modified mRNA monotherapy prolongs survival after composite facial allografting through the induction of mixed chimerism

Vascularized composite allotransplantation has great potential in face transplantation by supporting functional restoration following tissue grafting. However, the need for lifelong administration of immunosuppressive drugs still limits its wide use. Modified mRNA (modRNA) technology provides an efficient and safe method to directly produce protein in vivo. Nevertheless, the use of IL-10 modRNA-based protein replacement, which exhibits anti-inflammatory properties, has not been shown to prolong composite facial allograft survival. In this study, IL-10 modRNA was demonstrated to produce functional IL-10 protein in vitro, which inhibited pro-inflammatory cytokines and in vivo formation of an anti-inflammatory environments. We found that without any immunosuppression, C57BL/6J mice with fully major histocompatibility complex (MHC)-mismatched facial allografts and local injection of IL-10 modRNA had a significantly prolonged survival rate. Decreased lymphocyte infiltration and pro-inflammatory T helper 1 subsets and increased anti-inflammatory regulatory T cells (Tregs) were seen in IL-10 modRNA-treated mice. Moreover, IL-10 modRNA induced multilineage chimerism, especially the development of donor Treg chimerism, which protected allografts from destruction because of recipient alloimmunity. These results support the use of monotherapy based on immunomodulatory IL-10 cytokines encoded by modRNA, which inhibit acute rejection and prolong allograft survival through the induction of donor Treg chimerism.

The comparative analysis of selected interleukins and proinflammatory factors in CSF among de novo diagnosed patients with RRMS

OBJECTIVES

Cytokines play a key role in neuroinflammation, which is present in every subset of multiple sclerosis (MS). The aim of the study was to assess levels of selected interleukins and proinflammatory factors in cerebrospinal fluid (CSF) among patients diagnosed with relapsing-remitting multiple sclerosis (RRMS).

METHODS

One hundred eighteen patients diagnosed de novo with RRMS were enrolled in the study. We analysed the relationships between selected cytokines' levels depending on the age at diagnosis, time from the first symptoms to diagnosis and presence of MRI lesions.

RESULTS

Among the study group the levels of IL-5 and IL-13 increased with the age at the diagnosis of MS. The concentration of IL-10 was lower in group of patients over the age of 35. The levels of IFN-γ, TNF-α, IL-5, IL-10 and IL-15 increased with the longer time from the first symptoms to diagnosis. Positive correlations were found between the levels of IL-2 and IL-12, IL-17, IL-4, IL-1RA as well as IL-1 and IL-4, IL-17. The concentration of IL-5 correlated positively with IL-4, IL-9 and IL-13. The level of IL-10 increased with IL-6 and IL-9 concentrations. A negative correlation was found for IL-10 and IL-4. In turn, between IL-13 and both IL-5 and IL-9, the relationship was positive. The level of IL-2 was significantly higher among patients without gadolinium-enhanced (Gd(+)) MRI lesions.

CONCLUSIONS

The results of the study provide new insight into the role of selected molecules in the development of inflammation in MS. It might be crucial in planning the most adequate immunomodulatory therapy.

The contribution of gut-brain axis to development of neurological symptoms in COVID-19 recovered patients: A hypothesis and review of literature

The gut microbiota undergoes significant alterations in response to viral infections, particularly the novel SARS-CoV-2. As impaired gut microbiota can trigger numerous neurological disorders, we suggest that the long-term neurological symptoms of COVID-19 may be related to intestinal microbiota disorders in these patients. Thus, we have gathered available information on how the virus can affect the microbiota of gastrointestinal systems, both in the acute and the recovery phase of the disease, and described several mechanisms through which this gut dysbiosis can lead to long-term neurological disorders, such as Guillain-Barre syndrome, chronic fatigue, psychiatric disorders such as depression and anxiety, and even neurodegenerative diseases such as Alzheimer's and Parkinson's disease. These mechanisms may be mediated by inflammatory cytokines, as well as certain chemicals such as gastrointestinal hormones (e.g., CCK), neurotransmitters (e.g., 5-HT), etc. (e.g., short-chain fatty acids), and the autonomic nervous system. In addition to the direct influences of the virus, repurposed medications used for COVID-19 patients can also play a role in gut dysbiosis. In conclusion, although there are many dark spots in our current knowledge of the mechanism of COVID-19-related gut-brain axis disturbance, based on available evidence, we can hypothesize that these two phenomena are more than just a coincidence and highly recommend large-scale epidemiologic studies in the future.

The level pro-inflammatory and anti-inflammatory biomarkers in patients with chronic mechanical low back pain under pulse radiofrequency therapy

Low back pain is a frequent and recurrent condition, often with a non-specific cause. Conventional treatment methods are generally insufficient in the treatment of chronic low back pain. The aim of the study was to estimate the level of IFN, IL-1, IL-6 (proinflammatory), IL-10, IL-4 (anti-inflammatory) and VEGF proteins in the serum of patients with chronic mechanical low back pain under Pulse radiofrequency (PRF) therapy. The study was carried out on 40 patients 20-60 years old, diagnosed with chronic low back pain for at least 4 months, primary complaint on lumbosacral low back pain, pain intensity VAS (visual analog scale) score of 5 and above, not responding well to conservative treatment (analgesic drugs, physiotherapy, etc.). Therapeutic Radiofrequency applications were carried out with an RF generator (RFG 3C Plus, Radionics). Blood samples were taken 1 day before interventional treatment (control), then 1 day (group1) and 15 days (group 2) after. The serum level of IFN, IL-1, IL-6, IL-10, IL-4 and VEGF l was analyzed with ELISA test. It was shown that as a result of PRF treatment the level of IL-1 was decreased while the levels of IL-4 and IL-6 were increased. It was concluded that the increase in serum levels of proinflammatory cytokines may be correlated with the severity of pain and that the increase in the level of anti-inflammatory cytokines reduces pain by reducing inflammation. Keywords: chronic low back pain, cytokines, radiofrequency therapy

Identification of Potential Biomarkers in the Peripheral Blood Mononuclear Cells of Relapsing-Remitting Multiple Sclerosis Patients

Multiple sclerosis (MS) is described as an immune disorder with inflammation and neurodegeneration. Relapsing-remitting MS (RRMS) is one of the most common types of MS. The diagnostic manner for this disorder typically includes the usage of magnetic resonance imaging (MRI); however, this is not always a very precise diagnostic method. Identification of molecular biomarkers in RRMS body fluids samples compared to healthy subjects can be useful to indicate the normal and pathogenic biological processes or pharmacological responses to drug interaction. In this regard, this study evaluated different miRNAs in isolated peripheral blood mononuclear cells (PBMCs) of RRMS compared to controls and their correlations with altered T regulatory type 1 (Tr1) cells, osteopontin (OPN), and interleukin 10 (IL-10) levels. The frequency of Tr1 cells was measured using flow cytometry. Also, the expressions of different miRNAs were evaluated via quantitative real-time polymerase chain reaction (RT-qPCR) and plasma levels of IL-10 and OPN were tested by enzyme-linked immunosorbent assay (ELISA). The obtained results showed the Tr1 cells' frequency, Let7c-5p, and miR-299-5p levels decreased in RRMS patients to about 59%, 0.69%, and 20% of HCs, respectively, (P < 0.05). The miR-106a-5p levels increased about 7.5-fold in RRMS patients in comparison to HCs (P < 0.05). Moreover, the results showed that there was an increased negative association between Tr1 frequency and plasma-OPN levels in RRMS patients in comparison to HCs and also, we found a moderate positive correlation between plasma-IL-10 and miR-299-5p expression of RRMS patients. Overall, it may be possible to use these biomarkers to improve the diagnostic process. These biomarkers may also be considered for clinical and therapeutic studies in the future.

IL-10 revisited in systemic lupus erythematosus

IL-10 is a cytokine with pleiotropic functions, particularly known for its suppressive effects on various immune cells. Consequently, it can limit the pathogenesis of inflammatory diseases, such as multiple sclerosis (MS), inflammatory bowel disease, Crohn’s disease, and Epidermolysis bullosa acquisita, among others. Recent evidence however indicates that it plays dual roles in Systemic lupus Erythematosus (SLE) where it may inhibit pro-inflammatory effector functions but seems to be also a main driver of the extrafollicular antibody response, outside of germinal centers (GC). In line, IL-10 promotes direct differentiation of activated B cells into plasma cells rather than stimulating a GC response. IL-10 is produced by B cells, myeloid cells, and certain T cell subsets, including extrafollicular T helper cells, which are phenotypically distinct from follicular helper T cells that are relevant for GC formation. In SLE patients and murine lupus models extrafollicular T helper cells have been reported to support ongoing extrafollicular formation of autoreactive plasma cells, despite the presence of GCs. Here, we discuss the role of IL-10 as driver of B cell responses, its impact on B cell proliferation, class switch, and plasma cells.

Role of the gut microbiome in multiple sclerosis: From etiology to therapeutics

Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS that affects around one million people in the United States. Predisposition or protection from this disease is linked with both genetic and environmental factors. In recent years, gut microbiome has emerged as an important environmental factor in the pathobiology of MS. The gut microbiome supports various physiologic functions, including the development and maintenance of the host immune system, the perturbation of which is known as dysbiosis and has been linked with multiple diseases including MS. We and others have shown that people with MS (PwMS) have gut dysbiosis that is characterized by specific gut bacteria being enriched or depleted. Consequently, there is an emphasis on determining the mechanism(s) through which gut bacteria and/or their metabolites alter the course of MS through their ability to provide protection, predispose individuals, or promote disease progression. Improving our understanding of these mechanisms will allow us to harness the enormous potential of the gut microbiome as a diagnostic and/or therapeutic agent. In this chapter, we will discuss current advances in microbiome research in the context of MS, including a review of specific bacteria that are currently linked with this disease, potential mechanisms of disease pathogenesis, and the utility of microbiome-based therapy for PwMS.

Modifications of IL-6 by Hypochlorous Acids: Effects on Receptor Binding

Interleukin-6 (IL-6) has been implicated in the pathogenesis of inflammatory events including those seen with COVID-19 patients. Positive clinical responses to monoclonal antibodies directed against IL-6 receptors (IL-6Rs) suggest that interference with IL-6-dependent activation of pro-inflammatory pathways offers a useful approach to therapy. We exposed IL-6 to hypochlorous acid (HOCl) in vitro at concentrations reported to develop in vivo. After HOCl treatment, binding of IL-6 to IL-6R was reduced in a dose-dependent manner using a bioassay with human cells engineered to provide a luminescence response to signal transduction upon receptor activation. Similar results followed the exposure of IL-6 to N-chlorotaurine (NCT) and hypobromous acid (HOBr), two other reactive species produced in vivo. SDS-PAGE analysis of HOCl-treated IL-6 showed little to no fragmentation or aggregation up to 1.75 mM HOCl, suggesting that the modifications induced at concentrations below 1.75 mM took place on the intact protein. Mass spectrometry of trypsin-digested fragments identified oxidative changes to two amino acid residues, methionine 161 and tryptophan 157, both of which have been implicated in receptor binding of the cytokine. Our findings suggest that exogenous HOCl and NCT might bring about beneficial effects in the treatment of COVID-19. Further studies on how HOCl and HOBr and their halogenated amine derivatives interact with IL-6 and related cytokines in vivo may open up alternative therapeutic interventions with these compounds in COVID-19 and other hyperinflammatory diseases.

Th cytokine profile in childhood-onset systemic lupus erythematosus

Background

Childhood-onset systemic lupus erythematosus (cSLE) is a kind of chronic inflammatory disease characterized by a highly abnormal immune system. This study aimed to detect the serum levels of Th (T helper) cytokines (IL-2, IL-4, IL-5, IL-6, IL-9, IL-10, IL-13, IL-17A, IL-17F, IL-21, IL-22, IFN-γ and TNF-α) in cSLE and healthy controls, and then to elucidate their association with clinical manifestations, disease activity and laboratory parameters. In order to provide clues for early diagnosis and timely intervention treatment of cSLE patients.

Methods

A total of 33 children with cSLE and 30 healthy children were enrolled in this study. Children in the cSLE group were classified into the inactive or active cSLE group according to their SLE disease activity index 2000 (SLEDAI-2 K) score. Th cytokine profiles in the peripheral blood were detected and analysed.

Results

Levels of IL-2, IL-10 and IL-21 in the cSLE group were significantly higher than those in the healthy control group (P < 0.05, P < 0.01 and P < 0.01, respectively). Expression of IL-2, IL-10 and IL-21 in the active cSLE group was significantly higher than that in the healthy control group (P < 0.05, P < 0.01 and P < 0.05, respectively), but that of IL-22 expression was markedly lower in the active cSLE group than in the healthy control group (P < 0.001). IL-21 in the inactive SLE group was significantly higher than that in the healthy control group (P < 0.05), and levels of IL-2 and IL-10 in the active cSLE group were significantly higher than those in the inactive cSLE group (P < 0.01 and P < 0.05). In-depth analysis showed that after excluding age, gender and drug interference, the levels of IL-2 (P < 0.05), IL-6 (P < 0.05) and IL-10 (P < 0.05) were still positively correlated with SLEDAI-2 K scores. However, the levels of IL-6 (P < 0.05) and IFN- γ (P < 0.05) were still negatively correlated with CD4⁺/CD8⁺, and the concentration of IL-6 (P < 0.05) was still positively correlated with the occurrence of nephritis.

Conclusion

This study provides a theoretical basis for the discovery of effective methods to regulate imbalance in T lymphocyte subsets in cSLE, which may lead to new approaches for the diagnosis of cSLE.

Fitness Shifts the Balance of BDNF and IL-6 from Inflammation to Repair among People with Progressive Multiple Sclerosis

Physical sedentarism is linked to elevated levels of circulating cytokines, whereas exercise upregulates growth-promoting proteins such as brain-derived neurotrophic factor (BDNF). The shift towards a 'repair' phenotype could protect against neurodegeneration, especially in diseases such as multiple sclerosis (MS). We investigated whether having higher fitness or participating in an acute bout of maximal exercise would shift the balance of BDNF and interleukin-6 (IL-6) in serum samples of people with progressive MS (n = 14), compared to matched controls (n = 8). Participants performed a maximal graded exercise test on a recumbent stepper, and blood samples were collected at rest and after the test. We assessed walking speed, fatigue, and maximal oxygen consumption (V·O2max). People with MS achieved about 50% lower V·O2max (p = 0.003) than controls. At rest, there were no differences in BDNF between MS and controls; however, IL-6 was significantly higher in MS. Higher V·O2max was associated with a shift in BDNF/IL-6 ratio from inflammation to repair (R = 0.7, p = 0.001) when considering both groups together. In the MS group, greater ability to upregulate BDNF was associated with faster walking speed and lower vitality. We present evidence that higher fitness indicates a shift in the balance of blood biomarkers towards a repair phenotype in progressive MS.

Circ-AFF2/miR-650/CNP axis promotes proliferation, inflammatory response, migration, and invasion of rheumatoid arthritis synovial fibroblasts

BACKGROUND

Circular RNAs (circRNAs) are associated with rheumatoid arthritis (RA) development. The purpose of this study is to explore the function and mechanism of circRNA fragile mental retardation 2 (circ-AFF2) in the processes of rheumatoid arthritis fibroblast-like synoviocytes (RAFLSs).

METHODS

Circ-AFF2, microRNA (miR)-650, and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) levels were determined in synovial tissues of RA and RAFLSs by quantitative reverse transcription polymerase chain reaction or Western blotting. Cell proliferation, inflammatory response, apoptosis, caspase3 activity, migration, invasion, and epithelial-mesenchymal transition (EMT) were investigated using Cell Counting Kit-8 (CCK-8), enzyme-linked immunosorbent assay (ELISA), flow cytometry, Transwell, and Western blotting analyses. Dual-luciferase reporter, RNA immunoprecipitation (RIP), and pull-down assays were performed to assess the binding relationship.

RESULTS

Circ-AFF2 expression level was enhanced in synovial tissues of RA and RAFLSs. Circ-AFF2 overexpression facilitated cell proliferation, inflammatory response, migration, invasion, and EMT and repressed apoptosis in RAFLSs. Circ-AFF2 downregulation played an opposite role. Circ-AFF2 targeted miR-650, and miR-650 downregulation reversed the effect of circ-AFF2 interference on RAFLS processes. CNP was targeted by miR-650, and circ-AFF2 increased CNP expression by regulating miR-650. MiR-650 overexpression constrained cell proliferation, inflammatory response, migration, invasion, and EMT and contributed to apoptosis by decreasing CNP in RAFLSs.

CONCLUSION

Circ-AFF2 promoted proliferation, inflammatory response, migration, and invasion of RAFLSs by modulating the miR-650/CNP axis.

Identification of CD137-Expressing B Cells in Multiple Sclerosis Which Secrete IL-6 Upon Engagement by CD137 Ligand

The potent costimulatory effect of CD137 has been implicated in several murine autoimmune disease models. CD137 costimulates and polarizes antigen-specific T cells toward a potent Th1/Tc1 response, and is essential for the development of experimental autoimmune encephalomyelitis (EAE), a murine model of Multiple Sclerosis (MS). This study aimed to investigate a role of CD137 in MS. Immunohistochemical and immunofluorescence staining of MS brain tissues was used to identify expression of CD137. CD137⁺ cells were identified in MS brain samples, with active lesions having the highest frequency of CD137⁺ cells. CD137 expression was found on several leukocyte subsets, including T cells, B cells and endothelial cells. In particular, CD137⁺ B cells were found in meningeal infiltrates. In vitro experiments showed that CD137 engagement on activated B cells increased early TNF and persistent IL-6 secretion with increased cell proliferation. These CD137⁺ B cells could interact with CD137L-expressing cells, secrete pro-inflammatory cytokines and accumulate in the meningeal infiltrate. This study demonstrates CD137 expression by activated B cells, enhancement of the inflammatory activity of B cells upon CD137 engagement, and provides evidence for a pathogenic role of CD137⁺ B cells in MS.

The influence of glatiramer acetate on Th17-immune response in multiple sclerosis

Glatiramer acetate (GA) is approved for the treatment of multiple sclerosis (MS). However, the mechanism of action of GA in MS is still unclear. In particular, it is not known whether GA can modulate the pro-inflammatory Th17-type immune response in MS. We investigated the effects of original GA (Copaxone^®, Teva, Israel) and generic GA (Timexone^®, Biocad, Russia) on Th17- and Th1-type cytokine production in vitro in 25 patients with relapsing-remitting MS and 25 healthy subjects. Both original and generic GA at concentrations 50–200 μg/ml dose-dependently inhibited interleukin-17 and interferon-γ production by anti-CD3/anti-CD28-activated peripheral blood mononuclear cells from MS patients and healthy subjects. This effect of GA was reproduced using purified CD4⁺ T cells, suggesting that GA can directly modulate the functions of Th17 and Th1 cells. At high concentrations (100–200 μg/ml), GA also suppressed the production of Th17-differentiation cytokines (interleukin-1β and interleukin-6) by lipopolysaccharide (LPS)-activated dendritic cells (DCs). These GA/LPS-treated DCs induced lower interleukin-17 and interferon-γ production by autologous CD4⁺ T cells compared to LPS-treated DCs. These data suggest that GA can inhibit Th17-immune response and that this inhibitory effect is preferentially exercised by direct influence of GA on T cells. We also demonstrate a comparable ability of original and generic GA to modulate pro-inflammatory cytokine production.

Mendelian randomization study to evaluate the effects of interleukin-6 signaling on four neurodegenerative diseases

BACKGROUND

Multiple sclerosis (MS) is a complex neurological disease and chronic inflammatory disease. Until now, observational studies have reported positive association between serum interleukin-6 (IL-6) levels and MS risk. In order to develop effective therapies, we should establish the causal link between IL-6 signaling and MS. However, it is currently unknown whether IL-6 signaling is causally associated with the risk of MS.

METHODS

Here, we selected the increased soluble IL-6R (s-IL-6R) levels as the indirect markers for reduced IL-6 signaling, and performed a Mendelian randomization (MR) study using the rs2228145 variant as the instrumental variable to evaluate and quantify the effect of IL-6 signaling on the risk of MS. To be a comparison, we also evaluated the causal association of IL-6 signaling with the risk of other three neurodegenerative diseases including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS).

RESULTS

We found that the increased s-IL-6R levels (per 1 standard deviation) were significantly associated with decreased MS risk (OR = 0.96, 95% CI 0.94-0.98, P = 1.69E-04), but not associated with the risk of AD (OR = 1.01, 95% CI 0.92-1.11, P = 0.835), PD (OR = 0.94, 95% CI 0.84-1.05, P = 0.261), or ALS (OR = 1.00, 95% CI 0.92-1.10, P = 0.9411).

CONCLUSION

Our findings have the similar directional effects to an existing humanized anti-IL-6R monoclonal antibody Tocilizumab which could bind to the IL-6 binding site of human IL-6R and competitively inhibit IL-6 signaling. Hence, we provided genetic evidence that inhibiting the IL-6 signaling such as tocilizumab treatment might represent a novel therapy for MS.

Towards new TB vaccines

Mycobacterium tuberculosis remains the leading cause of death attributed to a single infectious organism. Bacillus Calmette-Guerin (BCG), the standard vaccine against M. tuberculosis, is thought to prevent only 5% of all vaccine-preventable deaths due to tuberculosis, thus an alternative vaccine is required. One of the principal barriers to vaccine development against M. tuberculosis is the complexity of the immune response to infection, with uncertainty as to what constitutes an immunological correlate of protection. In this paper, we seek to give an overview of the immunology of M. tuberculosis infection, and by doing so, investigate possible targets of vaccine development. This encompasses the innate, adaptive, mucosal and humoral immune systems. Though MVA85A did not improve protection compared with BCG alone in a large-scale clinical trial, the correlates of protection this has revealed, in addition to promising results from candidate such as VPM1002, M72/ASO1E and H56:IC31 point to a brighter future in the field of TB vaccine development.

FCRL3 promotes IL-10 expression in B cells through the SHP-1 and p38 MAPK signaling pathways

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system that is caused by the interaction of genetic and environmental factors. Current studies have shown that Fc-receptor like-3 (FCRL3) is closely related to MS, but the specific role of FCRL3 in MS has not yet been clarified. This study further found that FCRL3 and interleukin 10 (IL-10) expression was downregulated in MS patients, but the expression of these proteins was higher in the remission phase than that in the acute phase. The C allele of rs7528684 was associated with MS, and the CC genotype could lead to the upregulation of FCRL3 expression and the increase in IL-10 secretion. Further in vitro experiments with B cells found that lipopolysaccharide (LPS) promoted FCRL3 expression in a dose- and time-dependent manner, thereby promoting IL-10 secretion. LPS regulated Src homology region 2 domain-containing phosphatase-1 (SHP-1) expression and p38 mitogen-activated protein kinase (MAPK) pathway activation through FCRL3, and FCRL3 upregulated the SHP-1 expression and p38 phosphorylation levels. When SHP-1 small interfering RNA or a p38 pathway inhibitor was added, the effect of FCRL3 on IL-10 secretion was significantly inhibited. In addition, FCRL3 inhibited the secretion of inflammatory factors (tumor necrosis factor-α, IL-1β, IL-6, and IL-8); after inhibiting the expression of IL-10, the abovementioned effects of FCRL3 were blocked. These results suggest that FCRL3 can activate the SHP-1 and p38 MAPK pathways and then promote the secretion of IL-10 in B cells, thus inhibiting the secretion of inflammatory factors. Therefore, FCRL3 may play an immunoprotective role in MS, and it will be an effective target for the diagnosis and treatment of MS.

Hepatitis B Core Antigen Impairs the Polarization While Promoting the Production of Inflammatory Cytokines of M2 Macrophages via the TLR2 Pathway

Although several evidences suggesting the vital roles that innate immunity plays in the persistence and elimination of chronic hepatitis B virus (CHB) infection, the exact mechanism is still complicated. Here, we successfully polarized monocytes derived from healthy human peripheral blood mononuclear cells (PBMCs) into M1/M2 macrophages and detected the effects of hepatitis B core antigen (HBcAg) on the polarization and function of macrophages via the Toll-like receptor (TLR) 2 signaling pathway. The results showed that HBcAg had a negligible impact on M1 polarization, while it effectively impaired M2 polarization and promoted the production of pro-inflammatory cytokines such as IL-6 and TNF-α. Additionally, HBcAg treatment increased TLR2 expression on M2 macrophages and TLR2 blockade abolished the effects of HBcAg on the impaired phenotype and pro-inflammatory cytokine productions of M2 macrophages. Signaling pathway analysis revealed that the nuclear factor κB (NF-κB) pathway, the downstream of TLR2, was upregulated upon HBcAg treatment in both M1 and M2 macrophages. Furthermore, a CD8⁺ T-macrophage coculture system implied that compared with PBS stimulation, HBcAg-stimulated M2 macrophages regained their ability to activate CD8⁺ T cells with higher secretion of IFN-γ. Finally, we found impaired expression of M2-related molecules and increased levels of pro-inflammation cytokines in M2 macrophages from CHB patients upon HBcAg stimulation. In conclusion, these results imply a favorable role of HBcAg in the establishment of a pro-inflammatory microenvironment by macrophages, which may suggest a potential therapeutic strategy of HBcAg-induced macrophage activation in CHB infection.

Use of Azithromycin for the Prevention of Lung Injury in Mechanically Ventilated Preterm Neonates: A Randomized Controlled Trial

INTRODUCTION

Macrolides have anti-inflammatory and immunomodulatory properties that give this class of antibiotics a role that differs from its classical use as an antibiotic, which opens new therapeutic possibilities.

OBJECTIVE

The aim of this study was to evaluate the anti-inflammatory effect of azithromycin in preventing mechanical ventilation (MV)-induced lung injury in very-low-birth-weight preterm neonates.

METHODS

This is a randomized, double-blind, placebo-controlled trial of preterm neonates who received invasive MV within 72 h of birth. Patients were randomized to receive intravenous azithromycin (at a dose of 10/mg/kg/day for 5 days) or placebo (0.9% saline) within 12 h of the start of MV. Two blood samples were collected (before and after intervention) for measurement of interleukins (ILs) and PCR for Ureaplasma. Patients were followed up throughout the hospital stay for the outcomes of death and broncho-pulmonary dysplasia defined as need for oxygen for a period of ≥28 days of life (registered at ClinicalTrials.gov, No. NCT03485703).

RESULTS

Forty patients were analyzed in the azithromycin group and 40 in the placebo group. Five days after the last dose, serum IL-2 and IL-8 levels dropped significantly in the azithromycin group. There was a significant reduction in the incidence of death and O2 dependency at 28 days/death in azithromycin-treated patients regardless of the detection of Ureaplasma in blood.

CONCLUSIONS

Azithromycin has anti-inflammatory effects, with a decrease in cytokines after 5 days of use and a reduction in death and O2 dependency at 28 days/death in mechanically ventilated preterm neonates.

Efficacy of interleukin 10 gene hydrofection in pig liver vascular isolated 'in vivo' by surgical procedure with interest in liver transplantation

Aim

Liver transplantation is the only curative strategy for final stage liver diseases. Despite the great advances achieved during the last 20 years, the recipient immune response after transplantation is not entirely controlled. This results in high rates of acute cell rejection and, approximately, 10% of early mortality. Therapeutic treatment could be improved by efficiently transfecting genes that encode natural immunosuppressant proteins, employing safe procedures that could be transferred to clinical setting. In this sense, interleukin 10 plays a central role in immune tolerance response by acting at different levels.

Methods

hIL10 gene was hydrofected by retrograde hydrodynamic injection in pig liver with complete vascular exclusion mediated by an ‘in vivo’ surgical procedure. Levels of IL10 DNA, RNA and protein were determined within liver tissue 1 and 10 days after the injection and, more frequently, also the interleukin-10 protein in peripheral blood.

Results

The procedure was safe for the animals and neither hemodynamic parameters nor liver function determinations showed relevant alterations. The hIL10 hydrofection in watertight liver mediated efficient gene transfer and this was transcribed and translated to protein, achieving up to 110 pg/ml of IL10 in peripheral blood. This value is close to that considered able to reduce the activity of TNFα by half (IL10 IC₅₀ for TNFα = 124 pg/ml).

Conclusions

Results of this work suggest that IL10 liver hydrofection with vascular exclusion in vivo is a safe and transferable procedure that mediates plasma protein levels with potential clinical interest in immune modulation after transplantation.

Macrophage galactose-type lectin (MGL) is induced on M2 microglia and participates in the resolution phase of autoimmune neuroinflammation

BACKGROUND

Multiple sclerosis (MS) involves a misdirected immune attack against myelin in the brain and spinal cord, leading to profound neuroinflammation and neurodegeneration. While the mechanisms of disease pathogenesis have been widely studied, the suppression mechanisms that lead to the resolution of the autoimmune response are still poorly understood. Here, we investigated the role of the C-type lectin receptor macrophage galactose-type lectin (MGL), usually expressed on tolerogenic antigen-presenting cells (APCs), as a negative regulator of autoimmune-driven neuroinflammation.

METHODS

We used in silico, immunohistochemical, immunofluorescence, quantitative real-time polymerase chain reaction (qRT-PCR) and flow cytometry analysis to explore the expression and functionality of MGL in human macrophages and microglia, as well as in MS post-mortem tissue. In vitro, we studied the capacity of MGL to mediate apoptosis of experimental autoimmune encephalomyelitis (EAE)-derived T cells and mouse CD4⁺ T cells. Finally, we evaluated in vivo and ex vivo the immunomodulatory potential of MGL in EAE.

RESULTS

MGL plays a critical role in the resolution phase of EAE as MGL1-deficient (Clec10a^-/-) mice showed a similar day of onset but experienced a higher clinical score to that of WT littermates. We demonstrate that the mouse ortholog MGL1 induces apoptosis of autoreactive T cells and diminishes the expression of pro-inflammatory cytokines and inflammatory autoantibodies. Moreover, we show that MGL1 but not MGL2 induces apoptosis of activated mouse CD4⁺ T cells in vitro. In human settings, we show that MGL expression is increased in active MS lesions and on alternatively activated microglia and macrophages which, in turn, induces the secretion of the immunoregulatory cytokine IL-10, underscoring the clinical relevance of this lectin.

CONCLUSIONS

Our results show a new role of MGL-expressing APCs as an anti-inflammatory mechanism in autoimmune neuroinflammation by dampening pathogenic T and B cell responses, uncovering a novel clue for neuroprotective therapeutic strategies with relevance for in MS clinical applications.

Human Induced Pluripotent Stem Cell-Derived Astrocytes Are Differentially Activated by Multiple Sclerosis-Associated Cytokines

Recent studies highlighted the importance of astrocytes in neuroinflammatory diseases, interacting closely with other CNS cells but also with the immune system. However, due to the difficulty in obtaining human astrocytes, their role in these pathologies is still poorly characterized. Here, we develop a serum-free protocol to differentiate human induced pluripotent stem cells (hiPSCs) into astrocytes. Gene expression and functional assays show that our protocol consistently yields a highly enriched population of resting mature astrocytes across the 13 hiPSC lines differentiated. Using this model, we first highlight the importance of serum-free media for astrocyte culture to generate resting astrocytes. Second, we assess the astrocytic response to IL-1β, TNF-α, and IL-6, all cytokines important in neuroinflammation, such as multiple sclerosis. Our study reveals very specific profiles of reactive astrocytes depending on the triggering stimulus. This model provides ideal conditions for in-depth and unbiased characterization of astrocyte reactivity in neuroinflammatory conditions.

Activation of Macrophages in vitro by Phospholipids from Brain of Katsuwonus pelamis (Skipjack Tuna)

The biological activities of phospholipids (PLs) have attracted people's attention, especially marine phospholipids with omega-3 polyunsaturated fatty acids DHA and EPA. In this study, we investigated the immunity activation of macrophages in vitro by phospholipids from skipjack brain. The phospholipids were extracted with hexane and ethanol ultrasonication instead of the traditional method of methanol and chloroform. The content of phospholipids from Skipjack brain was 19.59 g/kg by the method (the ratio of hexane and ethanol 2:1, 40 min, 35°C, 1:9 of the ratio of material to solvent, ultrasonic power 300W, ultrasonic extraction 2 times). The RAW264.7 macrophages were stimulated by the phospholipids from the Skipjack, by which the volume, viability and phagocytosis of macrophages were increased. The concentration of NO and the activity of SOD of the cells were also enhanced. The gene expressions of IL-1β, IL-6, iNOS and TNF-α mRNA assayed by RT-PCR were up-regulated. Phospholipids from brain of Skipjack Tuna could activate macrophages immunity which displayed to induce pro-inflammatroy cytokines mRNA expression.

Cerebrospinal fluid level of Nogo receptor 1 antagonist lateral olfactory tract usher substance (LOTUS) correlates inversely with the extent of neuroinflammation

Background

Although inflammation in the central nervous system is responsible for multiple neurological diseases, the lack of appropriate biomarkers makes it difficult to evaluate inflammatory activities in these diseases. Therefore, a new biomarker reflecting neuroinflammation is required for accurate diagnosis, appropriate therapy, and comprehension of pathogenesis of these neurological disorders. We previously reported that the cerebrospinal fluid (CSF) concentration of lateral olfactory tract usher substance (LOTUS), which promotes axonal growth as a Nogo receptor 1 antagonist, negatively correlates with disease activity in multiple sclerosis, suggesting that variation in LOTUS reflects the inflammatory activities and is a useful biomarker to evaluate the disease activity. To extend this observation, we analyzed the variation of LOTUS in the CSF of patients with bacterial and viral meningitis, which are the most common neuroinflammatory diseases.

Methods

CSF samples were retrospectively obtained from patients with meningitis (n = 40), who were followed up by CSF study at least twice, and from healthy controls (n = 27). Patients were divided into bacterial (n = 14) and viral meningitis (n = 18) after exclusion of eight patients according to the criteria of this study. LOTUS concentrations, total protein levels, and CSF cell counts in the acute and recovery phases were analyzed chronologically. We also used lipopolysaccharide-injected mice as a model of neuroinflammation to evaluate LOTUS mRNA and protein expression in the brain.

Results

Regardless of whether meningitis was viral or bacterial, LOTUS concentrations in the CSF of patients in acute phase were lower than those of healthy controls. As the patients recovered from meningitis, LOTUS levels in the CSF returned to the normal range. Lipopolysaccharide-injected mice also exhibited reduced LOTUS mRNA and protein expression in the brain.

Conclusions

CSF levels of LOTUS correlated inversely with disease activity in both bacterial and viral meningitis, as well as in multiple sclerosis, because neuroinflammation downregulated LOTUS expression. Our data strongly suggest that variation of CSF LOTUS is associated with neuroinflammation and is useful as a biomarker for a broader range of neuroinflammatory diseases.

Featured Article: Modulation of the OGF-OGFr pathway alters cytokine profiles in experimental autoimmune encephalomyelitis and multiple sclerosis

The endogenous neuropeptide opioid growth factor, chemically termed [Met⁵]-enkephalin, has growth inhibitory and immunomodulatory properties. Opioid growth factor is distributed widely throughout most tissues, is autocrine and paracrine produced, and interacts at the nuclear-associated receptor, OGFr. Serum levels of opioid growth factor are decreased in patients with multiple sclerosis and in animals with experimental autoimmune encephalomyelitis suggesting that the OGF-OGFr pathway becomes dysregulated in this disease. This study begins to assess other cytokines that are altered following opioid growth factor or low-dose naltrexone modulation of the OGF-OGFr axis in mice with experimental autoimmune encephalomyelitis using serum samples collected in mice treated for 10 or 20 days and assayed by a multiplex cytokine assay for inflammatory markers. Cytokines of interest were validated in mice at six days following immunization for experimental autoimmune encephalomyelitis. In addition, selected cytokines were validated with serum from MS patients treated with low-dose naltrexone alone or low-dose naltrexone in combination with glatiramer acetate (Copaxone®). Experimental autoimmune encephalomyelitis mice had elevated levels of 7 of 10 cytokines. Treatment with opioid growth factor or low-dose naltrexone resulted in elevated expression levels of the IL-6 cytokine, and significantly reduced IL-10 values, relative to saline-treated experimental autoimmune encephalomyelitis mice. TNF-γ values were increased in experimental autoimmune encephalomyelitis mice relative to normal, but were not altered by opioid growth factor or low-dose naltrexone. IFN-γ levels were reduced in opioid growth factor- or low-dose naltrexone-treated experimental autoimmune encephalomyelitis mice relative to saline-treated mice at 10 days, and elevated relative to normal values at 20 days. Validation studies revealed that within six days of immunization, opioid growth factor or low-dose naltrexone modulated IL-6 and IL-10 cytokine expression. Validation in human serum revealed markedly reduced IL-6 cytokine levels in MS patients taking low-dose naltrexone relative to standard care. In summary, modulation of the OGF-OGFr pathway regulates some inflammatory cytokines, and together with opioid growth factor serum levels, may begin to form a panel of valid biomarkers to monitor progression of multiple sclerosis and response to therapy. Impact statement Modulation of the opioid growth factor (OGF)-OGF receptor (OGFr) alters inflammatory cytokine expression in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE). Multiplex cytokine assays demonstrated that mice with chronic EAE and treated with either OGF or low-dose naltrexone (LDN) had decreased expression of interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and the anti-inflammatory cytokine IL-10 within 10 days or treatment, as well as increased serum expression of the pro-inflammatory cytokine IL-6, relative to immunized mice receiving saline. Multiplex data were validated using ELISA kits and serum from MS patients treated with LDN and revealed decreased in IL-6 levels in patients taking LDN relative to standard care alone. These data, along with serum levels of OGF, begin to formulate a selective biomarker profile for MS that is easily measured and effective at monitoring disease progression and response to therapy.

Bronchoalveolar lavage fluid microbiota dysbiosis in infants with protracted bacterial bronchitis

Background

Protracted bacterial bronchitis (PBB) is a chronic purulent bronchitis which could cause recurrent coughing and wheezing in infants. Based on previous reports, main pathogens which caused PBB were identified in the patients, but their impacts on lung microbiota dysbiosis remain unclear.

Methods

In this study, bronchoalveolar lavage fluid (BALF) was collected from PBB infants and tracheomalacia (TM) infants younger than 3 years old under the instruction of Shenzhen Children's Hospital, and 12 samples were randomly selected for 16S rDNA analysis in each group. Based on the results of bacterial composition, the microbiota diversity and co-occurrence network in PBB and TM group were detected and compared.

Results

Microbiota diversity was significantly lower in PBB group than it in TM group (P<0.001 for the comparison of Shannon and Simpson indexes). The PBB group was found to harbor 25 accumulated bacterial agents by comparison with TM group, including Haemophilus (P<0.001) and Bacteroides (P<0.001). Whilst, the populations of Lactococcus (P<0.001) and Lactobacillus (P<0.001) were dramatically smaller in PBB group. The co-occurrence network in PBB group also differed from that of TM group. It contained four core nodes in PBB patients, including Haemophilus, Parabacteroides, Porphyromonas, and Cronobacter. Haemophilus was found to be negatively associated with most counterparts, including Clostridium and Bacillus.

Conclusions

PBB infants contained discrepant lung genera and co-occurrence network when compared with TM infants. This retrospective study may deepen our understanding of PBB pathogenesis, and it also provided a foundation for bacterial adjunctive therapy of infantile PBB in accordance with clinical treatment.

Tissue regeneration: The crosstalk between mesenchymal stem cells and immune response

Mesenchymal stem cells (MSCs) exist in almost all tissues with the capability to differentiate into several different cell types and hold great promise in tissue repairs in a cell replacement manner. The study of the bidirectional regulation between MSCs and immune response has ushered an age of rethinking of tissue regeneration in the process of stem cell-based tissue repairs. By sensing damaged signals, both endogenous and exogenous MSCs migrate to the damaged site where they involve in the reconstitution of the immune microenvironment and empower tissue stem/progenitor cells and other resident cells, whereby facilitate tissue repairs. This MSC-based therapeutic manner is conferred as cell empowerment. In this process, MSCs have been found to exert extensive immunosuppression on both innate and adaptive immune response, while such regulation needs to be licensed by inflammation. More importantly, the immunoregulation of MSCs is highly plastic, especially in the context of pathological microenvironment. Understanding the immunoregulatory properties of MSCs is necessary for appropriate application of MSCs. Here we review the current studies on the crosstalk of MSCs and immune response in disease pathogenesis and therapy.

The Effect of Levothyroxine on Serum Levels of Interleukin 10 and Interferon-gamma in Rat Model of Multiple Sclerosis

Background:

There is an increase in inflammatory and a reduction in anti-inflammatory cytokines in multiple sclerosis (MS). Considering the role of thyroid hormones in the development and regulation of both neural and immune systems, the aim of this study was to evaluate the effects of levothyroxine on serum concentrations of interleukin-10 (IL-10) and interferon gamma (IFN-γ) in animal models of MS.

Materials and Methods:

To induce demyelination in male Wistar rats, lysolecithin was injected into the optic chiasm. Then levothyroxine was injected intraperitoneally (20, 50, and 100 μg/kg) for 21 days. Serum levels of cytokines were measured by enzyme-linked immunosorbent assay at 7, 14, and 21 days after that.

Results:

The results showed that injection of lysolecithin to the optic chiasm only increased serum concentrations of IL-10 compared to the sham group (P < 0.05) at 7^th day, but this increase was prevented by all doses of levothyroxine. IFN-γ was decreased significantly (P < 0.001) 21 days after. Comparing to the sham group at all sampling time and with respect to the MS group at the days 7 and 21, levothyroxine decreased serum concentrations of IFN-γ significantly.

Conclusion:

The results showed that thyroid hormones probably could produce protective effects against induced demyelination through affecting immune responses.

The role of Th17 cells in auto-inflammatory neurological disorders

The role of T helper 17 (Th17) cells in auto-inflammatory neurological disorders such as Multiple Sclerosis (MS), Alzheimer's disease (AD), Parkinson's disease (PD) and schizophrenia has not been clarified completely. Th17-derived pro-inflammatory cytokines including IL-17, IL-21, IL-22, IL-23, GM-CSF, and IFN-γ have a critical role in the pathogenesis of these disorders. In this review, we demonstrate the role of Th17 cells and their related cytokines in the immunopathology of above-mentioned disorders to get a better understanding of neuroinflammatory mechanisms mediated by Th17 cells associated with events leading to neurodegeneration.

Galectin-1 inhibits oral-intestinal allergy syndrome

Background and aims

The pathogenesis of oral-intestinal allergy syndrome (OIAS) has not been well understood. Published data indicate that galectin (Gal) 1 has immune regulatory functions. This study tests a hypothesis that Gal1 inhibits oral-intestinal allergy syndrome.

Methods

Mice were sensitized to peanut extracts (PE) via the buccal mucosa with or without using Gal1 together.

Results

Upon re-exposure to specific antigen, the OIAS mice showed the systemic allergic response, the oral allergic reactions, and intestinal allergic inflammation, including increases in serum histamine, drop of the core temperature, higher levels of PE-specific IgE and interleukin (IL)-4. Increases in mast cell and eosinophil in the oral mucosa and intestinal mucosa were also observed. The OIAS was inhibited by co-administration with Gal1 via a mechanism of suppressing micro RNA (miR)-98 and reversing the expression of IL-10 in CD14+ cells in the intestine.

Conclusions

The OIAS can be induced by applying specific antigens to the oral mucosa, which can be inhibited by co-administration with Gal1.

iNKT cells prevent obesity-induced hepatic steatosis in mice in a C-C chemokine receptor 7-dependent manner

Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis are characterized by an increase in hepatic triglyceride content with infiltration of immune cells, which can cause steatohepatitis and hepatic insulin resistance. C-C chemokine receptor 7 (CCR7) is primarily expressed in immune cells, and CCR7 deficiency leads to the development of multi-organ autoimmunity, chronic renal disease and autoimmune diabetes. Here, we investigated the effect of CCR7 on hepatic steatosis in a mouse model and its underlying mechanism. Our results demonstrated that body and liver weights were higher in the CCR7^−/− mice than in the wild-type (WT) mice when they were fed a high-fat diet. Further, glucose tolerance and insulin sensitivity were markedly diminished in CCR7^−/− mice. The number of invariant natural killer T (iNKT) cells was reduced in the livers of the CCR7^−/− mice. Moreover, liver inflammation was detected in obese CCR7^−/− mice, which was ameliorated by the adoptive transfer of hepatic mononuclear cells from WT mice, but not through the transfer of hepatic mononuclear cells from CD1d^−/− or interleukin-10-deficient (IL-10^−/−) mice. Overall, these results suggest that CCR7⁺ mononuclear cells in the liver could regulate obesity-induced hepatic steatosis via induction of IL-10-expressing iNKT cells.

IL-33-matured dendritic cells promote Th17 cell responses via IL-1β and IL-6

IL-33 is associated with a variety of autoimmune diseases, such as sclerosis, inflammatory bowel disease, and rheumatoid arthritis. Although IL-33 is mainly involved in the induction of Th2 cells, however, the relationship between IL-33 and Th17 cells is still largely unknown. In this study, we investigated the effects of IL-33 on DC-mediated CD4⁺ T cell activation and Th17 cell differentiation because DCs are essential cells for presenting self-antigens to CD4⁺ T cells in autoimmune disease conditions. OT-II mice were injected with IL-33-treated DCs or untreated DCs that were primed by OVA_323-339 peptide, and their Th17 cell responses were compared. Th17 cell population and IL-17 expression levels were significantly increased in draining lymph nodes of mice injected with IL-33-treated DCs, compared with those in mice injected with untreated DCs. IL-33 treatment maturated DCs to present self-antigens and to increase production of proinflammatory cytokines such as IL-1β and IL-6, which have a crucial role in Th17 cell differentiation. We found that the IL-33-matured DCs enhanced the expression of an early T cell activation marker (CD69) and the Th17 master transcription factor (RORγt), but IL-33 did not directly affect CD4⁺ T cell differentiation or increase Th17 polarization. Notably, neutralizing IL-1β and/or IL-6 significantly decreased IL-17 expression levels and Th17 cell population which were increased by the coculture of CD4⁺ T cells with IL-33-matured DCs, indicating that IL-33 may induce Th17 cell responses via IL-1β and IL-6 derived from IL-33-matured DCs.

Diversity of immune cell types in multiple sclerosis and its animal model: Pathological and therapeutic implications

Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system with an autoimmune attack on the components of the myelin sheath and axons. The etiology of the disease remains largely unknown, but it is commonly acknowledged that the development of MS probably results from the interaction of environmental factors in conjunction with a genetic predisposition. Current therapeutic approaches can only ameliorate the clinical symptoms or reduce the frequency of relapse in MS. Most drugs used in this disease broadly suppress the functions of immune effector cells, which can result in serious side effects. Thus, new therapeutic methods resulting in greater efficacy and lower toxicity are needed. Toward this end, cell-based therapies are of increasing interest in the treatment of MS. Several immunoregulatory cell types, including regulatory T cells, regulatory B cells, M2 macrophages, tolerogenic dendritic cells, and stem cells, have been developed as novel therapeutic tools for the treatment of MS. In this Review, we summarize studies on the application of these cell populations for the treatment of MS and its animal model, experimental autoimmune encephalomyelitis, and call for further research on applications and mechanisms by which these cells act in the treatment of MS. © 2017 The Authors Journal of Neuroscience Research Published by Wiley Periodicals, Inc.

Efficacy of hydrodynamic interleukin 10 gene transfer in human liver segments with interest in transplantation

Different diseases lead, during their advanced stages, to chronic or acute liver failure, whose unique treatment consists in organ transplantation. The success of intervention is limited by host immune response and graft rejection. The use of immunosuppressant drugs generally improve organ transplantation, but they cannot completely solve the problem. Also, their management is delicate, especially during the early stages of treatment. Thus, new tools to set an efficient modulation of immune response are required. The local expression of interleukin (IL) 10 protein in transplanted livers mediated by hydrodynamic gene transfer could improve the organ acceptance by the host because it presents the natural ability to modulate the immune response at different levels. In the organ transplantation scenario, IL10 has already demonstrated positive effects on graft tolerance. Hydrodynamic gene transfer has been proven to be safe and therapeutically efficient in animal models and could be easily moved to the clinic. In the present work, we evaluated efficacy of human IL10 gene transfer in human liver segments and the tissue natural barriers for gene entry into the cell, employing gold nanoparticles. In conclusion, the present work shows for the first time that hydrodynamic IL10 gene transfer to human liver segments ex vivo efficiently delivers a human gene into the cells. Indexes of tissue protein expression achieved could mediate local pharmacological effects with interest in controlling the immune response triggered after liver transplantation. On the other hand, the ultrastructural study suggests that the solubilized plasmid could access the hepatocyte in a passive manner mediated by the hydric flow and that an active mechanism of transportation could facilitate its entry into the nucleus. Liver Transplantation 23:50-62 2017 AASLD.

Characterisation of the Immunophenotype of Dogs with Primary Immune-Mediated Haemolytic Anaemia

Background

Immune-mediated haemolytic anaemia (IMHA) is reported to be the most common autoimmune disease of dogs, resulting in significant morbidity and mortality in affected animals. Haemolysis is caused by the action of autoantibodies, but the immunological changes that result in their production have not been elucidated.

Aims

To investigate the frequency of regulatory T cells (Tregs) and other lymphocyte subsets and to measure serum concentrations of cytokines and peripheral blood mononuclear cell expression of cytokine genes in dogs with IMHA, healthy dogs and dogs with inflammatory diseases.

Animals

19 dogs with primary IMHA, 22 dogs with inflammatory diseases and 32 healthy control dogs.

Methods

Residual EDTA-anti-coagulated blood samples were stained with fluorophore-conjugated monoclonal antibodies and analysed by flow cytometry to identify Tregs and other lymphocyte subsets. Total RNA was also extracted from peripheral blood mononuclear cells to investigate cytokine gene expression, and concentrations of serum cytokines (interleukins 2, 6 10, CXCL-8 and tumour necrosis factor α) were measured using enhanced chemiluminescent assays. Principal component analysis was used to investigate latent variables that might explain variability in the entire dataset.

Results

There was no difference in the frequency or absolute numbers of Tregs among groups, nor in the proportions of other lymphocyte subsets. The concentrations of pro-inflammatory cytokines were greater in dogs with IMHA compared to healthy controls, but the concentration of IL-10 and the expression of cytokine genes did not differ between groups. Principal component analysis identified four components that explained the majority of the variability in the dataset, which seemed to correspond to different aspects of the immune response.

Conclusions

The immunophenotype of dogs with IMHA differed from that of dogs with inflammatory diseases and from healthy control dogs; some of these changes could suggest abnormalities in peripheral tolerance that permit development of autoimmune disease. The frequency of Tregs did not differ between groups, suggesting that deficiency in the number of these cells is not responsible for development of IMHA.

Glatiramer acetate treatment normalized the monocyte activation profile in MS patients to that of healthy controls

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system, and monocytes contribute to MS-associated neuroinflammation. While classically activated monocytes promote inflammation, type II-activated monocytes improve the course of MS. This study investigated type II activation of monocytes and their two main subsets, namely CD14⁺ (CD14⁺⁺CD16^- subset) and CD16⁺ monocytes (CD14⁺CD16⁺ subset), by glatiramer acetate (GA) or intravenous immunoglobulin-associated immune complexes (IC), both of which are known MS treatments. Total monocytes and subsets were isolated from peripheral blood mononuclear cells (PBMC) of healthy controls, untreated MS patients (MS) and GA-treated MS patients (GA-MS). In contrast to the more activated ex vivo profile of monocytes from the MS group, monocytes from the GA-MS group resembled those from healthy controls. In vitro type II activation with GA primarily reduced CD40, CD86 and IL-12p40 whereas type II activation with IC consistently reduced CD40 but increased interleukin-10 (IL-10), suggesting that the GA and IC activation pathways are distinct. Moreover, while GA treatment reduced IL-12p40 by both CD14⁺ and CD16⁺ subsets, IC treatment only enhanced IL-10 by the CD16⁺ subset. Further analysis of the CD16⁺ subset revealed that MS patients had a greatly expanded CD14⁺CD16^int population while both CD14⁺CD16^int and CD14^lowCD16^high monocyte populations were expanded in GA-MS patients. Finally, a global analysis of the ex vivo monocyte data indicated that GA treatment distinctly altered the monocyte profile of MS patients, further supporting the idea that GA directly targets monocytes.