Human and Murine Interleukin 23 Receptors Are Novel Substrates for A Disintegrin and Metalloproteases ADAM10 and ADAM17

Effect of Systemic Administration of CD4+ T cells and Local Administration of T-cell Stimulants on T-cell Activity in Psoriatic Skin Xenografts on NOG Mice

Immunodeficient mice engrafted with psoriatic human skin are widely used for the preclinical evaluation of new drug candidates. However, the T-cell activity, including the IL23/IL17 pathway, declines in the graft over time after engraftment, which likely affects the study data. Here, we investigated whether the T-cell activity could be sustained in xenografted psoriatic skin by local stimulation of T cells or systemic injection of autologous CD4 + T cells. We surgically transplanted human psoriatic skin from 5 untreated patients onto female NOG mice. Six days after surgery, mice received an intraperitoneal injection of autologous human CD4+ T cells, a subcutaneous injection under the grafts of a T-cell stimulation cocktail consisting of recombinant human IL2, human IL23, antihuman CD3, and antihuman CD28, or saline. Mice were euthanized 21 d after surgery and spleens and graft biopsies were collected for analysis. Human T cells were present in the grafts, and 60% of the grafts maintained the psoriatic phenotype. However, neither local T-cell stimulation nor systemic injection of autologous CD4+ T cells affected the protein levels of human IL17A, IL22, IFN γ, and TNF α in the grafts. In conclusion, NOG mice seem to accept psoriatic skin grafts, but the 2 approaches studied here did not affect human T-cell activity in the grafts. Therefore, NOG mice do not appear in this regard to be superior to other immunodeficient mice used for psoriasis xenografts.

Leveraging Exosomes as the Next-Generation Bio-Shuttles: The Next Biggest Approach against Th17 Cell Catastrophe

In recent years, the launch of clinical-grade exosomes is rising expeditiously, as they represent a new powerful approach for the delivery of advanced therapies and for diagnostic purposes for various diseases. Exosomes are membrane-bound extracellular vesicles that can act as biological messengers between cells, in the context of health and disease. In comparison to several lab-based drug carriers, exosome exhibits high stability, accommodates diverse cargo loads, elicits low immunogenicity and toxicity, and therefore manifests tremendous perspectives in the development of therapeutics. The efforts made to spur exosomes in drugging the untreatable targets are encouraging. Currently, T helper (Th) 17 cells are considered the most prominent factor in the establishment of autoimmunity and several genetic disorders. Current reports have indicated the importance of targeting the development of Th17 cells and the secretion of its paracrine molecule, interleukin (IL)-17. However, the present-day targeted approaches exhibit drawbacks, such as high cost of production, rapid transformation, poor bioavailability, and importantly, causing opportunistic infections that ultimately hamper their clinical applications. To overcome this hurdle, the potential use of exosomes as vectors seem to be a promising approach for Th17 cell-targeted therapies. With this standpoint, this review discusses this new concept by providing a snapshot of exosome biogenesis, summarizes the current clinical trials of exosomes in several diseases, analyzes the prospect of exosomes as an established drug carrier and delineates the present challenges, with an emphasis on their practical applications in targeting Th17 cells in diseases. We further decode the possible future scope of exosome bioengineering for targeted drug delivery against Th17 cells and its catastrophe.

The role of A Disintegrin and Metalloproteinase (ADAM)-10 in T helper cell biology

A Disintegrin and Metalloproteinases (ADAM)-10 is a member of a family of membrane-anchored proteinases that regulate a broad range of cellular functions with central roles within the immune system. This has spurred the interest to modulate ADAM activity therapeutically in immunological diseases. CD4 T helper (Th) cells are the key regulators of adaptive immune responses. Their development and function is strongly dependent on Notch, a key ADAM-10 substrate. However, Th cells rely on a variety of additional ADAM-10 substrates regulating their functional activity at multiple levels. The complexity of both, the ADAM substrate expression as well as the functional consequences of ADAM-mediated cleavage of the various substrates complicates the analysis of cell type specific effects. Here we provide an overview on the major ADAM-10 substrates relevant for CD4 T cell biology and discuss the potential effects of ADAM-mediated cleavage exemplified for a selection of important substrates.

Immune Responses to IAV Infection and the Roles of L-Selectin and ADAM17 in Lymphocyte Homing

Influenza A virus (IAV) infection is a global public health burden causing up to 650,000 deaths per year. Yearly vaccination programmes and anti-viral drugs currently have limited benefits; therefore, research into IAV is fundamental. Leukocyte trafficking is a crucial process which orchestrates the immune response to infection to protect the host. It involves several homing molecules and receptors on both blood vessels and leukocytes. A key mediator of this process is the transmembrane glycoprotein L-selectin, which binds to vascular addressins on blood vessel endothelial cells. L-selectin classically mediates homing of naïve and central memory lymphocytes to lymph nodes via high endothelial venules (HEVs). Recent studies have found that L-selectin is essential for homing of activated CD8⁺ T cells to influenza-infected lungs and reduction in virus load. A disintegrin and metalloproteinase 17 (ADAM17) is the primary regulator of cell surface levels of L-selectin. Understanding the mechanisms that regulate these two proteins are central to comprehending recruitment of T cells to sites of IAV infection. This review summarises the immune response to IAV infection in humans and mice and discusses the roles of L-selectin and ADAM17 in T lymphocyte homing during IAV infection.

Neonatal inflammatory skin and bowel disease type 1 caused by a complex genetic defect and responsive to combined anti-TNF-alpha and IL-12/23 blockade

ADAM17, encoding ADAM metallopeptidase domain 17, is a membrane-bound shedding protease which plays an essential role during normal development and in the regulation of inflammation. Bi-allelic variants in ADAM17, resulting in complete loss of ADAM17 expression, have been reported in individuals affected by the rare neonatal inflammatory skin and bowel disease 1 (NISBD1). We report here on a young female individual with NISBD1 featuring erythroderma, atrichia, nail dystrophy, esophageal strictures, intractable diarrhea, profound failure to thrive and recurrent cutaneous and systemic infections. NISBD1 was found in this case to result from a complex compound heterozygous defect consisting of a large genomic deletion spanning exons 6 and 7 as well as a splice site variant causing exon 17 skipping. Skin manifestations dramatically improved in response to combined anti-TNF-alpha and IL-12/23 blockade while gastrointestinal symptoms were controlled with budesonide. Our study further expands the phenotypic and genetic spectrum of NISBD1 type 1 and suggests that combined immunosuppressive treatments may be indicated in this complex condition.

Tryptophan (W) at position 37 of murine IL-12/IL-23 p40 is mandatory for binding to IL-12Rβ1 and subsequent signal transduction

Interleukin (IL)-12 and IL-23 are composite cytokines consisting of p35/p40 and p19/p40, respectively, which signal via the common IL-12 receptor β1 (IL-12Rβ1) and the cytokine-specific receptors IL-12Rβ2 and IL-23R. Previous data showed that the p40 component interacts with IL-12Rβ1, whereas p19 and p35 subunits solely bind to IL-23R and IL-12Rβ2, resulting in tetrameric signaling complexes. In the absence of p19 and p35, p40 forms homodimers and may induce signaling via IL-12Rβ1 homodimers. The critical amino acids of p19 and p35 required for binding to IL-23R and IL-12Rβ2 are known, and two regions of p40 critical for binding to IL-12Rβ1 have recently been identified. In order to characterize the involvement of the N-terminal region of p40 in binding to IL-12Rβ1, we generated deletion variants of the p40-p19 fusion cytokine. We found that an N-terminal deletion variant missing amino acids M23 to P39 failed to induce IL-23-dependent signaling and did not bind to IL-12Rβ1, whereas binding to IL-23R was maintained. Amino acid replacements showed that p40W37K largely abolished IL-23-induced signal transduction and binding to IL-12Rβ1, but not binding to IL-23R. Combining p40W37K with D36K and T38K mutations eliminated the biological activity of IL-23. Finally, homodimeric p40D36K/W37K/T38K did not interact with IL-12Rβ1, indicating binding of homodimeric p40 to IL-12Rβ1 is comparable to the interaction of IL-23/IL-12 and IL-12Rβ1. In summary, we have defined D36, W37, and T38 as hotspot amino acids for the interaction of IL-12/IL-23 p40 with IL-12Rβ1. Structural insights into cytokine–cytokine receptor binding are important to develop novel therapeutic strategies.

IL-23/IL-17 axis and soluble receptors isoforms sIL-23R and sIL-17RA in patients with rheumatoid arthritis-presenting periodontitis

BACKGROUND

Rheumatoid arthritis (RA) and periodontitis (P) are chronic inflammatory diseases characterized by joint and radiographic bone loss, respectively. IL-23 and IL-17 have an essential role in the immunopathogenesis of RA, and P. IL-23 stimulates Th17 cells through which produces IL-17, IL-21, and RANKL. IL-17 stimulates fibroblasts to produce RANKL, which initiates bone loss in the joints in RA and the periodontal tissue in periodontitis. The aim of this study was to determine the expression pattern of IL-23/IL-17 axis and soluble receptors isoforms sIL-23R and sIL-17RA of patients with RA presenting P (RAP).

MATERIAL AND METHODS

Healthy subjects (HS) (n = 42), patients with P (n = 40), RA (n = 20), and patients with RAP (n = 40) were included. Plasma samples were obtained to evaluate the IL-23, IL-17A, sIL-23R, and sIL-17RA by ELISA technique. A nonparametric Mann-Whitney U test was used to compare the differences between groups. A Chi-square was used to compare gender, grade and stage of periodontitis, and DAS28-ESR between the groups. Spearman's rank correlation coefficient was used to study the association between the molecules and clinical parameters.

RESULTS

IL-23 levels were increased in the RAP group, and lower sIL-23R levels were found in the RAP groups. However, IL-17A was lower in the P and RAP group but not in RA patients. RAP group showed a decrease IL-17A levels in advanced stages of the periodontal disease.

CONCLUSION

These results suggest that IL-23 and IL-17A tend to downregulate their expression patterns when patients present both rheumatoid arthritis and periodontitis.

MicroRNA-146a-5p enhances T helper 17 cell differentiation via decreasing a disintegrin and metalloprotease 17 level in primary sjögren's syndrome

In clinical practice, we found that microRNA (miR)-146a-5p is significantly up-regulated in peripheral blood mononuclear cells (PBMCs) of primary sjögren’s syndrome (pSS) patients. In vitro experiments confirmed that miR-146a-5p promotes T helper 17 (Th17) cell differentiation, but the specific mechanism is still unknown. To solve this problem, 20 pSS patients and 20 healthy subjects were enrolled in this study and PBMCs were isolated from their blood. The expression of the membrane IL-23 R (mIL-23 R) in PBMCs was determined. CD3⁺ T cells were also isolated and used to further analyze the relationship between the ectodomain shedding of mIL-23 R and a disintegrin and metalloprotease 17 (ADAM17). Finally, miR-146a-5p inhibitor and mimics were transfected into PBMCs to evaluate the relationship between ADAM17 and mIL-23 R, and explore the role of mIL-23 R and ADAM17 in Th17 cell differentiation. Our results revealed a significantly increased expression of miR-146a-5p in PBMCs from pSS patients and significantly increased percentage of Th17 cells compared to PBMCs from healthy controls. Under polarization culture conditions, pSS patient-derived PBMCs can more easily differentiate into Th17 cells, which was, to a great extent, attributable to the increased expression of mIL-23 R. Moreover, ADAM17, an ectodomain sheddase of mIL-23 R, was targeted and negatively regulated by miR-146a-5p, which reduced the ectodomain shedding of mIL-23 R. Overall, our results suggested that miR-146a-5p could promote Th17 cell differentiation through targeting and negatively regulating ADAM17. Thus, these results might offer a new approach in the treatment of pSS.

Inverse behavior of IL-23R and IL-17RA in chronic and aggressive periodontitis

Purpose

Periodontitis is associated with a dysbiosis of periodontopathic bacteria, which stimulate the interleukin (IL)-23/IL-17 axis that plays an essential role in the immunopathogenesis of this disease, leading to alveolar bone destruction through receptor activator of nuclear factor κB ligand (RANKL). IL-23 receptor mRNA (IL-23R) has been identified in periodontitis, and IL-17 receptor A mRNA (IL-17RA) and its protein have not yet been evaluated in patients with periodontitis. In this study was measure IL-23R and IL-17RA in gingival tissue (GT) from patients with generalized chronic periodontitis (GCP) and generalized aggressive periodontitis (GAP) and to explore correlations with clinical parameters.

Methods

We included 16 healthy subjects (HS), 18 patients with GCP, and 14 with GAP. GT samples were collected during periodontal surgery. Both IL-23R and IL-17RA were detected by enzyme-linked immunosorbent assay.

Results

The results were analyzed with Mann-Whitney U test and Spearman' rank correlation coefficients using SPSS version 25.0. We found lower IL-23R levels in patients with GCP and GAP than in HS. Contrarily, we observed higher IL-17RA levels in GCP and GAP patients than in HS. Moreover, we found negative correlations between IL-23R in GT and probing depth and clinical attachment loss (CAL). Likewise, a positive correlation of IL-17RA in GT with CAL was found.

Conclusions

The results of these findings suggest that the reverse behavior between IL-23R and IL-17RA in periodontitis patients may also be involved with the activation of RANKL, which promotes alveolar bone loss.

Elevated MicroRNA-326 Levels Regulate the IL-23/IL-23R/Th17 Cell Axis in Hashimoto's Thyroiditis by Targeting a Disintegrin and Metalloprotease 17

Background: MicroRNAs (miRNAs) are a class of critical epigenetic regulators involved in several autoimmune diseases. Our previous study reported an miR-326-induced increase in T helper (Th) 17 cells in a mouse model of Hashimoto's thyroiditis (HT), but the pathogenic effect of miR-326 in HT patients has not been verified. The goal of the present study was to explore the pathogenic role of miR-326 and its underlying molecular mechanism in HT patients. Methods: A total of 58 HT patients and 55 normal controls were enrolled in this study. We examined whether Th17 cells and miR-326 were aberrantly altered in the peripheral blood mononuclear cells (PBMCs) of HT patients with flow cytometry and real-time polymerase chain reaction. Levels of membrane interleukin (IL)-23R (mIL-23R) were determined by flow cytometry and Western blot to explore the critical role of mIL-23R in the development of Th17 cells. Isolated CD3⁺ T cells were used to further investigate the ectodomain shedding of mIL-23R by a disintegrin and metalloprotease (ADAM17). Furthermore, miR-326 inhibitor and mimics were transfected into PBMCs derived from HT patients and healthy controls to verify the regulation of ADAM17 by miR-326. Results: We observed elevated miR-326 levels in the PBMCs of HT patients compared with those in the PBMCs of healthy controls. Consistent with IL-23-induced STAT3 overactivation, substantially more HT patient-derived PBMCs differentiated into Th17 cells under polarization culture conditions, which may, at least in part, have resulted from enhanced mIL-23R levels. Furthermore, ADAM17, an ectodomain sheddase of mIL-23R, was targeted and negatively regulated by miR-326. Inhibiting ADAM17 might attenuate the ectodomain shedding of mIL-23R. Conclusions: Our findings suggest that the effect of miR-326 on the IL-23/IL-23R/Th17 cell axis in HT patients might be partially due to the targeting of ADAM17.

Interleukin (IL)-12 and IL-23 and Their Conflicting Roles in Cancer

The balance of proinflammatory cytokines interleukin (IL)-12 and IL-23 plays a key role in shaping the development of antitumor or protumor immunity. In this review, we discuss the role IL-12 and IL-23 plays in tumor biology from preclinical and clinical data. In particular, we discuss the mechanism by which IL-23 promotes tumor growth and metastases and how the IL-12/IL-23 axis of inflammation can be targeted for cancer therapy.

SIRT4 interacts with OPA1 and regulates mitochondrial quality control and mitophagy

The stress-responsive mitochondrial sirtuin SIRT4 controls cellular energy metabolism in a NAD⁺-dependent manner and is implicated in cellular senescence and aging. Here we reveal a novel function of SIRT4 in mitochondrial morphology/quality control and regulation of mitophagy. We report that moderate overexpression of SIRT4, but not its enzymatically inactive mutant H161Y, sensitized cells to mitochondrial stress. CCCP-triggered dissipation of the mitochondrial membrane potential resulted in increased mitochondrial ROS levels and autophagic flux, but surprisingly led to increased mitochondrial mass and decreased Parkin-regulated mitophagy. The anti-respiratory effect of elevated SIRT4 was accompanied by increased levels of the inner-membrane bound long form of the GTPase OPA1 (L-OPA1) that promotes mitochondrial fusion and thereby counteracts fission and mitophagy. Consistent with this, upregulation of endogenous SIRT4 expression in fibroblast models of senescence either by transfection with miR-15b inhibitors or by ionizing radiation increased L-OPA1 levels and mitochondrial fusion in a SIRT4-dependent manner. We further demonstrate that SIRT4 interacts physically with OPA1 in co-immunoprecipitation experiments. Overall, we propose that the SIRT4-OPA1 axis is causally linked to mitochondrial dysfunction and altered mitochondrial dynamics that translates into aging-associated decreased mitophagy based on an unbalanced mitochondrial fusion/fission cycle.

Recent Advances in ADAM17 Research: A Promising Target for Cancer and Inflammation

Since its discovery, ADAM17, also known as TNFα converting enzyme or TACE, is now known to process over 80 different substrates. Many of these substrates are mediators of cancer and inflammation. The field of ADAM metalloproteinases is at a crossroad with many of the new potential therapeutic agents for ADAM17 advancing into the clinic. Researchers have now developed potential drugs for ADAM17 that are selective and do not have the side effects which were seen in earlier chemical entities that targeted this enzyme. ADAM17 inhibitors have broad therapeutic potential, with properties ranging from tumor immunosurveillance and overcoming drug and radiation resistance in cancer, as treatments for cardiac hypertrophy and inflammatory conditions such as inflammatory bowel disease and rheumatoid arthritis. This review focuses on substrates and inhibitors identified more recently for ADAM17 and their role in cancer and inflammation.

Synthetic Deletion of the Interleukin 23 Receptor (IL-23R) Stalk Region Led to Autonomous IL-23R Homodimerization and Activation

Interleukin 23 (IL-23) regulates the development of TH17 cells, which are important for antimicrobial and antifungal responses and autoimmune and chronic inflammatory diseases. IL-23-induced Jak/STAT signaling is mediated via the heterodimeric IL-23 receptor (IL-23R)-IL-12 receptor β1 (IL-12Rβ1) complex. The typical signal-transducing receptor of the IL-6/IL-12 family contains three extracellular-membrane-proximal fibronectin type III (FNIII) domains, which are not involved in cytokine binding but are mandatory for signal transduction. In place of FNIII-type domains, IL-23R has a structurally undefined stalk. We hypothesized that the IL-23R stalk acts as a spacer to position the cytokine binding domains at a defined distance from the plasma membrane to enable signal transduction. Minor deletions of the murine, but not of the human, IL-23R stalk resulted in unresponsiveness to IL-23. Complete deletion of the human IL-23R stalk and the extended murine IL-23R stalk, including a 20-amino-acid-long duplication of domain 3, however, induced ligand-independent, autonomous receptor activation, as determined by STAT3 phosphorylation and cell proliferation. Ligand-independent, autonomous activity was caused by IL-23R homodimers and was independent of IL-12Rβ1. Our data show that deletion of the stalk results in biologically active IL-23R homodimers, thereby creating an as-yet-undescribed receptor complex of the IL-6/IL-12 cytokine family.

SheddomeDB: the ectodomain shedding database for membrane-bound shed markers

BACKGROUND

A number of membrane-anchored proteins are known to be released from cell surface via ectodomain shedding. The cleavage and release of membrane proteins has been shown to modulate various cellular processes and disease pathologies. Numerous studies revealed that cell membrane molecules of diverse functional groups are subjected to proteolytic cleavage, and the released soluble form of proteins may modulate various signaling processes. Therefore, in addition to the secreted protein markers that undergo secretion through the secretory pathway, the shed membrane proteins may comprise an additional resource of noninvasive and accessible biomarkers. In this context, identifying the membrane-bound proteins that will be shed has become important in the discovery of clinically noninvasive biomarkers. Nevertheless, a data repository for biological and clinical researchers to review the shedding information, which is experimentally validated, for membrane-bound protein shed markers is still lacking.

RESULTS

In this study, the database SheddomeDB was developed to integrate publicly available data of the shed membrane proteins. A comprehensive literature survey was performed to collect the membrane proteins that were verified to be cleaved or released in the supernatant by immunological-based validation experiments. From 436 studies on shedding, 401 validated shed membrane proteins were included, among which 199 shed membrane proteins have not been annotated or validated yet by existing cleavage databases. SheddomeDB attempted to provide a comprehensive shedding report, including the regulation of shedding machinery and the related function or diseases involved in the shedding events. In addition, our published tool ShedP was embedded into SheddomeDB to support researchers for predicting the shedding event on unknown or unrecorded membrane proteins.

CONCLUSIONS

To the best of our knowledge, SheddomeDB is the first database for the identification of experimentally validated shed membrane proteins and currently may provide the most number of membrane proteins for reviewing the shedding information. The database included membrane-bound shed markers associated with numerous cellular processes and diseases, and some of these markers are potential novel markers because they are not annotated or validated yet in other databases. SheddomeDB may provide a useful resource for discovering membrane-bound shed markers. The interactive web of SheddomeDB is publicly available at http://bal.ym.edu.tw/SheddomeDB/ .

Expanding Diversity in Molecular Structures and Functions of the IL-6/IL-12 Heterodimeric Cytokine Family

The interleukin (IL)-6/IL-12 family cytokines have pleiotropic functions and play critical roles in multiple immune responses. This cytokine family has very unique characteristics in that they comprise two distinct subunits forming a heterodimer and each cytokine and receptor subunit shares with each other. The members of this cytokine family are increasing; currently, there are more than six cytokines, including the tentatively named cytokines IL-Y (p28/p40), IL-12 (p35/p40), IL-23 (p19/p40), IL-27 [p28/Epstein–Barr virus-induced protein 3 (EBI3)], IL-35 (p35/EBI3), and IL-39 (p19/EBI3). This family of cytokines covers a very broad range of immune responses, including pro-inflammatory responses, such as helper T (Th)1, Th2, and Th17, to anti-inflammatory responses, such as regulatory T (Treg) cells and IL-10-producing Treg cells. IL-12 is the first member of this family, and IL-12, IL-23, and IL-27 are mainly produced by activated antigen-presenting cells, such as dendritic cells and macrophages. IL-12 plays a critical role in the promotion of Th1 immune responses by inducing interferon-γ production to combat pathogens and malignant tumors. IL-23 induces IL-17 production and is necessary to maintain pathogenic Th17 cells that cause inflammatory and autoimmune diseases. IL-27 was initially reported to play a critical role in promotion of Th1 differentiation; however, subsequent studies revealed that IL-27 has broader stimulatory and inhibitory roles by inducing IL-10-producing Treg cells. IL-35 is produced by forkhead box P3⁺ Treg cells and activated B cells and has immunosuppressive functions to maintain immune tolerance. The most recently identified cytokine, IL-39, is produced by activated B cells and has pro-inflammatory functions. The cytokine tentatively named IL-Y seems to have anti-inflammatory functions by inhibiting Th1 and Th17 differentiation. In addition, individual cytokine subunits were also shown to have self-standing activities. Thus, promiscuity within the IL-6/IL-12 family cytokines complicates structural and functional clarification and assignment of individual cytokines. A better understanding of the recent advances and expanding diversity in molecular structures and functions of the IL-6/IL-12 family cytokines could allow the creation of novel therapeutic strategies by using them as tools and targeted molecules.