The CD40/CD40L system: a new therapeutic target for disease

Side Effects of Immunosuppressant Drugs After Liver Transplant

Liver transplantation (LT) is the standard of care for both end-stage liver failure and hepatocellular carcinoma (HCC). Side effects of the main used immunosuppressive drugs have a noteworthy impact on the long-term outcome of LT recipients. Consequently, to achieve a balance between optimal immunosuppression and minimal side effects is a cornerstone of the post-LT period. Today, there are no validated markers for overimmunosuppression and underimmunosuppression, only a few drugs have therapeutic drug monitoring, and immunosuppression regimens vary from center to center and from country to country. Currently, there are many drugs with different efficacy and safety profiles. Using different agents permits a decrease in the dosage and minimizes the toxicities. A small subset of recipients achieves immunotolerance with the chance to stop immunosuppressive therapy. This article focuses on the side effects of immunosuppressive drugs, which significantly impact long-term outcomes for LT recipients. The primary aim is to highlight the balance between achieving effective immunosuppression and minimizing adverse effects, emphasizing the role of personalized therapeutic strategies. Moreover, this review evaluates the mechanisms of action and specific complications associated with immunosuppressive agents. Finally, special attention is given to strategies for reducing immunosuppressive burdens, improving patient quality of life, and identifying immunotolerant individuals.

Impact of statin therapy on CD40:CD40L signaling: mechanistic insights and therapeutic opportunities

Statins are widely utilized to reduce cholesterol levels, particularly in cardiovascular diseases. They interface with cholesterol synthesis by inhibiting the 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA) reductase enzyme. Besides their primary effect, statins demonstrate anti-inflammatory and immune-modulating properties in various diseases, highlighting the pleiotropic effect of these drugs. The CD40:CD40L signaling pathway is considered a prominent inflammatory pathway in multiple diseases, including autoimmune, inflammatory, and cardiovascular diseases. The findings from clinical trials and in vitro and in vivo studies suggest the potential anti-inflammatory effect of statins in modulating the CD40 signaling pathway and downstream inflammatory mediator. Accordingly, as its classic ligand, statins can suppress immune responses in autoimmune diseases by inhibiting CD40 expression and blocking its interaction with CD40L. Additionally, statins affect intracellular signaling and inhibit inflammatory mediator secretion in chronic inflammatory diseases like asthma and autoimmune disorders such as myasthenia gravis, multiple sclerosis, systemic lupus erymanthus, and cardiovascular diseases like atherosclerosis. However, it is essential to note that the anti-inflammatory effect of statins may vary depending on the specific type of statin used. In this study, we aim to explore the potential anti-inflammatory effects of statins in treating inflammatory diseases by examining their role in regulating immune responses, particularly their impact on the CD40:CD40L signaling pathway, through a comprehensive review of existing literature.

Past and future in vitro and in vivo approaches toward circulating factors and biomarkers in idiopathic nephrotic syndrome

Predicting the risks of progression to chronic kidney disease (CKD) stage 5 in idiopathic nephrotic syndrome (NS) and recurrence of the disease (rNS) following kidney transplantation (KT) is a key assessment to provide essential management information. NS has been categorized etiologically as genetic and immune-based. A genetic cause can be identified in ~ 30% of children with steroid-resistant NS (SRNS), a finding associated with a very low risk of rNS following KT. In immune-based NS, clinical overlap is observed among steroid-sensitive NS, secondary-resistant NS, and SRNS not associated with disease-causing genetic variants (non-monogenic SRNS). While ~ 50% of SRNS patients with no identified monogenic disease respond to intensified immunosuppressive treatments, the ones that do not respond to this therapy have a high risk of progression to CKD stage 5 and post-KT rNS. Secondary-resistant patients who progress to CKD stage 5 display the highest risk of post-KT rNS. The proposed shared underlying mechanism of the immune-based NS associated with post-KT rNS is based on a systemic circulating factor (CF) that affects glomerular permeability by inducing foot process effacement and focal segmental glomerulosclerosis. However, identifying patients without a detected genetic form who will recur post-KT is a major challenge. Extensive efforts, therefore, have been made to identify CFs and biomarkers potentially capable of predicting the risk of progression to CKD stage 5 and post-KT rNS. This review discusses the in vitro and in vivo approaches employed to date to identify and characterize potential CFs and CF-induced biomarkers of recurrent NS and offers an assessment of their potential to improve outcomes of KT in this patient population.

Soluble CD40 Ligand as a Promising Biomarker in Cancer Diagnosis

Cancer remains a significant challenge in medicine due to its complexity and heterogeneity. Biomarkers have emerged as vital tools for cancer research and clinical practice, facilitating early detection, prognosis assessment, and treatment monitoring. Among these, CD40 ligand (CD40L) has gained attention for its role in immune response modulation. Soluble CD40 ligand (sCD40L) has shown promise as a potential biomarker in cancer diagnosis and progression, reflecting interactions between immune cells and the tumor microenvironment. This review explores the intricate relationship between sCD40L and cancer, highlighting its diagnostic and prognostic potential. It discusses biomarker discovery, emphasizing the need for reliable markers in oncology, and elucidates the roles of CD40L in inflammatory responses and interactions with tumor cells. Additionally, it examines sCD40L as a biomarker, detailing its significance across various cancer types and clinical applications. Moreover, the review focuses on therapeutic interventions targeting CD40L in malignancies, providing insights into cellular and gene therapy approaches and recombinant protein-based strategies. The clinical effectiveness of CD40L-targeted therapy is evaluated, underscoring the need for further research to unlock the full potential of this signaling pathway in cancer management.

B-cell targeted therapies in autoimmune encephalitis: mechanisms, clinical applications, and therapeutic potential

Autoimmune encephalitis (AE) broadly refers to inflammation of the brain parenchyma mediated by autoimmune mechanisms. In most patients with AE, autoantibodies against neuronal cell surface antigens are produced by B-cells and induce neuronal dysfunction through various mechanisms, ultimately leading to disease progression. In recent years, B-cell targeted therapies, including monoclonal antibody (mAb) therapy and chimeric antigen receptor T-cell (CAR-T) therapy, have been widely used in autoimmune diseases. These therapies decrease autoantibody levels in patients and have shown favorable results. This review summarizes the mechanisms underlying these two B-cell targeted therapies and discusses their clinical applications and therapeutic potential in AE. Our research provides clinicians with more treatment options for AE patients whose conventional treatments are not effective.

Investigation of Immunostimulatory Effects of IFN-γ Cytokine and CD40 Ligand Costimulatory Molecule for Development of HIV-1 Therapeutic Vaccine Candidate

The most crucial disadvantage of DNA-based vaccines is their low immunogenicity; therefore, finding an effectual adjuvant is essential for their development. Herein, immunostimulatory effects of IFNγ cytokine and a CD40 ligand (CD40L) costimulatory molecule are evaluated as combined with an antigen, and also linked to an antigen in mice. For this purpose, after preparation of the HIV-1 Nef, IFNγ, and CD40L DNA constructs, and also their recombinant protein in an Escherichia coli expression system, nine groups of female BALB/c mice are immunized with different regimens of DNA constructs. About 3 weeks and also 3 months after the last injection, humoral and cellular immune responses are assessed in mice sera and splenocytes. Additionally, mice splenocytes are exposed to single-cycle replicable (SCR) HIV-1 virions for evaluating their potency in the secretion of cytokines in vitro. The data indicate that the linkage of IFNγ and CD40L to Nef antigen can significantly induce the Th-1 pathway and activate cytotoxic T lymphocytes compared to other regimens. Moreover, groups receiving the IFNγ-Nef and CD40L-Nef fusion DNA constructs show higher secretion of IFNγ and TNF-α from virion-infected lymphocytes than other groups. Therefore, the IFNγ-Nef and CD40L-Nef fusion DNA constructs are suggested to be a potential option for development of an efficient HIV-1 vaccine.

Role of the CD40-CD40L expression level pathway in the diagnosis of unexplained recurrent pregnancy loss

BACKGROUND

Unexplained recurrent spontaneous pregnancy loss (URPL) lacks effective treatment and reliable early diagnosis and prediction. Immunologic dysfunction can be an underlying cause of recurrent pregnancy loss (RPL). Considering the regulatory role of CD40-CD40L in immune responses, we explored its clinical significance in URPL.

METHODS

The 108 women with URPL who were treated in Hebei Yanda Hospital from January 2020 to December 2022 were selected as study subjects, and another 108 healthy women who were not pregnant and matched with the age and body mass index of the study group were selected as the control group. CD40 and CD4 + CD25 + Treg cells in peripheral blood mononuclear cells (PBMCs) and CD40L in peripheral blood platelets were measured by flow cytometry. The predictive value of CD40-CD40L in URPL for the risk of RPL was determined by receiver operating characteristic (ROC) curves. The correlations of CD40-CD40L with CD4 + CD25 + Treg cells and serum pro-inflammatory factors were assessed by Pearson's analysis.

RESULTS

CD40 on the surface of PBMCs and CD40L on the surface of platelets were up-regulated in URPL patients. CD40 in combination with CD40L had high predictive value for the risk of RPL in URPL patients. Peripheral blood CD40-CD40L was positively linked to IL-17 and IL-23, and negatively to CD4 + CD25 + Treg cells and IL-10 in URPL patients.

CONCLUSIONS

The CD40-CD40L pathway expression in peripheral blood can help predict the risk of RPL in URPL patients.

CD40/CD40L expression and its prognostic value in cervical cancer

CD40, a member of the tumor necrosis factor receptor (TNFR) family, is known to be involved in immune system regulation, acting as a costimulatory molecule, and in antitumor responses against cancer cells. It is a protein that is expressed in different types of cells, including immune cells and cancer cells (e.g., cervical cancer, breast cancer, melanoma). In this study, we investigated CD40/CD40L transcriptional and protein levels in cervical cancer cell lines and tumors. Higher CD40 expression was observed in cervical cancer cell lines derived from squamous cell carcinomas than from adenocarcinomas. Search of CD40/CD40L expression in cervical cancer tissues in public data sets revealed that about 83% of squamous cell carcinomas express CD40 compared to other cervical tumor subtypes. Moreover, expression of CD40 and CD40L in squamous cervical carcinomas is associated with better overall survival. Therefore, these proteins could be explored as prognostic markers in cervical cancers.

Immune Mediators Profiles in the Aqueous Humor of Patients with Simple Diabetic Retinopathy

Various immune mediators identified to date are associated with the development of advanced forms of diabetic retinopathy (DR), such as proliferative DR and diabetic macular edema, although the exact pathophysiological mechanisms of early stages of DR such as simple DR remain unclear. We determined the immune mediator profile in the aqueous humor of eyes with simple DR. Fifteen eyes of fifteen patients with simple DR were studied. Twenty-two eyes of twenty-two patients with cataracts and no DR served as controls. Undiluted aqueous humor samples were collected, and a cytometric bead array was used to determine the aqueous humor concentrations of 32 immune mediators comprising 13 interleukins (IL), interferon-γ, interferon-γ-inducible protein-10 (IP-10), monocyte chemoattractant protein-1, macrophage inflammatory protein (MIP)-1α, MIP-1β, regulated on activation, normal T cell expressed and secreted (RANTES), monokine induced by interferon-γ, basic fibroblast growth factor (bFGF), Fas ligand, granzyme A, granzyme B, interferon-inducible T-cell alpha chemoattractant (ITAC), fractalkine, granulocyte macrophage colony-stimulating factor, granulocyte colony-stimulating factor (G-CSF), vascular endothelial growth factor (VEGF), angiogenin, tumor necrosis factor-α, and CD40 ligand. Among the 32 immune mediators, 10 immune mediators, including bFGF, CD40 ligand, fractalkine, G-CSF, IL-6, IL-8, MIP-α, MIP-1β, and VEGF, showed significantly higher aqueous humor concentrations and the Fas ligand had significantly lower concentration (p < 0.05) in eyes with simple DR compared with control eyes. Of these 10 cytokines with significant concentration alteration, protein-protein interaction analysis revealed that 8 established an intricate interaction network. Various immune mediators may contribute to the pathogenesis of simple DR. Attention should be given to the concentrations of immune mediators in ocular fluids even in simple DR. Large-scale studies are warranted to assess whether altered aqueous humor concentrations of these 10 immune mediators are associated with an increased risk of progression to advanced stages of DR.

Cytokine patterns in the blister fluid and plasma of patients with fracture blisters

BACKGROUND

Fracture blister (FB) is a complication of fracture, which damages to the skin integrity and increases the risk of infection. Inflammation plays an important role in the formation and development of FBs, but its specific mechanism is still unclear. The aim of this study was to investigate the patterns and dynamic changes of inflammatory cytokines in fracture blister fluid (FBF) and plasma.

MATERIALS AND METHODS

FBF and plasma were collected simultaneously from patients with lower extremity fractures with FBs on the first and fifth day after blisters formation. 92 inflammation-related protein biomarkers were measured in plasma and FBF using Proximity Extension Assay (PEA). We analyzed the cytokine patterns and their dynamic changes in FBF and plasma. Cytokine patterns in plasma from FB patients, fracture without blister patients, and healthy subjects were also analyzed.

RESULT

The cytokine pattern in FBF and plasma of patients with FBs was different but 11 cytokines were significantly correlated in the two sample types. 23 cytokines were different in plasma across FB patients, fracture without blister patients and healthy subjects. In the analysis of plasma from FB patients and fracture without blister patients, 15 cytokines were significantly different and they may be potential risk factors for the occurrence of FBs. The FBF and plasma showed different cytokine patterns in the early and late stages, with 50 cytokines significantly changed in FBF and 20 cytokines in plasma.

CONCLUSION

The different cytokine patterns in plasma between FB patients and fracture without blisters patients may be the potential factors for the occurrence of blisters. The cytokine patterns in FBF and plasma showed a dynamic change from the inflammatory stage to the proliferative and repair stage, which indicates that FBs may have new clinical importance in addition to being a soft tissue injury.

A novel immune checkpoints-based signature to predict prognosis and response to immunotherapy in lung adenocarcinoma

Background

Except for B7-CD28 family members, more novel immune checkpoints are being discovered. They are closely associated with tumor immune microenvironment and regulate the function of many immune cells. Various cancer therapeutic studies targeting these novel immune checkpoints are currently in full swing. However, studies concerning novel immune checkpoints phenotypes and clinical significance in lung adenocarcinoma (LUAD) are still limited.

Methods

We enrolled 1883 LUAD cases from nine different cohorts. The samples from The Cancer Genome Atlas (TCGA) were used as a training set, whereas seven microarray data cohorts and an independent cohort with 102 qPCR data were used for validation. The immune profiles and potential mechanism of the system were also explored.

Results

After univariate Cox proportional hazards regression and stepwise multivariable Cox analysis, a novel immune checkpoints-based system (LTA, CD160, and CD40LG) were identified from the training set, which significantly stratified patients into high- and low-risk groups with different survivals. Furthermore, this system has been well validated in different clinical subgroups and multiple validation cohorts. It also acted as an independent prognostic factor for patients with LAUD in different cohorts. Further exploration suggested that high-risk patients exhibited distinctive immune cells infiltration and suffered an immunosuppressive state. Additionally, this system is closely linked to various classical immunotherapy biomarkers.

Conclusion

we constructed a novel immune checkpoints-based system for LUAD, which predicts prognosis and immunotherapeutic implications. We believe that these findings will not only aid in clinical management but will also shed some light on screening appropriate patients for immunotherapy.

CDCA8 Contributes to the Development and Progression of Thyroid Cancer through Regulating CDK1

Background: This study aims to reveal regulatory role of cell division cycle associated 8 (CDCA8) in thyroid cancer progression and metastasis.

Methods: A series of experiments in vivo and in vitro were performed to explore the function of CDCA8 in thyroid cancer.

Results: Immunohistochemical analysis showed that CDCA8 expression levels were upregulated in thyroid cancer tissues compared with normal tissues, and were statistically correlated with tumor stage. Results of in vitro loss-of-function assay showed that downregulation of endogenous expression of CDCA8 could significantly inhibit cell proliferation, colony formation, cell migration, and promote apoptosis. Thyroid cancer cells lacking CDCA8 expression also had reduced tumorigenicity in vivo. Further, results of preliminary mechanistic exploration showed that CDK1 may be a potential downstream molecule of CDCA8 in regulating thyroid cancer progression. We subsequently confirmed that CDK1 itself exerted a significant regulatory function in thyroid cancer by loss- and gain-of-function experiments. Moreover, overexpression of CDK1 could weaken the tumor suppressive effect caused by CDCA8 knockdown.

Conclusions: CDCA8 functions as an oncogene in thyroid cancer, and CDCA8 knockdown suppresses cancer development in vitro and in vivo. Additionally, CDK1 was further identified as a potential target of CDCA8 in thyroid cancer.

Antibody Therapies in Autoimmune Neuromuscular Junction Disorders: Approach to Myasthenic Crisis and Chronic Management

Myasthenia gravis (MG) is a neurological autoimmune disorder characterized by muscle weakness and fatigue. It is a B cell-mediated disease caused by pathogenic antibodies directed against various components of the neuromuscular junction (NMJ). Despite the wide range of adverse effects, current treatment is still based on non-specific immunosuppression, particularly on long-term steroid usage. The increasing knowledge regarding the pathogenic mechanisms of MG has however allowed to create more target-specific therapies. A very attractive therapeutic approach is currently offered by monoclonal antibodies (mAbs), given their ability to specifically and effectively target different immunopathological pathways, such as the complement cascade, B cell-related cluster of differentiation (CD) proteins, and the human neonatal Fc receptor (FcRn). Up to now, eculizumab, a C5-directed mAb, has been approved for the treatment of generalized MG (gMG) and efgartigimod, a FcRn inhibitor, has just been approved by the U.S. Food and Drug Administration for the treatment of anti-acetylcholine receptor (AChR) antibody positive gMG. Other mAbs are currently under investigation with encouraging preliminary results, further enriching the new range of therapeutic possibilities for MG. This review article provides an overview of the present status of mAb-based therapies for MG, which offer an exciting promise for better outcomes by setting the basis of a precision medicine approach.

Platelets: a potential role in chronic respiratory diseases?

Platelets are small anucleate cells known for their role in haemostasis and thrombosis. In recent years, an increasing number of observations have suggested that platelets are also immune cells and key modulators of immunity. They express different receptors and molecules that allow them to respond to pathogens, and to interact with other immune cells. Platelets were linked to the pathogenesis of some inflammatory disorders including respiratory diseases such as asthma and idiopathic pulmonary fibrosis. Here, we discuss the involvement of platelets in different immune responses, and we focus on their potential role in various chronic lung diseases.

In addition to their essential role in haemostasis and thrombosis, platelets are strong modulators of different immune responses, and could be involved in the physiopathology of several chronic airway diseaseshttps://bit.ly/3cB6Xnj

Post-GWAS functional studies reveal an RA-associated CD40-induced NF-kB signal transduction and transcriptional regulation network targeted by class II HDAC inhibitors

Currently, it remains difficult to identify which single nucleotide polymorphisms (SNPs) identified by genome-wide association studies (GWAS) are functional and how various functional SNPs (fSNPs) interact and contribute to disease susceptibility. GWAS have identified a CD40 locus that is associated with rheumatoid arthritis (RA). We previously used two techniques developed in our laboratory, single nucleotide polymorphism-next-generation sequencing (SNP-seq) and flanking restriction enhanced DNA pulldown-mass spectrometry (FREP-MS), to determine that the RA risk gene RBPJ regulates CD40 expression via a fSNP at the RA-associated CD40 locus. In the present work, by applying the same approach, we report the identification of six proteins that regulate RBPJ expression via binding to two fSNPs on the RA-associated RBPJ locus. Using these findings, together with the published data, we constructed an RA-associated signal transduction and transcriptional regulation network (STTRN) that functionally connects multiple RA-associated risk genes via transcriptional regulation networks (TRNs) linked by CD40-induced nuclear factor kappa B (NF-kB) signaling. Remarkably, this STTRN provides insight into the potential mechanism of action for the histone deacetylase inhibitor givinostat, an approved therapy for systemic juvenile idiopathic arthritis. Thus, the generation of disease-associated STTRNs based on post-GWAS functional studies is demonstrated as a novel and effective approach to apply GWAS for mechanistic studies and target identification.

Elevation of CD40/CD40L Inflammatory Pathway Molecules in Carotid Plaques from Moderate-and-Severe Obstructive Sleep Apnea Patients

A chronic inflammatory process characteristic of obstructive sleep apnea promotes vascular endothelial dysfunction and atherogenesis. This process can lead to destabilization and rupture of cardiovascular plaques, which clinically manifests as an acute coronary syndrome or stroke. The aim of this study was to investigate the inflammatory pathway leading to plaque destabilization in non-to-mild and moderate-to-severe groups of OSA patients. This prospective study involved enrollment of patients scheduled for endarterectomy. A sleep study was performed prior to surgery. Immunohistochemistry was performed on atherosclerotic plaques from carotid arteries obtained during standard open endarterectomy to determine levels of CD40, CD40L receptors, MCP-1, and MMP-9. The 46 patients included 14 controls, 13 with mild, 11 with moderate, and 8 with severe OSA. Increased expression of CD40, CD40L receptors, MCP-1, and MMP-9 were found to be proportionate with OSA severity. However, significant differences among groups were observed only for MCP-1 (p = 0.014). Increased expression of inflammatory markers (CD40, CD40L, MCP-1, MMP-9) is associated with increasing OSA severity. This suggests the CD40-CD4-L inflammatory pathway may contribute to plaque instability and rupture in OSA patients.

The Role of the Proteasome in Platelet Function

Platelets are megakaryocyte-derived acellular fragments prepped to maintain primary hemostasis and thrombosis by preserving vascular integrity. Although they lack nuclei, platelets harbor functional genomic mediators that bolster platelet activity in a signal-specific manner by performing limited de novo protein synthesis. Furthermore, despite their limited protein synthesis, platelets are equipped with multiple protein degradation mechanisms, such as the proteasome. In nucleated cells, the functions of the proteasome are well established and primarily include proteostasis among a myriad of other signaling processes. However, the role of proteasome-mediated protein degradation in platelets remains elusive. In this review article, we recapitulate the developing literature on the functions of the proteasome in platelets, discussing its emerging regulatory role in platelet viability and function and highlighting how its functional coupling with the transcription factor NF-κB constitutes a novel potential therapeutic target in atherothrombotic diseases.

Effects and Side Effects of Platelet Transfusion

Aside from their canonical role in hemostasis, it is increasingly recognized that platelets have inflammatory functions and can regulate both adaptive and innate immune responses. The main topic this review aims to cover is the proinflammatory effects and side effects of platelet transfusion. Platelets prepared for transfusion are subject to stress injury upon collection, preparation, and storage. With these types of stress, they undergo morphologic, metabolic, and functional modulations which are likely to induce platelet activation and the release of biological response modifiers (BRMs). As a consequence, platelet concentrates (PCs) accumulate BRMs during processing and storage, and these BRMs are ultimately transfused alongside platelets. It has been shown that BRMs present in PCs can induce immune responses and posttransfusion reactions in the transfusion recipient. Several recent reports within the transfusion literature have investigated the concept of platelets as immune cells. Nevertheless, current and future investigations will face the challenge of encompassing the immunological role of platelets in the scope of transfusion.

IL-1 and CD40/CD40L platelet complex: elements of induction of Crohn's disease and new therapeutic targets

Ulcerative colitis (UC) and Crohn's disease (CD) are chronic and multifactorial diseases that affect the intestinal tract, both characterized by recurrent inflammation of the intestinal mucosa, resulting in abdominal pain, diarrhea, vomiting and, rectal bleeding. Inflammatory bowel diseases (IBD) regroup these two disorders. The exact pathological mechanism of IBD remains ambiguous and poorly known. In genetically predisposed patients, defects in intestinal mucosal barrier are due to an uncontrolled inflammatory response to normal flora. In addition to the genetic predisposition, these defects could be triggered by environmental factors or by a specific lifestyle which is widely accepted as etiological hypothesis. The involvement of the CD40/CD40L platelet complex in the development of IBD has been overwhelmingly demonstrated. CD40L is climacteric in cell signalling in innate and adaptive immunity, the CD40L expression on the platelet cell surface gives them an immunological competence. The IL-1, a major inflammation mediator could be involved in different ways in the development of IBD. Here, we provide a comprehensive review regarding the role of platelet CD40/CD40L in the pathophysiological effect of IL-1 in the development of Crohn's disease (CD). This review could potentially help future approaches aiming to target these two pathways for therapeutic purposes and elucidate the immunological mechanisms driving gut inflammation.

Immunoregulatory Roles of Extracellular Vesicles and Associated Therapeutic Applications in Lung Cancer

Lung cancer represents a fatal condition that has the highest morbidity and mortality among malignancies. The currently available treatments fall short of improving the survival and quality of life of late-stage lung cancer patients. Extracellular vesicles (EVs) secreted by tumors or immune cells transport proteins, lipids, and nucleic acids to other cells, thereby mediating immune regulation in the tumor microenvironment. The cargo carried by EVs vary by cellular state or extracellular milieu. So far, multiple studies have suggested that EVs from lung tumor cells (TEVs) or immune cells promote tumor progression mainly through suppressing antitumor immunity. However, modified or engineered EVs can be used as vaccines to elicit antitumor immunity. In addition, blocking the function of immunosuppressive EVs and using EVs carrying immunogenic medicine or EVs from certain immune cells also shows great potential in lung cancer treatment. To provide information for future studies on the role of EVs in lung cancer immunity, this review focus on the immunoregulatory role of EVs and associated treatment applications in lung cancer.

Identification of Four Potential Biomarkers Associated With Coronary Artery Disease in Non-diabetic Patients by Gene Co-expression Network Analysis

Background

Coronary artery disease (CAD) is a type of cardiovascular disease that greatly hurts the health of human beings. Diabetic status is one of the largest clinical factors affecting CAD-associated gene expression changes. Most of the studies focus on diabetic patients, whereas few have been done for non-diabetic patients. Since the pathophysiological processes may vary among these patients, we cannot simply follow the standard based on the data from diabetic patients. Therefore, the prognostic and predictive diagnostic biomarkers for CAD in non-diabetic patient need to be fully recognized.

Materials and Methods

To screen out candidate genes associated with CAD in non-diabetic patients, weighted gene co-expression network analysis (WGCNA) was constructed to conduct an analysis of microarray expression profiling in patients with CAD. First, the microarray data GSE20680 and GSE20681 were downloaded from NCBI. We constructed co-expression modules via WGCNA after excluding the diabetic patients. As a result, 18 co-expression modules were screened out, including 1,225 differentially expressed genes (DEGs) that were obtained from 152 patients (luminal stenosis ≥50% in at least one major vessel) and 170 patients (stenosis of <50%). Subsequently, a Pearson's correlation analysis was conducted between the modules and clinical traits. Then, a functional enrichment analysis was conducted, and we used gene network analysis to reveal hub genes. Last, we validated the hub genes with peripheral blood samples in an independent patient cohort using RT-qPCR.

Results

The results showed that the midnight blue module and the yellow module played vital roles in the pathogenesis of CAD in non-diabetic patients. Additionally, CD40, F11R, TNRC18, and calcium/calmodulin-dependent protein kinase type II gamma (CAMK2G) were screened out and validated using enzyme-linked immunosorbent assay (ELISA) in an independent patient cohort and immunohistochemical (IHC) staining in an atherosclerosis mouse model.

Conclusion

Our findings demonstrate that hub genes, CD40, F11R, TNRC18, and CAMK2G, are surrogate diagnostic biomarkers and/or therapeutic targets for CAD in non-diabetic patients and require deeper validation.

Expression of CD40L by the ALVAC-Simian Immunodeficiency Virus Vector Abrogates T Cell Responses in Macaques

Immunization with recombinant ALVAC/gp120 alum vaccine provided modest protection from human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) acquisition in humans and macaques. Vaccine-mediated protection was associated with the elicitation of IgG against the envelope V2 loop and of envelope-specific CD4+ T cell responses. We hypothesized that the simultaneous expression of the costimulatory molecule CD40L (CD154) by the ALVAC-HIV vector could increase both protective humoral and cellular responses. We engineered an ALVAC-SIV coexpressing CD40L with SIVmac251 (ALVAC-SIV/CD40L) gag, pol, and env genes. We compared its immunogenicity in macaques with that of a canonical ALVAC-SIV, with both given as a vector-prime/gp120 in alum boost strategy. The ALVAC-SIV/CD40L was superior to the ALVAC-SIV regimen in inducing binding and tier 1 neutralizing antibodies against the gp120. The increase in humoral responses was associated with the expression of the membrane-bound form of the CD40L by CD4+ T cells in lymph nodes. Unexpectedly, the ALVAC-SIV/CD40L vector had a blunting effect on CD4+ Th1 helper responses and instead favored the induction of myeloid-derived suppressor cells, the immune-suppressive interleukin-10 (IL-10) cytokine, and the down-modulatory tryptophan catabolism. Ultimately, this strategy failed to protect macaques from SIV acquisition. Taken together, these results underlie the importance of balanced vaccine-induced activating versus suppressive immune responses in affording protection from HIV.IMPORTANCE CD40-CD40 ligand (CD40L) interaction is crucial for inducing effective cytotoxic and humoral responses against pathogens. Because of its immunomodulatory function, CD40L has been used to enhance immune responses to vaccines, including candidate vaccines for HIV. The only successful vaccine ever tested in humans utilized a strategy combining canarypox virus-based vector (ALVAC) together with an envelope protein (gp120) adjuvanted in alum. This strategy showed limited efficacy in preventing HIV-1/SIV acquisition in humans and macaques. In both species, protection was associated with vaccine-induced antibodies against the HIV envelope and CD4+ T cell responses, including type 1 antiviral responses. In this study, we tested whether augmenting CD40L expression by coexpressing it with the ALVAC vector could increase the protective immune responses. Although coexpression of CD40L did increase humoral responses, it blunted type 1 CD4+ T cell responses against the SIV envelope protein and failed to protect macaques from viral infection.

Mycophenolate mofetil, azathioprine and tacrolimus: mechanisms in rheumatology

The introduction of biologic DMARDs into rheumatology has resulted in a substantial reduction of the burden of many rheumatic diseases. In the slipstream of the success achieved with these biologic DMARDs, some conventional immunosuppressive drugs have also found use in new indications. Notably, mycophenolate mofetil, azathioprine and tacrolimus have made their way from solid organ transplantation drugs to become useful assets in rheumatology practice. Mycophenolate mofetil and azathioprine inhibit the purine pathway and subsequently diminish cell proliferation. Both drugs have a pivotal role in the treatment of various rheumatic diseases, including lupus nephritis. Tacrolimus inhibits lymphocyte activation by inhibiting the calcineurin pathway. Mycophenolate mofetil and tacrolimus are, among other indications, increasingly being recognized as useful drugs in the treatment of interstitial lung disease in systemic rheumatic diseases and skin fibrosis in systemic sclerosis. A broad array of trials with mycophenolate mofetil, azathioprine and/or tacrolimus are ongoing within the field of rheumatology that might provide further novel avenues for the use of these drugs. In this Review, we discuss the historical perspective, pharmacodynamics, clinical indications and novel avenues for mycophenolate mofetil, azathioprine and tacrolimus in rheumatology.

Macrophages affect immune inflammation and proliferation in benign prostatic hyperplasia via androgen receptor and CD40/CD40L signaling pathway

OBJECTIVE

Considering the association of macrophage migration inhibitory factor with development of prostate diseases, this study aims to explore the effect and mechanism of macrophages (MAs) in inflammation and proliferation of benign prostate hyperplasia (BPH) cells.

METHODS

Totally 85 prostate tissues (75 from BPH patients and 10 from brain death patients) were collected for determination of biomarkers of T lymphocyte (CD4 and CD8), B lymphocyte (CD20) and MAs (CD68), as well as androgen receptor (AR) and CD40/CD40L. MAs stimulated by phorbol myristate acetate (PMA) were cultured with BPH cells (BPH-1), followed by AR inhibitor or anti-CD40 L antibody treatment. Proliferation and cell apoptosis were observed by MTT assay, colony formation assay and flow cytometer. Expressions of apoptotic related proteins and MAPK signaling pathway-related proteins were determined by qRT-PCR and Western blot.

RESULTS

BPH tissues had increased expressions of AR, CD40 and CD40 L, as well as elevated expressions of inflammation biomarkers (CD4, CD8, CD20 and CD68) in comparison to normal prostate tissues. MAs could increase the expressions of lymphocytes and inflammation biomarkers, in addition to promoting cell proliferation and inhibiting cell apoptosis. Cell proliferation and inflammation reaction could be attenuated by anti-CD40 L antibody and AR inhibitor in a concentration dependent manner through inhibiting the phosphorylation of JNK, ERK1/2 and p38.

CONCLUSION

MAs regulate AR and CD40/CD40L expression to promote the inflammation and proliferation as well as inhibiting apoptosis of BPH-1 cells through activation of the MAPK signaling pathway. This conclusion may provide a therapeutic strategy for BPH patients.

Myasthenia gravis: State of the art and new therapeutic strategies

Myasthenia Gravis (MG) - an autoimmune neuromuscular disease - is known by the production of autoantibodies against components of the neuromuscular junction mainly to the acetylcholine receptor, which cause the destruction and compromises the synaptic transmission. This disease is characterized by fluctuating and fatigable muscle weakness, becoming more intensive with activity, but with an improvement under resting. There are many therapeutic strategies used to alleviate MG symptoms, either by improving the transmission of the nerve impulse or by ameliorating autoimmune reactions with e.g. steroids, immunosuppressant drugs, or monoclonal antibodies (rituximab and eculizumab). Many breakthroughs in the discovery of new therapeutic targets have been reported, but MG remains to be a chronic disease where the symptoms are kept in the majority of patients. In this review, we discuss the different therapeutic strategies that have been used over the years to alleviate MG symptoms, as well as innovative therapeutic approaches currently under study.

Therapies Directed Against B-Cells and Downstream Effectors in Generalized Autoimmune Myasthenia Gravis: Current Status

Myasthenia gravis is a rare, heterogeneous, classical autoimmune disease characterized by fatigable skeletal muscle weakness, which is directly mediated by autoantibodies targeting various components of the neuromuscular junction, including the acetylcholine receptor, muscle specific tyrosine kinase, and lipoprotein-related protein 4. Subgrouping of myasthenia gravis is dependent on the age of onset, pattern of clinical weakness, autoantibody detected, type of thymic pathology, and response to immunotherapy. Generalized immunosuppressive therapies are effective in all subgroups of myasthenia gravis; however, approximately 15% remain refractory and more effective treatments with improved safety profiles are needed. In recent years, successful utilization of targeted B-cell therapies in this disease has triggered renewed focus in unraveling the underlying immunopathology in attempts to identify newer therapeutic targets. While myasthenia gravis is predominantly B-cell mediated, T cells, T cell-B cell interactions, and B-cell-related factors are increasingly recognized to play key roles in its immunopathology, particularly in autoantibody production, and novel therapies have focused on targeting these specific immune system components. This overview describes the current understanding of myasthenia gravis immunopathology before discussing B-cell-related therapies, their therapeutic targets, and the rationale and evidence for their use. Several prospective studies demonstrated efficacy of rituximab in various myasthenia gravis subtypes, particularly that characterized by antibodies against muscle-specific tyrosine kinase. However, a recent randomized control trial in patients with acetylcholine receptor antibodies was negative. Eculizumab, a complement inhibitor, has recently gained regulatory approval for myasthenia gravis based on a phase III trial that narrowly missed its primary endpoint while achieving robust results in all secondary endpoints. Zilucoplan is a subcutaneously administered terminal complement inhibitor that recently demonstrated significant improvements in functional outcome measures in a phase II trial. Rozanolixizumab, CFZ533, belimumab, and bortezomib are B-cell-related therapies that are in the early stages of evaluation in treating myasthenia gravis. The rarity of myasthenia gravis, heterogeneity in its clinical manifestations, and variability in immunosuppressive regimens are challenges to conducting successful trials. Nonetheless, these are promising times for myasthenia gravis, as renewed research efforts provide novel insights into its immunopathology, allowing for development of targeted therapies with increased efficacy and safety.

Antithymocyte Globulin Antibody Titer Congruent With Kidney Transplantation: Analysis of Incidence, Outcomes, Cost, and Alternative Targets

Rabbit antithymocyte globulin (rATG) use for immunosuppression induction is widespread but is contraindicated by the presence of anti-rATG antibodies. This study reports the incidence of positive anti-rATG antibody titers in patients before and after renal transplant and evaluates associated outcomes and costs. In addition, it will correlate CD40L and interleukin (IL)-21 with anti-rATG antibody titers.

METHODS

Clinical and billing records from the Indiana University Transplant Laboratory were reviewed for positive versus negative anti-rATG antibody titers, graft survival, and 7-day readmission costs between 2004 and 2018. Serum from patients with positive and negative rATG antibody titers were quantitated for CD40L and IL-21 by enzyme-linked immunosorbent assay.

RESULTS

On average, between 2004 and May 2018, 163 kidney transplants per year were performed. Anti-rATG antibody titers were ordered for 17 patients/year, of which 18.2% were positive at 1:100 titer either pre- or post-transplant. Time to graft loss correlated with a positive rATG titer at time of readmission. Moreover, second kidney transplant increased the anti-rATG positive rate. A weak correlation was observed between anti-rATG titer and recipient age. Seven-day readmission treatment costs were significantly lower in patients with positive anti-rATG titer. IL-21 and CD40L were significantly greater in patients with positive anti-rATG titers after transplant when compared with negative anti rATG patients.

CONCLUSIONS

Positive anti-rATG antibody titer is associated with a significant negative impact on outcomes. Monitoring of anti-rATG antibody titer is recommended to optimize treatment options in patients, especially in the setting of second transplants. Elucidation of the mechanisms associated with positive anti-rATG antibody is required. IL-21 and CD40L are potential targets for future study.

Blood Mixing Upregulates Platelet Membrane-Bound CD40 Ligand Expression In Vitro Independent of Abo Compatibility

Platelets play a central role in the inflammation response via CD40 ligand (CD40L) expression, which may lead to transfusion reactions. The precise role of platelet CD40L-mediated inflammation in transfusion reactions is unclear. Therefore, we assessed the effects of in vitro blood mixing on platelet CD40L expression. In addition, we examined the effect of ABO compatibility on CD40L expression. Donor-packed red blood cells were acquired from a blood bank, and recipient blood was obtained from patients undergoing cardiac surgery and prepared as washed platelets. Donor blood was mixed with suspended, washed recipient platelets to obtain a final mixing ratio of 1%, 5%, or 10% (vol/vol). The blood mixtures were divided into three groups: group M, cross-matched blood-type mixing (n = 20); group S, ABO type-specific uncross-matched blood (n = 20); and group I, ABO incompatibility (not ABO type-specific blood and not process cross-matched) mixing (n = 20). The blood mixtures were used to detect platelet membrane-bound CD40L expression by flow cytometry. Blood mixing resulted in an increase in CD40L expression in group M (P < 0.001), group S (P < 0.001), and group I (P < 0.001). CD40L expression after blood mixing potentially led to a transfusion reaction in each of the groups. There were no differences in CD40L expression among the three groups (P = 0.988) correlated with ABO compatibility or incompatibility. This indicates that the reactions between red blood cell surface antigens and plasma antibodies do not play a role in the induction of CD40L expression.

Comparison of survivor scores for differentiation therapy of cancer to those for checkpoint inhibition: Half full or half empty

Differentiation therapy is directed to the self-renewing cancer stem cells, as well as their progeny transit amplifying cells, to force them to mature to terminal differentiation. Differentiation therapy is effective in treatment of neuroblastomas and myeloid leukemias. Checkpoint inhibition therapy removes blocks to cancer reactive T-killer cells and allows them to react to malignant cells and limit the growth of cancer. The percentage of patients with a given cancer that responds to either therapy is less than hoped for, and the duration of response is variable. Multiplying the response rate (percentage of patients responding to therapy) by the duration of response may be used to derive a survival score for patients treated with differentiation therapy or checkpoint inhibition. By this criterion, differentiation therapy gives better survival scores than checkpoint inhibition. Yet, checkpoint inhibition is considered a great success, mostly because it may be applied to many different types of cancer, and differentiation therapy is considered relatively ineffective because it is limited to a few specific cancers. On the other hand, the cost of checkpoint inhibition treatment is 10-20 times more per patient than that of differentiation therapy. Hopefully, future combined treatments and advances in both approaches will increase the effectiveness of these cancer treatments.

Evidence of CD40L/CD40 pathway involvement in experimental transfusion-related acute lung injury

Platelet transfusions can cause adverse reactions in their recipients, including transfusion-related acute lung injury (TRALI). The pathophysiology of TRALI depends on a number of signaling pathways and the inflammatory role played by blood platelets remains controversial. Platelets are important in inflammation, particularly via the immunomodulator complex CD40/CD40L. We studied the specific function of the CD40/CD40L interaction in regulating an experimental TRALI Two-hit model. A mouse model of immune TRALI was triggered by injection of LPS and an anti-MHC I antibody, and the effect of injection of a neutralizing anti-CD40L antibody before induction of TRALI investigated. The characteristics of TRALI were decreased body temperature, pulmonary lesions, and immune cell infiltration into the alveolar space. Pulmonary infiltration was evaluated by blood counts of specific immune cells and their detection in lung sections. Inhibition of the CD40/CD40L immunomodulator interaction significantly reduced communication between immune and/or endothelial cells and the development of pulmonary edema. Hence, our results indicate that targeting of the CD40/CD40L interaction could be an important method to prevent TRALI. While considering that our work concerned a mouse model, we postulate that improvement of the conditions under which platelet concentrates are prepared/stored would assist in alleviating the risk of TRALI.

High Serum sCD40L Levels During the First Week of Malignant Middle Cerebral Artery Infarction and Mortality

BACKGROUND

Higher circulating soluble cluster of differentiation 40 ligand (sCD40L) levels at admission of an ischemic stroke have been found in nonsurvivor than in survivor patients. The objectives of this study were to determine whether serum sCD40L levels during the first week of a severe malignant middle cerebral artery infarction (MMCAI) are higher in nonsurvivor than in survivor patients and whether they could be used as biomarker of mortality prediction.

METHODS

This multicenter study included patients with severe MMCAI (defined as Glasgow Coma Scale score <9). We determined serum sCD40L concentrations at days 1, 4, and 8 and performed receiver operating characteristic analyses to determine their capacity for 30-day mortality prediction.

RESULTS

Nonsurvivors (n = 34) showed higher sCD40L levels on days 1 (P < 0.001), 4 (P = 0.004), and 8 (P < 0.001) than did survivor patients (n = 34). Areas under the curve of serum sCD40L concentrations at days 1, 4, and 8 of severe MMCAI for 30-day mortality prediction were 83% (P < 0.001), 89% (P < 0.001), and 87% (P < 0.001), respectively.

CONCLUSIONS

The findings that nonsurvivors showed higher serum sCD40L levels during the first week of MMCAI than did survivors and that serum sCD40L levels during the first week of MMCAI could be used as a mortality predictor biomarker are 2 novel findings.

Cytokine Profiling in Patients With Exudative Age-Related Macular Degeneration and Polypoidal Choroidal Vasculopathy

Purpose

The purpose of this study was to investigate the cytokine profiles in plasma and aqueous humor of patients with choroidal neovascularization (CNV) due to exudative AMD and polypoidal choroidal vasculopathy (PCV).

Methods

In this cross-sectional study, 16 patients clinically diagnosed with AMD, 18 patients with PCV, and 50 age- and sex-matched cataract patients without AMD/PCV (controls) were enrolled. Study subjects were treatment naïve, and 200 μL undiluted aqueous humor and 5 mL peripheral venous blood were collected from the study subjects. Clinical samples were analyzed for 41 different cytokines by Luminex bead-based multiplex assay. Cytokines concentrations with detection rates of 50% or more were included for the analysis, and the differences in plasma and aqueous humor cytokines levels between each group were analyzed.

Results

The age of the patients with AMD and PCV was 70.62 ± 10.15 (mean ± SD) and 71.48 ± 9.08 years, respectively, and that in the control group was 62.8 ± 10.67 years. Aqueous humor cytokines growth-regulated oncogene (GRO), macrophage-derived chemokine (MDC), and macrophage inflammatory protein (MIP)-1α were significantly higher in AMD patients than controls (all P < 0.04), and GRO, MDC, MIP-1α, IL-8, IFN-γ-inducible protein 10, and monocyte chemotactic protein levels were significantly higher in PCV patients than controls (all P < 0.03). Soluble CD40 ligand and platelet-derived growth factor-AA levels were higher in plasma of healthy controls compared with AMD subjects. No significant differences in cytokine levels were observed between AMD and PCV patients for both plasma and aqueous humor.

Conclusions

In AMD and PCV patients, our data suggest that the pathologic changes are primarily driven by dysregulation of local immune factors in the eye, whereas the plasma cytokine levels are not elevated.

Retracted: Combined therapy using LHRH-PE40 and anti-CD40 dendritic cells substantially eliminate tumor cells

LHRH-PE40 was used to promote the proliferation of bone marrow derived cell (BMDC) and improve the antigen-presenting ability of BMDC as well as the immune function via the CD40 signal pathway. LHRH-PE40 was also implicated in cancer treatment, targeting a variety of cancer cells that express luteinizing hormone-releasing hormone receptor (LHRHR). In the present study, the mechanism and efficacy of LHRH-PE40 were addressed in the following three aspects. Enzyme-linked immunosorbent assay was performed to confirm the binding specificity of LHRH-PE40 to LHRHR. The killing effect of LHRH-PE40 on target cells was mediated by LHRHR, which specifically killed LHRHR-positive target cells while the minimal cytotoxicity of LHRHR-negative cells is negligible. Spiegelmers, a molecule mutually exclusive with GnRH and developed by Sven Klussmann and Dr Sven Klussmann of NOXXON Pharmaceuticals in Germany, demonstrated that LHRH-PE40 maintains a combinatory characteristics of LHRH and LHRHR. In the end, the mechanism of LHRH-PE40 underlying induction of apoptosis at low concentration and prolonged conditions was firstly demonstrated by the basic method of detecting apoptosis to induce apoptosis. It provided a scientific basis for clinical application of LHRH-PE40 and laid a foundation for the further study of LHRH-PE40 on inducing apoptosis of target cells. The target cells herein refer to tumor cells that overexpress LHRHR. This study shows that activated DC can more effectively promote the proliferation of CD4+ T cells, and initially proved that DC carrying anti-CD40 antibody promoted the immune treatment of the tumor. Combining LHRH-PE40 with anti-CD40 DCs achieved substantially improved efficacy in killing tumor cells.

siRNA-silencing of CD40 attenuates unilateral ureteral obstruction-induced kidney injury in mice

Background

The costimulatory CD40-CD40L pathway plays a role in kidney inflammation. We have previously reported that renal CD40 upregulation precedes cellular interstitial infiltrate and fibrosis in the unilateral ureteral obstruction (UUO) model. Here we sought to evaluate whether the administration of siRNA-CD40 has a therapeutic effect in a reversible unilateral ureteral obstruction (D-UUO) mice model.

Methods

Eight week-old C57BL6J male mice were divided into four groups: Vehicle (Phosphate-buffered saline) (n = 8); siRNA SC (non-specific siRNA) (n = 6); siRNA-CD40 (n = 8) and WT (wild type) (n = 6) mice. UUO was performed with a microvascular clamp. At day 3 after surgery, the ureteral clamp was removed and nephrectomy of the contralateral kidney was performed. Immediately, PBS, siRNA SC (50μg) or siRNA-CD40 (50μg) was administrated via the tail vein. Mice were killed 48h hours after the siRNA or saline administration. Wild type (WT) mice were used as controls. Blood samples were collected for measuring creatinine and blood urea nitrogen (BUN). Histology and kidney mRNA expression were performed.

Results

The administration of siRNA-CD40 reduced significantly the severity of acute renal failure associated with UUO. Pathologic analysis showed reduction of tubular dilation, interstitial fibrosis, F4/80 macrophage and CD3 (T cell) infiltration in animals treated with siRNA-CD40. Furthermore, kidney mRNA gene expression analysis showed significantly lower levels of macrophage markers (F4/80 and Mannose receptor), fibrosis matrix proteins (Fibronectin, MMP-9, Collagen IV and α-SMA), pro-inflammatory cytokines (iNOS and MCP-1) and the pro-fibrotic molecule TGF-β1 in siRNA-CD40.

Conclusions

The administration of siRNA-CD40 therapy reduces the severity of the acute kidney injury induced by obstructive uropathy and promotes kidney repair. This strategy seems suitable to be tested in humans.

Targeting the CD40-CD40L pathway in autoimmune diseases: Humoral immunity and beyond

CD40 is a TNF receptor superfamily member expressed on both immune and non-immune cells. Interactions between B cell-expressed CD40 and its binding partner, CD40L, predominantly expressed on activated CD4+ T cells, play a critical role in promoting germinal center formation and the production of class-switched antibodies. Non-hematopoietic cells expressing CD40 can also engage CD40L and trigger a pro-inflammatory response. This article will highlight what is known about the biology of the CD40-CD40L axis in humans and describe the potential contribution of CD40 signaling on both hematopoietic and non-hematopoietic cells to autoimmune disease pathogenesis. Additionally, novel therapeutic approaches to target this pathway, currently being evaluated in clinical trials, are discussed.

Allosteric Modulators of Protein-Protein Interactions (PPIs)

Protein-protein interactions (PPIs) represent promising drug targets of broad-spectrum therapeutic interests due to their critical implications in both health and disease circumstances. Hence, they are widely accepted as the Holy Grail of drug development. Historically, PPIs were rendered "undruggable" for their large, flat, and pocket-less structures. Current attempts to drug these "intractable" targets include orthosteric and allosteric methodologies. Previous efforts employing orthosteric approaches like protein therapeutics and orthosteric small molecules frequently suffered from poor performance caused by the difficulties in directly targeting PPI interfaces. As structural biology progresses rapidly, allosteric modulators, which direct to the allosteric regulatory sites remote to the PPI surfaces, have gradually established as a potential solution. Allosteric pockets are topologically distal from the PPI orthosteric sites, and their ligands do not need to compete with the PPI partners, which helps to improve the physiochemical and pharmacological properties of allosteric PPI modulators. Thus, exploiting allostery to tailor PPIs is regarded as a tempting strategy in future PPI drug discovery. Here, we provide a comprehensive review of our representative achievements along the way we utilize allosteric effects to tame the difficult PPI systems into druggable targets. Importantly, we provide an in-depth mechanistic analysis of this success, which will be instructive to future related lead optimizations and drug design. Finally, we discuss the current challenges in allosteric PPI drug discovery. Their solutions as well as future perspectives are also presented.

Increased expression of the membrane-bound CD40 ligand on peripheral CD4+ T cells in the acute phase of AQP4-IgG-seropositive neuromyelitis optica spectrum disorders

Currently, no data are available regarding the expression levels of CD40L on CD4⁺ T cells in patients with neuromyelitis optica spectrum disorders (NMOSD). The percentage of circulating CD40L⁺CD4⁺ T cells was measured by flow cytometry in 23 NMOSD patients and 10 healthy controls. The ratio of CD40L⁺CD4⁺ to CD4⁺ T cells in patients at acute phase (18.28 ± 15.56%) was significantly higher than that in healthy controls (7.23 ± 5.94%, P = .032) and was positively correlated with disease severity (r = 0.532, P = .041). Thus, our results suggest an important role of this molecule in acute attacks of NMOSD.

New prognostic biomarkers of mortality in patients undergoing liver transplantation for hepatocellular carcinoma

The outcome prediction of hepatocellular carcinoma (HCC) patients undergoing liver transplantation (LT) was classically established using various macromorphological factors and serum alpha-fetoprotein levels prior to LT. However, other biomarkers have recently been reported to be associated with the prognosis of HCC patients undergoing to LT. This review summarizes clinical data on these new biomarkers. High blood levels of malondialdehyde, total antioxidant capacity, caspase-cleaved cytokeratin-18, soluble CD40 ligand, substance P, C-reactive protein, and vascular endothelial growth factor, increased neutrophil to lymphocyte ratio and platelet to lymphocyte ratio in blood, high peripheral blood expression of human telomerase reverse transcriptase messenger ribonucleic acid, and high HCC expression of dickkopf-1 have recently been associated with decreased survival rates. In addition, high blood levels of des-gamma-carboxy prothrombin, and high HCC expression of glypican-3, E-cadherin and beta-catenin have been associated with increased HCC recurrence. Additional research is necessary to establish the prognostic role of these biomarkers in HCC prior to LT. Furthermore, some of these biomarkers are also interesting because their potential modulation could help to create new research lines for improving the outcomes of those patients.

Soluble CD40 ligand directly alters glomerular permeability and may act as a circulating permeability factor in FSGS

CD40/CD40 ligand (CD40L) dyad, a co-stimulatory bi-molecular complex involved in the adaptive immune response, has also potent pro-inflammatory actions in haematopoietic and non-haematopoietic cells. We describe here a novel role for soluble CD40L (sCD40L) as modifier of glomerular permselectivity directly acting on glomerular epithelial cells (GECs). We found that stimulation of CD40, constitutively expressed on GEC cell membrane, by the sCD40L rapidly induced redistribution and loss of nephrin in GECs, and increased albumin permeability in isolated rat glomeruli. Pre-treatment with inhibitors of CD40-CD40L interaction completely prevented these effects. Furthermore, in vivo injection of sCD40L induced a significant reduction of nephrin and podocin expression in mouse glomeruli, although no significant increase of urine protein/creatinine ratio was observed after in vivo injection. The same effects were induced by plasma factors partially purified from post-transplant plasma exchange eluates of patients with focal segmental glomerulosclerosis (FSGS), and were blocked by CD40-CD40L inhibitors. Moreover, 17 and 34 kDa sCD40L isoforms were detected in the same plasmapheresis eluates by Western blotting. Finally, the levels of sCD40Lwere significantly increased in serum of children both with steroid-sensitive and steroid-resistant nephrotic syndrome (NS), and in adult patients with biopsy-proven FSGS, compared to healthy subjects, but neither in children with congenital NS nor in patients with membranous nephropathy.

Our results demonstrate that sCD40L directly modifies nephrin and podocin distribution in GECs. Moreover, they suggest that sCD40L contained in plasmapheresis eluates from FSGS patients with post-transplant recurrence may contribute, presumably cooperating with other mediators, to FSGS pathogenesis by modulating glomerular permeability.

High serum soluble CD40L levels previously to liver transplantation in patients with hepatocellular carcinoma are associated with mortality at one year

PURPOSE

CD40L and its soluble form (sCD40L) are proteins of the tumor necrosis factor superfamily (TNFSF) that exhibit prothrombotic and proinflammatory properties when binding to CD40, which is a cell surface receptor of the tumor necrosis factor receptor superfamily (TNFRSF). High circulating levels of sCD40L have been associated with poor prognosis in patients with hepatocellular carcinoma (HCC). However, it is unknown whether there is an association between circulating sCD40L levels and survival in patients with HCC underwent to liver transplantation (LT), and this was the objective of that study.

METHODS

Serum sCD40L levels were measured in a total of 139 patients before LT (124 survivors at 1year of LT and 15 non-survivors). The end-point study was 1year survival after liver LT.

RESULTS

We found that 1-year non-surviving patients showed higher serum sCD40L levels than survivor patients (p=0.02). We found in logistic regression analysis that serum sCD40L levels higher than 321pg/mL (Odds Ratio=6.86; 95% confidence interval=2.06-22.76; p=0.002) and age of LT deceased donor were associated with death at 1year.

CONCLUSIONS

The new finding of our study was that high serum sCD40L levels previously to LT in patients with HCC are associated with higher mortality at one year.

Non-survivor septic patients have persistently higher serum sCD40L levels than survivors

INTRODUCTION

Soluble CD40 ligand (sCD40L) is a protein with proinflammatory and prothrombotic effects. Previously we found higher circulating sCD40L levels in non-survivor than in survivor patients at sepsis diagnosis. Now some questions arise such as how are serum sCD40L levels during the first week of severe sepsis?, is there an association between serum sCD40L levels during the first week and mortality?, and serum sCD40L levels during the first week could be used as sepsis mortality biomarker?. This study was developed to answer these asks.

METHODS

Study from 6 Spanish Intensive Care Units with 291 severe septic patients. There were determined serum levels of sCD40L and tumor necrosis factor (TNF)-alpha during the first week. The end-point study was 30-day mortality.

RESULTS

We found that serum sCD40L at days 1, 4, and 8 could predict mortality at 30days, and are associated with mortality.

CONCLUSIONS

The novel findings of our study were that there were higher serum sCD40L levels persistently during the first week in non-survivor than in survivor patients, that there is an association between serum sCD40L levels during the first week and sepsis mortality, and that serum sCD40L levels during the first week could be used as sepsis mortality biomarker.

Regulatory role of cytosolic phospholipase A2 alpha in the induction of CD40 in microglia

Background

The aberrant expression of CD40, a co-stimulatory receptor found on the antigen-presenting cells, is involved in the pathogenesis of various degenerative diseases. Our previous study demonstrated that the reduction of cytosolic phospholipase A₂ alpha (cPLA₂α) protein overexpression and activation in the spinal cord of a mouse model of ALS, hmSOD1 G93A, inhibited CD40 upregulation in microglia. The present study was designed to determine whether cPLA₂α has a direct, participatory role in the molecular events leading to CD40 induction.

Methods

Cultures of primary mouse microglia or BV-2 microglia cell line exposed to lipopolysaccharide (LPS) or interferon gamma (IFNγ) for different periods of time, in order to study the role of cPLA₂α in the events leading to CD40 protein induction.

Results

Addition of LPS or IFNγ caused a significant upregulation of cPLA₂α and of CD40, while prevention of cPLA₂α upregulation by a specific oligonucleotide antisense (AS) prevented the induction of CD40, suggesting a role of cPLA₂α in the induction of CD40. Addition of LPS to microglia caused an immediate activation of cPLA₂α detected by its phosphorylated form, while addition of IFNγ induced cPLA₂α activation at a later time scale (4 h). The activation of cPLA₂α is mediated by ERK activity. Suppression of cPLA₂α activity inhibited superoxide production by NOX2-NADPH oxidase and activation of NF-κB detected by the phosphorylation of p65 on serine 536 at 15 min by LPS and at 4 h by IFNγ. Inhibition of NOX2 prevented NF-κB activation and CD40 induction but did not affect cPLA₂α activation, suggesting cPLA₂α is located upstream to NOX2 and NF-κB. The activation of cPLA₂ by LPS was mediated by both adaptor proteins downstream to LPS receptor; TRIF and MyD88, while the activation of cPLA₂α by IFNγ was mediated by the secreted TNF-α at 4 h. The early activation of STAT1α (detected by phospho-serine727 and phoshpo-tyrosine701) by IFNγ and the late activation of STAT1α by LPS were not affected in the presence of cPLA₂α inhibitors, indicating that STAT1α is not under cPLA₂α regulation.

Conclusions

Our results show for the first time that cPLA₂ upregulates CD40 protein expression induced by either LPS or IFNγ, and this regulatory effect is mediated via the activation of NOX2-NADPH oxidase and NF-κB. Cumulatively, our results indicate that cPLA₂α may serve as a pivotal amplifier of the inflammatory response in the CNS.

Preclinical Rationale and Clinical Considerations for Radiotherapy Plus Immunotherapy: Going Beyond Local Control

The use of radiation for cancer therapy has expanded and sparked interest in possible synergistic effects by combining it with current immunotherapies. In this review, we present a case of a patient who responded to programmed cell death 1 (PD1) blockade and radiation therapy and discuss possible mechanisms. We provide background on the blockade of the cytotoxic T-lymphocyte antigen 4 (CTLA-4) and PD1 checkpoints and highlight future immune-based therapies that may synergize with radiation, including cytosine-phosphate-guanine vaccines, OX40 agonists, CD40 agonists, regulatory T-cell depletion, and metabolic "rewiring" of cancer cells. Clinical considerations are noted for combining radiation with immunotherapies to extend the benefit of immunotherapy to more patients. New trials are needed to appropriately investigate the best sequencing and radiation dose to prime an immune response and to identify predictive biomarkers of such responses.

CD40-Mediated NF-κB Activation in B Cells Is Increased in Multiple Sclerosis and Modulated by Therapeutics

CD40 interacts with CD40L and plays an essential role in immune regulation and homeostasis. Recent research findings, however, support a pathogenic role of CD40 in a number of autoimmune diseases. We previously showed that memory B cells from relapsing-remitting multiple sclerosis (RRMS) patients exhibited enhanced proliferation with CD40 stimulation compared with healthy donors. In this study, we used a multiparameter phosflow approach to analyze the phosphorylation status of NF-κB and three major MAPKs (P38, ERK, and JNK), the essential components of signaling pathways downstream of CD40 engagement in B cells from MS patients. We found that memory and naive B cells from RRMS and secondary progressive MS patients exhibited a significantly elevated level of phosphorylated NF-κB (p-P65) following CD40 stimulation compared with healthy donor controls. Combination therapy with IFN-β-1a (Avonex) and mycophenolate mofetil (Cellcept) modulated the hyperphosphorylation of P65 in B cells of RRMS patients at levels similar to healthy donor controls. Lower disease activity after the combination therapy correlated with the reduced phosphorylation of P65 following CD40 stimulation in treated patients. Additionally, glatiramer acetate treatment also significantly reduced CD40-mediated P65 phosphorylation in RRMS patients, suggesting that reducing CD40-mediated p-P65 induction may be a general mechanism by which some current therapies modulate MS disease.

Stratification of ST-elevation myocardial infarction patients based on soluble CD40L longitudinal changes

Involvement of soluble CD40 ligand (sCD40L) in thrombosis and inflammation on the context of coronary artery disease is currently being revised. In that perspective, we had studied the association of sCD40L with markers of platelet activation and markers of endothelial and vascular function. On that cohort, a stratification of patients with acute myocardial infarction (AMI) 1 month after percutaneous coronary intervention (PCI) was observed based on concentrations of sCD40L. The study intended to identify the groups of AMI patients with different profiles of sCD40L concentrations and verify how medication, clinical evolution, biochemical data, and markers of regulation of endothelial function at genetic (endothelial nitric oxide synthase polymorphisms) and post-transcriptional levels (circulating microRNAs) affect sCD40L serum levels. Lower quartiles of sCD40L (<2.3 ng/mL) were associated with higher concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP), high frequency of G894T polymorphism, and altered expression of a set of microRNAs assumed to be involved in the regulation of endothelial and cardiac function and myocardium hypertrophy, relative to patients in sCD40L upper quartiles. A characteristic sCD40L variation pattern in STEMI patients was identified. Low levels of sCD40L 1 month after PCI distinguish STEMI patients with worse prognosis, a compromised cardiac healing, and a persistent endothelial dysfunction, as given by the association between sCD40L, NT-proBNP, G894T polymorphism, and specific profile of miRNA expression. These results suggest sCD40L could have a prognostic value in STEMI patients.

Dendritic cells induce Tc1 cell differentiation via the CD40/CD40L pathway in mice after exposure to cigarette smoke

Dendritic cells and CD8(+) T cells participate in the pathology of chronic obstructive pulmonary disease, including emphysema, but little is known of the involvement of the CD40/CD40L pathway. We investigated the role of the CD40/CD40L pathway in Tc1 cell differentiation induced by dendritic cells in a mouse model of emphysema, and in vitro. C57BL/6J wild-type and CD40(-/-) mice were exposed to cigarette smoke (CS) or not (control), for 24 wk. In vitro experiments involved wild-type and CD40(-/-) dendritic cells treated with CS extract (CSE) or not. Compared with the control groups, the CS mice (both wild type and CD40(-/-)) had a greater percentage of lung dendritic cells and higher levels of major histocompatability complex (MHC) class I molecules and costimulatory molecules CD40 and CD80. Relative to the CS CD40(-/-) mice, the CS wild type showed greater signs of lung damage and Tc1 cell differentiation. In vitro, the CSE-treated wild-type cells evidenced more cytokine release (IL-12/p70) and Tc1 cell differentiation than did the CSE-treated CD40(-/-) cells. Exposure to cigarette smoke increases the percentage of lung dendritic cells and promotes Tc1 cell differentiation via the CD40/CD40L pathway. Blocking the CD40/CD40L pathway may suppress development of emphysema in mice exposed to cigarette smoke.