The role of CD40-CD154 interactions in autoimmunity and the benefit of disrupting this pathway

Assessment of CD40L and TSAB serum level in Graves disease patients

BACKGROUND

The autoimmune disorder known as Graves' disease. The condition is due to the binding of thyroid-stimulating immunoglobulins to the thyrotropin receptor located on the thyroid gland. The result is an excess of thyroidal hormones. symptoms of hyperthyroidism, and the formation of diffuse goiter.

OBJECTIVES

This research intends to quantify the levels of CD40L, TSAB in people who suffer from Graves' disease. It also aims to determine the relationship between TSAB and the duration of the disease, as well as analyze the role of CD40L as a predictive marker for Graves' disease using medcalc Statistical Software version 16.4.3 and SAS (2018).

METHODS

In a case-control study, randomly selected 90 graves disease patients were included, the randomly selected patients were divided equally and matched into a case group who have graves disease and graves disease-free patients as a control group. For both groups whole blood sample was examined to compare for (TSAB), and (CD40L) levels determination by ELISA technique.

RESULTS

The average serum levels of CD40L showed a highly significant correlation (P value < 0.01) among the groups examined for Graves' disease. The patient group consisted of 13 males (28.89%) and 32 females (71.11%). No significant correlation was identified between TSAB and the duration of the condition.

CONCLUSION

Thyroid stimulating antibody (TSAb) test and ultrasonography of the thyroid gland are valuable diagnostic techniques for autoimmune Graves' disease (GD). CD40L could potentially serve as a predictive diagnostic marker for Graves' disease. However, there is no observed link between the duration of the disease and the concentration of TSAB.

Co-stimulators CD40-CD40L, a potential immune-therapy target for atherosclerosis: A review

The interaction between CD40 and CD40 ligand (CD40L) a crucial co-stimulatory signal for activating adaptive immune cells, has a noteworthy role in atherosclerosis. It is well-known that atherosclerosis is linked to immune inflammation in blood vessels. In atherosclerotic lesions, there is a multitude of proinflammatory cytokines, adhesion molecules, and collagen, as well as smooth muscle cells, macrophages, and T lymphocytes, particularly the binding of CD40 and CD40L. Therefore, research on inhibiting the CD40-CD40L system to prevent atherosclerosis has been ongoing for more than 30 years. However, it's essential to note that long-term direct suppression of CD40 or CD40L could potentially result in immunosuppression, emphasizing the critical role of the CD40-CD40L system in atherosclerosis. Thus, specifically targeting the CD40-CD40L interaction on particular cell types or their downstream signaling pathways may be a robust strategy for mitigating atherosclerosis, reducing potential side effects. This review aims to summarize the potential utility of the CD40-CD40L system as a viable therapeutic target for atherosclerosis.

First trimester sCD40L levels associated with adverse neonatal outcomes in euthyroid pregnant women with positive TPOAb

Backgrounds

It remained unclear whether isolated positive thyroid peroxidative antibodies (TPOAb) were associated with adverse maternal and neonatal outcomes. The purpose of this study was to observe adverse neonatal outcomes among euthyroid pregnant women with positive TPOAb and to investigate the underlying risk factors.

Methods

Euthyroid pregnant women with TPOAb positivity were enrolled and followed up in our study. Adverse neonatal outcomes such as preterm birth, low birth weight, and fetal macrosomia were observed. Clinical data in the first trimester were collected and compared between groups with or without adverse neonatal outcomes. Maternal serum soluble CD40 ligand (sCD40L) was also measured at the same time.

Results

A total of 176 euthyroid pregnant women with TPOAb positivity were finally enrolled and analyzed in our study. Thirty-nine (22.16%) euthyroid women with TPOAb positivity were found to have adverse neonatal outcomes. Thirteen participants received assisted reproductive technology (ART) in our study, and seven participants were in the adverse neonatal outcome group. Preterm birth, low birth weight, and fetal macrosomia were the most common comorbidities. The proportion of receiving ART and the levels of sCD40L and platelet were significantly higher in the adverse neonatal outcome group (all P < 0.05). Multivariate regression analysis showed that sCD40L and receiving ART were the independent risk factors for adverse neonatal outcomes. The odds ratio values of sCD40L higher than 5.625 ng/ml were 2.386 [95% confidence interval (CI) = 1.017 to 5.595; P = 0.046] for overall adverse neonatal outcome, 3.900 (95% CI = 1.194 to 12.738; P = 0.024) for preterm birth, and 3.149 (95% CI = 0.982 to 10.101; P = 0.054) for low birth weight.

Conclusions

Approximately one of the four euthyroid women with TPOAb positivity might have adverse neonatal outcomes. Measurement of sCD40L in first trimester might have a predictive value for adverse neonatal outcomes in euthyroid pregnant women with positive TPOAb.

Modulating CD40 and integrin signaling in the proinflammatory nexus using a 15-amino-acid peptide, KGYY15

CD40 signaling has long been a target in autoimmunity. Attempts to block signaling between CD40 and CD154 during clinical trials using monoclonal antibodies suffered severe adverse events. Previously, we developed a peptide, KGYY15, that targets CD40 and, in preclinical trials, prevents type 1 diabetes in >90% of cases and reverses new-onset hyperglycemia in 56% of cases. It did so by establishing normal effector T-cell levels rather than ablating the cells and causing immunosuppression. However, the relationship between KGYY15 and other elements of the complex signaling network of CD40 is not clear. Studying interactions between proteins from autoimmune and nonautoimmune mice, we demonstrate interactions between CD40 and integrin CD11a/CD18, which complicates the understanding of the inflammatory nexus and how to prevent autoinflammation. In addition to interacting with CD40, KGYY15 interacts with the integrins CD11a/CD18 and CD11b/CD18. We argue that modulation of CD40-CD154 signaling may be more advantageous than complete inhibition because it may preserve normal immunity to pathogens.

Population Pharmacokinetics and Exposure-Response for Dapirolizumab Pegol From a Phase 2b Trial in Patients With Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a systemic, autoimmune disease characterized by chronic inflammation and organ damage. Dapirolizumab pegol inhibits CD40 ligand (CD40L) and is currently undergoing phase 3 trials for the treatment of SLE. To describe the pharmacokinetic characteristics of dapirolizumab pegol and the relationship between exposure and probability of achieving a British Isles Lupus Assessment Group-based Composite Lupus Assessment (BICLA) response, a population pharmacokinetic (popPK) model and an exposure-response model were developed, based on results of the phase 2b trial (RISE; NCT02804763) of dapirolizumab pegol in SLE. Dapirolizumab pegol pharmacokinetics were found to be dose proportional and well described by a 2-compartment model with first-order elimination from the central compartment. In the popPK model, body weight was the only significant covariate. The average concentration of dapirolizumab pegol, derived from the popPK model, was incorporated into the exposure-response model. Overall, the exposure-response model showed that treatment with dapirolizumab pegol increased the probability of transitioning from BICLA "Nonresponder" to "Responder." No significant covariates on BICLA responder status were identified. Notably, the half maximal effective concentration was greater for the transition from "Responder" to "Nonresponder" (150 µg/mL) than the transition from "Nonresponder" to "Responder" (12 µg/mL), indicating that sustained dapirolizumab pegol concentrations may be required to maintain BICLA response. In conclusion, dapirolizumab pegol pharmacokinetics were as expected for a PEGylated molecule and results from the exposure-response model indicate that a favorable dapirolizumab pegol effect was identified for both BICLA "Nonresponder" to "Responder" and "Responder" to "Nonresponder" transition probabilities.

Genetics and epigenetics of autoimmune thyroid diseases: Translational implications

Hashimoto's thyroiditis (HT) and Graves' disease (GD) are prevalent autoimmune disorders, representing opposite ends of the clinical spectrum of autoimmune thyroid diseases (AITD). The pathogenesis involves a complex interplay between environment and genes. Specific susceptibility genes have been discovered that predispose to AITD, including thyroid-specific and immune-regulatory genes. Growing evidence has revealed that genetic and epigenetic variants can alter autoantigen presentation during the development of immune tolerance, can enhance self-peptide binding to MHC (major histocompatibility complex), and can amplify stimulation of T- and B-cells. These gene-driven mechanistic discoveries lay the groundwork for novel treatment targets. This review summarizes recent advances in our understanding of key AITD susceptibility genes (Tg1, TSHR, HLA-DR3, and CD40) and their translational therapeutic potential.

A pregnancy hormone-cell death link promotes enhanced lupus-specific immunological effects

Women of reproductive age demonstrate an increased incidence of systemic lupus erythematosus, and reproductive hormones have been implicated in disease progression. Additionally, pregnancy can be associated with disease "flares", the reasons for which remain obscure. While apoptotic bodies are believed to provide an autoantigenic trigger in lupus, whether autoantigenic constituents vary with varying cellular insults, and whether such variations can be immunologically consequential in the context of pregnancy, remains unknown. As assessed by antigenicity and mass spectrometry, apoptotic bodies elicited by different drugs demonstrated the differential presence of lupus-associated autoantigens, and varied in the ability to elicit lupus-associated cytokines from lupus splenocytes and alter the phenotype of lupus B cells. Immunization of tamoxifen-induced apoptotic bodies in lupus-prone mice generated higher humoral autoreactive responses than did immunization with cisplatin-induced apoptotic bodies, and both apoptotic bodies were poorly immunogenic in healthy mice. Incubation of lupus splenocytes (but not healthy splenocytes) with the pregnancy hormone human chorionic gonadotropin (hCG) along with tamoxifen-induced apoptotic bodies (but not cisplatin-induced apoptotic bodies) induced increases in the secretion of lupus-associated cytokines and in the up-modulation of B cell phenotypic markers. In addition, levels of secreted autoantibodies (including of specificities linked to lupus pathogenesis) were enhanced. These events were associated with the heightened phosphorylation of several signaling intermediates. Observations suggest that hCG is a potential disease-promoting co-stimulant in a lupus-milieu; when combined with specific apoptotic bodies, it enhances the intensity of multiple lupus-associated events. These findings deepen mechanistic insight into the hormone's links with autoreactive responses in lupus-prone mice and humans.

Autoantibodies in Neuropsychiatric Systemic Lupus Erythematosus (NPSLE): Can They Be Used as Biomarkers for the Differential Diagnosis of This Disease?

Systemic lupus erythematosus is a complex immunological disease where both environmental factors and genetic predisposition lead to the dysregulation of important immune mechanisms. Eventually, the combination of these factors leads to the production of self-reactive antibodies that can target any organ or tissue of the human body. Autoantibodies can form immune complexes responsible for both the organ damage and the most severe complications. Involvement of the central nervous system defines a subcategory of the disease, generally known with the denomination of neuropsychiatric systemic lupus erythematosus. Neuropsychiatric symptoms can range from relatively mild manifestations, such as headache, to more severe complications, such as psychosis. The evaluation of the presence of the autoantibodies in the serum of these patients is the most helpful diagnostic tool for the assessment of the disease. The scientific progresses achieved in the last decades helped researchers and physicians to discover some of autoepitopes targeted by the autoantibodies, although the majority of them have not been identified yet. Additionally, the central nervous system is full of epitopes that cannot be found elsewhere in the human body, for this reason, autoantibodies that selectively target these epitopes might be used for the differential diagnosis between patients with and without the neuropsychiatric symptoms. In this review, the most relevant data is reported with regard to mechanisms implicated in the production of autoantibodies and the most important autoantibodies found among patients with systemic lupus erythematosus with and without the neuropsychiatric manifestations.

Composition and regulation of the immune microenvironment of salivary gland in Sjögren’s syndrome

Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by exocrine gland dysfunction and inflammation. Patients often have dry mouth and dry eye symptoms, which seriously affect their lives. Improving dry mouth and eye symptoms has become a common demand from patients. For this reason, researchers have conducted many studies on external secretory glands. In this paper, we summarize recent studies on the salivary glands of pSS patients from the perspective of the immune microenvironment. These studies showed that hypoxia, senescence, and chronic inflammation are the essential characteristics of the salivary gland immune microenvironment. In the SG of pSS, genes related to lymphocyte chemotaxis, antigen presentation, and lymphocyte activation are upregulated. Interferon (IFN)-related genes, DNA methylation, sRNA downregulation, and mitochondrial-related differentially expressed genes are also involved in forming the immune microenvironment of pSS, while multiple signaling pathways are involved in regulation. We further elucidated the regulation of the salivary gland immune microenvironment in pSS and relevant, targeted treatments.

Anti-C1q autoantibodies from systemic lupus erythematosus patients enhance CD40-CD154-mediated inflammation in peripheral blood mononuclear cells in vitro

Objectives

Systemic lupus erythematosus (SLE) is a clinically heterogeneous autoimmune disease with complex pathogenic mechanisms. Complement C1q has been shown to play a major role in SLE, and autoantibodies against C1q (anti‐C1q) are strongly associated with SLE disease activity and severe lupus nephritis suggesting a pathogenic role for anti‐C1q. Whereas C1q alone has anti‐inflammatory effects on human monocytes and macrophages, C1q/anti‐C1q complexes favor a pro‐inflammatory phenotype. This study aimed to elucidate the inflammatory effects of anti‐C1q on peripheral blood mononuclear cells (PBMCs).

Methods

Isolated monocytes, isolated T cells and bulk PBMCs of healthy donors with or without concomitant T cell activation were exposed to C1q or complexes of C1q and SLE patient‐derived anti‐C1q (C1q/anti‐C1q). Functional consequences of C1q/anti‐C1q on cells were assessed by determining cytokine secretion, monocyte surface marker expression, T cell activation and proliferation.

Results

Exposure of isolated T cells to C1q or C1q/anti‐C1q did not affect their activation and proliferation. However, unspecific T cell activation in PBMCs in the presence of C1q/anti‐C1q resulted in increased TNF, IFN‐γ and IL‐10 secretion compared with C1q alone. Co‐culture and inhibition experiments showed that the inflammatory effect of C1q/anti‐C1q on PBMCs was due to a direct CD40–CD154 interaction between activated T cells and C1q/anti‐C1q‐primed monocytes. The CD40‐mediated inflammatory reaction of monocytes involves TRAF6 and JAK3‐STAT5 signalling.

Conclusion

In conclusion, C1q/anti‐C1q have a pro‐inflammatory effect on monocytes that depends on T cell activation and CD40–CD154 signalling. This signalling pathway could serve as a therapeutic target for anti‐C1q‐mediated inflammation.

sCD40L Is Increased and Associated with the Risk of Gestational Diabetes Mellitus in Pregnant Women with Isolated TPOAb Positivity

BACKGROUND

Autoimmune disorders are associated with gestational diabetes mellitus (GDM) in pregnant women who were positive for thyroid peroxidase antibody (TPOAb). Soluble CD40 ligand (sCD40L) and soluble interleukin-2 receptor (sCD25) are abnormally expressed in autoimmune diseases and are reliable markers of inflammation. The purpose of this study was to evaluate sCD40L and sCD25 in early pregnancy and investigate their correlation with GDM and TPOAb.

METHODS

A total of 126 pregnant women in the first trimester were enrolled for analysis: 93 were positive for TPOAb and 33 were negative for TPOAb. Demographical and clinical data in early pregnancy were collected. A total of 123 participants underwent a 75 g oral glucose tolerance test in the second trimester. Serum sCD40L and sCD25 levels were measured by ELISA.

RESULTS

The incidence of GDM was 24.4% in pregnant women with isolated TPOAb positivity in our study. Both sCD40L and sCD25 were positively correlated with TPOAb (r = 0.476, P < 0.001; r = 0.188, P < 0.05). sCD40L was highest in (P < 0.001) Ab-positive women with GDM group (P < 0.05). After adjusting for TPOAb, age, TSH, FT4, triglycerides, and low-density lipoprotein cholesterol, multivariate logistic regression analysis showed that sCD40L was an independent risk factor for GDM in pregnant women with TPOAb positivity (odds ratio = 3.235, 95% confidence interval 1.024-10.218, P < 0.05).

CONCLUSIONS

About a quarter of pregnant women with isolated positive TPOAb might have GDM. sCD40L was an independent risk factor for GDM in women with isolated TPOAb positivity.

CD40L protects against mouse hepatitis virus-induced neuroinflammatory demyelination

Neurotropic mouse hepatitis virus (MHV-A59/RSA59) infection in mice induces acute neuroinflammation due to direct neural cell dystrophy, which proceeds with demyelination with or without axonal loss, the pathological hallmarks of human neurological disease, Multiple sclerosis (MS). Recent studies in the RSA59-induced neuroinflammation model of MS showed a protective role of CNS-infiltrating CD4⁺ T cells compared to their pathogenic role in the autoimmune model. The current study further investigated the molecular nexus between CD4⁺ T cell-expressed CD40Ligand and microglia/macrophage-expressed CD40 using CD40L^-/- mice. Results demonstrate CD40L expression in the CNS is modulated upon RSA59 infection. We show evidence that CD40L^-/- mice are more susceptible to RSA59 induced disease due to reduced microglia/macrophage activation and significantly dampened effector CD4⁺ T recruitment to the CNS on day 10 p.i. Additionally, CD40L^-/- mice exhibited severe demyelination mediated by phagocytic microglia/macrophages, axonal loss, and persistent poliomyelitis during chronic infection, indicating CD40-CD40L as host-protective against RSA59-induced demyelination. This suggests a novel target in designing prophylaxis for virus-induced demyelination and axonal degeneration, in contrast to immunosuppression which holds only for autoimmune mechanisms of inflammatory demyelination.

MS is primarily considered an autoimmune CNS disease, but its potential viral etiology cannot be ignored. Myelin-specific CD40L⁺CD4⁺ T cells migration into the CNS and resultant neuroinflammation is considered pathogenic in autoimmune MS. In contrast, CD40L⁺CD4⁺ T infiltration into the MHV-induced inflamed CNS and their interaction with CD40⁺ microglia/macrophages are shown to be protective in our study. Considering differential etiology but comparable demyelination and axonal loss, immunosuppressive treatments may not necessarily ameliorate MS in all patients. MHV-induced demyelination in this study indicates that the interaction between CD40L on CD4⁺T cells and CD40 on microglia/macrophage plays an important protective role against MHV-induced chronic progressive demyelination.

Cladribine Alters Immune Cell Surface Molecules for Adhesion and Costimulation: Further Insights to the Mode of Action in Multiple Sclerosis

Cladribine (CLAD) is a deoxyadenosine analogue prodrug which is given in multiple sclerosis (MS) as two short oral treatment courses 12 months apart. Reconstitution of adaptive immune function following selective immune cell depletion is the presumed mode of action. In this exploratory study, we investigated the impact of CLAD tablets on immune cell surface molecules for adhesion (CAMs) and costimulation (CoSs) in people with MS (pwMS). We studied 18 pwMS who started treatment with CLAD and 10 healthy controls (HCs). Peripheral blood mononuclear cells were collected at baseline and every 3 months throughout a 24-month period. We analysed ICAM-1, LFA-1, CD28, HLADR, CD154, CD44, VLA-4 (CD49d/CD29), PSGL-1 and PD-1 with regard to their expression on B and T cells (T helper (Th) and cytotoxic T cells (cT)) and surface density (mean fluorescence intensity, MFI) by flow cytometry. The targeted analysis of CAM and CoS on the surface of immune cells in pwMS revealed a higher percentage of ICAM-1 (B cells, Th, cT), LFA-1 (B cells, cT), HLADR (B cells, cT), CD28 (cT) and CD154 (Th). In pwMS, we found lower frequencies of Th and cT cells expressing PSGL-1 and B cells for the inhibitory signal PD-1, whereas the surface expression of LFA-1 on cT and of HLADR on B cells was denser. Twenty-four months after the first CLAD cycle, the frequencies of B cells expressing CD44, CD29 and CD49d were lower compared with the baseline, together with decreased densities of ICAM-1, CD44 and HLADR. The rate of CD154 expressing Th cells dropped at 12 months. For cT, no changes were seen for frequency or density. Immune reconstitution by oral CLAD was associated with modification of the pro-migratory and -inflammatory surface patterns of CAMs and CoSs in immune cell subsets. This observation pertains primarily to B cells, which are key cells underlying MS pathogenesis.

B Cells in Rheumatoid Arthritis：Pathogenic Mechanisms and Treatment Prospects

Rheumatoid arthritis (RA) is a common, chronic, systemic autoimmune disease, and its clinical features are the proliferation of joint synovial tissue, the formation of pannus and the destruction of cartilage. The global incidence of RA is about 1%, and it is more common in women. The basic feature of RA is the body’s immune system disorders, in which autoreactive CD4⁺T cells, pathogenic B cells, M1 macrophages, inflammatory cytokines, chemokines and autoantibodies abnormally increase in the body of RA patients B cell depletion therapy has well proved the important role of B cells in the pathogenesis of RA, and the treatment of RA with B cells as a target has also been paid more and more attention. Although the inflammatory indicators in RA patients receiving B-cell depletion therapy have been significantly improved, the risk of infection and cancer has also increased, which suggests that we need to deplete pathogenic B cells instead of all B cells. However, at present we cannot distinguish between pathogenic B cells and protective B cells in RA patients. In this review, we explore fresh perspectives upon the roles of B cells in the occurrence, development and treatment of RA.

B Cell Aberrance in Lupus: the Ringleader and the Solution

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease with high heterogeneity but the common characterization of numerous autoantibodies and systemic inflammation which lead to the damage of multiple organs. Aberrance of B cells plays a pivotal role in the immunopathogenesis of SLE via both antibody-dependent and antibody-independent manners. Escape of autoreactive B cells from the central and peripheral tolerance checkpoints, over-activation of B cells and their excessive cytokines release which drive T cells and dendritic cells stimulation, and dysregulated surface molecules, as well as intracellular signal pathways involved in B cell biology, are all contributing to B cell aberrance and participating in the pathogenesis of SLE. Based on that rationale, targeting aberrance of B cells and relevant molecules and pathways is expected to be a promising strategy for lupus control. Multiple approaches targeting B cells through different mechanisms have been attempted, including B-cell depletion via monoclonal antibodies against B-cell-specific molecules, blockade of B-cell survival and activation factors, suppressing T-B crosstalk by interrupting costimulatory molecules and inhibiting intracellular activation signaling cascade by targeting pathway molecules in B cells. Though most attempts ended in failure, the efficacy of B-cell targeting has been encouraged by the FDA approval of belimumab that blocks B cell-activating factor (BAFF) and the recommended use of anti-CD20 as a remedial therapy in refractory lupus. Still, quantities of clinical trials targeting B cells or relevant molecules are ongoing and some of them have displayed promising preliminary results. Additionally, advances in multi-omics studies help deepen our understandings of B cell biology in lupus and may promote the discovery of novel potential therapeutic targets. The combination of real-world data with basic research achievements may pave the road to conquering lupus.

Targeted Biologic Therapy for Systemic Lupus Erythematosus: Emerging Pathways and Drug Pipeline

Following the approval of belimumab, the first drug to be approved for systemic lupus erythematosus (SLE) in over 50 years, advances in our understanding of the pathogenesis of the disease have led to a remarkable number of clinical trials for investigational drugs, each with a unique mechanism of action. These include, but are not limited to, antibodies targeting B or T cells or their interaction, dendritic cells, interferon, and other cytokines. Frustratingly, this boost of studies has not been accompanied by a corresponding success and subsequent approval of novel agents, for reasons only partly attributed to the efficacy of the drugs per se. Successful phase II trials are often followed by failed phase III studies, which typically require many more patients. Nevertheless, recent successes, such as the ustekinumab and baricitinib trials and the positive results from the phase III TULIP-2 study of anifrolumab, provide room for cautious optimism. In this review, we attempt to draw the current landscape of the drug pipeline in SLE, focusing on the rationale behind each drug development, its mechanism of action, and the available preclinical and clinical data. We also highlight lessons learned from failed attempts that have helped to optimize clinical trial design for this challenging disease. We conclude with a look into the future, commenting on the surge of studies in the field of biomarkers and the use of omics technologies in lupus, which aim to pinpoint different disease phenotypes and, ideally, identify subsets of patients with disease that will respond to different biologic drugs.

TJ-M2010-5, a novel MyD88 inhibitor, corrects R848-induced lupus-like immune disorders of B cells in vitro

B cell hyperactivities are involved in the development of systemic lupus erythematosus (SLE). Toll-like receptor 7 (TLR7) in the B cells plays a pivotal role in the pathogenesis of SLE. Previous studies have focused on the intrinsic role of B cells in TLR7/MyD88 signaling and consequently on immune activation, autoantibody production, and systemic inflammation. However, a feasible treatment for this immune disorder remains to be discovered. The in vitro cellular response that have been studied likely plays a central role in the production of some important autoantibodies in SLE. We successfully used R848 to build a lupus-like B cell model in vitro; these B cells were overactivated, differentiated into plasma cells, escaped apoptosis, massively proliferated, and produced large amounts of autoantibodies and cytokines. In the present study, we found that TJ-M2010-5, a novel MyD88 inhibitor previously synthesized in our lab, seemed to inhibit the lupus-like condition of B cells, including overactivation, massive proliferation, differentiation into plasma cells, and overproduction of autoantibodies and cytokines. TJ-M2010-5 also induce B cells apoptosis. Furthermore, TJ-M2010-5 was found to remarkably inhibit NF-κB and MAPK signaling. In summary, TJ-M2010-5 might correct R848-induced lupus-like immune disorders of B cells by blocking the TLR7/MyD88/NF-κB and TLR7/MyD88/MAPK signaling pathways.

Soluble CD40 Ligand Levels in Children with Newly Diagnosed Graves’ Disease

OBJECTIVE

Soluble CD40 ligand (sCD40L) is elevated in various autoimmune disorders, which may have diagnostic and therapeutic implications. The aims of the current study were to evaluate serum sCD40L concentrations in children with newly diagnosed Graves’ disease (GD) and to correlate its levels with patients’ clinical and laboratory parameters.

METHODS

This study included 48 children with newly diagnosed GD and 48 healthy children. Serum thyroid-stimulating hormone (TSH) (TSH, fT4 and fT3), TSH receptor antibodies (TRAbs), high sensitivity C-reactive protein (hsCRP) and sCD40L levels and thyroid volume were measured.

RESULTS

Compared to control subjects, children with GD had higher thyroid volume standard deviation scores (SDS) (p=0.001), and higher levels of hsCRP (p=0.001), TRAbs (p=0.001) and sCD40L (p=0.001). Significant correlations were found between sCD40L and age (p=0.01), thyroid volume SDS (p=0.001), hsCRP (p=0.01) and TRAbs (p=0.001). In multivariate analysis, sCD40L concentrations were correlated with TRAbs [odds ratio (OR)=3.1, 95% confidence intervals (CI): 2.2-2.7, p=0.001] and thyroid volume SDS (OR=2.1, 95% CI: 1.2-2.7, p=0.001).

CONCLUSION

This preliminary study has evidence of high concentrations of sCD40L in children with newly diagnosed GD and a correlation between sCD40L and both TRAbs and thyroid volume, which may indicate a biologically active role for sCD40L in the pathogenesis of GD.

Rationale for CD40 pathway blockade in autoimmune rheumatic disorders

CD40 and its ligand CD40L (CD154) belong to the tumor necrosis factor receptor superfamily and are expressed by a variety of immune and non-immune cells. CD40L plays a central role in co-stimulation and regulation of the immune response via activation of cells expressing CD40. Imbalance of the CD40-CD40L co-stimulatory pathway has been reported in many autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, and Sjögren's syndrome, thus supporting its role in the breach of immune tolerance that is typical of these diseases. Targeting CD40-CD40L signalling might represent a novel therapeutic option for several autoimmune disorders.

B cell checkpoints in autoimmune rheumatic diseases

B cells have important functions in the pathogenesis of autoimmune diseases, including autoimmune rheumatic diseases. In addition to producing autoantibodies, B cells contribute to autoimmunity by serving as professional antigen-presenting cells (APCs), producing cytokines, and through additional mechanisms. B cell activation and effector functions are regulated by immune checkpoints, including both activating and inhibitory checkpoint receptors that contribute to the regulation of B cell tolerance, activation, antigen presentation, T cell help, class switching, antibody production and cytokine production. The various activating checkpoint receptors include B cell activating receptors that engage with cognate receptors on T cells or other cells, as well as Toll-like receptors that can provide dual stimulation to B cells via co-engagement with the B cell receptor. Furthermore, various inhibitory checkpoint receptors, including B cell inhibitory receptors, have important functions in regulating B cell development, activation and effector functions. Therapeutically targeting B cell checkpoints represents a promising strategy for the treatment of a variety of autoimmune rheumatic diseases.

Association of soluble CD40 levels with -1 C > T CD40 polymorphism and chronic kidney disease in systemic lupus erythematosus

Background

CD40 is a transmembrane protein mainly expressed on the antigen‐presenting cells surface. CD40 plays a crucial role in immunoglobulin class switching and antibodies production. Genetic polymorphisms in the CD40 gene have been associated with increased risk of systemic lupus erythematosus (SLE) in several populations. This study aimed to evaluate the association of CD40 polymorphisms (−1 C > T, rs1883832 and 6,048 G > T, rs4810485) with SLE susceptibility, as well as with mRNA expression and soluble CD40 (sCD40) levels.

Methods

The study included 293 patients with SLE and 294 control subjects (CS). Genotyping was performed by PCR‐RFLP method. CD40 mRNA expression was determined by quantitative real‐time PCR, and ELISA quantified sCD40 levels.

Results

The CD40 polymorphisms −1 C > T and 6,048 G > T were associated with SLE susceptibility. There was no difference between CD40 mRNA expression and CD40 polymorphisms. The sCD40 levels were lower in SLE patients with TT haplotype, whereas higher sCD40 levels were associated with damage and impaired renal function according to SLICC and KDIGO. The sCD40 levels were negatively correlated with eGFR.

Conclusion

The CD40 gene polymorphisms increase the risk of SLE in the western Mexican population. The sCD40 levels are associated with −1 C > T polymorphism and chronic kidney disease.

B cell dysregulation in primary Sjögren's syndrome: A review

Primary Sjögren’s syndrome is a chronic autoimmune disorder of unknown etiology and is characterized by progressive focal lymphocytic infiltration of the lacrimal and salivary glands. Comparison of B cell subsets from the peripheral blood and salivary glands of patients with primary Sjögren’s syndrome and those from healthy individuals shows dysregulation and derangement of B cell subsets in both peripheral circulation and in inflamed glandular tissues. This dysregulation is expressed as a decrease in the percentage of CD27+ memory B cells in peripheral blood and an increase in the CD27+ memory B cells in the affected glands. Further, the overall percentage of long-lived autoantibodies-producing plasma cells within the affected glands is increased. In the last two decades, several studies have shown growing evidences that B cells play multiple roles in primary Sjögren’s syndrome pathophysiology, and that dysregulation of these cells may actually play a central role in the disease development.

A CD40 targeting peptide prevents severe symptoms in experimental autoimmune encephalomyelitis

CD40/CD154-interaction is critical in the development of Experimental Autoimmune Encephalomyelitis (EAE; mouse model of Multiple Sclerosis). Culprit CD4⁺CD40⁺ T cells drive a more severe form of EAE than conventional CD4 T cells. Blocking CD40/CD154-interaction with CD154-antibody prevents or ameliorates disease but had thrombotic complications in clinical trials. We targeted CD40 using a CD154-sequence based peptide. Peptides in human therapeutics demonstrate good safety. A small peptide, KGYY₆, ameliorates EAE when given as pretreatment or at first symptoms. KGYY₆ binds Th40 and memory T cells, affecting expression of CD69 and IL-10 in the CD4 T cell compartment, ultimately hampering disease development.

Potential Markers of Autoimmune Diseases, Alleles rs115662534(T) and rs548231435(C), Disrupt the Binding of Transcription Factors STAT1 and EBF1 to the Regulatory Elements of Human CD40 Gene

CD40 receptor is expressed on B lymphocytes and other professional antigen-presenting cells. The binding of CD40 to its ligand CD154 on the surface of T helper cells plays an important role in the activation of B lymphocytes required for production of antibodies, in particular, against autoantigens. Association of several single nucleotide polymorphisms (SNPs) located in the non-coding areas of human CD40 locus with the elevated risk of autoimmune diseases has been demonstrated. The most studied of these SNPs is rs4810485 located in the first intron of the CD40 gene. Expression of the CD40 gene in B lymphocytes of donors homozygous for the common allelic variant of this polymorphism (G) is higher than in B cells from donors carrying the minor (T) variant. We investigated the enhancer activity of this fragment of the CD40 locus in human B cell lines and showed that it is independent on the rs4810485 alleles. However, the minor allelic variants of the rs4810485-linked SNPs rs548231435 and rs115662534 were associated with a significant decrease in the activity of the CD40 promoter due to the impairments in the binding of EBF1 and STAT1 transcription factors, respectively.

Immune receptors CD40 and CD86 in oral keratinocytes and implications for oral lichen planus

Lichen planus (LP) is a chronic T-cell-mediated mucocutaneous inflammatory disease that targets stratified epithelia, including those lining the oral cavity. The intraoral variant of LP (OLP) is associated with interferon (IFN)-γ production by infiltrating T lymphocytes; however, the role of epithelial cells in the etiopathogenesis OLP is not completely understood. There is however a growing body of evidence regarding the involvement of epithelial-derived cytokines, immune receptors, and costimulatory molecules in the pathobiological processes that promote and sustain OLP. In the present study, we used a reverse transcriptase-polymerase chain reaction assay to assess whether CD40-a receptor found mainly on antigen presenting cells-and the costimulatory molecule CD86 were expressed in oral keratinocytes (three strains of primary normal oral keratinocytes and the H357 cell line) in the presence or absence of IFN-γ. To further characterize the involvement of CD40 in OLP, expression and distribution of receptor and ligand (CD40/CD154) in tissues from OLP were evaluated by immunohistochemistry. The present results are the first to show that both CD40 and CD86 are constitutively expressed at low levels in oral keratinocytes and that their expression was enhanced by IFN-γ stimulation. The intensity of CD40 staining in OLP tissues was strong. Taken together, the results strongly suggest that CD40 and CD86 play a role in the pathophysiology of oral inflammatory diseases such as OLP.

Therapeutic effects of anti-CD154 antibody in cynomolgus monkeys with advanced rheumatoid arthritis

Rheumatoid arthritis is one major chronic inflammatory systemic autoimmune disease. The CD154-CD40 interactions play a critical role in the regulation of immune responses and the maintenance of autoimmunity. Therefore, we aimed to determine whether anti-CD154 antibody treatment show positive effects on immunomodulation and clinical improvement of sustained severe rheumatoid arthritis in cynomolgus monkeys. Arthritis was induced using chicken type II collagen (CII) and arthritic monkey were divided into control and anti-CD154 treatment groups based on their concentrations of anti-CII antibodies on week 7 post-immunization. Blood and tissue samples were collected on week 16 post-immunization. Anti-CD154 antibody treatment improved arthritis and movement, and significantly decreased the numbers of proliferating B cells and the serum levels of anti-type II collagen antibody and sCD154 compared with non-treatment group. Further anti-CD154 antibody treatment significantly decreased the percentage of CD4+ cells and the ratio of CD4+ to CD8+ T cells and significantly increased the percentage of CD8+ cells and effector memory CD8+ cells in peripheral blood. We have shown for the first time in a nonhuman primate model of RA that CD154 blockade has beneficial effects. This study might be valuable as preclinical data of CD154 blockade in nonhuman primate models of severe rheumatoid arthritis.

Tumor necrosis factor-α blockade treatment decreased CD154 (CD40-ligand) expression in rheumatoid arthritis

Contexts

CD154 (commonly referred to as CD40-ligand) is a critical T cell factor that participates in the pathogenesis of autoimmune and is over-expressed in rheumatoid arthritis (RA). TNF-α blockade treatment had dramatic efficacy in RA.

Objective

To investigate whether TNF-α blockade treatment can inhibit CD154 expression in RA.

Methods

Blood samples were collected from 33 patients with rheumatoid arthritis before and 3 months after TNF-α blockade treatment. Clinical serological data determined by standard assays and T cell CD154 expression levels determined by flow cytometry were statistically analyzed for these two time points.

Results

The percentage of CD154 expression on gated CD4+ T cells of PBMCs from RA patients after 3 months TNF-α blockade treatment was significantly lower than before treatment (2.94 ± 3.21% vs. 7.21 ± 5.64%; p = 0.0001). The disease activity and anti-CCP antibody levels were also significantly reduced after TNF-α blockade treatment. The CD154 expression levels were positively correlated with disease activity index DAS28, and CRP. The post-stimulated CD154 expression percentage of purified CD4+ T cells between baseline and after TNF-α blockade treatment was not significantly different (p = 0.221). Baseline CD154 levels were positively correlated with treatment-induced changes in DAS28 (p = 0.014; r2 = 0.187).

Conclusions

TNF-α blockade treatment significantly decreased the CD154 expression on CD4+ T cells, disease activity and anti-CCP antibody simultaneously in RA patients. However TNF-α blockade did not impair T cell capacity to express CD154 after stimulation. These results suggest that decreased CD154 expression after TNF-α blockade may be due to decreased RA disease activity but not direct inhibition of CD154 responsiveness of T cells.

Lupus nephritis and B-cell targeting therapy

INTRODUCTION

Lupus Nephritis (LN) is a severe manifestation of Systemic Lupus Erythematosus (SLE) with a significant prognostic impact. Over a prolonged course, an exhaustion of treatment alternatives may occur and further therapeutic options are needed. B cells play a pivotal role in disease pathogenesis and represent an attractive therapeutic target. Areas covered: This review provides an update regarding targeting B cells in LN. The rational for this approach, as well as currently available and future targets are discussed. Expert commentary: Despite its wide clinical use and the encouraging results from retrospective studies, a role of rituximab in LN has not been prospectively confirmed. Trial design methodologies as well as intrinsic limitations of this approach may be responsible and rituximab use is currently limited as a rescue treatment or in settings where a strong steroid sparing effect is warranted. Despite belimumab now being licensed for use in SLE, the evidence in LN is weak although prospective trials are on-going. The combination of different targeted approaches as well as a focus on new clinical end-points may be strategies to identify new therapeutic options.

Repeated administration of dapirolizumab pegol in a randomised phase I study is well tolerated and accompanied by improvements in several composite measures of systemic lupus erythematosus disease activity and changes in whole blood transcriptomic profiles

Objectives

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease associated with diffuse immune cell dysfunction. CD40–CD40 ligand (CD40L) interaction activates B cells, antigen-presenting cells and platelets. CD40L blockade might provide an innovative treatment for systemic autoimmune disorders. We investigated the safety and clinical activity of dapirolizumab pegol, a polyethylene glycol conjugated anti-CD40L Fab' fragment, in patients with SLE.

Methods

This 32-week randomised, double-blind, multicentre study (NCT01764594) evaluated repeated intravenous administration of dapirolizumab pegol in patients with SLE who were positive for/had history of antidouble stranded DNA/antinuclear antibodies and were on stable doses of immunomodulatory therapies (if applicable). Sixteen patients were randomised to 30 mg/kg dapirolizumab pegol followed by 15 mg/kg every 2 weeks for 10 weeks; eight patients received a matched placebo regimen. Randomisation was stratified by evidence of antiphospholipid antibodies. Patients were followed for 18 weeks after the final dose.

Results

No serious treatment-emergent adverse events, thromboembolic events or deaths occurred. Adverse events were mild or moderate, transient and resolved without intervention. One patient withdrew due to infection.

Efficacy assessments were conducted only in patients with high disease activity at baseline. Five of 11 (46%) dapirolizumab pegol-treated patients achieved British Isles Lupus Assessment Group-based Composite Lupus Assessment response (vs 1/7; 14% placebo) and 5/12 (42%) evaluable for SLE Responder Index-4 responded by week 12 (vs 1/7; 14% placebo). Mechanism-related gene expression changes were observed in blood RNA samples.

Conclusions

Dapirolizumab pegol could be an effective biological treatment for SLE. Further studies are required to address efficacy and safety.

Trial registration number

NCT01764594.

Association between CD40 rs1883832 and immune-related diseases susceptibility: A meta-analysis

Background/objective

It has been reported that CD40 rs1883832 might be associated with immune-related diseases susceptibility. Owing to mixed and inconclusive results, we conducted a meta-analysis of case–control studies to summarize and clarify this association.

Methods/main results

A systematic search of studies on the association between CD40 rs1883832 and immune-related diseases susceptibility was conducted in databases. Odds ratios and 95% confidence intervals were used to pool the effect size. 40 articles were included in our meta-analysis.

Conclusions

CD40 rs1883832 is associated with decreased risk of Graves’ disease, especially in Asian; CD40 rs1883832 is associated with increased risk of multiple sclerosis; CD40 -1C>T (rs1883832) is not associated with the susceptibility of Hashimoto's thyroiditis, systemic sclerosis or Asthma; there is insufficient data to fully confirm the association between CD40 rs1883832 and systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Behçet's disease (BD), myasthenia gravis (MG), Crohn's disease (CD), ulcerative colitis (UC), Sarcoidosis, Fuch uveitis syndrome (FUS), Vogt-Koyanagi-Harada syndrome (VKH), Kawasaki disease (KD), giant cell arteritis (GCA) or Immune thrombocytopenia (ITP).

Type I Interferon Gene Response Is Increased in Early and Established Rheumatoid Arthritis and Correlates with Autoantibody Production

Background

Rheumatoid arthritis (RA) is an inflammatory debilitating disease that affects the joints in the early and productive phases of an individual’s life. Several cytokines have been linked to the disease pathogenesis and are known to contribute to the inflammatory state characteristic of RA. The participation of type I interferon (IFN) in the pathogenesis of the disease has been already described as well as the identity of the genes that are regulated by this molecule, which are collectively known as the type I IFN signature. These genes have several functions associated with apoptosis, transcriptional regulation, protein degradation, Th2 cell induction, B cell proliferation, etc. This article evaluated the expression of several genes of the IFN signature in different stages of disease and their correlation with the levels of anticitrullinated protein antibodies (ACPA) anticarbamylated protein (Anti-CarP) antibodies.

Methods

Samples from individuals with early and established RA, high-risk individuals (ACPA+ and ACPA−), and healthy controls were recruited at “Unidad de Artritis y Rheumatismo” (Rheumatism and Arthritis Unit) in Guadalajara Jalisco Mexico. Determinations of ACPA were made with Eurodiagnostica ACPA plus kit. Anti-CarP determinations were made according to previously described protocols. RNA was isolated, and purity and integrity were determined according to RNA integrity number >6. Gene expression analysis was made by RT-qPCR using specific primers for mRNAs of the type I IFN signature. Relative gene expression was calculated according to Livak and Schmitgen.

Results

Significant differences in gene expression were identified when comparing the different groups for MXA and MXB (P < 0.05), also when comparing established RA and ACPA− in both IFIT 1 and G15. An increased expression of ISG15 was identified (P < 0.05), and a clear tendency toward increase was identified for HERC5. EPSTRI1, IFI6, and IFI35 were found to be elevated in the chronic/established RA and early RA (P < 0.05). Significant correlations were identified for the IFN signature genes with the levels of ACPA and anti-CarP (P < 0.05).

Conclusion

Our data confirm previous observations in the role of IFN signature and the pathogenesis of RA. Also, we provide evidence of an association between several genes of the IFN signature (that regulate Th2 cells and B cell proliferation) with the levels of anti-CarP antibodies and ACPA.

CD40 Signaling in Graves Disease Is Mediated Through Canonical and Noncanonical Thyroidal Nuclear Factor κB Activation

CD40, a tumor necrosis factor receptor, is a major immune-modulating susceptibility gene for Graves disease (GD) as well as for a variety of other autoimmune diseases. Its broad association with autoimmunity underscores its paramount role in the development of a normal adaptive immune response, primarily in coordinating effective antigen presentation. The molecular pathways by which CD40 activation in the thyroid induces GD are unknown. In this study, we investigated whether NF-κB, a ubiquitious family of transcription factors, mediates the downstream effects of thyroid-specific CD40 activation. Cultured primary human thyrocytes, from patients with and without GD, underwent CD40 stimulation. Once stimulated, cytokines and transcription factors specific for either the canonical nuclear factor κB (NF-κB)1 pathway [interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α], which primarily recruits cells for innate immunity, or the noncanonical NF-κB2 pathway [B cell-activating factor of the TNF family, CC chemokine ligand (CCL)21], which directs B cell viability, were analyzed. Significant upregulation in the messenger RNA and protein levels of both canonical and noncanonical pathway cytokines was observed. Western blot analyses of the specific transcription factors for the NF-κB1 and NF-κB2 pathways (p65 and p100/p52, respectively) demonstrated that p65 is constitutively expressed. In contrast, CD40 stimulation robustly increased the expression of the NF-κB2 p52 transcription factor, and the upregulation was significantly more profound in the GD tissue than in the normal thyroid tissue. Our data show that CD40 activity in thyrocytes is prominently mediated via NF-κB and furthermore suggest that the NF-κB1 and NF-κB2 pathways both contribute to the triggering and the progression of GD.

Thyrotropin and CD40L Stimulate Interleukin-12 Expression in Fibrocytes: Implications for Pathogenesis of Thyroid-Associated Ophthalmopathy

BACKGROUND

Increased numbers of bone marrow-derived progenitor cells, known as fibrocytes, populate the peripheral circulation, orbit, and thyroid of patients with Graves' disease (GD). These cells have been implicated in the development of thyroid-associated ophthalmopathy. They can differentiate into myofibroblasts or adipocytes, produce inflammatory cytokines, and remodel tissue. This study sought to determine whether thyrotropin (TSH) and CD40 ligand (CD40L), implicated in the pathogenesis of GD, induce interleukin-12 (IL-12) in human fibrocytes.

MATERIALS AND METHODS

IL-12 protein concentrations and mRNA levels were measured by Luminex and real-time polymerase chain reaction, respectively. Flow cytometry assessed intracellular IL-12 concentrations. Vector containing IL-12p40 promoter was transfected into cultured fibrocytes, and promoter activity was monitored using luciferase assay.

RESULTS

TSH and CD40L stimulated intracellular IL-12 protein accumulation in peripheral blood fibrocytes. Inhibiting Akt and nuclear factor-κB (NF-κB) activity diminished IL-12 expression in fibrocytes, while TSH did not induce promoter activity. TSH-mediated IL-12 production required de novo synthesized proteins and augmented IL-12 mRNA stability. IL-12 production mediated by CD40L required tumor necrosis factor receptor-associated factor 6.

CONCLUSION

TSH and CD40L induce IL-12 expression in fibrocytes, and Akt and NF-κB mediate this activity. Given the importance of IL-12 in immune function, its production by fibrocytes may promote an inflammatory immune response and tissue remodeling in thyroid-associated ophthalmopathy.

The Interaction of CD154 with the α5β1 Integrin Inhibits Fas-Induced T Cell Death

CD154, a critical regulator of the immune response, is usually associated with chronic inflammatory, autoimmune diseases as well as malignant disorders. In addition to its classical receptor CD40, CD154 is capable of binding other receptors, members of the integrin family, the αIIbβ3, αMβ2 and α5β1. Given the role attributed to integrins and particularly the β1 integrins in inhibiting apoptotic events in normal as well as malignant T cells, we were highly interested in investigating the role of the CD154/α5β1 interaction in promoting survival of malignant T cells contributing as such to tumor development and/or propagation. To support our hypothesis, we first show that soluble CD154 binds to the T-cell acute lymphoblastic leukemia cell line, Jurkat E6.1 in a α5β1-dependent manner. Binding of soluble CD154 to α5β1 integrin of Jurkat cells leads to the activation of key survival proteins, including the p38 and ERK1/2 mitogen-activated protein kinases (MAPKs), phosphoinositide 3 kinase (PI-3K), and Akt. Interestingly, soluble CD154 significantly inhibits Fas-mediated apoptosis in T cell leukemia-lymphoma cell lines, Jurkat E6.1 and HUT78 cells, an important hallmark of T cell survival during malignancy progression. These anti-apoptotic effects were mainly mediated by the activation of the PI-3K/Akt pathway but also involved the p38 and the ERK1/2 MAPKs cascades. Our data also demonstrated that the CD154-triggered inhibition of the Fas-mediated cell death response was dependent on a suppression of caspase-8 cleavage, but independent of de novo protein synthesis or alterations in Fas expression on cell surface. Together, our results highlight the impact of the CD154/α5β1 interaction in T cell function/survival and identify novel targets for the treatment of malignant disorders, particularly of T cell origin.

Nanovesicle-targeted Kv1.3 knockdown in memory T cells suppresses CD40L expression and memory phenotype

Ca(2+) signaling controls activation and effector functions of T lymphocytes. Ca(2+) levels also regulate NFAT activation and CD40 ligand (CD40L) expression in T cells. CD40L in activated memory T cells binds to its cognate receptor, CD40, on other cell types resulting in the production of antibodies and pro-inflammatory mediators. The CD40L/CD40 interaction is implicated in the pathogenesis of autoimmune disorders and CD40L is widely recognized as a therapeutic target. Ca(2+) signaling in T cells is regulated by Kv1.3 channels. We have developed lipid nanoparticles that deliver Kv1.3 siRNAs (Kv1.3-NPs) selectively to CD45RO(+) memory T cells and reduce the activation-induced Ca(2+) influx. Herein we report that Kv1.3-NPs reduced NFAT activation and CD40L expression exclusively in CD45RO(+) T cells. Furthermore, Kv1.3-NPs suppressed cytokine release and induced a phenotype switch of T cells from predominantly memory to naïve. These findings indicate that Kv1.3-NPs operate as targeted immune suppressive agents with promising therapeutic potentials.

Immunometabolic biomarkers of inflammation in Behçet's disease: relationship with epidemiological profile, disease activity and therapeutic regimens

Behcet's disease (BD) is a systemic inflammatory disease with a still unclear pathogenesis. Although several inflammatory molecules have been studied, current biomarkers are largely insensitive in BD and unable to predict disease progression and response to treatment. Our primary aim was to explore serum levels of soluble CD40 L (sCD40L), soluble intracellular adhesion molecule (sICAM-1), monocyte chemoattractant protein-1 (MCP-1), myeloperoxidase (MPO), leptin, resistin, osteoprotegerin (OPG), soluble type 1 tumour necrosis factor receptor (sTNFR), interleukin (IL)-6 and serum amyloid A (SAA) serum concentration in a cohort of 27 BD patients. The secondary aim was to evaluate potential correlations between the putative circulating biomarkers, demographic profile of patients, the status of disease activity, the specific organ involvement at the time of sample collection and different therapeutic regimens. Serum concentrations of sTNFR (P = 0·008), leptin (P = 0·0011), sCD40L (P < 0·0001) and IL-6 (P = 0·0154) were significantly higher in BD patients than in HC, while no difference was found in MCP-1, MPO and resistin serum levels. Moreover, we observed significantly higher sTNFR serum concentrations in BD patients presenting inactive disease than HC (P = 0·0108). A correlation between sTNFR and age was also found, with higher levels in patients over 40 years than HC (P = 0·0329). Although further research is warranted to elucidate the role of circulating biomarkers, some of that may contribute to the understanding of the physiopathology processes underlying BD activity and damage as well as to provide useful tools for prognostic purposes and a personalized treatment approach.

Molecular Genetic Advances in Uveitis

Uveitis is usually considered as an intraocular inflammation characterized by variety of clinical features. Behcet's disease (BD), Vogt-Koyanagi-Harada (VKH) syndrome, acute anterior uveitis (AAU), and birdshot chorioretinopathy (BCR) are examples of noninfectious forms of uveitis. Although the precise pathogenesis remains unclear, accumulating evidence shows that complex genetic backgrounds coupled with an aberrant immune response may be implicated in the development of uveitis. The complement and pattern recognition systems are both important factors of the innate immune system and are involved in the pathogenesis of uveitis. Copy number variants (CNVs) of complement component 4 have been found to be associated with BD and VKH syndrome, but not with AAU. Several CNVs and gene polymorphisms of toll-like receptors were found to be associated with BD. Leukocytes are an important part of the adaptive immune system and various molecules on these cells play an important role in the development of uveitis. Genes encoding for human leukocyte antigens (HLAs) have been shown to be associated with certain uveitis entities, including BD (HLA-B51), VKH syndrome (HLA-DR4, DRB1/DQA1), AAU (HLA-B27), and BCR (HLA-A29). Genome wide association studies showed that the IL-23R locus was a shared risk factor for multiple uveitis entities including BD, AAU, and VKH syndrome. In addition, various other non-HLA genes are also associated with BD or VKH syndrome, such as IL-10, STAT4, STAT3, and UBAC2. These studies support the hypothesis that genetic factors play a key role in the pathogenesis of uveitis.

The Role of Type I Interferon Subtypes and Interferon-Gamma in Type I Interferon Diabetes Inhibitory Activity in the NOD Mouse

As in bacterial infections and endotoxin shock, type I interferons (IFNs) also have complex and often opposing effects in various models of autoimmune disease. We have shown that type I IFN paradoxically inhibits autoimmune diabetes in the nonobese diabetic mouse (NOD) and biobreeding (BB) rat. We hypothesize that type I IFN activity differs by IFN subtype and interaction with IFN-gamma. We examined the structure-function relationship of the type I IFN molecule and the mechanism of its diabetes-sparing activity in the NOD mouse. While both recombinant human IFN-alpha A/D (bgl 11) (rHuIFN-alphaA/D) and ovine IFN-tauImod (ovIFN-tau) potently inhibited the development of diabetes (P < 0.01), neither recombinant human IFN-alpha B/D (rHuIFN-alphaB/D) nor recombinant human IFN-alpha consensus (CIFN) were efficacious. The activity of IFN subtypes correlate with their NH3-terminal amino acid sequences. All type I IFN save CIFN, which has no diabetes-sparing activity, inhibited the accessory cell function. IFN-tau administration decreased the expression of Fas and ICAM on total cells, class II MHC expression on B cells, and CD40L expression on T cells by 39%, 45%, 45%, and 60%, respectively. In addition, IFN-tau inhibited the development of diabetes in the NOD.IL4(null) but not the NOD.IFN-gamma(null) mice, suggesting a coordinated interaction between type I and type II IFNs to suppress diabetes development. Thus, the amino terminal portion of the type I IFN molecule influences its ability to inhibit the development of autoimmune diabetes in NOD mice. These data also support the contention that IFN-gamma may have a role in mediating the diabetes-sparing effect of high-dose type I IFNs by the inhibition of the IFN-gamma-inducible immune modulators, class II MHC, Fas, ICAM, and CD40L.

CDP7657, an anti-CD40L antibody lacking an Fc domain, inhibits CD40L-dependent immune responses without thrombotic complications: an in vivo study

INTRODUCTION

CD40 ligand (CD40L) blockade has demonstrated efficacy in experimental autoimmune models. However, clinical trials of hu5c8, an anti-human CD40L IgG1 antibody, in systemic lupus erythematosus (SLE) were halted due to an increased incidence of thrombotic events. This study evaluated CDP7657, a high affinity PEGylated monovalent Fab' anti-CD40L antibody fragment, to assess whether an Fc-deficient molecule retains efficacy while avoiding the increased risk of thrombotic events observed with hu5c8.

METHODS

The potency and cross-reactivity of CDP7657 was assessed in in vitro assays employing human and non-human primate leukocytes, and the capacity of different antibody formats to activate platelets in vitro was assessed using aggregometry and dense granule release assays. Given the important role CD40L plays in regulating humoral immunity, in vivo efficacy was assessed by investigating the capacity of Cynomolgus monkeys to generate immune responses to the tetanus toxoid antigen while the potential to induce thrombotic events in vivo was evaluated after repeat dosing of antibodies to Rhesus monkeys. A PEGylated anti-mouse CD40L was generated to assess efficacy in the New Zealand Black/White (NZB/W) mouse model of SLE.

RESULTS

CDP7657 dose-dependently inhibited antigen-specific immune responses to tetanus toxoid in Cynomolgus monkeys, and in contrast to hu5c8, there was no evidence of pulmonary thrombovasculopathy in Rhesus monkeys. Aglycosyl hu5c8, which lacks Fc receptor binding function, also failed to induce thrombotic events in Rhesus monkeys. In vitro experiments confirmed that antibody constructs lacking an Fc, including CDP7657, did not induce human or monkey platelet activation. A PEGylated monovalent Fab' anti-mouse CD40L antibody also inhibited disease activity in the NZB/W mouse model of SLE after administration using a therapeutic dosing regimen where mice received antibodies only after they had displayed severe proteinuria.

CONCLUSIONS

These findings demonstrate for the first time that anti-CD40L antibodies lacking a functional Fc region do not induce thrombotic events in Rhesus monkeys and fail to activate platelets in vitro but, nevertheless retain pharmacological activity and support the investigation of CDP7657 as a potential therapy for systemic lupus erythematosus and other autoimmune diseases.

Immunogenetics of autoimmune thyroid diseases: A comprehensive review

Both environmental and genetic triggers factor into the etiology of autoimmune thyroid disease (AITD), including Graves' disease (GD) and Hashimoto's thyroiditis (HT). Although the exact pathogenesis and causative interaction between environment and genes are unknown, GD and HT share similar immune-mediated mechanisms of disease. They both are characterized by the production of thyroid autoantibodies and by thyroidal lymphocytic infiltration, despite being clinically distinct entities with thyrotoxicosis in GD and hypothyroidism in HT. Family and population studies confirm the strong genetic influence and inheritability in the development of AITD. AITD susceptibility genes can be categorized as either thyroid specific (Tg, TSHR) or immune-modulating (FOXP3, CD25, CD40, CTLA-4, HLA), with HLA-DR3 carrying the highest risk. Of the AITD susceptibility genes, FOXP3 and CD25 play critical roles in the establishment of peripheral tolerance while CD40, CTLA-4, and the HLA genes are pivotal for T lymphocyte activation and antigen presentation. Polymorphisms in these immune-modulating genes, in particular, significantly contribute to the predisposition for GD, HT and, unsurprisingly, other autoimmune diseases. Emerging evidence suggests that single nucleotide polymorphisms (SNPs) in the immunoregulatory genes may functionally hinder the proper development of central and peripheral tolerance and alter T cell interactions with antigen presenting cells (APCs) in the immunological synapse. Thus, susceptibility genes for AITD contribute directly to the key mechanism underlying the development of organ-specific autoimmunity, namely the breakdown in self-tolerance. Here we review the major immune-modulating genes that are associated with AITD and their potential functional effects on thyroidal immune dysregulation.

Role of CD154 in cancer pathogenesis and immunotherapy

Many factors and molecules have been investigated as potential players in the pathogenesis or immunosurveillance of cancer. Among these, CD154 has been recognized as a co-stimulatory molecule with high potential for treating cancer, in addition to its contribution in the development of the disease. CD154 was initially described for its pivotal role in T cell-dependent humoral responses via an interaction with its classical receptor, CD40. Subsequent studies showed that CD154 is also implicated in cell-mediated immunity and inflammation via an interaction with CD40 alone or in combination with newly identified receptors, members of the integrin family, leading to the development of chronic inflammatory and autoimmune diseases. In the current article, we present an overview of the role of CD154 as a potential etiological factor in tumors inducing proliferation of malignant cells, their rescue from apoptosis and their invasiveness. In addition, this review describes the immuno-regulatory functions of CD154 against cancer reflected by its stimulation of antigen-presenting cells and the subsequent activation of effector cells, its enhancement of malignant cells' immunogenicity, its modulation of immune settings around tumors, and its initiation of proliferation inhibiting effects in malignant cells. In vitro as well as in vivo studies are outlined and a particular attention is given to clinical studies and progress reached at this point. Findings reviewed herein will improve our knowledge of the role of the CD154 system in cancers from causative to immunotherapeutic functions, paving the way for the identification of new targets for prevention and/or treatment of malignant disorders.

First-in-human trial of the safety, pharmacokinetics and immunogenicity of a PEGylated anti-CD40L antibody fragment (CDP7657) in healthy individuals and patients with systemic lupus erythematosus

OBJECTIVE

The objective of this paper is to investigate the safety, pharmacokinetics (PK) and immunogenicity of CDP7657, a PEGylated anti-CD40L antibody fragment, in healthy individuals and patients with systemic lupus erythematosus (SLE).

METHODS

This randomized, double-blind, single-dose, dose-escalation phase I study consisted of two parts. In part 1, 28 healthy individuals received CDP7657 IV (0.004-5 mg/kg) or placebo. In part 2, 17 patients with SLE received CDP7657 IV (5-60 mg/kg) or placebo. The CDP7657:placebo ratio was 3:1.

RESULTS

Adverse events (AEs) were reported by 76% of healthy individuals and 100% of patients with SLE treated with CDP7657; most were mild or moderate in intensity. Two healthy individuals reported serious AEs (SAEs), one of which was considered treatment related (infusion-related reaction; 5 mg/kg cohort). One patient with SLE (60 mg/kg cohort) experienced three SAEs, one of which was considered treatment related (herpes zoster infection). No thromboembolic events were reported. CPD7657 exposure increased in a dose-proportional manner. Low anti-CDP7657 antibody titres were detected in the majority of CDP7657-treated participants with no apparent impact on the PK of CDP7657.

CONCLUSION

Single doses of CDP7657 showed predictable PK in healthy individuals and patients with SLE and were well tolerated, with no safety signals of concern. These findings support further investigation of CDP7657 as a therapy for SLE.

New frontiers for platelet CD154

The role of platelets extends beyond hemostasis. The pivotal role of platelets in inflammation has shed new light on the natural history of conditions associated with acute or chronic inflammation. Beyond the preservation of vascular integrity, platelets are essential to tissue homeostasis and platelet-derived products are already used in the clinics. Unanticipated was the role of platelets in the adaptative immune response, allowing a renewed conceptual approach of auto-immune diseases. Platelets are also important players in cancer growth and dissemination. Platelets fulfill most of their functions through the expression of still incompletely characterized membrane-bound or soluble mediators. Among them, CD154 holds a peculiar position, as platelets represent a major source of CD154 and as CD154 contributes to most of these new platelet attributes. Here, we provide an overview of some of the new frontiers that the study of platelet CD154 is opening, in inflammation, tissue homeostasis, immune response, hematopoiesis and cancer.

The signaling role of CD40 ligand in platelet biology and in platelet component transfusion

The CD40 ligand (CD40L) is a transmembrane molecule of crucial interest in cell signaling in innate and adaptive immunity. It is expressed by a variety of cells, but mainly by activated T-lymphocytes and platelets. CD40L may be cleaved into a soluble form (sCD40L) that has a cytokine-like activity. Both forms bind to several receptors, including CD40. This interaction is necessary for the antigen specific immune response. Furthermore, CD40L and sCD40L are involved in inflammation and a panoply of immune related and vascular pathologies. Soluble CD40L is primarily produced by platelets after activation, degranulation and cleavage, which may present a problem for transfusion. Soluble CD40L is involved in adverse transfusion events including transfusion related acute lung injury (TRALI). Although platelet storage designed for transfusion occurs in sterile conditions, platelets are activated and release sCD40L without known agonists. Recently, proteomic studies identified signaling pathways activated in platelet concentrates. Soluble CD40L is a good candidate for platelet activation in an auto-amplification loop. In this review, we describe the immunomodulatory role of CD40L in physiological and pathological conditions. We will focus on the main signaling pathways activated by CD40L after binding to its different receptors.