The levels of soluble forms of CD21 and CD83 in multiple sclerosis

The role of CD83 in the pathogenesis of immune thrombocytopenia

BACKGROUND

CD83 are closely related to the pathogenesis of immune thrombocytopenia (ITP), but the exact mechanism remains unclear.

AIM

To explore the relationship between CD83 and CD4+ T cell subsets and clarify the role of CD83 in the pathogenesis of ITP.

METHODS

RT-qPCR and Flow cytometry were used to illustrate CD83 expression. The downregulation and overexpression of DC-CD83 were co-cultured with CD4+ T cells to detect cell proliferation, co-cultured supernatant cytokines and Tregs expression.

RESULTS

The results indicate that the ITP patients showed higher expression of CD83 than the healthy controls. The proliferation of CD4+ T cells was inhibited by downregulation of DCs-CD83 but promoted by overexpression of DCs-CD83. siRNA-CD83 inhibited proinflammatory IFN-γ and IL-17 secretion while raising TGF-β, IL-10 concentrations. Overexpression of DCs-CD83 promoted Tregs expression.

CONCLUSION

The Th1/Th2 and Th17/Tregs polarization were reversed via interfering DCs with siRNA-CD83. CD83 plays an important role in ITP pathogenesis, suggesting novel treatment for ITP patients.

CD83+ B cells alleviate uveitis through inhibiting DCs by sCD83

Soluble CD83 (sCD83) exerts immunosuppressive functions in many autoimmune diseases, including experimental autoimmune uveitis (EAU), but the cells and mechanisms involved are unclear. This study showed that CD83+ B cells were the main sources of sCD83. They alleviated the symptoms of EAU and decreased the percentage of T cells and DCs in the eyes and lymph nodes. These CD83+ B cells decreased IL-1β, IL-18 and IFN-γ secretion by DCs through sCD83. sCD83 interacted with GTPase Ras-related protein (Rab1a) in DCs to promote Rab1a accumulation in autolysosomes and inhibit mTORC1 phosphorylation and NLRP3 expression. Hence, CD83+ B cells play a regulatory role in EAU by secreting sCD83. The lack of regulation of CD83+ B cells might be an important factor leading to hyperimmune activation in patients with autoimmune uveitis. CD83+ B cells suppress activated DCs in uveitis, indicating the potential therapeutic role of CD83+ B cells in uveitis.

Exploring the impact of miR-128 in inflammatory diseases: A comprehensive study on autoimmune diseases

microRNAs (miRNAs) play a crucial role in various biological processes, including immune system regulation, such as cell proliferation, tolerance (central and peripheral), and T helper cell development. Dysregulation of miRNA expression and activity can disrupt immune responses and increase susceptibility to neuroimmune disorders. Conversely, miRNAs have been shown to have a protective role in modulating immune responses and preventing autoimmunity. Specifically, reducing the expression of miRNA-128 (miR-128) in an Alzheimer's disease (AD) mouse model has been found to improve cognitive deficits and reduce neuropathology. This comprehensive review focuses on the significance of miR-128 in the pathogenesis of neuroautoimmune disorders, including multiple sclerosis (MS), AD, Parkinson's disease (PD), Huntington's disease (HD), epilepsy, as well as other immune-mediated diseases such as inflammatory bowel disease (IBD) and rheumatoid arthritis (RA). Additionally, we present compelling evidence supporting the potential use of miR-128 as a diagnostic or therapeutic biomarker for neuroimmune disorders. Collectively, the available literature suggests that targeting miR-128 could be a promising strategy to alleviate the behavioral symptoms associated with neuroimmune diseases. Furthermore, further research in this area may uncover new insights into the molecular mechanisms underlying these disorders and potentially lead to the development of novel therapeutic approaches.

CD83 Regulates the Immune Responses in Inflammatory Disorders

Activating the immune system plays an important role in maintaining physiological homeostasis and defending the body against harmful infections. However, abnormalities in the immune response can lead to various immunopathological responses and severe inflammation. The activation of dendritic cells (DCs) can influence immunological responses by promoting the differentiation of T cells into various functional subtypes crucial for the eradication of pathogens. CD83 is a molecule known to be expressed on mature DCs, activated B cells, and T cells. Two isotypes of CD83, a membrane-bound form and a soluble form, are subjects of extensive scientific research. It has been suggested that CD83 is not only a ubiquitous co-stimulatory molecule but also a crucial player in monitoring and resolving inflammatory reactions. Although CD83 has been involved in immunological responses, its functions in autoimmune diseases and effects on pathogen immune evasion remain unclear. Herein, we outline current immunological findings and the proposed function of CD83 in inflammatory disorders.

Tilting the Balance: Therapeutic Prospects of CD83 as a Checkpoint Molecule Controlling Resolution of Inflammation

Chronic inflammatory diseases and transplant rejection represent major challenges for modern health care. Thus, identification of immune checkpoints that contribute to resolution of inflammation is key to developing novel therapeutic agents for those conditions. In recent years, the CD83 (cluster of differentiation 83) protein has emerged as an interesting potential candidate for such a "pro-resolution" therapy. This molecule occurs in a membrane-bound and a soluble isoform (mCD83 and sCD83, respectively), both of which are involved in resolution of inflammation. Originally described as a maturation marker on dendritic cells (DCs), mCD83 is also expressed by activated B and T cells as well as regulatory T cells (Tregs) and controls turnover of MHC II molecules in the thymus, and thereby positive selection of CD4+ T cells. Additionally, it serves to confine overshooting (auto-)immune responses. Consequently, animals with a conditional deletion of CD83 in DCs or regulatory T cells suffer from impaired resolution of inflammation. Pro-resolving effects of sCD83 became evident in pre-clinical autoimmune and transplantation models, where application of sCD83 reduced disease symptoms and enhanced allograft survival, respectively. Here, we summarize recent advances regarding CD83-mediated resolution of inflammatory responses, its binding partners as well as induced signaling pathways, and emphasize its therapeutic potential for future clinical trials.

Epstein-Barr Virus and Neurological Diseases

Epstein-Barr virus (EBV), also known as human herpesvirus 4, is a double-stranded DNA virus that is ubiquitous in 90–95% of the population as a gamma herpesvirus. It exists in two main states, latent infection and lytic replication, each encoding viral proteins with different functions. Human B-lymphocytes and epithelial cells are EBV-susceptible host cells. EBV latently infects B cells and nasopharyngeal epithelial cells throughout life in most immunologically active individuals. EBV-infected cells, free viruses, their gene products, and abnormally elevated EBV titers are observed in the cerebrospinal fluid. Studies have shown that EBV can infect neurons directly or indirectly via infected B-lymphocytes, induce neuroinflammation and demyelination, promote the proliferation, degeneration, and necrosis of glial cells, promote proliferative disorders of B- and T-lymphocytes, and contribute to the occurrence and development of nervous system diseases, such as Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, acute cerebellar ataxia, meningitis, acute disseminated encephalomyelitis, and brain tumors. However, the specific underlying molecular mechanisms are unclear. In this paper, we review the mechanisms underlying the role of EBV in the development of central nervous system diseases, which could bebeneficial in providing new research ideas and potential clinical therapeutic targets for neurological diseases.

The pathogenic, therapeutic and diagnostic role of exosomal microRNA in the autoimmune diseases

Exosomes are a nano-vesicle surrounded by a bilipid layer that can release from almost all cells and could be detected in tissues and biological liquids. These vesicles contain lipids, proteins, and nucleic acids (including DNA, mRNA, and miRNA) inside and on the exosomes' surface constitute their content. Exosomes can transfer their cargo into the recipient cell, which can modify recipient cells' biological activities. Recently it has been deciphering that the miRNA pattern of exosomes reveals the cellular pathophysiological situation and modifies various biological processes. Increasing data regarding exosomes highlights that the exosomes and their cargo, especially miRNAs, are implicated in the pathophysiology of various disorders, such as autoimmune disease. The current evidence on the deciphering of mechanisms in which exosomal miRNAs contributed to autoimmunity was indicated that exosomal miRNA might hold information that can reprogram the function of many of the immune cells involved in autoimmune diseases' pathogenesis. In the present study, we summarized the pathogenic role of exosomal miRNAs in several autoimmune diseases, including myasthenia gravis (MG), psoriasis, inflammatory bowel disease (IBD), type 1 diabetes (T1D), multiple sclerosis (MS), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjogren's Syndrome (SS), systemic sclerosis (SSc), vitiligo, and autoimmune thyroid diseases (AITD). Moreover, in this work, we present evidence of the potential role of exosomal miRNAs as therapeutic and diagnostic agents in autoimmune diseases.

Illuminating the in vitro effects of Epstein-Barr virus and vitamin D on immune response in multiple sclerosis patients

Given the complexity of immune complex diseases including multiple sclerosis (MS) and the plausible interactions between different risk factors, delineating the interplay between them would be imperative. The current study aimed to evaluate the in vitro effects of Epstein-Barr virus (EBV) and vitamin D on immune response in MS patients and healthy controls. The status of vitamin D and EBV load was evaluated using multiple techniques. In vitro EBV-infected peripheral blood mononuclear cells (PBMCs), in the presence or absence of vitamin D, were checked for IL-10, IFN-γ, and vitamin D receptor. MS patients showed significantly higher plasma levels of 1,25-(OH)2D but not 25-OHD, increased EBV load, and lower levels of vitamin D receptor (VDR) expression compared with healthy controls. Interestingly, an inverse correlation was observed between VDR expression and EBV load in PBMCs. Indeed, the levels of IFN-γ and IL-10 production were significantly higher in supernatant collected from in vitro EBV-infected PBMCs in MS patients compared with controls. While all vitamin D-treated PBMCs showed reduced levels of IFN-γ production, in vitro treatment of vitamin D showed no influence in IL-10 production. EBV and vitamin D were found to exert opposite in vitro effects on immune dysregulation in these patients. Our results highlight the complex interactions of different risk factors with immune system.

Soluble CD83 suppresses experimental food allergy via regulating aberrant T helper 2 responses

Aberrant T helper-2 (Th2) responses play a critical role in the pathogenesis of allergic diseases. The underlying mechanism is to be further investigated. It is reported that soluble CD83 (sCD83) has immune-regulatory effects. This study aims to investigate the role of sCD83 in the regulation of Th2 polarization. Blood samples were collected from pediatric patients with food allergy (FA). The Th2 response was analyzed by pertinent immunological approaches. An FA murine model was developed to test the role of sCD83 in the regulation of FA response. We found that the serum sCD83 levels were lower in FA patients. A negative correlation was detected between serum sCD83 levels and serum Th2 cytokine levels. The presence of sCD83 suppressed Th2 cell differentiation and antigen-specific Th2 cell activation. sCD83 upregulated the T-bet expression and suppressed the GATA3 expression in CD4+ T cells. Administration of sCD83 suppressed experimental FA. Pediatric FA patients have low serum sCD83 levels. Administration of sCD83 can alleviate experimental FA via suppression of aberrant Th2 polarization.

The CD83 Molecule - An Important Immune Checkpoint

The CD83 molecule has been identified to be expressed on numerous activated immune cells, including B and T lymphocytes, monocytes, dendritic cells, microglia, and neutrophils. Both isoforms of CD83, the membrane-bound as well as its soluble form are topic of intensive research investigations. Several studies revealed that CD83 is not a typical co-stimulatory molecule, but rather plays a critical role in controlling and resolving immune responses. Moreover, CD83 is an essential factor during the differentiation of T and B lymphocytes, and the development and maintenance of tolerance. The identification of its interaction partners as well as signaling pathways have been an enigma for the last decades. Here, we report the latest data on the expression, structure, and the signaling partners of CD83. In addition, we review the regulatory functions of CD83, including its striking modulatory potential to maintain the balance between tolerance versus inflammation during homeostasis or pathologies. These immunomodulatory properties of CD83 emphasize its exceptional therapeutic potential, which has been documented in specific preclinical disease models.

Soluble CD83 alleviates experimental allergic rhinitis through modulating antigen-specific Th2 cell property

Background and aims: Dysfunction of the immune regulatory system plays a role in the pathogenesis of allergic rhinitis (AR). The underlying mechanism needs to be further investigated. Published data indicate that soluble CD83 (sCD83) has immune regulatory activities. This study aims to investigate the role of sCD83 in the alleviation of experimental AR. Methods: Peripheral blood samples were obtained from AR patients. Serum levels of sCD83 were determined by enzyme-linked immunosorbent assay. A murine AR model was developed to test the effects of sCD83 on suppressing experimental AR. Results: We found that serum levels of sCD83 in the AR group were lower than that in the healthy control group. A negative correlation was identified between the serum sCD83 levels and the frequency of T helper-2 (Th2) cells. The low serum sCD83 levels were also associated with the Bcl2L12 expression in antigen-specific Th2 cells. Exposure to sCD83 enhanced the responsiveness of antigen-specific Th2 cells to apoptosis inducers via suppressing the Bcl2L12 expression. Administration of sCD83 efficiently suppressed experimental AR. Conclusions: sCD83 contributes to immune homeostasis by regulating CD4+ T cell activities. Administration of sCD83 may have translational potential for the treatment of AR or other allergic diseases.

Assessment of IL-7RA T244I Polymorphism as a Risk Factor of Multiple Sclerosis in Turkish Population

Introduction

The T244I variant of the IL-7RA gene, rs6897932, is one of the first polymorphisms found to be associated with the development of multiple sclerosis (MS). Although several studies provided evidence for the association of MS and this variant, other studies could not confirm this result. These inconsistent results suggest that the role of this polymorphism in the development of disease is associated with ethnicity.

Methods

We investigated rs6897932 polymorphisms in a large cohort of patients with MS and healthy controls in a turkish population.

Results

In our study, there were no significant differences in genotype frequencies in the IL-7RA rs6897932 polymorphism and no significant difference between C and T alleles in patients with MS and controls.

Conclusion

This study is the first to evaluate the risk of the rs6897932 polymorphism in turkish patients with MS.

CD83: Activation Marker for Antigen Presenting Cells and Its Therapeutic Potential

CD83 is a member of the immunoglobulin (Ig) superfamily and is expressed in membrane bound or soluble forms. Membrane CD83 (mCD83) can be detected on a variety of activated immune cells, although it is most highly and stably expressed by mature dendritic cells (DC). mCD83 regulates maturation, activation and homeostasis. Soluble CD83 (sCD83), which is elevated in the serum of patients with autoimmune disease and some hematological malignancies is reported to have an immune suppressive function. While CD83 is emerging as a promising immune modulator with therapeutic potential, some important aspects such as its ligand/s, intracellular signaling pathways and modulators of its expression are unclear. In this review we discuss the recent biological findings and the potential clinical value of CD83 based therapeutics in various conditions including autoimmune disease, graft-vs.-host disease, transplantation and hematological malignancies.

Putative loss of CD83 immunosuppressive activity in long-standing complication-free juvenile diabetic patients during disease progression

The CD83 molecule is a known marker of dendritic cell differentiation process, and its soluble form (sCD83) exerts immunosuppressive functions. In our research, we examined whether the sCD83 plasma concentration is impaired in DM1 children and if the expected changes are in line with the disturbed process of monocyte's transformation into mCD83+ monocyte-derived cells. 28 newly diagnosed (ND-DM1) and 30 long-standing (LS-DM1) patients were enrolled into our study. We revealed that the examined cells show a high mCD83 expression level in ND-DM1, which was significantly downregulated by the TNF-α stimulation. The results were in line with those from healthy controls. We also observed that monocyte differentiation process into CD83+ cells was much defective in LS-DM1 children and the mCD83 expression level seems not to be controlled by TNF-α. Moreover, the sCD83 level was significantly decreased in plasma from LS-DM1 children and it was negatively related to HbA1c levels, while no correlations were observed between TNF-α plasma concentration or disease duration. Summarizing, our results suggest that reduced sCD83 levels may correspond with a poor metabolic control in LS-DM1 patients and therapeutic administration of this molecule may indicate a new therapy approach in the chronic phase of diabetes.