RORγt inhibition selectively targets IL-17 producing iNKT and γδ-T cells enriched in Spondyloarthritis patients

Interleukin 17-producing C-C motif chemokine receptor 6 + conventional CD4+ T cells are arthritogenic in an animal model of spondyloarthritis

OBJECTIVE

Spondyloarthritis (SpA) is a group of chronic inflammatory disorders associated with the human leukocyte antigen (HLA) class I allele HLA-B27. Transgenic rats expressing HLA-B27 and human β2-microglobulin (B27 rats) develop clinical manifestations resembling SpA called rat SpA. IL-17 and TNF are key proinflammatory cytokines implicated in both human and rat SpA. We aimed to determine which T cell subset(s) produce IL-17 and TNF during rat SpA, characterize their tissue distribution and tested their pathogenicity in vivo.

METHODS

Cytokine production by T cell subsets was evaluated in target tissues and lymphoid organs during rat SpA. Pathogenicity of purified IL-17+ cells was assessed in vivo by cell transfer. Blood samples were used to translate B27 rats findings to SpA patients.

RESULTS

Conventional CD4+ T cells (Foxp3-; Tconv) and γδ T cells were the main producers of both IL-17 and TNF in B27 rats. IL-17-producing Tconv and γδ T cells were expanded in the colon of premorbid 3-weeks-old B27 rats. C-C motif chemokine receptor 6 (CCR6) allowed the isolation of IL-17+ Tconv (Th17) in rat. Transfer of B27 rat IL-17-producing CCR6+ Tconv but not of γδ T cells into disease-free nude B27 rats induced arthritis, directly demonstrating for the first time the arthritogenic potential of Th17 cells in SpA. Finally, a CCR6+ IL-17+ Tconv expansion enriched for IL-17F production was evidenced in SpA patients.

CONCLUSION

Our study demonstrates that IL-17+TNF+CCR6+ Th17 cells and IL-17+ γδ T cells are expanded preceding SpA onset in B27 rats and that only IL-17+TNF+CCR6+ Th17 cells can trigger arthritis.

Biomarkers for successful tapering of a tumor necrosis factor inhibitor in patients with radiographic axial spondyloarthritis: A pilot study

Background

Tumor necrosis factor inhibitors are the most widely used biological disease-modifying antirheumatic drugs for radiographic axial spondyloarthritis. After achieving remission with tumor necrosis factor inhibitor treatment, experts recommend tapering tumor necrosis factor inhibitor. However, biomarkers for successful tumor necrosis factor inhibitor tapering in radiographic axial spondyloarthritis have not been identified.

Objectives

To identify biomarkers associated with successful tumor necrosis factor inhibitor tapering in patients with radiographic axial spondyloarthritis.

Design

We prospectively collected blood samples from radiographic axial spondyloarthritis patients at single tertiary hospital.

Methods

Patients with radiographic axial spondyloarthritis who achieved remission (axial spondyloarthritis disease activity score < 1.3) after treatment with tumor necrosis factor inhibitor were enrolled. Baseline demographics, medication history, and laboratory data were collected when the tumor necrosis factor inhibitor dose was tapered. The percentage of helper T cell subtypes (Th1/Th2/Th17/Th22) in peripheral blood, and serum levels of tumor necrosis factor-α, interleukin-12, IL-17A, IL-22, IL-23, interferon (IFN)-γ, soluble CD14, and zonulin, were measured. Patients were assigned to tumor necrosis factor inhibitor tapering success (axial spondyloarthritis disease activity score < 2.1) or failure (axial spondyloarthritis disease activity score ⩾ 2.1) groups according to disease activity (assessed at 12 weeks posttumor necrosis factor inhibitor tapering).

Results

Twenty radiographic axial spondyloarthritis patients were enrolled (median age, 31.0 years; 65% males). Most (80%) were positive for human leukocyte antigen-B27. The change of axial spondyloarthritis disease activity score in the tumor necrosis factor inhibitor-tapering failure group was 1.36, while that in the tumor necrosis factor inhibitor-tapering success group was 0.07. The percentage of Th1 and Th17 cells was significantly lower, and that of Th2 cells higher, in the tumor necrosis factor inhibitor-tapering success group. In addition, serum levels of IL-12, IL-17A, IL-22, IFN-γ, tumor necrosis factor-α, zonulin, and soluble CD14 were significantly lower in the tumor necrosis factor inhibitor-tapering success group.

Conclusion

Patients with radiographic axial spondyloarthritis who achieve successful tumor necrosis factor inhibitor tapering had lower percentages of Th1 and Th17 cells, a higher percentage of Th2 cells, and lower serum levels of IL-12, IL-17A, IL-22, IFN-γ, tumor necrosis factor-α, zonulin, and soluble CD14 at the time of tumor necrosis factor inhibitor tapering. These findings may help to identify patients with radiographic axial spondyloarthritis for whom tumor necrosis factor inhibitor tapering is appropriate.

Treatment with cyclosporine attenuates the inflammatory process and severity of bisphosphonate-induced osteonecrosis of the jaws in rats

INTRODUCTION

Osteonecrosis usually occurs with necrotic bone exposure in the mandible asymptomatically for long periods but can evolve to present pain, fistula, odor, bleeding, and suppuration.

OBJECTIVE

To evaluate the influence of cyclosporine treatment and its influence on osteonecrosis in a rat model.

METHODS

The animals were randomly divided into 05 groups (n = 8/group). The negative control group (SAL), positive control group treated with zoledronic acid (ZA + SAL), and test groups were treated with cyclosporine A (CsA) at 5, 2.5, and 1.25 mg/kg and treated with ZA. The left lower second molars were extracted. The animals were euthanized 1 month after tooth extraction. Digital radiographs, histological slides, and immunoexpression of IL-2, IL-6, TNF-α, PPAR-γ, c-Fos, c-Jun, FoxP3, and INF-γ were analyzed. Western blot assays were performed to investigate the expression of RORyT. In addition, hematological analysis, body mass variation, and femur mechanical tests were performed.

RESULTS

Radiographs showed that in the groups treated with ZA, there was an increase in the radiolucent area suggestive of osteonecrosis, and treatment with cyclosporine did not reduce this parameter (p < 0.001). In the western blot analysis, animals treated with ZA showed increased expression of RORyT (1.887 ± 0.114) compared to the saline group (0.799 ± 0.107), and treatment with the highest dose of cyclosporine (0.652 ± 0.070) reduced this expression (p < 0.001).

DISCUSSION

Studies have observed bone health in animals treated with CsA. Treatment with this immunosuppressant showed a bone-protective effect of CsA, which corroborates our findings.

CONCLUSION

Treatment with CsA reduced the immunoexpression of pro-inflammatory cytokines such as IL-2 and TNF-α and decreased the expression of RORyT.

Depolymerization by transition metal complexes: strategic approaches to convert polymeric waste into feedstocks

At present, plastic pollution is a global environmental catastrophe and a major threat to mankind. Moreover, the increasing manufacture of various plastic products is causing rapid depletion of precious resources. Thus, transforming plastic waste into feedstock, which can maintain a circular economy, has emerged as a significant technique for waste management and carbon resource conservation. Furthermore, the urgent development of effective depolymerization methods is vital to save our planet from man-made plastic pollution. Among various chemical depolymerization techniques developed thus far, cleavage of the polymeric skeleton by transition metal complexes is a highly emerging, effective and exciting strategy. In this context, herein, we have summarized mechanistic approaches for cleaving various polymeric bonds using organometallic catalysts. The recently developed strategies, catalyst design and mechanisms for depolymerization of synthetic and natural polymers with polar (C-N, C-O, C-Cl, and Si-O) and non-polar (C-C) skeletal bonds are systematically discussed in detail.

Experimental Realization of On-Chip Surface Acoustic Wave Metasurfaces at Sub-GHz

Metasurfaces, consisting of subwavelength-thickness units with different wave responses, provide an innovative possible method to manipulate elastic and acoustic waves efficiently. The application of metasurfaces to manipulate on-chip surface acoustic wave (SAW) at sub-GHz frequencies requires further exploration since their wave functions are highly demanded in nanoelectromechanical systems (NEMS), sensing, communications, microfluid control and quantum processing. Here, the experimental realization of on-chip SAW metasurfaces is reported, consisting of gradient submicron niobium (Nb) rectangular pillars positioned on a 128°Y-cut lithium niobate (LiNbO3) substrate that operate at hundreds of megahertz. The proposed SAW metasurfaces are able to manipulate transmitted SAW wavefront functions by designing on-demand pillar's profile distributions. Broadband subwavelength focusing effects as the typical functions of SAW metasurfaces are experimentally demonstrated. This study opens a door for realizing on-chip SAW metasurfaces for diverse potential applications at micro- and nanoscale.

IL-23 tunes inflammatory functions of human mucosal-associated invariant T cells

IL-23 signaling plays a key role in the pathogenesis of chronic inflammatory and infectious diseases, yet the cellular targets and signaling pathways affected by this cytokine remain poorly understood. We show that IL-23 receptors are expressed on the large majority of human mucosal-associated invariant T (MAIT), but not of conventional T cells. Protein and transcriptional profiling at the population and single cell level demonstrates that stimulation with IL-23 or the structurally related cytokine IL-12 drives distinct functional profiles, revealing a high level of plasticity of MAIT cells. IL-23, in particular, affects key molecules and pathways related to autoimmunity and cytotoxic functions. Integrated analysis of transcriptomes and chromatin accessibility, supported by CRISPR-Cas9 mediated deletion, shows that AP-1 transcription factors constitute a key regulatory node of the IL-23 pathway in MAIT cells. In conclusion, our findings indicate that MAIT cells are key mediators of IL-23 functions in immunity to infections and chronic inflammatory diseases.

Transcription factors in the development and treatment of immune disorders

Immune function is highly controlled at the transcriptional level by the binding of transcription factors (TFs) to promoter and enhancer elements. Several TF families play major roles in immune gene expression, including NF-κB, STAT, IRF, AP-1, NRs, and NFAT, which trigger anti-pathogen responses, promote cell differentiation, and maintain immune system homeostasis. Aberrant expression, activation, or sequence of isoforms and variants of these TFs can result in autoimmune and inflammatory diseases as well as hematological and solid tumor cancers. For this reason, TFs have become attractive drug targets, even though most were previously deemed "undruggable" due to their lack of small molecule binding pockets and the presence of intrinsically disordered regions. However, several aspects of TF structure and function can be targeted for therapeutic intervention, such as ligand-binding domains, protein-protein interactions between TFs and with cofactors, TF-DNA binding, TF stability, upstream signaling pathways, and TF expression. In this review, we provide an overview of each of the important TF families, how they function in immunity, and some related diseases they are involved in. Additionally, we discuss the ways of targeting TFs with drugs along with recent research developments in these areas and their clinical applications, followed by the advantages and disadvantages of targeting TFs for the treatment of immune disorders.

The IL-23R and Its Genetic Variants: A Hitherto Unforeseen Bridge Between the Immune System and Cancer Development

IL-23R (interleukin-23 receptor), found on the surface of several immune cells, plays a key role in the immune system. Indeed, this process is not limited to the inflammatory response but also plays a role in the adaptive immune response. The binding between IL-23R and its specific ligand, the interleukin 23, initiates a number of specific signals by modulating both properties and behavior of immune cells. In particular, it is critical for the regulation of T helper 17 cells (Th17). Th17s are a subset of T cells involved in autoimmune and inflammatory diseases, as well as in cancer. The clinical relevance of IL-23R is underscored by its association with an elevated susceptibility or diminished vulnerability to a spectrum of diseases, including psoriasis, ankylosing spondylitis, and inflammatory bowel disease (IBD). Evidence has emerged that suggests it may also serve to predict both tumor progression and therapeutic responsiveness. It is noteworthy that the IL-23/IL-23R pathway is emerging as a promising therapeutic target. A number of biologic drugs, such as monoclonal antibodies, are currently developing with the aim of blocking this interaction, thus reducing inflammation. This represents a significant advancement in the field of medicine, offering new hope for pursuing more effective and personalized treatments. Recent studies have also investigated the role of such a pathway in autoimmune diseases, and its potential impact on infections as well as in carcinogenesis. The aim of this review is to focus on the role of IL-23R in immune genetics and its potential for modulating the natural history of neoplastic disease.

No causal relationship between ankylosing spondylitis and Parkinson's disease: Insights from Mendelian randomization studies

Background

Retrospective cohort and cross-sectional studies have indicated an association between ankylosing spondylitis (AS) and Parkinson's disease (PD). However, owing the multitude of limitations, a consistent conclusion has not been determined. Furthermore, whether a causal relationship exists between these two diseases remains unclear.

Methods

We conducted a two-way Mendelian randomization (MR) analysis using genome-wide association study data. For patients with PD, we utilised data from the ieu-b-7 database, whereas for patients with AS, we employed the three databases with the largest sample sizes for a combined analysis. These databases included ebi-a-GCST005529, finn-b-M13 ANKYLOSPON, and finn-b-M13 ANKYLOSPON STRICT. Our primary method of analysis was inverse variance weighting (IVW), supplemented by four other effective methods, to comprehensively infer a potential causal relationship between AS and PD. Additionally, we conduct various sensitivity analyses to assess the robustness of our estimates.

Results

Based on our IVW MR analysis, no significant causal relationship between AS and PD was observed (odds ratio [OR] = 1.01, 95 % confidence interval [CI] = 0.99-1.03, P = 0.26). Additionally, our reverse MR analysis found no evidence supporting a significant causal relationship between PD and AS (OR = 0.93, 95 % CI = 0.85-1.01, P = 0.068). These results were substantiated by comprehensive sensitivity analyses that indicated minimal bias in the causal estimates.

Conclusion

In contrast to numerous existing clinical studies, this study failed to provide evidence supporting a significant impact of AS on PD risk, or vice versa. Further investigations regarding the potential causal mechanisms linking AS and PD are warranted.

Shared lung and joint T cell repertoire in early rheumatoid arthritis driven by cigarette smoking

OBJECTIVES

Smoking has been associated with an increased risk of developing rheumatoid arthritis (RA) in individuals carrying shared epitope (SE) HLA-DRB1 alleles. Yet, little is known about the regional and systemic T cell dynamics of smoking and a potential link to T cell infiltration in inflamed synovia. In this study, we, therefore, sought to study T cell features in lung and inflamed joints in smoking versus non-smoking patients.

METHODS

We set up a framework to monitor T cells in paired bronchoalveolar lavage fluid, blood and inflamed synovium tissue samples from 17 new-onset treatment naïve anticitrullinated protein antibody+RA patients. T cell receptor (TCR) repertoire of index-sorted tissue residing in T cells was determined by single-cell TCR sequencing coupled with deep immunophenotyping.

RESULTS

A significant enrichment of CD4+ and CD8+ T cells was seen in synovial samples from smoking versus non-smoking patients, along with an increase in expanded T cell clonotypes. This was particularly pronounced among SE+smokers, suggestive of a synergic gene-smoke effect. Strikingly, identical TCR clonalities were present in matched lung and joint samples of RA smokers, the majority being also detectable in circulation. This was mirrored by an increased clustering of lung and synovium TCRs across patients, suggesting a shared specificity by conserved motifs. The lung-joint shared T cell clonotypes showed a restricted TCR gene usage and exhibited a particular 4-1BB+CD57 hi effector profile within the inflamed synovium.

CONCLUSION

The data indicate a profound interplay between a strong MHC predisposition, smoking and induction of autoimmunity by shaping the TCR repertoire.

On-Demand Picoliter-Level-Droplet Inkjet Printing for Micro Fabrication and Functional Applications

With the advent of Internet of Things (IoTs) and wearable devices, manufacturing requirements have shifted toward miniaturization, flexibility, environmentalization, and customization. Inkjet printing, as a non-contact picoliter-level droplet printing technology, can achieve material deposition at the microscopic level, helping to achieve high resolution and high precision patterned design. Meanwhile, inkjet printing has the advantages of simple process, high printing efficiency, mask-free digital printing, and direct pattern deposition, and is gradually emerging as a promising technology to meet such new requirements. However, there is a long way to go in constructing functional materials and emerging devices due to the uncommercialized ink materials, complicated film-forming process, and geometrically/functionally mismatched interface, limiting film quality and device applications. Herein, recent developments in working mechanisms, functional ink systems, droplet ejection and flight process, droplet drying process, as well as emerging multifunctional and intelligence applications including optics, electronics, sensors, and energy storage and conversion devices is reviewed. Finally, it is also highlight some of the critical challenges and research opportunities. The review is anticipated to provide a systematic comprehension and valuable insights for inkjet printing, thereby facilitating the advancement of their emerging applications.

Type 17 immunity: novel insights into intestinal homeostasis and autoimmune pathogenesis driven by gut-primed T cells

The IL-23 signaling pathway in both innate and adaptive immune cells is vital for orchestrating type 17 immunity, which is marked by the secretion of signature cytokines such as IL-17, IL-22, and GM-CSF. These proinflammatory mediators play indispensable roles in maintaining intestinal immune equilibrium and mucosal host defense; however, their involvement has also been implicated in the pathogenesis of chronic inflammatory disorders, such as inflammatory bowel diseases and autoimmunity. However, the implications of type 17 immunity across diverse inflammation models are complex. This review provides a comprehensive overview of the multifaceted roles of these cytokines in maintaining gut homeostasis and in perturbing gut barrier integrity, leading to acute and chronic inflammation in various models of gut infection and colitis. Additionally, this review focuses on type 17 immunity interconnecting multiple organs in autoimmune conditions, with a particular emphasis on the pathogenesis of autoimmune arthritis and neuroinflammation driven by T cells primed within the gut microenvironment.

Cedirogant in adults with psoriasis: a phase II, randomized, placebo-controlled clinical trial

BACKGROUND

Dysregulated interleukin (IL)-17/IL-23 signalling contributes to psoriasis pathogenesis. Cedirogant is an inverse agonist of nuclear receptor ROR-gamma isoform 2 (RORyt), a key transcription factor responsible for IL-17 synthesis and a regulator of the T helper 17 cell lineage programme.

OBJECTIVES

To evaluate the efficacy and safety of cedirogant to treat moderate-to-severe psoriasis.

METHODS

In this phase IIb, multicentre, double-blind, 16-week study (NCT05044234), adults aged 18-65 years were randomized 1 : 1 : 1 : 1 to once-daily oral cedirogant 75 mg, 150 mg, 375 mg or placebo. Assessments included: ≥ 50%/75%/90%/100% improvement from baseline in Psoriasis Area and Severity Index (PASI 50/75/90/100), static Physician's Global Assessment 0/1, Psoriasis Symptoms Scale 0 and improvements in itch; adverse events (AEs); pharmacokinetics; and IL-17A/F biomarker levels. Efficacy results based on observed cases were summarized descriptively.

RESULTS

Of 156 enrolled patients, most were male (70.5%); 39 patients were randomized to each treatment. Only 47 patients completed the study; the study was terminated early owing to preclinical findings. At week 16, PASI 75 achievement rates (primary endpoint) were 29%, 8% and 42% in the cedirogant 75-mg, 150-mg and 375-mg groups, respectively, and 0% in the placebo group. AE rates were similar in the cedirogant 75-mg, 150-mg and placebo groups, and higher in the cedirogant 375-mg group; most AEs were mild or moderate.

CONCLUSIONS

Patients with psoriasis who received cedirogant showed PASI improvement, and cedirogant was generally well tolerated. The results should be interpreted in the context of early study termination. Cedirogant development has been discontinued.

Liquid Metal Composites-Enabled Real-Time Hand Gesture Recognizer with Superior Recognition Speed and Accuracy

Prosthetic hands play a vital role in restoring forearm functionality for patients who have suffered hand loss or deformity. The hand gesture intention recognition system serves as a critical component within the prosthetic hand system. However, accurately and swiftly identifying hand gesture intentions remains a challenge in existing approaches. Here, a real-time motion intention recognition system utilizing liquid metal composite sensor bracelets is proposed. The sensor bracelet detects pressure signals generated by forearm muscle movements to recognize hand gesture intent. Leveraging the remarkable pressure sensitivity of liquid metal composites and the efficient classifier based on the optimized recognition algorithm, this system achieves an average offline and real-time recognition accuracy of 98.2% and 92.04%, respectively, with an average recognition speed of 0.364 s. Thus, this wearable system shows advantages in superior recognition speed and accuracy. Furthermore, this system finds applications in master-slave control of prosthetic hands in unmanned scenarios, such as electrically powered operations, space exploration, and telemedicine. The proposed system promises significant advances in next-generation intent-controlled prosthetic hands and robots.

Illuminating the impact of γδ T cells in man and mice in spondylarthritides

Spondylarthritides (SpA) are a group of autoinflammatory diseases affecting the spine, peripheral joints, and entheses, including axial spondyloarthritis (axSpA) and psoriatic arthritis. AxSpA has a multifactorial etiology that involves genetic predispositions, such as HLA-B27 and IL-23R. Although HLA-B27 is strongly associated with axSpA, its role remains unclear. GWAS studies have demonstrated that genetic polymorphisms related to the IL-23 pathway occur throughout the spectrum of SpA, including but not limited to axSpA and PsA. IL-23 promotes the production of IL-17, which drives inflammation and tissue damage. This pathway contributes not only to peripheral enthesitis but also to spinal inflammation. γδ T cells in axSpA express IL-23R and RORγt, crucial for their activation, although specific pathogenic cells and factors remain elusive. Despite drug efficacy in PsA, IL-23R inhibition is ineffective in axSpA. Murine models provide valuable insights into the intricate cellular and molecular interactions that contribute to the development and progression of SpA. Those models are useful tools to elucidate the dynamics of γδ T cell involvement, offering insights into disease mechanisms and potential therapeutic targets. This review aims to illuminate the complex interplay between IL-23 and γδ T cells in SpA pathogenesis, emphasizing their roles in chronic inflammation, tissue damage, and disease heterogeneity.

A Smartphone-Mediated "All-In-One" Biosensing Chip for Visual and Value-Assisted Detection

A smartphone-mediated self-powered biosensor is fabricated for miRNA-141 detection based on the CRISPR/Cas12a cross-cutting technique and a highly efficient nanozyme. As a novel nanozyme and a signal-amplified coreaction accelerator, the AuPtPd@GDY nanozyme exhibits an excellent ability to catalyze cascade color reactions and high conductivity to enhance the electrochemical signal for miRNA-141 assays. After CRISPR/Cas12a cross-cutting of S2-glucose oxidase (S2-GOD), the electrochemical signal is weakened, and miRNA-141 is detected by monitoring the decrease in the signal. On the other hand, a cascade reaction among glucose, H2O2, and TMB is catalyzed by GOD and AuPtPd@GDY, respectively, resulting in a color change of the solution, which senses miRNA-141. The self-powered biosensor enables value-assisted and visual detection of miRNA-141 with limits of detection of 3.1 and 15 aM, respectively. Based on the dual-modal self-powered sensing system, a smartphone-mediated "all-in-one" biosensing chip is designed to achieve the real-time and intelligent monitoring of miRNA-141. This work provides a new approach to design multifunctional biosensors to realize the visualization and portable detection of tumor biomarkers.

Looking back on 51 years of the Carol Nachman Prize in Rheumatology-significance for the field of spondyloarthritis research

The city and casino of Wiesbaden, capital of the German state Hessen, have endowed the Carol Nachman Prize to promote research work in the field of rheumatology since 1972. The prize, endowed with 37,500 €, is the second highest medical award in Germany and serves to promote clinical, therapeutic, and experimental research work in the field of rheumatology. In June 2022, the 50-year anniversary was celebrated. In the symposium preceding the award ceremony, an overview was given on the significance of spondyloarthritis for the work of the awardees in the past 30 years. This overview has now been put together to inform the interested community of the work performed, including the opinion of the awardees regarding what they consider to be their most important contribution.

Thymic development of human natural killer T cells: recent advances and implications for immunotherapy

Invariant natural killer T (iNKT) cells are a subset of lipid-reactive, unconventional T cells that have anti-tumor properties that make them a promising target for cancer immunotherapy. Recent studies have deciphered the developmental pathway of human MAIT and Vγ9Vδ2 γδ-T cells as well as murine iNKT cells, yet our understanding of human NKT cell development is limited. Here, we provide an update in our understanding of how NKT cells develop in the human body and how knowledge regarding their development could enhance human treatments by targeting these cells.

The management of axial spondyloarthritis with cutting-edge therapies: advancements and innovations

INTRODUCTION

Axial involvement in spondyloarthritis has significantly evolved from the original 1984 New York criteria for ankylosing spondylitis, leading to an improved understanding of axial spondyloarthritis (axSpA) as a disease continuum encompassing non- radiographic axSpA (nr-axSpA) and radiographic axSpA (r-axSpA). A clear definition for early axSpA has been established, underscoring the need for early intervention with biological and targeted synthetic drugs to mitigate pain, reduce functional impairment, and prevent radiographic progression.

AREAS COVERED

This review explores therapeutic strategies in axSpA management, focusing on biological and targeted synthetic therapies and recent advancements. Biologics targeting TNFα or IL-17 and targeted synthetic disease-modifying antirheumatic drugs (DMARDs) are primary treatment options. These therapies significantly impact clinical outcomes, radiographic progression, and patient-reported functional improvement.

EXPERT OPINION

AxSpA treatment has evolved significantly, offering various therapeutic options. Biological DMARDs, particularly TNFα inhibitors, have transformed treatment, significantly enhancing patient outcomes. However, challenges persist for patients unresponsive or intolerant to existing therapies. Emerging therapeutic targets promise to address these challenges. Comprehensive management strategies and personalized approaches, considering extra-articular manifestations and individual patient factors, are crucial for achieving optimal outcomes in axSpA management.

Crosstalk between bone and the immune system

Bone functions not only as a critical element of the musculoskeletal system but also serves as the primary lymphoid organ harboring hematopoietic stem cells (HSCs) and immune progenitor cells. The interdisciplinary field of osteoimmunology has illuminated the dynamic interactions between the skeletal and immune systems, vital for the maintenance of skeletal tissue homeostasis and the pathogenesis of immune and skeletal diseases. Aberrant immune activation stimulates bone cells such as osteoclasts and osteoblasts, disturbing the bone remodeling and leading to skeletal disorders as seen in autoimmune diseases like rheumatoid arthritis. On the other hand, intricate multicellular network within the bone marrow creates a specialized microenvironment essential for the maintenance and differentiation of HSCs and the progeny. Dysregulation of immune-bone crosstalk in the bone marrow environment can trigger tumorigenesis and exacerbated inflammation. A comprehensive deciphering of the complex "immune-bone crosstalk" leads to a deeper understanding of the pathogenesis of immune diseases as well as skeletal diseases, and might provide insight into potential therapeutic approaches.

Single Transition-Metal Atom Anchored on a Rhenium Disulfide Monolayer: An Efficient Bifunctional Electrocatalyst for the Oxygen Evolution and Oxygen Reduction Reactions

Developing efficient oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) bifunctional electrocatalysts is attractive for rechargeable metal-air batteries. Meanwhile, single metal atoms embedded in 2D layered transition metal chalcogenides (TMDs) have become a very promising catalyst. Recently, many attentions have been paid to the 2D ReS2 electrocatalyst due to its unique distorted octahedral 1T' crystal structure and thickness-independent electronic properties. Here, the catalytic activity of different transition metal (TM) atoms embedded in ReS2 using the density functional theory is investigated. The results indicate that TM@ReS2 exhibits outstanding thermal stability, good electrical conductivity, and electron transfer for electrochemical reactions. And the Ir@ReS2 and Pd@ReS2 can be used as OER/ORR bifunctional electrocatalysts with a lower overpotential for OER (ηOER) of 0.44 V and overpotentials for ORR (ηORR) of 0.26 V and 0.27 V, respectively. The excellent catalytic activity is attributed to the optimal adsorption strength for oxygen intermediates coming from the effective modulation of the electronic structure of ReS2 after Ir/Pd doping. The results can help to deeply understand the catalytic activity of TM@ReS2 and develop novel and highly efficient OER/ORR electrocatalysts.

Functional genomics implicates natural killer cells in the pathogenesis of ankylosing spondylitis

Objective

Multiple lines of evidence indicate that ankylosing spondylitis (AS) is a lymphocyte-driven disease. However, which lymphocyte populations are critical in AS pathogenesis is not known. In this study, we aimed to identify the key cell types mediating the genetic risk in AS using an unbiased functional genomics approach.

Methods

We integrated genome-wide association study (GWAS) data with epigenomic and transcriptomic datasets of human immune cells. To quantify enrichment of cell type-specific open chromatin or gene expression in AS risk loci, we used three published methods that have successfully identified relevant cell types in other diseases. We performed co-localization analyses between GWAS risk loci and genetic variants associated with gene expression (eQTL) to find putative target genes.

Results

Natural killer (NK) cell-specific open chromatin regions are significantly enriched in heritability for AS, compared to other immune cell types such as T cells, B cells, and monocytes. This finding was consistent between two AS GWAS. Using RNA-seq data, we validated that genes in AS risk loci are enriched in NK cell-specific gene expression. Using the human Space-Time Gut Cell Atlas, we also found significant upregulation of AS-associated genes predominantly in NK cells. Co-localization analysis revealed four AS risk loci affecting regulation of candidate target genes in NK cells: two known loci, ERAP1 and TNFRSF1A, and two under-studied loci, ENTR1 (aka SDCCAG3) and B3GNT2.

Conclusion

Our findings suggest that NK cells may play a crucial role in AS development and highlight four putative target genes for functional follow-up in NK cells.

Double-negative T cells ameliorate psoriasis by selectively inhibiting IL-17A-producing γδlow T cells

BACKGROUND

Psoriasis is a chronic immune-mediated skin condition. Although biologic treatments are effective in controlling psoriasis, some patients do not respond or lose response to these therapies. Thus, new strategies for psoriasis treatment are still urgently needed. Double-negative T cells (DNT) play a significant immunoregulatory role in autoimmune diseases. In this study, we aimed to evaluate the protective effect of DNT in psoriasis and explore the underlying mechanism.

METHODS

We conducted a single adoptive transfer of DNT into an imiquimod (IMQ)-induced psoriasis mouse model through tail vein injection. The skin inflammation and IL-17A producing γδ T cells were evaluated.

RESULTS

DNT administration significantly reduced the inflammatory response in mouse skin, characterized by decreased skin folds, scales, and red patches. After DNT treatment, the secretion of IL-17A by RORc+ γδlow T cells in the skin was selectively suppressed, resulting in an amelioration of skin inflammation. Transcriptomic data suggested heightened expression of NKG2D ligands in γδlow T cells within the mouse model of psoriasis induced by IMQ. When blocking the NKG2D ligand and NKG2D (expressed by DNT) interaction, the cytotoxic efficacy of DNT against RORc+IL17A+ γδlow T cells was attenuated. Using Ccr5-/- DNT for treatment yielded evidence that DNT migrates into inflamed skin tissue and fails to protect IMQ-induced skin lesions.

CONCLUSIONS

DNT could migrate to inflamed skin tissue through CCR5, selectively inhibit IL-17-producing γδlow T cells and finally ameliorate mouse psoriasis. Our study provides feasibility for using immune cell therapy for the prevention and treatment of psoriasis in the clinic.

Decidual leukocytes respond to African lineage Zika virus infection with mild anti-inflammatory changes during acute infection in rhesus macaques

Zika virus (ZIKV) can be vertically transmitted during pregnancy resulting in a range of adverse pregnancy outcomes. The decidua is commonly found to be infected by ZIKV, yet the acute immune response to infection remains understudied in vivo. We hypothesized that in vivo African-lineage ZIKV infection induces a pro-inflammatory response in the decidua. To test this hypothesis, we evaluated the decidua in pregnant rhesus macaques within the first two weeks following infection with an African-lineage ZIKV and compared our findings to gestationally aged-matched controls. Decidual leukocytes were phenotypically evaluated using spectral flow cytometry, and cytokines and chemokines were measured in tissue homogenates from the decidua, placenta, and fetal membranes. The results of this study did not support our hypothesis. Although ZIKV RNA was detected in the decidual tissue samples from all ZIKV infected dams, phenotypic changes in decidual leukocytes and differences in cytokine profiles suggest that the decidua undergoes mild anti-inflammatory changes in response to that infection. Our findings emphasize the immunological state of the gravid uterus as a relatively immune privileged site that prioritizes tolerance of the fetus over mounting a pro-inflammatory response to clear infection.

Aryl hydrocarbon receptor gene expression in ankylosing spondylitis and its correlation with interleukin-17, RAR-related orphan receptor gamma t expression, and disease activity indices

Objectives

Considering the role of T helper (Th)17 cells in the pathogenesis of ankylosing spondylitis (AS), the aim of this study was to determine the correlation between aryl hydrocarbon receptor (AHR) gene expression and the expression of Th17-related genes including interleukin (IL)-17 and RAR-related orphan receptor gamma t (RORγt) transcription factor.

Patients and methods

Thirty patients with AS (26 males, 4 females; mean age: 36.1±8.1 years) and 30 age- and sex-matched healthy individuals (26 males, 4 females; mean age: 36.2±14.6 years) were recruited for the case-control study between June 2021 and January 2022. Ribonucleic acid (RNA) was extracted from peripheral blood cells and expression levels of AHR, IL-17, RORγt, and AHR repressor (AHRR) genes were evaluated using real-time polymerase chain reaction technique. The serum level of IL-17 was evaluated with enzyme-linked immunosorbent assay.

Results

The results showed a nonsignificant elevation of AHR, IL-17, and RORγt gene expression in the patient group compared to the control. There was a direct correlation between AHR gene expression and IL-17 and RORγt genes and a negative correlation between AHR and AHRR expression. Moreover, AHR gene expression showed a weak correlation with disease activity indices, including Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Metrology Index, Bath Ankylosing Spondylitis Global Score, and Ankylosing Spondylitis Quality of Life. Moreover, the serum level of IL-17 was higher in AS patients compared to the healthy group (p=0.02).

Conclusion

Upregulated expression of the AHR gene in ankylosing spondylitis and its correlation with IL-17 and ROR-γ t gene expression suggests that it could be a potential diagnostic and therapeutic target for AS.

Mast cells express IL17A, IL17F and RORC, are activated and persist with IL-17 production in resolved skin of patients with chronic plaque-type psoriasis

Little is known about IL-17 expression in psoriasis and the actual cellular source of IL-17 remains incompletely defined. We show that high numbers of IL-17 + mast cells persisted in resolved lesions after treatment (anti-IL-17A, anti-IL-23, UVB or topical dithranol) and correlated inversely with the time span in remission. IL-17 + mast cells were found in T cell-rich areas and often close to resident memory T cells (Trm) in active psoriasis and resolved lesional skin. Digital cytometry by deconvolution of RNA-seq data showed that activated mast cells were increased in psoriatic skin, while resting mast cells were almost absent and both returned to normal levels after treatment. When primary human skin mast cells were stimulated with T cell cytokines (TNFα, IL-22 and IFNγ), they responded by releasing more IL-17A, as measured by ELISA. In situ mRNA detection using padlock probes specific for transcript variants of IL17A, IL17F, and RORC (encoding the Th17 transcription factor RORγt) revealed positive mRNA signals for IL17A, IL17F, and RORCin tryptase + cells, demonstrating that mast cells have the transcriptional machinery to actively produce IL-17. Mast cells thus belong to the center of the IL-23/IL-17 axis and high numbers of IL-17 + mast cells predict an earlier disease recurrence.

Reproducible and High-Performance WOLEDs Based on Independent High-Efficiency Triplet Harvesting of Yellow Hot-Exciton ESIPT and Blue TADF Emitters

Hot exciton organic light-emitting diode (OLED) emitters can balance the high performance of a device and reduce efficiency roll-off by fast reverse intersystem crossing from high-lying triplets (hRISC). In this study, an excited-state intramolecular proton transfer (ESIPT) fluorophore of 2-(benzo[d]thiazol-2-yl)-4-(pyren-1-yl)phenol (PyHBT) with the typical characteristic properties of a hot exciton is developed. With high efficiency of utilization of the exciton (91%), its yellow OLED exhibited high external quantum efficiency (EQE) of 5.6%, current efficiency (CE) of 16.8 cd A-1 , and power efficiency (PE) of 17.3 lm W-1 . The performance of the yellow emissive "hot exciton" ESIPT fluorophores is among the highest recorded. Due to the large Stokes shift of the ESIPT emitter, non-energy-transferred high-performance white OLEDs (WOLEDs) are developed, which are reproducible and highly efficient. This is possible because of the independent harvesting of most of the triplets in both complementary-color emitters without the interference of energy transfer. The PyHBT-based WOLEDs exhibit a maximum EQE of 14.3% and CE of 41.1 cd A-1 , which facilitates the high-yield mass production of inexpensive WOLEDs.

Hidradenitis Suppurativa: An Understanding of Genetic Factors and Treatment

Hidradenitis suppurativa (HS), recognized as a chronic and debilitating skin disease, presents significant challenges in both diagnosis and treatment. This review explores the clinical manifestations, genetic landscape, and molecular mechanisms underlying HS. The disease's association with a predisposing genetic background, obesity, smoking, and skin occlusion underscores the complexity of its etiology. Genetic heterogeneity manifests in sporadic, familial, and syndromic forms, with a focus on mutations in the γ-secretase complex genes, particularly NCSTN. The dysregulation of immune mediators, including TNF-α, IL-17, IL-1β, and IL-12/23, plays a crucial role in the chronic inflammatory nature of HS. Recent advancements in genetic research have identified potential therapeutic targets, leading to the development of anti-TNF-α, anti-IL-17, anti-IL-1α, and anti-IL-12/23 therapies and JAK inhibitors. These interventions offer promise in alleviating symptoms and improving the quality of life for HS patients.

Single-cell transcriptomics reveal different maturation stages and sublineage commitment of human thymic invariant natural killer T cells

Invariant natural killer T cells are a rare, heterogeneous T-cell subset with cytotoxic and immunomodulatory properties. During thymic development, murine invariant natural killer T cells go through different maturation stages differentiating into distinct sublineages, namely, invariant natural killer T1, 2, and 17 cells. Recent reports indicate that invariant natural killer T2 cells display immature properties and give rise to other subsets, whereas invariant natural killer T1 cells seem to be terminally differentiated. Whether human invariant natural killer T cells follow a similar differentiation model is still unknown. To define the maturation stages and assess the sublineage commitment of human invariant natural killer T cells during thymic development, in this study, we performed single-cell RNA sequencing analysis on human Vα24+Vβ11+ invariant natural killer T cells isolated from thymocytes. We show that these invariant natural killer T cells displayed heterogeneity, and our unsupervised analysis identified 5 clusters representing different maturation stages, from an immature profile with high expression of genes important for invariant natural killer T cell development and proliferation to a mature, fully differentiated profile with high levels of cytotoxic effector molecules. Evaluation of expression of sublineage-defining gene sets revealed mainly cells with an invariant natural killer T2 signature in the most immature cluster, whereas the more differentiated ones displayed an invariant natural killer T1 signature. Combined analysis with a publicly available single-cell RNA sequencing data set of human invariant natural killer T cells from peripheral blood suggested that the 2 main subsets exist both in thymus and in the periphery, while a third more immature one was restricted to the thymus. Our data point to the existence of different maturation stages of human thymic invariant natural killer T cells and provide evidence for sublineage commitment of invariant natural killer T cells in the human thymus.

Clinically relevant differences in spinal mobility related to daytime performance in patients with axial spondyloarthritis

OBJECTIVE

Patients with axial spondyloarthritis (axSpA) suffer from clinical symptoms like morning stiffness and back pain. Mobility of patients with axSpA is often impaired. The aim of this study is to compare the performance of patients with axSpA regarding mobility measures including performance-based tests and objective electronic assessments with the Epionics SPINE device (ES) at different times of the day compared with healthy controls (HC).

METHODS

Observational trial, consecutive inpatients with axSpA (n=100) and 20 HCs were examined in the morning (V1: before 10:00 am) and in the afternoon (V2: after 02:00 pm) by the Bath Ankylosing Spondylitis Metrology Index (BASMI), the AS physical performance index (ASPI), the Short Physical Performance Battery (SPPB) and ES measurements, including range of motion (RoM) and range of kinematics (RoK).

RESULTS

The assessments of patients with axSpA performed in the morning clearly differed from those in the afternoon, especially regarding performance-based tests. Significant improvements were seen for BASMI (4.0±3.8 to 3.8±1.9; p<0.001), ASPI (36.2±18.3 to 28.8±11.9 s; p<0.001), SPPB (10.1±1.5 to 10.7±1.4 points; p<0.001) and for ES measures of speed (RoK; p<0.018) but not for RoM, except for lateral flexion (13.3±7.4 to 14.7±8.2°; p=0.002). This time of assessment-related variability was not observed in HC.

CONCLUSION

The spinal mobility of patients with axSpA was worse in the morning but significantly improved in the afternoon. This was captured best by performance-based measures and was not seen in HC. The diurnal variation of mobility has implications for clinical studies, suggesting that the time of assessments needs to be standardised.

Interleukin 23 receptor: Expression and regulation in immune cells

The importance of IL-23 and its specific receptor, IL-23R, in the pathogenesis of several chronic inflammatory diseases has been established, but the underlying pathological mechanisms are not fully understood. This review focuses on IL-23R expression and regulation in immune cells.

T cells in the pathogenesis of axial spondyloarthritis

Axial spondyloarthritis (axSpA) is the prototype of the spondyloarthritis spectrum. The involvement of T cells in its pathogenesis has long been suspected on the basis of the association with the major histocompatibility complex I molecule HLA-B27 and the pivotal role of interleukin 17 in the inflammatory mechanisms associated with the disease. Moreover, the presence of unconventional or "innate-like" T cells within the axial enthesis suggests an important role for these cells in the pathophysiology of the disease. In this review, we describe the characteristics and the interleukin 17 secretion capacity of the T-cell subsets identified in axSpA. We discuss the genetic and epigenetic mechanisms that support the alteration of T-cell functions and promote their activation in axSpA. We also discuss recent data on T cells that could explain the extra-articular manifestations of the SpA spectrum.

The role of γδ T cells in the immunopathogenesis of inflammatory diseases: from basic biology to therapeutic targeting

The γδ T cells are lymphocytes with an innate-like phenotype that can distribute to different tissues to reside and participate in homeostatic functions such as pathogen defense, tissue modeling, and response to stress. These cells originate during fetal development and migrate to the tissues in a TCR chain-dependent manner. Their unique manner to respond to danger signals facilitates the initiation of cytokine-mediated diseases such as spondyloarthritis and psoriasis, which are immune-mediated diseases with a very strong link with mucosal disturbances, either in the skin or the gut. In spondyloarthritis, γδ T cells are one of the main sources of IL-17 and, therefore, the main drivers of inflammation and probably new bone formation. Remarkably, this population can be the bridge between gut and joint inflammation.

Bifidobacterium longum subsp. infantis B6MNI Alleviates Collagen-Induced Arthritis in Rats via Regulating 5-HIAA and Pim-1/JAK/STAT3 Inflammation Pathways

The immunomodulatory potential of certain bacterial strains suggests that they could be beneficial in the treatment of rheumatoid arthritis (RA). In this study, we investigated the effects of Bifidobacterium longum subsp. infantis B6MNI on the progression of collagen-induced arthritis (CIA) in rats as well as its influence on the gut microbiota and fecal metabolites. Forty-eight female Wistar rats were divided into six groups that included a B6MNI group with CIA and intragastrically administered B. longum subsp. infantis B6MNI (109 CFU/day/rat), a control group (CON), and a CIA group, both of which were intracardiacally administered the same volume of saline. Rats were sacrificed after short-term (ST, 4 weeks) or long-term (LT, 6 weeks) administration. The results indicate that B. longum subsp. infantis B6MNI can modulate the gut microbiota and fecal metabolites, including 5-hydroxyindole-3-acetic acid (5-HIAA), which in turn impacts the expression of Pim-1 and immune cell differentiation, then through the JAK-STAT3 pathway affects joint inflammation, regulates osteoclast differentiation factors, and delays the progression of RA. Our results also suggest that B. longum subsp. infantis B6MNI is most efficacious for the early or middle stages of RA.

Gut Inflammation in Axial Spondyloarthritis Patients is Characterized by a Marked Type 17 Skewed Mucosal Innate-like T Cell Signature

OBJECTIVE

Patients with spondyloarthritis (SpA) often present with microscopic signs of gut inflammation, a risk factor for progressive disease. We investigated whether mucosal innate-like T cells are involved in dysregulated interleukin-23 (IL-23)/IL-17 responses in the gut-joint axis in SpA.

METHODS

Ileal and colonic intraepithelial lymphocytes (IELs), lamina propria lymphocytes (LPLs), and paired peripheral blood mononuclear cells (PBMCs) were isolated from treatment-naive patients with nonradiographic axial SpA with (n = 11) and without (n = 14) microscopic gut inflammation and healthy controls (n = 15) undergoing ileocolonoscopy. The presence of gut inflammation was assessed histopathologically. Immunophenotyping of innate-like T cells and conventional T cells was performed using intracellular flow cytometry. Unsupervised clustering analysis was done by FlowSOM technology. Serum IL-17A levels were measured via Luminex.

RESULTS

Microscopic gut inflammation in nonradiographic axial SpA was characterized by increased ileal intraepithelial γδ-hi T cells, a γδ-T cell subset with elevated γδ-T cell receptor expression. γδ-hi T cells were also increased in PBMCs of patients with nonradiographic axial SpA versus healthy controls and were strongly associated with Ankylosing Spondylitis Disease Activity Score. The abundance of mucosal-associated invariant T cells and invariant natural killer T cells was unaltered. Innate-like T cells in the inflamed gut showed increased RORγt, IL-17A, and IL-22 levels with loss of T-bet, a signature that was less pronounced in conventional T cells. Presence of gut inflammation was associated with higher serum IL-17A levels. In patients treated with tumor necrosis factor blockade, the proportion of γδ-hi cells and RORγt expression in blood was completely restored.

CONCLUSION

Intestinal innate-like T cells display marked type 17 skewing in the inflamed gut mucosa of patients with nonradiographic axial SpA. γδ-hi T cells are linked to intestinal inflammation and disease activity in SpA.

Updates on ankylosing spondylitis: pathogenesis and therapeutic agents

Ankylosing spondylitis (AS) is an autoinflammatory disease that manifests with the unique feature of enthesitis. Gut microbiota, HLA-B*27, and biomechanical stress mutually influence and interact resulting in setting off a flame of inflammation. In the HLA-B*27 positive group, dysbiosis in the gut environment disrupts the barrier to exogenous bacteria or viruses. Additionally, biomechanical stress induces inflammation through enthesial resident or gut-origin immune cells. On this basis, innate and adaptive immunity can propagate inflammation and lead to chronic disease. Finally, bone homeostasis is regulated by cytokines, by which the inflamed region is substituted into new bone. Agents that block cytokines are constantly being developed to provide diverse therapeutic options for preventing the progression of inflammation. In addition, some antibodies have been shown to distinguish disease selectively, which support the involvement of autoimmune immunity in AS. In this review, we critically analyze the complexity and uniqueness of the pathogenesis with updates on the findings of immunity and provide new information about biologics and biomarkers.

Innate immune memory in inflammatory arthritis

The concept of immunological memory was demonstrated in antiquity when protection against re-exposure to pathogens was observed during the plague of Athens. Immunological memory has been linked with the adaptive features of T and B cells; however, in the past decade, evidence has demonstrated that innate immune cells can exhibit memory, a phenomenon called 'innate immune memory' or 'trained immunity'. Innate immune memory is currently being defined and is transforming our understanding of chronic inflammation and autoimmunity. In this Review, we provide an up-to-date overview of the memory-like features of innate immune cells in inflammatory arthritis and the crosstalk between chronic inflammatory milieu and cell reprogramming. Aberrant pro-inflammatory signalling, including cytokines, regulates the metabolic and epigenetic reprogramming of haematopoietic progenitors, leading to exacerbated inflammatory responses and osteoclast differentiation, in turn leading to bone destruction. Moreover, imprinted memory on mature cells including terminally differentiated osteoclasts alters responsiveness to therapies and modifies disease outcomes, commonly manifested by persistent inflammatory flares and relapse following medication withdrawal.

Interleukin-23 Involved in Fibrotic Autoimmune Diseases: New Discoveries

Interleukin (IL)-23 is a central pro-inflammatory cytokine with a broad range of effects on immune responses. IL-23 is pathologically linked to the induction of the production of the pro-inflammatory cytokines IL-17 and IL-22, which stimulate the differentiation and proliferation of T helper type 17 (Th17) cells. Recent discoveries suggest a potential pro-fibrotic role for IL-23 in the development of chronic inflammatory autoimmune diseases characterized by intense fibrosis. In this review, we summarized the biological features of IL-23 and gathered recent research on the role of IL-23 in fibrotic autoimmune conditions, which could provide a theoretical basis for clinical targeting and drug development.

The emerging paradigm of Unconventional T cells as a novel therapeutic target for celiac disease

Celiac disease (CD) is an organ-specific autoimmune disorder that occurs in genetically predisposed individuals when exposed to exogenous dietary gluten. This exposure to wheat gluten and related proteins from rye and barley triggers an immune response which leads to the development of enteropathy associated with symptoms of bloating, diarrhea, or malabsorption. The sole current treatment is to follow a gluten-free diet for the rest of one's life. Intestinal barriers are enriched with Unconventional T cells such as iNKT, MAIT, and γδ T cells, which lack or express only a limited range of rearranged antigen receptors. Unconventional T cells play a crucial role in regulating mucosal barrier function and microbial colonization. Unconventional T cell populations are widely represented in diseased conditions, where changes in disease activity related to iNKT and MAIT cell reduction, as well as γδ T cell expansion, are demonstrated. In this review, we discuss the role and potential employment of Unconventional T cells as a therapeutic target in the pathophysiology of celiac disease.

RORγt inhibition ameliorates IL-23 driven experimental psoriatic arthritis by predominantly modulating γδ-T cells

OBJECTIVE

Divergent therapeutic outcomes on different disease domains have been noted with IL-23 and IL-17A-blockade in PsA. Therefore, elucidating the role of RORγt, the master regulator of type 17 immune responses, is of potential therapeutic interest. To this end, RORγt inhibition was assessed in combined skin, joint and gut inflammation in vivo, using a PsA model.

METHODS

We tested the efficacy of a RORγt antagonist in B10.RIII mice challenged with systemic overexpression of IL-23 by hydrodynamic injection of IL-23 enhanced episomal vector (IL-23 EEV). Clinical outcomes were evaluated by histopathology. Bone density and surface erosions were examined using micro-computed tomography. Cytokine production was measured in serum and by intracellular flow cytometry. Gene expression in PsA-related tissues was analysed by qPCR.

RESULTS

RORγt-blockade significantly ameliorated psoriasis, peripheral arthritis and colitis development in IL-23 EEV mice (improvement of clinical scores and weight loss respectively by 91.8%, 58.2% and 7.0%, P < 0.001), in line with profound suppression of an enhanced type IL-17 immune signature in PsA-affected tissues. Moreover, inflammation-induced bone loss and bone erosions were reduced (P < 0.05 in calcaneus, P < 0.01 in tibia). Sustained IL-23 overexpression resulted in only mild signs of sacroiliitis. Gamma-delta (γδ)-T cells, the dominant source of T cell-derived IL-17A and IL-22, were expanded during IL-23 overexpression, and together with Th17 cells, clearly countered by RORγt inhibition (P < 0.001).

CONCLUSION

RORγt-blockade shows therapeutic efficacy in a preclinical PsA model with protection towards extra-musculoskeletal manifestations, reflected by a clear attenuation of type 17 cytokine responses by γδ-T cells and Th17 cells.

Pathophysiology and immunolgical basis of axial spondyloarthritis

Over the recent years the wider availability and application of state-of-the-art immunological technologies greatly advanced the insight into the mechanisms that play an important role in axial spondyloarthritis (axSpA) pathophysiology. This increased understanding has facilitated the development of novel treatments that target disease relevant pathways, hereby improving outcome for axSpA patients. In axSpA pathophysiology genetic and environmental factors as well as immune activation by mechanical or bacterial stress resulting in a chronic inflammatory response have a central role. The TNF and IL-23/IL-17 immune pathways play a pivotal role in these disease mechanisms. This review provides an outline of the immunological basis of axSpA with a focus on key genetic risk factors and their link to activation of the pathological immune response, as well as on the role of the gut and entheses in the initiation of inflammation with subsequent new bone formation in axSpA.

The paradigm of IL-23-independent production of IL-17F and IL-17A and their role in chronic inflammatory diseases

Interleukin-17 family (IL-17s) comprises six structurally related members (IL-17A to IL-17F); sequence homology is highest between IL-17A and IL-17F, displaying certain overlapping functions. In general, IL-17A and IL-17F play important roles in chronic inflammation and autoimmunity, controlling bacterial and fungal infections, and signaling mainly through activation of the nuclear factor-kappa B (NF-κB) pathway. The role of IL-17A and IL-17F has been established in chronic immune-mediated inflammatory diseases (IMIDs), such as psoriasis (PsO), psoriatic arthritis (PsA), axial spondylarthritis (axSpA), hidradenitis suppurativa (HS), inflammatory bowel disease (IBD), multiple sclerosis (MS), and asthma. CD4+ helper T cells (Th17) activated by IL-23 are well-studied sources of IL-17A and IL-17F. However, other cellular subtypes can also produce IL-17A and IL-17F, including gamma delta (γδ) T cells, alpha beta (αβ) T cells, type 3 innate lymphoid cells (ILC3), natural killer T cells (NKT), or mucosal associated invariant T cells (MAIT). Interestingly, the production of IL-17A and IL-17F by innate and innate-like lymphocytes can take place in an IL-23 independent manner in addition to IL-23 classical pathway. This would explain the limitations of the inhibition of IL-23 in the treatment of patients with certain rheumatic immune-mediated conditions such as axSpA. Despite their coincident functions, IL-17A and IL-17F contribute independently to chronic tissue inflammation having somehow non-redundant roles. Although IL-17A has been more widely studied, both IL-17A and IL-17F are overexpressed in PsO, PsA, axSpA and HS. Therefore, dual inhibition of IL-17A and IL-17F could provide better outcomes than IL-23 or IL-17A blockade.

Hierarchical Synergistic Structure for High Resolution Strain Sensor with Wide Working Range

Strain sensors have been attracting tremendous attention for the promising application of wearable devices in recent years. However, the trade-off between high resolution, high sensitivity, and broad detection range is a great challenge for the application of strain sensors. Herein, a novel design of hierarchical synergistic structure (HSS) of Au micro cracks and carbon black (CB) nanoparticles is reported to overcome this challenge. The strain sensor based on the designed HSS exhibit high sensitivity (GF > 2400), high strain resolution (0.2%) even under large loading strain, broad detection range (>40%), outstanding stability (>12000 cycles), and fast response speed simultaneously. Further, the experiments and simulation results demonstrate that the carbon black layer greatly changed the morphology of Au micro-cracks, forming a hierarchical structure of micro-scale Au cracks and nano-scale carbon black particles, thus enabling synergistic effect and the double conductive network of Au micro-cracks and CB nanoparticles. Based on the excellent performance, the sensor is successfully applied to monitoring tiny signals of the carotid pulse during body movement, which illustrates the great potential in the application of health monitoring, human-machine interface, human motion detection, and electronic skin.

Topotecan alleviates acetic acid-induced ulcerative colitis in rats via attenuation of the RORγT transcription factor

AIMS

Ulcerative colitis is characterized as a chronic immune-mediated inflammatory condition, affecting the intestinal gastroenteric tissue. Previous studies revealed that Th-17 cells are key players in the pathogenesis of ulcerative colitis. RORγT (Retinoic-acid-receptor-related orphan receptor-gamma T) is a lineage-specific transcription factor of Th-17 cells and thus has a role in their differentiation. Transient inhibition of RORγT has been reported to attenuate the differentiation of Th-17 cells and secretion of interleukin-17 (IL-17). Here, we investigated the efficacy of topotecan in ameliorating ulcerative colitis in rodents, via inhibition of the RORγT transcription factor.

MAIN METHODS AND KEY FINDINGS

Experimental ulcerative colitis was induced in rats by intrarectal acetic acid administration. Topotecan attenuated the severity of ulcerative colitis in rats by revoking neutrophils and macrophage infiltration to the colon. It also alleviated diarrhea and rectal bleeding and improved body weight. Further, attenuation of RORγT and IL-17 expression was observed in topotecan treated animals. Levels of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β in the colon tissue were reduced by topotecan treatment. Significant reduction in malondialdehyde level, elevation of superoxide dismutase (SOD) and catalase activity was observed in the colon tissue of rats treated with topotecan compared to the diseased group.

SIGNIFICANCE

This study shows the therapeutic potential of topotecan in attenuating ulcerative colitis in rats probably via inhibition of the RORγT transcription factor and downstream mediators of Th-17 cells.

Pathogenic Role of IL-17 and Therapeutic Targeting of IL-17F in Psoriatic Arthritis and Spondyloarthropathies

The interleukin 17 (IL-17) family, a subset of cytokines consisting of IL-17A-F, plays crucial roles in host defence against microbial organisms and the development of inflammatory diseases, including psoriasis (PsO), axial spondyloarthritis (axSpA), and psoriatic arthritis (PsA). IL-17A is the signature cytokine produced by T helper 17 (Th17) cells and is considered the most biologically active form. The pathogenetic involvement of IL-17A in these conditions has been confirmed, and its blockade with biological agents has provided a highly effective therapeutical approach. IL-17F is also overexpressed in the skin and synovial tissues of patients with these diseases, and recent studies suggest its involvement in promoting inflammation and tissue damage in axSpA and PsA. The simultaneous targeting of IL-17A and IL-17F by dual inhibitors and bispecific antibodies may improve the management of Pso, PsA, and axSpA, as demonstrated in the pivotal studies of dual specific antibodies such as bimekizumab. The present review focuses on the role of IL-17F and its therapeutic blockade in axSpA and PsA.

Distinct innate and adaptive immunity phenotypic profile at the circulating single-cell level in Psoriatic Arthritis

Mass cytometry was employed to investigate 47 circulating leukocyte subsets in patients with active psoriatic arthritis (PsA, n = 16) compared to healthy controls (n = 13), seropositive (RF and/or anti-CCP, n = 12) and seronegative (n = 9) RA patients. Comparing PsA to controls, different cell frequencies were found in both innate and adaptive immunity cell subsets, as well as in cells bridging innate and adaptive immunity. In some T-cell subsets increased costimulatory molecules' expression in PsA, was also noted..No changes were observed in patients who remained disease-active after 3 months of treatment, in contrast to those who achieved remission/low-disease activity. Comparing PsA to seropositive RA, elevated frequencies of naïve and activated CD8⁺ T-cells, B-cells, MAIT/iNKT and ILCs were found, while the opposite was the case for terminal effector, senescent, and Th2-like-cells. Strikingly, the composition of the leukocyte pool in PsA was comparable to seronegative RA, providing evidence for the pathogenetic similarities between these two entities.

Recent Advances in Mechanical Vibration Energy Harvesters Based on Triboelectric Nanogenerators

With the development of autonomous/smart technologies and the Internet of Things (IoT), tremendous wireless sensor nodes (WSNs) are of great importance to realize intelligent mechanical engineering, which is significant in the industrial and social fields. However, current power supply methods, cable and battery for instance, face challenges such as layout difficulties, high cost, short life, and environmental pollution. Meanwhile, vibration is ubiquitous in machinery, vehicles, structures, etc., but has been regarded as an unwanted by-product and wasted in most cases. Therefore, it is crucial to harvest mechanical vibration energy to achieve in situ power supply for these WSNs. As a recent energy conversion technology, triboelectric nanogenerator (TENG) is particularly good at harvesting such broadband, weak, and irregular mechanical energy, which provides a feasible scheme for the power supply of WSNs. In this review, recent achievements of mechanical vibration energy harvesting (VEH) related to mechanical engineering based on TENG are systematically reviewed from the perspective of contact-separation (C-S) and freestanding modes. Finally, existing challenges and forthcoming development orientation of the VEH based on TENG are discussed in depth, which will be conducive to the future development of intelligent mechanical engineering in the era of IoT.

Pathways driving tendinopathy and enthesitis: siblings or distant cousins in musculoskeletal medicine?

Tendinopathy and enthesitis share clinical, anatomical, and molecular parallels. However, their relationship is complex, presenting challenges in diagnosis and treatment. The biomechanics underlying these pathologies, together with relative immune and stromal contributions to pathology, are characterised by crucial comparative elements. However, methodologies used to study enthesitis and tendinopathy have been divergent, which could account for discrepancies in how these conditions are perceived and treated. In this Review, we summarise key clinical parallels between these two common presentations in musculoskeletal medicine and address factors that currently preclude development of more effective therapeutics. Furthermore, we describe molecular similarities and disparities that govern pathological mechanisms in tendinopathy and enthesitis, thus informing translational studies and treatment strategies.

The Interleukine-17 Cytokine Family: Role in Development and Progression of Spondyloarthritis, Current and Potential Therapeutic Inhibitors

Spondyloarthritis (SpA) encompasses a group of chronic inflammatory rheumatic diseases with a predilection for the spinal and sacroiliac joints, which include axial spondyloarthritis, psoriatic arthritis, reactive arthritis, arthritis associated with chronic inflammatory bowel disease, and undifferentiated spondyloarthritis. The prevalence of SpA in the population varies from 0.5 to 2%, most commonly affecting young people. Spondyloarthritis pathogenesis is related to the hyperproduction of proinflammatory cytokines (TNFα, IL-17A, IL-23, etc.). IL-17A plays a key role in the pathogenesis of spondyloarthritis (inflammation maintenance, syndesmophites formation and radiographic progression, enthesites and anterior uveitis development, etc.). Targeted anti-IL17 therapies have established themselves as the most efficient therapies in SpA treatment. The present review summarizes literature data on the role of the IL-17 family in the pathogenesis of SpA and analyzes existing therapeutic strategies for IL-17 suppression with monoclonal antibodies and Janus kinase inhibitors. We also consider alternative targeted strategies, such as the use of other small-molecule inhibitors, therapeutic nucleic acids, or affibodies. We discuss advantages and pitfalls of these approaches and the future prospects of each method.