IFN-α induces IL-10 production and tilt the balance between Th1 and Th17 in Behçet disease

Immunotherapeutic effects of TCL-E5 and TCL-E5-pulsed DCs: two novel HPV therapeutic vaccine candidates

AIM

This study investigated the potential of HPV16 E5 oncoprotein-modified tumor cell lysate (TCL-E5) and dendritic cells (DCs) pulsed with TCL-E5 (TCL-E5-pulsed DCs) to enhance antitumor immunity in a murine model.

MATERIALS AND METHODS

For generation of TCL-E5, TC1 tumor cells were transduced with lentiviral particles harboring E5 protein. Moreover, the cell supernatants were prepared from DCs pulsed with TCL-E5. Their immunological responses and antitumor effects were investigated in a mouse model.

RESULTS

The TCL-E5-pulsed DCs regimen could direct immunity toward Th1 and CTL responses, leading to tumor volume reduction and high percentage of tumor-free mice.

CONCLUSION

The TCL-pulsed DCs regimen could not induce significant antitumor effects compared to TCL-E5-pulsed-DCs regimen indicating main role of E5 in vaccine development.

Identification and validation of diagnostic genes IFI44 and IRF9 in insomnia-associated autoimmune uveitis

Objective

Insomnia is increasingly recognized as a significant factor in the development of various autoimmune diseases, including autoimmune uveitis (AU). We investigated insomnia-associated genes that may contribute to AU pathogenesis and sought to identify potential biomarkers for insomnia-associated AU.

Methods

Microarray data related to insomnia and AU were downloaded from the Gene Expression Omnibus (GEO) database and analyzed. The GEO2R tool was used to identify differentially expressed genes (DEGs) that were common between insomnia and AU. Weighted gene co-expression network analysis (WGCNA), protein-protein interaction (PPI), functional enrichment, and CMap analyses were then performed to identify pathogenic genes, underlying mechanisms, and potential therapeutic drugs for insomnia-associated AU. Least absolute shrinkage and selection operator regression was employed to screen for candidate biomarkers, and their diagnostic performance was evaluated using receiver operating characteristic (ROC) curves and quantitative polymerase chain reaction (qPCR). Finally, molecular docking was applied to verify binding activities.

Results

We identified 138 up-regulated and 85 down-regulated DEGs that were common to insomnia and AU. PPI network analysis highlighted 10 key genes, CMap analysis identified 30 compounds, and WGCNA revealed 54 key genes and 30 compounds. Intersection of the above-mentioned key genes and compounds identified six genes and five compounds. After verification by qPCR and ROC curve analysis, IFI44 and IRF9 were confirmed as hub genes. Finally, two compounds were selected based on docking scores of less than -7 kcal/mol.

Conclusion

Our study demonstrated involvement of the viral response in both insomnia and AU and identified the diagnostic significance of IFI44 and IRF9 in these conditions. These findings provide novel insights for future diagnostic and therapeutic strategies to treat insomnia-associated AU.

The underlying mechanism and therapeutic potential of IFNs in viral-associated cancers

Interferons (IFNs) are a diverse family of cytokines secreted by various cells, including immune cells, fibroblasts, and certain viral-parasitic cells. They are classified into three types and encompass 21 subtypes based on their sources and properties. The regulatory functions of IFNs closely involve cell surface receptors and several signal transduction pathways. Initially investigated for their antiviral properties, IFNs have shown promise in combating cancer-associated viruses, making them a potent therapeutic approach. Most IFNs have been identified for their role in inhibiting cancer; however, they have also demonstrated cancer-promoting effects under specific conditions. These mechanisms primarily rely on immune regulation and cytotoxic effects, significantly impacting cancer progression. Despite widespread use of IFN-based therapies in viral-related cancers, ongoing research aims to develop more effective treatments. This review synthesizes the signal transduction pathways and regulatory capabilities of IFNs, highlighting their connections with viruses, cancers, and emerging clinical treatments.

Genetic predisposition to Behcet's disease mediated by a IL10RA enhancer polymorphism

Background

Several studies suggested the genetic association between IL10RA variants and susceptibility to Behcet's disease (BD). However, the precise mechanism of the association is still unknown. The purpose of this study was to investigate the mechanism underlying the genetic associations between IL10RA polymorphisms and the risk of BD.

Methods

To analyse the genetic susceptibility to BD mediated by IL10RA causal polymorphisms, we performed a study on data from our previous genome-wide association studies (GWAS), the bioinformatic analysis of post-annotation of GWAS and relevant mechanism verification experiments, including chromatin immunoprecipitation, luciferase gene-reporter assay, electrophoretic mobility shift assays, and enzyme-linked immunosorbent assay.

Results

Among 125 single nucleotide polymorphisms (SNPs) with P < 1 × 10-5 identified in our previous GWAS study on BD, rs4936415 (G/C) was predicted with the highest conserved score as an expression quantitative-trait-locus SNP for IL10RA in whole blood. There were H3K27ac and H3K4Me1 enhancer-specific enrichments around SNP rs4936415. Luciferase gene-reporter assays revealed that the rs4936415 G-allele construct showed a higher enhancer activity as compared to the empty and the C-allele construct. NF-κB1 was identified to bind the C-allele rather than the G-allele, although the enhancer SNP (rs4936415) region was found to control transcription factor binding sites. Interaction of C-allele and NF-κB1 gene construct resulted in an increased enhancer activity. BD patients showed a significantly lower serum level of the IL-10Rα.

Conclusions

This study identified a single functional causal SNP, rs4936415, in the IL10RA super-enhancer, conferring BD susceptibility. The protective G-allele of non-coding rs4936415 located inside an enhancer region of IL10RA promoted the enhancer activity and increased the expression of IL10RA.The risk C-allele is able to specifically bind NF-κB1 and, in turn, promotes enhancer activity of IL10RA. This subsequently leads to an increased expression of IL10RA. Low expression of IL-10RA suggests a relative deficiency of NF-κB1 in BD.

Effect of curcumin regulated memory Th7 cells in mice with DSS-induced colitis

Abnormal activation or dysfunction of memory helper T (mTh) cells is closely associated with the development of ulcerative colitis (UC). Curcumin (Cur), the main component of turmeric, plays a critical role in the treatment of UC due to its favorable anti-inflammatory and immunomodulatory bioactivities. However, whether Cur modulates mTh7 cells to alleviate UC is unknown. In the present study, dextran sulphate sodium (DSS) was administered to establish a colitis model in mice. Our current findings indicated that Cur effectively ameliorated the manifestations of colitis in mice, and had a significant effect in reducing disease activity index (DAI), as well as in the colonic weight and the proportion of colonic weight to colonic length. While Cur reduced the pathological injuries of the colon, restore the length of the colon, inhibited the secretion of IL-7 and IL-21, restored the secretion of IL-2, IL-4, and IL-10. Furthermore, Cur had a regulatory effect on mTh7 cells and their subpopulation status. The results of molecular docking simulations and Surface Plasmon Resonance (SPR) indicated that Cur demonstrates strong interaction capabilities with both IL-7 and IL-7R and reduced the expression levels of IL-7/IL-7R mRNA and protein. It is suggested that the alleviation of DSS-induced colitis by Cur may be achieved by reducing the level of mTh7 cells and inhibiting the activation of IL-7/IL-7R signaling.

IL-10: A Key Regulator and potential therapeutic target in uveitis

Uveitis is a prevalent inflammatory eye disease that primarily affects working-age individuals and can lead to blindness if untreated. Interleukin-10 (IL-10) is a multifunctional cytokine with broad immunosuppressive properties and plays a significant role in various pathological and physiological processes. However, its specific role and underlying mechanisms in uveitis remain incompletely understood. This review aims to shed light on the biological characteristics of IL-10, its involvement in the uveitis pathophysiology, and its potential as a novel therapeutic target. By examining existing literature, the review analyzes IL-10 expression levels and regulatory mechanisms in different types of uveitis, discussing its role in immune regulation. Despite IL-10 being expressed variably across various forms of autoimmune uveitis, studies consistently highlight its protective role, prompting research into ways to enhance its bioavailability in the eye. IL-10 is often upregulated in infectious uveitis, contributing to pathogen immune evasion. Furthermore, primary intraocular lymphoma (PIOL), which shares clinical similarities with uveitis, also shows upregulated IL-10 levels, whereas IL-6 is more commonly elevated in uveitis. This differential expression suggests that IL-6 and IL-10 could be diagnostic markers to distinguish between PIOL and uveitis. Future research should continue to focus on elucidating the molecular mechanisms of IL-10 in uveitis, exploring its potential therapeutic applications, and developing targeted treatments that leverage the immunomodulatory effects of IL-10 to prevent and manage this sight-threatening condition.

Shelterin dysfunction promotes CD4+ T cell senescence in Behçet's disease

OBJECTIVES

To investigate the potential role of shelterin dysfunction in naïve CD4+ T cells in the pathogenesis of Behçet's disease (BD).

METHODS

Naïve CD4+ T cells were isolated from 40 BD patients and 40 sex- and age-matched healthy controls (HC). Senescent profiles, shelterin subunits expression, telomere length, telomerase activity and critical DNA damage response (DDR) were evaluated. Telomere repeat factor-2 (TRF2) silencing was conducted for further validation.

RESULTS

Compared with HC, BD patients had significantly decreased naïve CD4+ T cells, increased cell apoptosis, senescence, and productions of TNF-α and IFN-γ upon activation. Notably, BD naïve CD4+ T cells had shortened telomere, impaired telomerase activity, and expressed lower levels of shelterin subunits TRF2, TRF1- and TRF2-Interacting Nuclear Protein 2 (TIN2) and Repressor/Activator Protein 1 (RAP1). Furthermore, BD naïve CD4+ T cells exhibited significantly increased DDR, evidenced by elevated phosphorylated ataxia telangiectasia (AT) mutated (pATM), phosphorylated p53 (pp53) and p21. Finally, TRF2 silencing markedly upregulated DDR, apoptosis and proinflammatory cytokines production in HC naïve CD4+ T cells.

CONCLUSION

Our study demonstrated that TRF2 deficiency in BD naïve CD4+ T cells promoted cell apoptosis and senescence, leading to proinflammatory cytokines overproduction. Therefore, restoring TRF2 might be a promising therapeutic strategy for BD.

Association of IL-23R and IL-10 variations with Behçet disease: a genetic analysis study

Behçet disease (BD) is an autoimmune and autoinflammatory disease mainly affecting the Silk Road countries. The interindividual severity of BD depends on differences in the polymorphic profiles of the patients. One of the most prominent markers, HLA-B51 positivity, is also observed in 40-60% of patients with BD on the Silk Road. Inflammatory markers such as interleukin 10 (IL-10) and interleukin 23 receptor (IL-23R) are also widely associated with BD etiology. The polymorphisms on these genes may change the susceptibility to BD. In this case-control study, we assessed the associations of IL-10 rs3024498 and IL-23R rs10889677 single-nucleotide polymorphisms (SNPs) with BD susceptibility, if any. Two hundred eighty HLA-B51-positive patients with BD and 300 healthy controls were genotyped for these SNPs using RFLP-PCR. The chi-square test was used for genotyping. We found that IL-23R rs10889677 CC and IL-10 rs3024498 CT genotype frequencies were higher in the BD group than in the control group (p < 0.0001 and p = 0.0293, respectively). The recessive model (AA + CC vs. AC) and combined genotype (AC + CT) results were also statistically significant (p < 0.0001 and p = 0.0364, respectively). We conclude that IL-23R rs10889677 and IL-10 rs3024498 SNPs may be associated with the susceptibility to BD.

Th1-related transcription factors and cytokines in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an inflammatory disorder related to immunity dysfunction. The Th1 cell family including Th1 cells, transcription factor T-bet, and related cytokines IFNγ, TNFα, IL-2, IL-18, TGF-β, and IL-12 have been widely discussed in autoimmunity, such as SLE. In this review, we will comprehensively discuss the expression profile of the Th1 cell family in both SLE patients and animal models and clarify how the family members are involved in lupus development. Interestingly, T-bet-related age-associated B cells (ABCs) and low-dose IL-2 treatment in lupus were emergently discussed as well. Collection of the evidence will better understand the roles of the Th1 cell family in lupus pathogenesis, especially targeting IL-2 in lupus.

Interferon-α2a induces CD4+ T cell apoptosis and suppresses Th1/Th17 responses via upregulating IRF1-mediated PDL1 expression in dendritic cells from Behcet's uveitis

Recombinant interferon-α2a (IFNα2a) has been widely used in the treatment of Behcet's uveitis (BU). However, the mechanism underlying its effects remains poorly understood. In this study, we investigated its effect on dendritic cells (DCs) and CD4⁺ T cells, which are essential for the development of BU. Our results showed that the expression of PDL1 and IRF1 was significantly decreased in DCs from active BU patients, and IFNα2a could significantly upregulate PDL1 expression in an IRF1-dependent manner. IFNα2a-treated DCs induced CD4⁺ T cells apoptosis and inhibited the Th1/Th17 immune response in association with reduced secretion of IFN-γ and IL-17. We also found that IFNα2a promoted Th1 cell differentiation and IL-10 secretion by CD4⁺ T cells. Finally, a comparison of patients before and after IFNα2a therapy revealed that the frequencies of Th1/Th17 cells significantly decreased in association with remission of uveitis after IFNα2a therapy. Collectively, these results show that IFNα2a could exert its effects by modulating the function of DCs and CD4⁺ T cells in BU.

Regulatory T cells and systemic vasculitis

PURPOSE OF THE REVIEW

Emerging data suggest that regulatory T-cells (Treg) alterations play a major role in systemic vasculitis pathophysiology. We performed a systematic review of recent advances in the role of Treg and interleukin (IL)-10 in the pathogenesis and treatment of systemic vasculitis, including giant cell arteritis (GCA), Takayasu arteritis, Behçet's disease, antineutrophil cytoplasm antibodies (ANCA) associated vasculitis (AAV), and cryoglobulinemia associated vasculitis.

RECENT FINDINGS

Emerging data suggest that Treg deficiencies are disease-specific, affecting distinct pathways in distinct vasculitides. Decreased peripheral blood frequencies of Treg are described in all vasculitis when compared to healthy donors. Altered Treg functions are reported in GCA, Takayasu arteritis, AAV, and Behçet's disease with different mechanisms proposed. Treatment with biologics, and sometimes other immunosuppressants, may restore Treg frequencies and/or immune activity with significant differences in active disease or disease in remission in several systemic vasculitis. IL-10 is elevated in GCA, AAV, cryoglobulinemia associated vasculitis. In Behçet's disease, IL-10 is decreased in peripheral blood and elevated in saliva. In Takayasu arteritis, IL-10 levels were essentially elevated in patients' vessel wall. Several new therapeutic approaches targeting Treg and Il-10 (low dose IL-2, CAR Treg…) are developed to treat patients with systemic vasculitis.

SUMMARY

Treg and IL-10 play a central role in the regulation of inflammation in vasculitis and new targeting approaches are emerging.

T cells in ocular autoimmune uveitis: Pathways and therapeutic approaches

Autoimmune uveitis is a non-infectious intraocular condition that affects the uveal tract of the eye and threatens vision if not treated properly. Increasing evidence suggests that activated CD4⁺ T cells are associated with progressive and permanent destruction of photoreceptors in ocular autoimmune diseases. As such, the purpose of this review is to offer an overview of the role of CD4⁺ T cells in autoimmune uveitis as well as a justification for the current development and assessment of innovative autoimmune uveitis medications targeting CD4⁺ T cells. With an emphasis on T helper (Th)17, Th1, and Th2 cells, follicular helper CD4⁺ T cells, and regulatory T cells, this review presents a summary of recent research related to the pathways and signaling that encourage CD4⁺ T cells to develop into specialized effector cells. We also describe immunotherapeutic approaches based on CD4⁺ T cell subsets and their potential as therapeutic agents for autoimmune disorders.

Understanding Immune Responses to Viruses-Do Underlying Th1/Th2 Cell Biases Predict Outcome?

Emerging and re-emerging viral diseases have increased in number and geographical extent during the last decades. Examples include the current COVID-19 pandemic and the recent epidemics of the Chikungunya, Ebola, and Zika viruses. Immune responses to viruses have been well-characterised within the innate and adaptive immunity pathways with the outcome following viral infection predominantly attributed to properties of the virus and circumstances of the infection. Perhaps the belief that the immune system is often considered as a reactive component of host defence, springing into action when a threat is detected, has contributed to a poorer understanding of the inherent differences in an individual's immune system in the absence of any pathology. In this review, we focus on how these host factors (age, ethnicity, underlying pathologies) may skew the T helper cell response, thereby influencing the outcome following viral infection but also whether we can use these inherent biases to predict patients at risk of a deviant response and apply strategies to avoid or overcome them.

Indications and effects of biological agents in the treatment of noninfectious uveitis

Noninfectious uveitis is a common blinding eye disease, and an autoimmune response is involved in its pathogenesis. Biological agents have gradually been introduced into the treatment of noninfectious uveitis. The authors reviewed the clinical application and side effects of different biological agents on noninfectious uveitis. Biological agents that target TNF-α are widely used in the clinic. Other biological agents, such as IL-6- and IL-1-neutralizing antibodies, are used in patients who do not respond to TNF inhibitors. The efficacy of IL-17 neutralizing antibodies in noninfectious uveitis is controversial. Biological agents targeting T cells and signaling pathways provide new drug options for treatment of noninfectious uveitis. However, it cannot be ignored that these biological agents have side effects, such as increasing risk of infection.

The Th17 Pathway in Vascular Inflammation: Culprit or Consort?

The involvement of IL-17A in autoimmune and inflammatory diseases has prompted the development of therapeutic strategies to block the Th17 pathway. Promising results came from their use in psoriasis and in ankylosing spondylitis. IL-17A acts on various cell types and has both local and systemic effects. Considering the premature mortality observed during chronic inflammatory diseases, IL-17A action on vascular cells was studied. Both in vitro and in vivo results suggest that this cytokine favors inflammation, coagulation and thrombosis and promotes the occurrence of cardiovascular events. These observations led to study the role of IL-17A in diseases characterized by vascular inflammation, namely allograft rejection and vasculitis. Increased circulating levels of IL-17A and histological staining reveal that the Th17 pathway is involved in the pathogenesis of these diseases. Vasculitis treatment faces challenges while the use of steroids has many side effects. Regarding results obtained in giant cell arteritis with IL-6 inhibitors, a cytokine involved in Th17 differentiation, the use of anti-IL-17 is a promising strategy. However, lessons from rheumatoid arthritis and multiple sclerosis must be learnt before targeting IL-17 in vasculitis, which may be culprit, consort or both of them.

Saliva and Serum Cytokine Profiles During Oral Ulceration in Behçet's Disease

Behçet's disease (BD) is a chronic, multi-systemic disorder of unknown aetiology typified by recurrent oral and genital mucocutaneous lesions, uveitis and vasculitis. Innate and adaptive immune system dysregulation has been implicated in pathogenesis with alterations in serum cytokine profiles. Few studies have investigated salivary cytokines in BD, despite more than 90% of BD patients first presenting with oral ulceration. The aim of this pilot study was twofold; firstly to investigate whether cytokine levels in matched serum and saliva samples show a differential profile in BD (with and without oral ulcers), recurrent aphthous stomatitis (RAS) and healthy controls (HCs), and secondly, to explore if any differential profiles in serum and/or saliva could provide a panel of cytokines with diagnostic and therapeutic potential for BD. Concentrations of 12 cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IFN-γ, TNF-α, TNF-β) were measured using the Human Th1/Th2 11-Plex FlowCytomix™ kit with IL-17A, in BD (N=20), RAS (N=6) and HCs (N=10). A differential range of cytokines was detected in serum and saliva with the majority of cytokine levels higher in saliva. The most prevalent salivary cytokines were IL-1β, IL-2, IL-8, IL-10 and TNF-α present in all samples in contrast to serum where the most prevalent cytokine detected was IL-8 (91.9%). The least abundant cytokine was IFN-γ in both saliva (43.2%) and serum (2.7%). After normalizing saliva for protein content, BD patients with oral ulcers (BD-MA) had significantly higher levels of salivary IL-1β (p=0.01), IL-8 (p=0.02), TNF-α (p=0.004) and IL-6 (p=0.01) than HCs. Notably, BD patients without oral ulcers (BD-MQ) also had significantly higher salivary IL-1β, IL-8 and TNF-α (p ≤ 0.05) than HCs. During relapsed (BD-RE) and quiet (BD-Q) systemic episodes, salivary IL-β and TNF-α were also significantly increased with IL-8 significantly higher only in BD-Q (p=0.02). BD oral ulcers signify a potential reactivation of systemic inflammation. Identifying cytokines released during asymptomatic episodes and oral ulceration might lead to targeted drug therapy to prevent recurrent oral ulcers and possible disease relapse. This is the first study to report salivary cytokine levels in BD. The detectable levels suggests cytokine profiling of BD saliva may provide an alternative, less invasive, sensitive procedure for frequent monitoring of disease activity and progression.

Immunopathogenesis of Behçet's disease and treatment modalities

INTRODUCTION

Behçet's disease (BD) is an auto-inflammatory disease, primarily characterized by recurrent painful mucocutaneous ulcerations.

METHODS

A literature search was performed to write a narrative review into the pathogenesis and current treatment options of BD.

RESULTS

The pathogenesis of BD remains to be elucidated, but is considered a genetically primed disease in which an external trigger causes immune activation resulting in inflammatory symptoms. GWAS data show an association between multiple genetic polymorphisms (HLA-B51, ERAP1, IL10 and IL23R-IL12RB2) and increased susceptibility to BD. Bacteria as streptococci, an unbalanced microbiome or molecular mimicry trigger the inflammation in BD. Increased production or responsiveness of pro-inflammatory components of the innate immune response (TLR, neutrophils, NK-cells or γδ T-cells) to these triggers may be a crucial step in the pathogenesis of BD. Additionally to an increased autoinflammatory response there is evidence of a dysregulated adaptive immune system, with a disturbed Th1/Th2 balance, expansion of Th17 cells and possibly a decrease in regulatory T cells, resulting in a surplus in pro-inflammatory cytokines. The inflammation causes a typical clinical phenotype including orogenital ulcerations, uveitis and skin lesions. Treatment is aimed at the aberrations found in the innate (neutrophils and γδ-T cells) and adaptive immune system (TNF-α, INF-γ, IL-1), directed at organ involvement and individualized based on patient characteristics.

CONCLUSION

We presented an extensive review into the pathogenesis and treatment options of BD.

Wip1 regulates the immunomodulatory effects of murine mesenchymal stem cells in type 1 diabetes mellitus via targeting IFN-α/BST2

Mesenchymal stem cells (MSCs) show significant therapeutic effects in type 1 diabetes mellitus (T1DM) as regulating the inflammatory processes. However, little is known about the detailed process of MSCs immunosuppression in T1DM. In this study, we investigated the effects of wild-type p53-induce phosphatase 1 (Wip1) on regulating MSCs immunosuppressive capacities in T1DM mice. We found that Wip1 knockout (Wip1-/-) MSCs had lower therapeutic effects in T1DM mice, and displayed weaker immunosuppressive capability. In vivo distribution analysis results indicated thatWip1-/-MSCs could home to the damaged pancreas and increase the expression of tumor necrosis factor-α (TNF-α), interleukin-17a (IL-17a), interferon-α(IFN-α), IFN-β, and IFN-γ, while decrease the expression of IL-4 and IL-10. Moreover, we confirmedWip1-/-MSCs exhibited weaker immunosuppressive capacity, as evidenced by enhanced expression of bone marrow stromal cell antigen 2(BST2) and IFN-α. In conclusion, these results revealed Wip1 affects MSCs immunomodulation by regulating the expression of IFN-α/BST2. Our study uncovered that Wip1 is required to regulate the therapeutic effects of MSCs on T1DM treatment, indicating a novel role of Wip1 in MSCs immunoregulation properties.

Experimental Therapeutic Solutions for Behcet's Disease

Behcet's disease (BD) is a chronic systemic vasculitis with inflammation attacks that involve multiple organs. In addition to numerous mucocutaneous symptoms, notably recurrent oral and genital ulcers, ocular, articular, vascular, gastrointestinal, cardiac, and neurological system involvement can be observed. Mucocutaneous lesions are the primary symptom of the disease in most patients, and they usually occur before major organ involvement and other symptoms of the disease. Recognizing the disease's mucocutaneous lesions is very important to diagnose at an early stage, control with appropriate treatment and close follow-up, and prevent major organ involvement. Genome-wide association studies (GWAS) in recent years have confirmed that HLA-B*51 is the most significant genetic predisposing factor. The majority of gene polymorphisms have been detected in molecules that respond to microorganisms and genes encoding cytokines and adhesion molecules. The infectious agent S. sanguinis -commonly found in the oral mucosa of patients with BD- or the differences in the salivary or intestinal microbiome composition can trigger innate immune-mediated inflammation sustained by acquired or adaptive immune responses. In antigen-presenting cells (APCs), epistatic interactions between HLA-B*51 and endoplasmic reticulum aminopeptidase 1 (ERAP1) variants lead to the disruption of T-cell homeostasis, especially the activation of Type1 T-helper and Th17 pathway and suppression of regulatory T-cells. Recent developments to clarify the disease's etiopathogenesis provided us with a better understanding of the mechanism of action of the relatively old drugs while opening a way for many new treatment methods. Apremilast has become an important option in the treatment of mucocutaneous symptoms with its high efficacy and safety. The disease increases the mortality rate, especially in young male patients. New treatments, especially anti-TNF-α agents, have provided significant progress and decreased the mortality rates with their rapid effect and high efficacy in patients with severe organ involvement and resistance to traditional immunosuppressive and immunomodulatory therapies. The use of IL-1, IL-6, IL-17, IL-12/IL-23 antagonists in different organ involvement has gradually increased, and the quality of life has significantly improved in many patients.

Safety of systemic treatments for Behçet's syndrome

INTRODUCTION

Treatment of Behçet's syndrome (BS) is aimed at controlling all symptoms of such a complex disorder, ensuring a good quality of life and preventing life-threatening complications. A better understanding of the pathogenic role of different chemokines has improved our knowledge of BS and elicited a more specific use of therapies currently available, minimizing the burden of potential side-effects related to treatment.

AREAS COVERED

This work aims to provide a detailed overview of the safety profile for current therapies available in the treatment of BS, focusing on the main side-effects, toxicity and contraindications.

EXPERT OPINION

The greatest experience in the management of BS has been achieved with the employment of monoclonal anti-tumor necrosis factor antibodies which have been advocated for BS refractory manifestations. Moreover, interleukin-1 inhibitors have proven to be effective as well as safe, despite escalation of their dosage, especially to manage the most severe and difficult-to-treat ocular manifestations. However, general treatment of BS patients remains awkward as protean clinical features may respond differently to the same treatment or even worsen. Therefore, patients' safety for therapies used in BS promotes the implementation of precision medicine, which could help targeting accurately the pathogenetic mechanisms concealed behind specific clinical phenotypes.

Clinical course of acute deep vein thrombosis of the legs in Behçet's syndrome

OBJECTIVES

Lower extremity deep vein thrombosis (LEDVT) is a serious complication of Behçet's syndrome. Management constitutes mainly of administration of immunosuppressives, but the predictors of relapse and the optimal choice of immunosuppressives remain unclear. In this prospective study, we aimed to detect the risk and predictors of relapse and treatment response to different modalities.

METHODS

All Behçet's syndrome patients who presented with a first episode of acute LEDVT between 2010 and 2014 were prospectively followed with a standard protocol. Acute LEDVT was confirmed by Doppler ultrasonography. Serial planned Doppler ultrasonography assessments were performed during follow-up and additionally repeated in case of clinical suspicion. Recanalization rate was assessed at each visit. Our first-line treatment strategy consisted of AZA and CSs. IFN-alpha was used in patients who were refractory to or could not tolerate AZA or had concomitant eye involvement requiring further treatment.

RESULTS

Thirty-three patients with LEDVT (26 M/7 F) were prospectively followed for 40.7 ± 13.4 months. Among the 33 patients, 23 relapses were observed in 15 patients. Relapse rates were 29%, 37% and 45% at 6, 12 and 24 months, respectively. Among the possible predictors of relapse, poor recanalization was the only significant factor [hazard ratio 4.34 (95% CI 1.96, 10.0)]. Overall 29 patients were treated with AZA and 17 with IFN-alpha. The relapse rate was lower and recanalization rate was higher with IFN-alpha compared with AZA (12% vs 45% and 86% vs 45%).

CONCLUSION

The relapse rate for LEDVT in Behçet's syndrome is high despite AZA treatment. IFN-alpha seems to be a promising agent for preventing LEDVT relapses and achieving good recanalization.

Behçet's Disease in Children: Diagnostic and Management Challenges

Behçet’s Disease (BD) is an inflammatory disease of unknown etiology with multisystemic involvement, being the main clinical manifestations represented by recurrent oral and genital ulcerations and uveitis. The disease has typically a chronic-relapsing course and may cause significant morbidity and mortality due to eye, vascular and neurological involvement. Although BD is more frequently diagnosed in adulthood, the disease onset can also be in pediatric age. Pediatric-onset BD is commonly featured by an incomplete clinical picture, and therefore the diagnosis represents a considerable clinical challenge for the physicians. The first classification criteria for pediatric BD, based on a scoring system, have been proposed few years ago. This work focuses on the main difficulties concerning both the diagnostic approach and the treatment of BD in pediatric age. The recommendation for the treatment of pediatric BD has been recently updated and allowed a considerable improvement of the therapeutic strategies. In particular, the use of anti-TNFα drugs as a second-line option for refractory BD, and as a first-line treatment in severe ocular and neurological involvement, has demonstrated to be effective in improving the outcome of BD patients. The knowledge about the molecular pathogenesis is progressively increasing, showing that BD shares common features with autoimmune and autoinflammatory disorders, and thus leading to the use of new biologic agents targeting the main mediators involved in the determination of BD. Anti-IL-17, anti-IL-23, anti-IL-1 and anti-IL-6 agents have shown promising results for the treatment of refractory BD in clinical trials and will represent an important alternative for the therapeutic approach to the disease.

Can Unconventional Immunomodulatory Agents Help Alleviate COVID-19 Symptoms and Severity?

Severe acute respiratory syndrome coronavirus 2 (SARS coronavirus 2, or SARS-CoV-2) is the cause of the respiratory infection known as COVID-19. From an immunopathological standpoint, coronaviruses such as SARS-CoV-2 induce increased levels of a variety of T-helper 1 (Th1) and inflammatory cytokines and chemokines, including interleukin-1 (IL-1), IL-6, CCL2 protein, and CXCL10 protein. In the absence of proven antiviral agents or an effective vaccine, substances with immunomodulatory activity may be able to inhibit inflammatory and Th1 cytokines and/or yield an anti-inflammatory and/or Th2 immune response to counteract COVID-19 symptoms and severity. This report briefly describes the following four unconventional but commercially accessible immunomodulatory agents that can be employed in clinical trials to evaluate their effectiveness at alleviating disease symptoms and severity: low-dose oral interferon alpha, microdose DNA, low-dose thimerosal, and phytocannabinoids.

AAV Mediated Delivery of Myxoma Virus M013 Gene Protects the Retina against Autoimmune Uveitis

Uveoretinitis is an ocular autoimmune disease caused by the activation of autoreactive T- cells targeting retinal antigens. The myxoma M013 gene is known to block NF-κB (Nuclear Factor kappa-light-chain-enhancer of activated B cells) and inflammasome activation, and its gene delivery has been demonstrated to protect the retina against lipopolysaccharide (LPS)-induced uveitis. In this report we tested the efficacy of M013 in an experimental autoimmune uveoretinitis (EAU) mouse model. B10RIII mice were injected intravitreally with AAV (adeno associated virus) vectors delivering either secreted GFP (sGFP) or sGFP-TatM013. Mice were immunized with interphotorecptor retinoid binding protein residues 161–180 (IRBP_161–180) peptide in complete Freund’s adjuvant a month later. Mice were evaluated by fundoscopy and spectral domain optical coherence tomography (SD-OCT) at 14 days post immunization. Eyes were evaluated by histology and retina gene expression changes were measured by reverse transcribed quantitative PCR (RT-qPCR). No significant difference in ERG or retina layer thickness was observed between sGFP and sGFP-TatM013 treated non-uveitic mice, indicating safety of the vector. In EAU mice, expression of sGFP-TatM013 strongly lowered the clinical score and number of infiltrative cells within the vitreous humor when compared to sGFP treated eyes. Retina structure was protected, and pro-inflammatory genes expression was significantly decreased. These results indicate that gene delivery of myxoma M013 could be of clinical benefit against autoimmune diseases.

Increased expression of hub gene CXCL10 in peripheral blood mononuclear cells of patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease, characterized by overactive inflammation and aberrant activation of lymphocytes. Chemokine C-X-C motif ligand 10 (CXCL10) has an important role in the initiation and deterioration of SLE. However, the expression levels of CXCL10 mRNA in T-helper (Th) cells and B lymphocytes from SLE patients have remained elusive. In the present study, a Bioinformatics analysis of differentially expressed gene (DEG) profiles obtained from RNA sequencing data for three matched samples was performed to explore the hub genes, mainly through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes and protein-protein interaction analysis. Furthermore, the expression of CXCL10 in peripheral blood mononuclear cells (PBMCs), CD4⁺ Th cells and CD19⁺ B cells of 108 subjects, including 66 SLE patients and 42 healthy controls, was confirmed by reverse transcription-quantitative PCR. In addition, 4 single-nucleotide polymorphism (SNP) loci in the 3'-untranslated region of CXCL10 were assessed using the Snapshot SNP genotyping assay. A total of 152 clustered DEGs mainly accumulated in immune-associated GO terms and interferon-associated pathways were identified. The expression of CXCL10, one of the central genes in the interaction network cluster (the degree of interaction, MCODE score=28.414), was 6.27-fold higher in SLE patients compared with control patients. Furthermore, CXCL10 mRNA was confirmed to be elevated in PBMCs and CD19⁺ B cells of patients with SLE (P<0.001 for the two cell types). However, no significant difference in CD4⁺ T lymphocytes was present (P=0.881). In addition, no polymorphism was identified in four selected loci from the samples. Taken together, the present results demonstrated that CXCL10, one of the hub genes in the pathogenesis of SLE, is upregulated in PBMCs and B lymphocytes of patients with SLE, although none of the SNPs selected for analysis in the present study were identified to have any potential associations with SLE.

Long-Term Outcome of Ustekinumab Therapy for Behçet's Disease

OBJECTIVE

Oral ulcers, the hallmark lesion of Behçet's disease (BD), can be disabling and resistant to conventional treatment, and there is a need for safe and effective treatment. We undertook this study to investigate the long-term safety and efficacy of ustekinumab therapy for BD-related oral ulcers that are resistant to colchicine.

METHODS

This multicenter, prospective, open-label study included 30 patients who fulfilled the criteria of the International Study Group for BD and who were diagnosed as having active oral ulcers resistant to colchicine. Patients were treated subcutaneously with ustekinumab 90 mg at inclusion, at week 4, and then once every 12 weeks. Each patient was assessed longitudinally for the presence and number of oral ulcers, and median numbers of oral ulcers (with interquartile range [IQR]) were calculated. The primary efficacy end point was the proportion of patients at week 12 who experienced complete response, defined as having no oral ulcers.

RESULTS

The median number of oral ulcers per patient during ustekinumab therapy was significantly lower at week 12 compared to baseline (0 [IQR 0-1] versus 2 [IQR 2-3]; P < 0.0001). Complete response was achieved in 60.0% and 88.9% of patients at weeks 12 and 24, respectively. The median Behçet's Syndrome Activity Score (in which higher scores indicate more active disease) was significantly lower at weeks 12 and 24 (17.5 [IQR 10-42.5] and 10 [IQR 8-11], respectively) versus baseline (70 [IQR 50-70]; P < 0.0001). After a median follow-up of 12 months (IQR 6-16 months), 26 patients (86.7%) were still receiving ustekinumab treatment. Reasons for ustekinumab discontinuation included BD flare (n = 3) and side effects (n = 1). Seven patients (23.3%) experienced adverse events, including headaches (n = 4) and asthenia (n = 2), with no serious side effects.

CONCLUSION

Ustekinumab seems to be effective in treating BD-related oral ulcers that are resistant to treatment with colchicine.

Effect of Interferon alfa-2a Treatment on Adaptive and Innate Immune Systems in Patients With Behçet Disease Uveitis

Purpose

To investigate the effect of interferon alfa-2a on T regulatory (Treg) cells, T helper 17 (Th17) cells, and expression of Toll-like receptors (TLRs) in Behçet disease (BD) patients with uveitis.

Methods

Twenty-seven patients who received interferon alfa-2a for active BD uveitis despite conventional immunomodulatory therapies and healthy controls were enrolled. Peripheral blood Treg and Th17 cell frequencies were determined by flow cytometry as gated cells for CD3+CD4+Foxp3+ and CD3+CD4+IL17A+, respectively. Th17 RAR-related orphan receptor (ROR)γt mRNA expression was verified by real-time PCR (RT-PCR). Treg and Th17 cell cytokines were detected by ELISA in the supernatant of short-term cell cultures. RT-PCR was used to assess expression of TLR-2, TLR-3, TLR-4, TLR-8, and TLR-9 using cDNA prepared from CD4+ T cells and monocytes.

Results

Treg and Th17 cell frequencies and Th17 RORγt expression were significantly elevated, and IL-10 concentration in Treg cell supernatants was significantly lower in BD patients than in controls. Th17 IL-17, IL-6, IL-21, IL-22, IL-23, IFN-γ, and TNF-α concentrations were significantly higher and all TLR expressions were significantly elevated in patients. Interferon alfa-2a led to a significant reversal in Treg and Th17 cell frequencies, Th17 RORγt expression, Treg and Th17 cell cytokine production, and TLR expression by CD4+ T cells and monocytes.

Conclusions

Despite a relative increase in Treg cells, impaired IL-10 production suggests that Treg dysfunction may play a role in induction of BD uveitis. Favorable effects of interferon alfa-2a may be associated with recovery of Treg cell function, suppression of Th17 cells, and reduced expression of TLRs on CD4+ T cells and monocytes.

Behçet's Disease: An Overview of Etiopathogenesis

Behçet's disease (BD) is a systemic inflammatory disease with a chronic, relapsing-remitting course of unknown etiology hallmarked predominantly by mucocutaneous lesions and ocular involvement. BD shares some common features with autoimmune and autoinflammatory diseases and spondyloarthropathies (MHC-I-opathies). It is related to more than one pathogenic pathway triggered by environmental factors such as infectious agents in genetically predisposed subjects. The interplay between genetic background and immune system is linked to the BD presentation. Genetic factors have been investigated extensively, and several recent genome-wide association studies have confirmed HLA-B ^* 51 to be the strongest genetic susceptibility factor. However, new non-HLA susceptibility genes have been identified. Genetic variations in the genes encoding the cytokines could affect their function and be associated with disease susceptibility. Infectious agents such as Streptococcus sanguinis or the differences in salivary or gut microbiome composition can be considered to trigger the innate-derived inflammation, which is, subsequently, sustained by adaptive immune responses. Altered trimming of microbial and/or endogenous peptides by endoplasmic reticulum aminopeptidase 1 (ERAP1), presented by HLA-B ^* 51, may play a key role in BD pathogenesis causing an alteration in T cell balance with downregulation of Tregs and expansion of Th1 and Th17. The activity of neutrophils is increased and there is an intense neutrophil infiltration in the early stage of inflammation in organs affected by the disease. Association with HLA-B ^* 51 and increased IL-17 response seems to have an important role in neutrophil activity. In this paper, we provide an overview of the most recent advances on BD etiopathogenesis.

Immunopathogenesis of Behcet's Disease

Behcet's disease (BD) is a chronic systemic inflammatory vasculitis of unknown etiology characterized by recurrent episodes of oral aphthous ulcers, genital ulcers, skin lesions, ocular lesions, and other manifestations. Although the pathogenesis of BD is unclear, some studies have shown that immunological aberrations play an important role in the development and progression of BD. Infection-related trigger factors, including antigens and autoantigens, are believed to mediate the development of BD in patients with a genetic predisposition and subsequently activate the innate and adaptive immune systems, resulting in the production of numerous cytokines and chemokines to combat the infection-related factors. The study of the immunological mechanism of BD paves the way for the development of innovative therapies. Recently, novel biotherapy approaches, including interferon-α (IFN-α), tumor necrosis factor-α (TNF-α) antagonists, and other agents that target interleukins and their receptors, have shown promising results in the treatment of patients with refractory BD and have improved the prognosis of BD. In this review, we provide the current concepts of BD immunopathogenesis.

[Efficacy and safety of metformin for Behcet's disease and its effect on Treg/Th17 balance: a single-blinded, before-after study]

OBJECTIVE

Behcet's disease (BD) is an autoimmune disorder that causes most commonly mouth and genital ulcerations and erythema nodules of the skin and currently has limited options of therapeutic medicines. Metformin is recently reported to suppress immune reaction, and we hypothesized that metformin could be an option for treatment of BD.

METHODS

Thirty patients with BD were enrolled in this perspective single-blinded, before-after study. We recorded the changes in the mucocutaneous activity index for BD (MAIBD), relapse frequency, C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) after metformin treatment to assess the changes in the disease activity. We also analyzed the changes in the protein and mRNA expression levels of Foxp3, interleukin-35 (IL-35), transforming growth factor-β (TGF-β), Ror-γt, IL-17, and tumor necrosis factor-α (TNF-α) in these patients using ELISA and qRT-PCR.

RESULTS

Of the 30 patients enrolled, 26 completed the trial. After the treatment, favorable responses were achieved in 88.46% (23/26) of the patients, and partial remission was obtained in 11.54% (4/26) of them. During the treatment, 8 patients complained of gastrointestinal side effects, for which 4 chose to withdraw from the study in the first week. Our results showed that metformin treatment decreased MAIBD and relapse frequency in the patients, and significantly lowered the clinical inflammatory indexes including CRP and ESR. The results of ELISA and qRT-PCR revealed that metformin treatment obviously increased Foxp3 and TGF-β expressions at both the protein and mRNA levels and significantly decreased the levels of ROR-γt, IL-17 and TNF-α as well as IL-35 level in these patients.

CONCLUSIONS

Metformin treatment relieves the clinical symptoms, reduces the inflammatory reaction indexes and regulates the Treg/Th17 axis in patients with BD, suggesting the potential of metformin as a candidate medicine for treatment of BD.

Unmet Needs in the Pathogenesis and Treatment of Vasculitides

Despite the progress in the last years on the field of vasculitides, there are several unmet needs regarding classification, disease activity assessment, predictors of flares and complications, and type of treatment for the different forms. The 1990 American College of Rheumatology (ACR) classification criteria currently used to define giant cell arteritis and Takayasu arteritis were designed to discriminate between different types of vasculitides but not to differentiate vasculitis from other disorders. Recently, efforts have been made to overcome the shortcomings of the ACR criteria. The lack of an accepted definition of disease activity in large-vessel vasculitides presents a major challenge in creating useful and valid outcome tools for the assessment of disease course. Identification of predictors of flares can aid in optimizing therapeutic strategies, minimizing disease flares, and reducing treatment-related side effects. It is furthermore important to recognize and characterize the risk factor that might predict the manifestations associated with poor outcome and prognosis. Two RCTs have evidenced the efficacy of tocilizumab in addition to glucocorticoids (GCs) in the treatment of giant cell arteritis (GCA). However, the role of tocilizumab or other biological agents without GCs needs to be investigated. Recent observational studies have suggested that rituximab is also effective in patients with eosinophilic granulomatosis with polyangiitis and in antineutrophil cytoplasmic antibodies (ANCA)-negative patients with granulomatosis with polyangiitis and microscopic polyangiitis. Rituximab or anti-TNF alfa may represent a possible alternative therapy in case of refractory or difficult to treat polyarteritis nodosa (PAN) patients. The new International Criteria for Behçet's Disease have shown a better sensitivity and a better accuracy compared to the older International Study Group on Behçet's Disease criteria. The EULAR recommendations for the management of Behçet's disease (BD) have been recently updated. However, the treatment of refractory disease is still a real challenge.

Elevated expression of TSLP and IL-33 in Behçet's disease skin lesions: IL-37 alleviate inflammatory effect of TSLP

The release of TSLP and IL-33 affect the skin integrity, which unsettled transcription factor regulators. We investigate TSLP and IL-33 in Behçet disease (BD) and we prove the effect of the anti-inflammatory cytokine IL-37 in BD skin lesions on TSLP production. TSLP, IL-33 and GATA-3/T-bet, were measured using PCR in BD skin lesions. We tested the suppressive effect of IL-37 on skin samples stimulated with a cytokine mixture inducing TSLP expression. TSLP and IL-33 were increased in BD patients particularly in patients having skin manifestations and correlate with indexed skin lesions. TSLP expression in BD with skin lesions correlates significantly with the transcription factors GATA3/Tbet ratio. The anti-inflammatory mediator IL-37 acted as a suppressor of TSLP-skin synthesis. The microenvironment in cutaneous lesions of BD patients' skin lesions is dominated by the expression of IL-33 and TSLP along an inflammatory Th2-type current. IL-37 acts as a booster to restore homeostasis.

Interleukin-26 is overexpressed in Behçet's disease and enhances Th17 related -cytokines

Behçet's disease (BD) is a multi-systemic inflammatory disorder characterized by the "triple symptom complex". Several pro-inflammatory cytokines, mainly derived from the immune Th17 axis, seem to be involved in different pathogenic pathways leading to development of the clinical manifestations. Here, we have analyzed the expression and role of IL-26 in active BD patients, an inflammatory disorder characterized by bronchoalveolar lavage fluid (BAL) and cerebrospinal fluid (CSF) inflammation. On this basis, the primary aim of our work was to study IL-26 levels in serum, BAL CSF) from active BD patients. Samples were collected from 95 BD patients (55 patients were in active stage) and 50 healthy controls (HC). They were investigated with ELISA for estimation of cytokines levels. Serum concentration of IL-26 resulted higher in both active [4.80±1.32] and inactive [2.77±1.026] BD than HC [0.31±0.14ng/ml; p<0.0001]. Level of IL-26 was associated with the BD clinical severity score from moderate to severe (P<0.0001). IL-26 was highly expressed in CSF [10.80±2.05ng/ml] and in BAL [12.89±3.03ng/ml] fluid from BD patients comparatively to their respective controls. IL-26 levels in CSF and in BAL fluid showed positive correlations with IL-17 level and an inversely correlation with IL-37. Interestingly, IL-26-stimulated CD4⁺ T cells and monocytes promote the generation of Th17 (IL-17A, IL-23) and suppress Treg (IL-10, TGF-β) cytokines. Our findings may suggest a signature of IL-26 probably responsible for the inflammatory process to correlate positively with Th17 cytokines and inversely with Treg mediators. This evidence could contribute to improve the knowledge regarding the role of IL-26 in BD severity. For the first time, IL-26 expression is demonstrated in BAL and CSF, supporting a role for this cytokine in the pathogenesis of BD. IL-26 thereby appears as a novel proinflammatory cytokine favoring the generation of Th17 cytokines.

Investigational drugs in systemic vasculitis

INTRODUCTION

Treatment of systemic vasculitis is based on glucocorticoids (GC) in association with immunosuppressive therapy. There are still unmet needs, including earlier onset of response, more targeted therapies, reduction of relapse-risk and decrease of long-term GC and classic immunosuppressants toxicities. Areas covered: In this review, we discuss investigational drugs in early phase clinical trials for induction of remission in vasculitis. We focus on ANCA-associated vasculitis, Behçet's disease, giant cell arteritis, Takayasu arteritis, and cryoglobulinemic vasculitis. We performed a comprehensive review of articles published on pubmed and a review of clinical trials registered online ( https://clinicaltrials.gov ) for each vasculitis. Expert opinion: Recent progress in the pathogenesis identifies new therapeutic targets. Some of these therapies are promising in GC sparing effects, in reducing relapse rate, and for their safety profile. These results need to be confirmed in large-scale phase III studies.

The Role of Th17 Cells in the Pathogenesis of Behcet's Disease

Behcet's disease (BD) is a polysymptomatic and recurrent systemic vasculitis with a chronic course and unknown cause. The pathogenesis of BD has not been fully elucidated; however, BD has been considered to be a typical Th1-mediated inflammatory disease, characterized by elevated levels of Th1 cytokines such as IFN-γ, IL-2, and TNF-α. Recently, some studies reported that Th17-associated cytokines were increased in BD; thus, Th17 cells and the IL17/IL23 pathway may play important roles in the pathogenesis of BD. In this chapter, we focus on the pathogenic role of Th17 cells in BD.

The Role of IFN-alpha in Experimental and Clinical Uveitis

PURPOSE

IFN-α is the only treatment capable of inducing long-term remission in some patients with ocular Behçet's disease. In this review, we focus on immune mechanisms of IFN-α in animal models and patients and compare the outcome of different clinical studies.

METHODS

Review of literature using PubMed and Google and original data from rat models with monophasic/chronic or relapsing experimental autoimmune uveitis treated with IFN-α.

RESULTS

The role of IFN-α and its effect on various cell types were investigated, in some cases with contradictory results. Some patients respond very well to IFN-α treatment, while others are non-responders, which was reflected in the uveitis rat models: relapsing uveitis was ameliorated, the monophasic/chronic disease even aggravated.

CONCLUSIONS

Despite intensive investigations in patients and animal models, the immune mechanisms explaining the therapeutic effect of IFN-α in ocular Behçet's disease are not yet fully understood and need further investigation.

Circulating NK cells and their subsets in Behçet's disease

Behçet's disease (BD) is an autoinflammatory, chronic relapsing/remitting disease of unknown aetiology with both innate and acquired immune cells implicated in disease pathogenesis. Peripheral blood natural killer (NK) cells and their CD56^Dim /CD56^Bright subsets were surface phenotyped using CD27 and CD16 surface markers in 60 BD patients compared to 60 healthy controls (HCs). Functional potential was assessed by production of interferon (IFN)-γ, granzyme B, perforin and the expression of degranulation marker CD107a. The effects of disease activity (BD^Active versus BD^Quiet ) and BD medication on NK cells were also investigated. Peripheral blood NK cells (P < 0·0001) and their constituent CD56^Dim (P < 0·0001) and CD56^Bright (P = 0·0015) subsets were depleted significantly in BD patients compared to HCs, and especially in those with active disease (BD^Active ) (P < 0·0001). BD patients taking azathioprine also had significantly depleted NK cells compared to HCs (P < 0·0001). A stepwise multivariate linear regression model confirmed BD activity and azathioprine therapy as significant independent predictor variables of peripheral blood NK percentage (P < 0·001). In general, CD56^Dim cells produced more perforin (P < 0·0001) and granzyme B (P < 0·01) expressed higher CD16 levels (P < 0·0001) compared to CD56^Bright cells, confirming their increased cytotoxic potential with overall higher NK cell CD107a expression in BD compared to HCs (P < 0·01). Interestingly, IFN-γ production and CD27 expression were not significantly different between CD56^Dim /CD56^Bright subsets. In conclusion, both BD activity and azathioprine therapy have significant independent depletive effects on the peripheral blood NK cell compartment.

Mammalian target of rapamycin inhibition counterbalances the inflammatory status of immune cells in patients with chronic granulomatous disease

BACKGROUND

Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by defective production of reactive oxygen species in phagocytic cells that results in life-threatening infections and severe inflammatory manifestations. The treatment of inflammatory manifestations remains challenging because it can be associated with an increased risk of infections. Previous studies have shown that phagocytes from patients with CGD display a defect in autophagy and a reactive oxygen species-independent activation of the inflammasome.

OBJECTIVE

Because the intersections between autophagy and the inflammasome have been observed in patients with various diseases and microbial infections, we investigated the possible benefit of restoring the autophagy defect through rapamycin, a potent autophagy inducer, in the setting of CGD.

METHODS

We studied 15 patients given a diagnosis of CGD and followed in our institution. All patients were free of any active infection at the time of the study.

RESULTS

We show that patients with CGD present a consistent inflammatory phenotype defined by (1) increased nonclassical and intermediate monocytes, (2) a proinflammatory state of mononuclear phagocytes with increased IL-1β and TNF-α content, (3) a T_H17 bias of CD4⁺ T cells, (4) and an increase in IL-17A-secreting neutrophil numbers. We document the reversion of CGD inflammatory status by the mammalian target of rapamycin inhibitor rapamycin on the different immune cell subsets. We also provide evidence for the enhancement of rapamycin's inhibitory effect on IL-1β secretion by the IL-1 receptor antagonist anakinra in phagocytes of patients with CGD.

CONCLUSION

Altogether, these data open new therapeutic approaches for CGD-related inflammatory manifestations.

Low-dose oral interferon modulates expression of inflammatory and autoimmune genes in cattle

While the safety and efficacy profiles of orally administered bovine interferon (IFN) alpha have been documented, the mechanism(s) that result in clinical benefits remain elusive. One approach to delineating the molecular pathways of IFN efficacy is through the use of gene expression profiling technologies. In this proof-of-concept study, different (0, 50, 200 and 800 units) oral doses of natural bovine IFN (type I) were tested in cattle to determine if oral IFN altered the expression of genes that may be pivotal to the development of systemic resistance to viral infections such as foot-and-mouth disease (FMD). Oral IFN was administered twice: Time 0 and 8h later. Blood was collected at 0, 8 and 24h after the first IFN administration, and DNA isolated from peripheral blood mononuclear cells (PBMCs) was employed in quantitative polymerase chain reaction (qPCR) microarray assays. Within 8h, 50 and 200 units of oral IFN induced significant (P<0.05) changes in expression of 41 of 92 tested autoimmune and inflammatory response-associated genes. These data suggest that orally administered IFN is a viable approach for providing short-term antiviral immunity to livestock exposed to viruses such as FMD virus (FMDV) until such a time that an effective vaccine can be produced and distributed to producers.

Behçet's disease in children, an overview

BD is a systemic inflammatory disease with a variable vasculitis. Paediatric onset is very rare and carries a strong genetic component. Oral ulcers and fever of unknown origin are frequent at onset and difficult to distinguish from other inflammatory disorders; therefore, expert opinion is still mandatory to recognize the disease early. An international expert consensus has recently proposed new classification criteria for children with BD. The clinical spectrum of BD is heterogeneous and influenced by gender, ethnicity and country of residence. Young males have the worst prognosis with significantly more frequent neurological, ocular and vascular involvement. BD treatment is aimed at alleviating inflammation. Among all drugs, TNFα inhibitors have become a standard to control severe ocular, neurological and digestive system involvement.

Behçet's disease physiopathology: a contemporary review

Behçet’s disease, also known as the Silk Road Disease, is a rare systemic vasculitis disorder of unknown etiology. Recurrent attacks of acute inflammation characterize Behçet’s disease. Frequent oral aphthous ulcers, genital ulcers, skin lesions and ocular lesions are the most common manifestations. Inflammation is typically self-limiting in time and relapsing episodes of clinical manifestations represent a hallmark of Behçet’s disease. Other less frequent yet severe manifestations that have a major prognostic impact involve the eyes, the central nervous system, the main large vessels and the gastrointestinal tract. Behçet’s disease has a heterogeneous onset and is associated with significant morbidity and premature mortality. This study presents a current immunological review of the disease and provides a synopsis of clinical aspects and treatment options.

DNA vaccination with a gene encoding Toxoplasma gondii Rhoptry Protein 17 induces partial protective immunity against lethal challenge in mice

Toxoplasma gondii is an obligate intracellular apicomplexan parasite that affects humans and various vertebrate livestock and causes serious economic losses. To develop an effective vaccine against T. gondii infection, we constructed a DNA vaccine encoding the T. gondii rhoptry protein 17 (TgROP17) and evaluated its immune protective efficacy against acute T. gondii infection in mice. The DNA vaccine (p3×Flag-CMV-14-ROP17) was intramuscularly injected to BALB/c mice and the immune responses of the vaccinated mice were determined. Compared to control mice treated with empty vector or PBS, mice immunized with the ROP17 vaccine showed a relatively high level of specific anti-T. gondii antibodies, and a mixed IgG1/IgG2a response with predominance of IgG2a production. The immunized mice also displayed a specific lymphocyte proliferative response, a Th1-type cellular immune response with production of IFN-γ and interleukin-2, and increased number of CD8(+) T cells. Immunization with the ROP17 DNA significantly prolonged the survival time (15.6 ± 5.4 days, P < 0.05) of mice after challenge infection with the virulent T. gondii RH strain (Type I), compared with the control groups which died within 8 days. Therefore, our data suggest that DNA vaccination with TgROP17 triggers significant humoral and cellular responses and induces effective protection in mice against acute T. gondii infection, indicating that TgROP17 is a promising vaccine candidate against acute toxoplasmosis.

Putative Role of Serum Amyloid-A and Proinflammatory Cytokines as Biomarkers for Behcet's Disease

Behcet's disease (BD) is a multisystemic disorder of unknown etiology characterized by relapsing oral-genital ulcers, uveitis, and involvement of vascular, gastrointestinal, neurological, and musculoskeletal system. Although disease pathogenesis is still unclear, both innate and adaptive immunity have shown to play a pivotal role, and multiple proinflammatory cytokines seem to be involved in different pathogenic pathways that eventually lead to tissue damage.The aims of our study were to evaluate serum cytokines levels of IL-8, IL-18, IFN-α2a, IL-6, IFN-γ, CXCL10, CXCL11, CXCL9, and SAA levels in patients with BD, in comparison to healthy controls (HC), and to correlate their levels to disease activity.We included 78 serum samples obtained from 58 BD patients and analyzed a set of proinflammatory cytokines including IL-8, IL-18, IFN-α2a, IL-6, IFN-γ, CXCL10, CXCL11, and CXCL9 by multiplex bead analysis as well as SAA by enzyme-linked immunosorbent assay.Compared to HC, BD patients showed elevated cytokine levels of IL-8, IL-18, IFN-α2a, and IL-6, and low levels of CXCL11. BD patients with SAA serum levels >20 mg/L showed higher levels of proinflammatory markers than HC or group with SAA ≤20 mg/L. IL-18, IFN-α2a, and IL-6 were higher in BD group with SAA >20 mg/L than HC, while IL-8 and CXCL9 levels were higher than in patients with SAA ≤20 mg/L and HC.Active BD patients with SAA >20 mg/L exhibited elevated levels of inflammatory mediators, suggesting that may exist a relationship between SAA and proinflammatory cytokines in the intricate scenario of BD pathogenesis.