Generation of pathogenic T(H)17 cells in the absence of TGF-β signalling

Global research landscape and emerging trends in Graves' disease: A bibliometric analysis

BACKGROUND

Graves' disease is a prevalent thyroid disorder and is the primary cause of hyperthyroidism. Significant progress has been made in understanding the epidemiology, pathogenesis, diagnosis, treatment, and prognosis of this disease. However, bibliometric analyses on Graves' disease are lacking. We aimed to comprehensively summarize the research, progression, and focal points of Graves' disease through data mining and integrated analysis of the existing literature.

METHODS

We retrieved relevant literature on Graves' disease from 2003 to 2023 from the Web of Science database. We performed bibliometric analysis using CiteSpace and the R package Bibliometrix.

RESULTS

We identified 10,901 publications from 132 countries, with a steady rise in the number of publications over the past 5 years. The US leads in publication volume, with the University of California System being the primary contributing institution. The journal Thyroid had the highest publication output, while the Journal of Clinical Endocrinology and Metabolism was the most frequently cited. These publications involved 2305 authors, with Antonelli Alessandro and Smith Terry being the most prolific. The most frequently cited articles were the "2016 American Thyroid Association guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis" and the "Thyroid Association/European Group on Graves' orbitopathy guidelines for the management of Graves' orbitopathy." Analysis of the bursts of cited references, keywords, and their clustering revealed that research on Graves' disease predominantly centers on clinical management, thyroid-stimulating hormone receptors, thyroid hormones, autoimmunity and inflammation, Graves' ophthalmopathy, thyroid nodules, and thyroid cancer.

CONCLUSION

This is the first comprehensive bibliometric study to summarize progress and trends in Graves' disease research. These results highlight recent research hotspots and promising directions, thereby providing a valuable reference for other scholars.

Photodegradation enhances the toxic effect of anthracene on skin

Anthracene, a polycyclic aromatic hydrocarbon (PAH), is a widespread environmental pollutant that poses potential risks to human health. Exposure to anthracene can result in various adverse health effects, including skin-related disorders. Photo exposure sufficiently removes the anthracene from the environment but also generates more degradation products which can be more toxic. The goal of this study was to assess the change in anthracene dermotoxicity caused by photodegradation and understand the mechanism of this change. In the present study, over 99.99% of anthracene was degraded within 24 h of sunlight exposure, while producing many intermediate products including 9,10-anthraquinone and phthalic acid. The anthracene products with different durations of photo exposure were applied to 2D and 3D human keratinocyte cultures. Although the non-degraded anthracene significantly delayed the cell migration, the cell viability and differentiation decreased dramatically in the presence of the photodegraded anthracene. Anthracene photodegradation products also altered the expression patterns of a number of inflammation-related genes in comparison to the control cells. Among these genes, il1a, il1b, il8, cxcl2, s100a9, and mmp1 were upregulated whereas the tlr4 and mmp3 were downregulated by the photodegraded anthracene. Topical deliveries of the photodegraded and non-degraded anthracene to the dorsal skin of hairless mice showed more toxic effects by the photodegraded anthracene. The 4-hour photodegradation products of anthracene thickened the epidermal layer, increased the dermal cellularity, and induced the upregulation of inflammatory markers, il1a, il1b, s100a9, and mmp1. In addition, it also prevented the production of a gap junction protein, Connexin-43. All the evidence suggested that photodegradation enhanced the toxicities of anthracene to the skin. The 4-hour photodegradation products of anthracene led to clinical signs similar to acute inflammatory skin diseases, such as atopic and contact dermatitis, eczema, and psoriasis. Therefore, the potential risk of skin irritation by anthracene should be also considered when an individual is exposed to PAHs, especially in environments with strong sunlight.

Aging and Inflammation

Aging can be conceptualized as the progressive disequilibrium between stochastic damage accumulation and resilience mechanisms that continuously repair that damage, which eventually cause the development of chronic disease, frailty, and death. The immune system is at the forefront of these resilience mechanisms. Indeed, aging is associated with persistent activation of the immune system, witnessed by a high circulating level of inflammatory markers and activation of immune cells in the circulation and in tissue, a condition called "inflammaging." Like aging, inflammaging is associated with increased risk of many age-related pathologies and disabilities, as well as frailty and death. Herein we discuss recent advances in the understanding of the mechanisms leading to inflammaging and the intrinsic dysregulation of the immune function that occurs with aging. We focus on the underlying mechanisms of chronic inflammation, in particular the role of NF-κB and recent studies targeting proinflammatory mediators. We further explore the dysregulation of the immune response with age and immunosenescence as an important mechanistic immune response to acute stressors. We examine the role of the gastrointestinal microbiome, age-related dysbiosis, and the integrated stress response in modulating the inflammatory "response" to damage accumulation and stress. We conclude by focusing on the seminal question of whether reducing inflammation is useful and the results of related clinical trials. In summary, we propose that inflammation may be viewed both as a clinical biomarker of the failure of resilience mechanisms and as a causal factor in the rising burden of disease and disabilities with aging. The fact that inflammation can be reduced through nonpharmacological interventions such as diet and exercise suggests that a life course approach based on education may be a successful strategy to increase the health span with few adverse consequences.

Immuno-metabolic reprogramming of T cell: a new frontier for pharmacotherapy of Rheumatoid arthritis

Rheumatoid arthritis (RA) is a persistent autoimmune condition characterized by ongoing inflammation primarily affecting the synovial joint. This inflammation typically arises from an increase in immune cells such as neutrophils, macrophages, and T cells (TC). TC is recognized as a major player in RA pathogenesis. The involvement of HLA-DRB1 and PTPN-2 among RA patients confirms the TC involvement in RA. Metabolism of TC is maintained by various other factors like cytokines, mitochondrial proteins & other metabolites. Different TC subtypes utilize different metabolic pathways like glycolysis, oxidative phosphorylation and fatty acid oxidation for their activation from naive TC (T0). Although all subsets of TC are not deleterious for synovium, some subsets of TC are involved in joint repair using their anti-inflammatory properties. Hence artificially reprogramming of TC subset by interfering with their metabolic status poised a hope in future to design new molecules against RA.

QingChang-XiaoPi decoction ameliorates intestinal inflammation of ulcerative colitis by regulating the pathogenicity of Th17 cells

BACKGROUND

QingChang-XiaoPi Decoction (QCXPY), a Chinese herbal prescription, has been employed in the treatment of ulcerative colitis (UC) in China. However, its molecular mechanism of action in UC remains unclear.

PURPOSE

To elucidate the therapeutic effects of QCXPY against UC and reveal its mechanism of action.

STUDY DESIGN

We conducted a single-arm observation to evaluate the clinical efficacy of QCXPY in patients with mild-to-moderate UC. Inclusion and exclusion criteria were established to ensure the eligibility of participants, with a focus on excluding patients with specific conditions or complications that could confound the results.

METHODS

The expression of inflammatory factors in patients' serum was detected using a Luminex assay. The main components of QCXPY were identified using UHPLC-Q-TOF-MS. Network pharmacology was employed to predict potential therapeutic targets and their mechanisms of action. The efficacy of QCXPY was evaluated using a dextran sulfate sodium (DSS)-induced mouse model. Disease activity index (DAI), histopathological score, cytokine detection by ELISA, T-helper 17 (Th17) cell proportion by flow cytometry, expression of the IL-23/IL-17 axis, and changes in the levels of its downstream effectors were detected by immunohistochemistry, immunofluorescence, and western blotting.

RESULTS

QCXPY could alleviate the symptoms of diarrhea, abdominal pain, abdominal distension, and purulent stool in patients with mild-to-moderate UC. Moreover, it reduced the expression of IL-6, IL-17, and IL-23 in serum; alleviated DSS-induced experimental colitis in mice; reduced DAI, pathological scores, and the expressions of IL-6, IL-17, and IL-23 in colon tissue; and decreased the proportion of pathogenic Th17 cells and the expression of STAT3 and phospho-STAT3.

CONCLUSION

This study confirmed for the first time that QCXPY could alleviate intestinal symptoms, reduce the levels of serum inflammatory factors, and improve the quality of life of patients with mild-to-moderate UC. Its mechanism of action may involve reducing the secretion of inflammatory cytokines, moderating the pathogenicity of Th17 cells, and inhibiting STAT3 phosphorylation, thereby alleviating intestinal inflammation in UC.

The role of CD4+ T cells in visceral leishmaniasis; new and emerging roles for NKG7 and TGFβ

Visceral leishmaniasis is a potentially devastating neglected tropical disease caused by the protozoan parasites Leishmania donovani and L. infantum (chagasi). These parasites reside in tissue macrophages and survive by deploying a number of mechanisms aimed at subverting the host immune response. CD4+ T cells play an important role in controlling Leishmania parasites by providing help in the form of pro-inflammatory cytokines to activate microbiocidal pathways in infected macrophages. However, because these cytokines can also cause tissue damage if over-produced, regulatory immune responses develop, and the balance between pro-inflammatory and regulatory CD4+ T cells responses determines the outcomes of infection. Past studies have identified important roles for pro-inflammatory cytokines such as IFNγ and TNF, as well as regulatory co-inhibitory receptors and the potent anti-inflammatory cytokine IL-10. More recently, other immunoregulatory molecules have been identified that play important roles in CD4+ T cell responses during VL. In this review, we will discuss recent findings about two of these molecules; the NK cell granule protein Nkg7 and the anti-inflammatory cytokine TGFβ, and describe how they impact CD4+ T cell functions and immune responses during visceral leishmaniasis.

Small extracellular vesicles derived from human mesenchymal stem cells prevent Th17-dominant neutrophilic airway inflammation via immunoregulation on Th17 cells

Type 17 helper T cells (Th17)-dominant neutrophilic airway inflammation is critical in the pathogenesis of steroid-resistant airway inflammation such as severe asthma. Small extracellular vesicles (sEV) derived from human mesenchymal stem cells (MSCs) display extensive therapeutic effects and advantages in many diseases. However, the role of MSC-sEV in Th17-dominant neutrophilic airway inflammation and the related mechanisms are still poorly studied. Here we found that MSC-sEV significantly alleviated the infiltration of inflammatory cells in peribronchial interstitial tissues and reduced levels of inflammatory cells, especially neutrophils, in bronchoalveolar lavage fluids (BALF) of mice with neutrophilic airway inflammation. Consistently, MSC-sEV significantly decreased levels of IL-17A in BALF and Th17 in lung tissues. Furthermore, we found that labelled MSC-sEV were taken up by human CD4+ T cells most obviously at 12 h after incubation, and distributed mostly in mouse lungs. More importantly, potential signaling pathways involved in the MSC-sEV mediated inhibition of Th17 polarization were found using RNA sequencing. Using Western blot, JAK2-STAT3 pathway was identified as an important role in the inhibition of Th17 polarization by MSC-sEV. We found that proteins in MSC-sEV were mostly involved in the therapeutic effects of MSC-sEV. In total, our study suggested that MSC-sEV could be a potential therapeutic strategy for the treatment of neutrophilic airway inflammation.

Stem-like T cells in cancer and autoimmunity

Stem-like T cells are characterized by their ability to self-renew, survive long-term, and give rise to a heterogeneous pool of effector and memory T cells. Recent advances in single-cell RNA-sequencing (scRNA-seq) and lineage tracing technologies revealed an important role for stem-like T cells in both autoimmunity and cancer. In cancer, stem-like T cells constitute an important arm of the anti-tumor immune response by giving rise to effector T cells that mediate tumor control. In contrast, in autoimmunity stem-like T cells perform an unfavorable role by forming a reservoir of long-lived autoreactive cells that replenish the pathogenic, effector T-cell pool and thereby driving disease pathology. This review provides background on the discovery of stem-like T cells and their function in cancer and autoimmunity. Moreover, the influence of the microbiota and metabolism on the stem-like T-cell pool is summarized. Lastly, the implications of our knowledge about stem-like T cells for clinical treatment strategies for cancer and autoimmunity will be discussed.

Clinical drug screening reveals clofazimine potentiates the efficacy while reducing the toxicity of anti-PD-1 and CTLA-4 immunotherapy

Emerging as the most potent and durable combinational immunotherapy, dual anti-PD-1 and CTLA-4 immune checkpoint blockade (ICB) therapy notoriously increases grade 3-5 immune-related adverse events (irAEs) in patients. Accordingly, attempts to improve the antitumor potency of anti-PD-1+CTLA-4 ICB by including additional therapeutics have been largely discouraged due to concerns of further increasing fatal toxicity. Here, we screened ∼3,000 Food and Drug Administration (FDA)-approved drugs and identified clofazimine as a potential third agent to optimize anti-PD-1+CTLA-4 ICB. Remarkably, clofazimine outperforms ICB dose reduction or steroid treatment in reversing lethality of irAEs, but unlike the detrimental effect of steroids on antitumor efficacy, clofazimine potentiates curative responses in anti-PD-1+CTLA-4 ICB. Mechanistically, clofazimine promotes E2F1 activation in CD8+ T cells to overcome resistance and counteracts pathogenic Th17 cells to abolish irAEs. Collectively, clofazimine potentiates the antitumor efficacy of anti-PD-1+CTLA-4 ICB, curbs intractable irAEs, and may fill a desperate clinical need to improve patient survival.

A TH17-intrinsic IL-1β-STAT5 axis drives steroid resistance in autoimmune neuroinflammation

Steroid resistance poses a major challenge for the management of autoimmune neuroinflammation. T helper 17 (TH17) cells are widely implicated in the pathology of steroid resistance; however, the underlying mechanisms are unknown. In this study, we identified that interleukin-1 receptor (IL-1R) blockade rendered experimental autoimmune encephalomyelitis (EAE) mice sensitive to dexamethasone (Dex) treatment. Interleukin-1β (IL-1β) induced a signal transducer and activator of transcription 5 (STAT5)-mediated steroid-resistant transcriptional program in TH17 cells, which promoted inflammatory cytokine production and suppressed Dex-induced anti-inflammatory genes. TH17-specific deletion of STAT5 ablated the IL-1β-induced steroid-resistant transcriptional program and rendered EAE mice sensitive to Dex treatment. IL-1β synergized with Dex to promote the STAT5-dependent expression of CD69 and the development of central nervous system (CNS)-resident CD69+ TH17 cells. Combined IL-1R blockade and Dex treatment ablated CNS-resident TH17 cells, reduced EAE severity, and prevented relapse. CD69+ tissue-resident TH17 cells were also detected in brain lesions of patients with multiple sclerosis. These findings (i) demonstrate that IL-1β-STAT5 signaling in TH17 cells mediates steroid resistance and (ii) identify a therapeutic strategy for reversing steroid resistance in TH17-mediated CNS autoimmunity.

Transforming growth factors β and their signaling pathway in renal cell carcinoma and peritumoral space-transcriptome analysis

PURPOSE

The aim of the study was to verify hypotheses: Are transforming growth factors TGFβ1-3, their receptors TGFβI-III, and intracellular messenger proteins Smad1-7 involved in the pathogenesis of kidney cancer? What is the expression of genes of the TGFβ/Smads pathway in renal cell carcinoma (RCC) tissues, peritumoral tissues (TME; tumor microenvironment), and in normal kidney (NK) tissue?.

METHODS

Twenty patients with RCC who underwent total nephrectomy were included into the molecular analysis. The mRNA expression of the genes was quantified by RT-qPCR.

RESULTS

The study showed that the expression of the genes of TGFβ/Smads pathway is dysregulated in both RCC and the TME: TGFβ1, TGFβ3 expression is increased in the TME in comparison to the NK tissues; TGFβ2, TGFβ3, TGFβRI, TGFβRIII, Smad1, Smad2, Smad3, and Smad6 are underexpressed in RCC comparing to the TME tissues; TGFβRI, TGFβRIII, and Smad2 are underexpressed in RCC in comparison to the NK tissues.

CONCLUSION

On the one hand, the underexpression of the TGFβ signaling pathway genes within the malignant tumor may result in the loss of the antiproliferative and pro-apoptotic activity of this cytokine. On the other hand, the overexpression of the TGFβ/Smads pathway genes in the TME than in tumor or NK tissues most probably results in an immunosuppressive effect in the space surrounding the tumor and may have an antiproliferative and pro-apoptotic effect on non-neoplastic cells present in the TME. The functional and morphological consistency of this area may determine the aggressiveness of the tumor and the time in which the neoplastic process will spread.

The Dysregulated IL-23/TH17 Axis in Endometriosis Pathophysiology

Endometriosis is a chronic inflammatory disease in which endometrial-like tissue grows ectopically, resulting in pelvic pain and infertility. IL-23 is a key contributor in the development and differentiation of TH17 cells, driving TH17 cells toward a pathogenic profile. In a variety of inflammatory and autoimmune disorders, TH17 cells secrete proinflammatory cytokines, including IL-17, contributing to disease pathophysiology. Our studies and others have implicated IL-17 and TH17 cell dysregulation in endometriosis, which is associated with disease severity. In this article, we address whether IL-23-driven TH17 cells contribute to cardinal features of lesion proliferation, vascularization, and inflammation in endometriosis using patient samples, representative cell lines, and our established mouse model of endometriosis. The results indicated dysregulated expression of key genes in the IL-23/TH17 axis in patient ectopic and eutopic endometrial samples and increased IL-23 protein in patient plasma compared with controls. In vitro studies using primary human TH cells determined that rIL-23 mixture treatment increased pathogenic TH17 cell frequency. Similarly, rIL-23 treatment of cell lines (12Z cells, EECCs, HUVECs, and hESCs) representative of the endometriotic lesion microenvironment increased cytokines and growth factors, which play a role in lesion establishment and maintenance. In a syngeneic mouse model of endometriosis, rIL-23 treatment altered numbers of myeloid and T cell subsets in peritoneal fluid and increased giant cells within the lesion. Lesions from rIL-23-treated mice did not reveal significant alterations in proliferation/vascularization, although trends of increased proliferation and vascularization were observed. Collectively, these findings provide insights into the impact of the IL-23/TH17 axis on local immune dysfunction and broadly on endometriosis pathophysiology.

Single-cell clonal tracing of glandular and circulating T cells identifies a population of CD9+ CD8+ T cells in primary Sjogren's syndrome

Primary Sjogren's syndrome (pSS) is a complex chronic autoimmune disease in which local tissue damage in exocrine glands is combined with broader systemic involvement across the body in tissues including the skin. These combined manifestations negatively impact patient health and quality of life. While studies have previously reported differences in immune cell composition in the peripheral blood of pSS patients relative to healthy control subjects, a detailed immune cell landscape of the damaged exocrine glands of these patients remains lacking. Through single-cell transcriptomics and repertoire sequencing of immune cells in paired peripheral blood samples and salivary gland biopsies, we present here a preliminary picture of adaptive immune response in pSS. We characterize a number of points of divergence between circulating and glandular immune responses that have been hitherto underappreciated, and identify a novel population of CD8+ CD9+ cells with tissue-residential properties that are highly enriched in the salivary glands of pSS patients. Through comparative analyses with other sequencing data, we also observe a potential connection between these cells and the tissue-resident memory cells found in cutaneous vasculitis lesions. Together, these results indicate a potential role for CD8+ CD9+ cells in mediating glandular and systemic effects associated with pSS and other autoimmune disorders.

Sphingolipid biosynthesis is essential for metabolic rewiring during TH17 cell differentiation

T helper 17 (TH17) cells are implicated in autoimmune diseases, and several metabolic processes are shown to be important for their development and function. In this study, we report an essential role for sphingolipids synthesized through the de novo pathway in TH17 cell development. Deficiency of SPTLC1, a major subunit of serine palmitoyl transferase enzyme complex that catalyzes the first and rate-limiting step of de novo sphingolipid synthesis, impaired glycolysis in differentiating TH17 cells by increasing intracellular reactive oxygen species (ROS) through enhancement of nicotinamide adenine dinucleotide phosphate oxidase 2 activity. Increased ROS leads to impaired activation of mammalian target of rapamycin C1 and reduced expression of hypoxia-inducible factor 1-alpha and c-Myc-induced glycolytic genes. SPTLCI deficiency protected mice from developing experimental autoimmune encephalomyelitis and experimental T cell transfer colitis. Our results thus show a critical role for de novo sphingolipid biosynthetic pathway in shaping adaptive immune responses with implications in autoimmune diseases.

IL-23 past, present, and future: a roadmap to advancing IL-23 science and therapy

Interleukin (IL)-23, an IL-12 cytokine family member, is a hierarchically dominant regulatory cytokine in a cluster of immune-mediated inflammatory diseases (IMIDs), including psoriasis, psoriatic arthritis, and inflammatory bowel disease. We review IL-23 biology, IL-23 signaling in IMIDs, and the effect of IL-23 inhibition in treating these diseases. We propose studies to advance IL-23 biology and unravel differences in response to anti-IL-23 therapy. Experimental evidence generated from these investigations could establish a novel molecular ontology centered around IL-23-driven diseases, improve upon current approaches to treating IMIDs with IL-23 inhibition, and ultimately facilitate optimal identification of patients and, thereby, outcomes.

Epithelial regulation of microbiota-immune cell dynamics

The mammalian gastrointestinal tract hosts a diverse community of trillions of microorganisms, collectively termed the microbiota, which play a fundamental role in regulating tissue physiology and immunity. Recent studies have sought to dissect the cellular and molecular mechanisms mediating communication between the microbiota and host immune system. Epithelial cells line the intestine and form an initial barrier separating the microbiota from underlying immune cells, and disruption of epithelial function has been associated with various conditions ranging from infection to inflammatory bowel diseases and cancer. From several studies, it is now clear that epithelial cells integrate signals from commensal microbes. Importantly, these non-hematopoietic cells also direct regulatory mechanisms that instruct the recruitment and function of microbiota-sensitive immune cells. In this review, we discuss the central role that has emerged for epithelial cells in orchestrating intestinal immunity and highlight epithelial pathways through which the microbiota can calibrate tissue-intrinsic immune responses.

Interplay of Cytokines and Chemokines in Aspergillosis

Aspergillosis is a fungal infection caused by various species of Aspergillus, most notably A. fumigatus. This fungus causes a spectrum of diseases, including allergic bronchopulmonary aspergillosis, aspergilloma, chronic pulmonary aspergillosis, and invasive aspergillosis. The clinical manifestations and severity of aspergillosis can vary depending on individual immune status and the specific species of Aspergillus involved. The recognition of Aspergillus involves pathogen-associated molecular patterns (PAMPs) such as glucan, galactomannan, mannose, and conidial surface proteins. These are recognized by the pathogen recognition receptors present on immune cells such as Toll-like receptors (TLR-1,2,3,4, etc.) and C-type lectins (Dectin-1 and Dectin-2). We discuss the roles of cytokines and pathogen recognition in aspergillosis from both the perspective of human and experimental infection. Several cytokines and chemokines have been implicated in the immune response to Aspergillus infection, including interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), CCR4, CCR17, and other interleukins. For example, allergic bronchopulmonary aspergillosis (ABPA) is characterized by Th2 and Th9 cell-type immunity and involves interleukin (IL)-4, IL-5, IL-13, and IL-10. In contrast, it has been observed that invasive aspergillosis involves Th1 and Th17 cell-type immunity via IFN-γ, IL-1, IL-6, and IL-17. These cytokines activate various immune cells and stimulate the production of other immune molecules, such as antimicrobial peptides and reactive oxygen species, which aid in the clearance of the fungal pathogen. Moreover, they help to initiate and coordinate the immune response, recruit immune cells to the site of infection, and promote clearance of the fungus. Insight into the host response from both human and animal studies may aid in understanding the immune response in aspergillosis, possibly leading to harnessing the power of cytokines or cytokine (receptor) antagonists and transforming them into precise immunotherapeutic strategies. This could advance personalized medicine.

Single-Molecule DNA Methylation Reveals Unique Epigenetic Identity Profiles of T Helper Cells

Both identity and plasticity of CD4 T helper (Th) cells are regulated in part by epigenetic mechanisms. However, a method that reliably and readily profiles DNA base modifications is still needed to finely study Th cell differentiation. Cytosine methylation in CpG context (5mCpG) and cytosine hydroxymethylation (5hmCpG) are DNA modifications that identify stable cell phenotypes, but their potential to characterize intermediate cell transitions has not yet been evaluated. To assess transition states in Th cells, we developed a method to profile Th cell identity using Cas9-targeted single-molecule nanopore sequencing. Targeting as few as 10 selected genomic loci, we were able to distinguish major in vitro polarized murine T cell subtypes, as well as intermediate phenotypes, by their native DNA 5mCpG patterns. Moreover, by using off-target sequences, we were able to infer transcription factor activities relevant to each cell subtype. Detection of 5mCpG and 5hmCpG was validated on intestinal Th17 cells escaping transforming growth factor β control, using single-molecule adaptive sampling. A total of 21 differentially methylated regions mapping to the 10-gene panel were identified in pathogenic Th17 cells relative to their nonpathogenic counterpart. Hence, our data highlight the potential to exploit native DNA methylation profiling to study physiological and pathological transition states of Th cells.

Hedgehog signalling in CD4+ T helper cell polarisation

CD4+ T cells are critical in orchestrating immune responses against various pathogens and cancer but can also be drivers of autoimmune disease, allergy and pro-tumour responses. Naïve CD4+ T cells polarise into specialised T helper cell subsets with unique effector functions. While the guiding transcription factors and effector molecules of the T helper cell lineages are well understood, the signalling pathways orchestrating the intricate T helper cell polarisation programmes remain poorly understood. Here we review an emerging role of Hedgehog signalling - a classical morphogen signalling pathway - in T helper cell polarisation. Importantly, the Hedgehog pathway is pharmacologically highly tractable and existing clinically-approved Hedgehog inhibitors may prove useful therapeutic modulators of T helper cell-driven immune responses.

TPN10475 Constrains Effector T Lymphocytes Activation and Attenuates Experimental Autoimmune Encephalomyelitis Pathogenesis by Facilitating TGF-β Signal Transduction

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) mediated by immune cells, in which auto-reactive CD4+ T cells have been implicated as a major driver in the pathogenesis of the disease. In this study, we aimed to investigate whether the artemisinin derivative TPN10475 could alleviate experimental autoimmune encephalomyelitis (EAE), a commonly used animal model of MS and its possible mechanisms. TPN10475 effectively resisted the reduction of TGF-β signal transduction induced by TCR stimulation, suppressed the activation and function of effector CD4+ T cells in vitro, and restricted the differentiation of pathogenic Th1 and Th17 cells. It was also found to negatively regulate the inflammatory response in EAE by reducing the peripheral activation drive of auto-reactive helper T lymphocytes, inhibiting the migration of inflammatory cells into the CNS to attenuate EAE. The above results suggested that the upregulation of TGF-β signal transduction may provide new ideas for the study of MS pathogenesis and have positive implications for the development of drugs for the treatment of autoimmune diseases.

TH17 cell: a double-edged sword in the development of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic nonspecific inflammatory disease of the gastrointestinal tract, and its pathogenesis has not been fully understood. Extensive dysregulation of the intestinal mucosal immune system is critical in the development and progression of IBD. T helper (Th) 17 cells have the characteristics of plasticity. They can transdifferentiate into subpopulations with different functions in response to different factors in the surrounding environment, thus taking on different roles in regulating the intestinal immune responses. In this review, we will focus on the plasticity of Th17 cells as well as the function of Th17 cells and their related cytokines in IBD. We will summarize their pathogenic and protective roles in IBD under different conditions, respectively, hoping to further deepen the understanding of the pathological mechanisms underlying IBD and provide insights for future treatment.

Role of the NLRP1 inflammasome in skin cancer and inflammatory skin diseases

Inflammasomes are cytoplasmic protein complexes that play a crucial role in protecting the host against pathogenic and sterile stressors by initiating inflammation. Upon activation, these complexes directly regulate the proteolytic processing and activation of proinflammatory cytokines interleukin (IL)-1β and IL-18 to induce a potent inflammatory response, and induce a programmed form of cell death called pyroptosis to expose intracellular pathogens to the surveillance of the immune system, thus perpetuating inflammation. There are various types of inflammasome complexes, with the NLRP1 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-1) inflammasome being the first one identified and currently recognized as the predominant inflammasome sensor protein in human keratinocytes. Human NLRP1 exhibits a unique domain structure, containing both an N-terminal pyrin (PYD) domain and an effector C-terminal caspase recruitment domain (CARD). It can be activated by diverse stimuli, such as viruses, ultraviolet B radiation and ribotoxic stress responses. Specific mutations in NLRP1 or related genes have been associated with rare monogenic skin disorders, such as multiple self-healing palmoplantar carcinoma; familial keratosis lichenoides chronica; autoinflammation with arthritis and dyskeratosis; and dipeptidyl peptidase 9 deficiency. Recent research breakthroughs have also highlighted the involvement of dysfunctions in the NLRP1 pathway in a handful of seemingly unrelated dermatological conditions. These range from monogenic autoinflammatory diseases to polygenic autoimmune diseases such as vitiligo, psoriasis, atopic dermatitis and skin cancer, including squamous cell carcinoma, melanoma and Kaposi sarcoma. Additionally, emerging evidence implicates NLRP1 in systemic lupus erythematosus, pemphigus vulgaris, Addison disease, Papillon-Lefèvre syndrome and leprosy. The aim of this review is to shed light on the implications of pathological dysregulation of the NLRP1 inflammasome in skin diseases and investigate the potential rationale for targeting this pathway as a future therapeutic approach.

Dysregulated autotaxin expression by T cells in multiple sclerosis

Multiple sclerosis (MS) is a demyelinating disease characterized by infiltration of autoreactive T cells into the central nervous system (CNS). In order to understand how activated, autoreactive T cells are able to cross the blood brain barrier, the unique molecular characteristics of pathogenic T cells need to be more thoroughly examined. In previous work, our laboratory found autotaxin (ATX) to be upregulated by activated autoreactive T cells in the mouse model of MS. ATX is a secreted glycoprotein that promotes T cell chemokinesis and transmigration through catalysis of lysophoshphatidic acid (LPA). ATX is elevated in the serum of MS patients during active disease phases, and we previously found that inhibiting ATX decreases severity of neurological deficits in the mouse model. In this study, ATX expression was found to be lower in MS patient immune cells during rest, but significantly increased during early activation in a manner not seen in healthy controls. The ribosomal binding protein HuR, which stabilizes ATX mRNA, was also increased in MS patients in a similar pattern to that of ATX, suggesting it may be helping regulate ATX levels after activation. The proinflammatory cytokine interleukin-23 (IL-23) was shown to induce prolonged ATX expression in MS patient Th1 and Th17 cells. Finally, through ChIP, re-ChIP analysis, we show that IL-23 may be signaling through pSTAT3/pSTAT4 heterodimers to induce expression of ATX. Taken together, these findings elucidate cell types that may be contributing to elevated serum ATX levels in MS patients and identify potential drivers of sustained expression in encephalitogenic T cells.

HMGB1 regulates Th17 cell differentiation and function in patients with psoriasis

BACKGROUND

Psoriasis is an immune-mediated chronic inflammatory skin disease, in which T helper 17 (Th17) cells and its effective cytokine interleukin (IL)-17A play a pivotal pathogenic role. High mobility group box 1 (HMGB1) is an important proinflammatory cytokine, which has been confirmed to be highly expressed in the peripheral circulation and epidermis tissues of psoriasis patients. The regulatory effect of HMGB1 on IL-17A expression and function has been reported in some inflammatory and autoimmune diseases by the HMGB1-Toll-like receptor 4 (TLR4)-interleukin (IL)-23-IL-17A pathway. While, in the pathological environment of psoriasis, whether HMGB1 can exert the regulatory effect on IL-17A is not clear.

OBJECTIVE

We aimed to evaluate the role of HMGB1-TLR4-IL-23-IL-17A pathway in the pathogenesis of psoriasis and explore the possible regulatory mechanism of HMGB1 on Th17 cell differentiation.

METHODS

Serum levels of HMGB1, TLR4, IL-23, and IL-17A were quantified in 50 patients with moderate-to-severe plaque psoriasis and 30 healthy controls. Peripheral blood mononuclear cells  were acquired from 10 severe psoriasis patients and administrated by different concentrations of recombinant-HMGB1 (rHMGB1) to detect the Th17 cell percentage, mRNA and protein levels of TLR4, IL-23, IL-17A and retinoid-related orphan receptor γt (RORγt).

RESULTS

The serum levels of HMGB1, TLR4, IL-23, and IL-17A in psoriasis patients were significantly higher than healthy controls, especially in severe patients, and positively correlated with the severity index. There were also positive correlations between every two detected indicators of HMGB1, TLR4, IL-23, and IL-17A. In vitro study, rHMGB1 can promote the elevated expression of Th17 cell percentage as well as TLR4, IL-23, IL-17A, and RORγt in a dose-dependent manner.

CONCLUSION

HMGB1 can contribute to the pathogenesis of psoriasis by regulating Th17 cell differentiation through HMGB1-TLR4-IL-23-RORγt pathway, then promotes IL-17A production and aggravates inflammation process. Targeting HMGB1 may be a possible potential candidate for the immunotherapy of psoriasis.

Th17 cell promotes apoptosis of IL-23R+ neurons in experimental autoimmune encephalomyelitis

Myelin antigen-reactive Th1 and Th17 cells are critical drivers of central nervous system (CNS) autoimmune inflammation. Transcription factors T-bet and RORγt play a crucial role in the differentiation and function of Th1 and Th17 cells, and impart them a pathogenic role in CNS autoimmune inflammation. Mice deficient in these two factors do not develop experimental autoimmune encephalomyelitis (EAE). While T-bet and RORγt are known to regulate the expression of several cell adhesion and migratory molecules in T cells, their role in supporting Th1 and Th17 trafficking to the CNS is not completely understood. More importantly, once Th1 and Th17 cells reach the CNS, how the function of these transcription factors modulates the local inflammatory response during EAE is unclear. In the present study, we showed that myelin oligodendrocyte glycoprotein 35-55 peptide (MOG35-55)-specific Th1 cells deficient in RORγt could cross the blood-brain barrier (BBB) but failed to induce demyelination, apoptosis of neurons, and EAE. Pathogenic Th17 cell-derived cytokines GM-CSF, TNF-α, IL-17A, and IL-21 significantly increased the surface expression of IL-23R on neuronal cells. Furthermore, we showed that, in EAE, neurons in the brain and spinal cord express IL-23R. IL-23-IL-23R signaling in neuronal cells caused phosphorylation of STAT3 (Ser727 and Tyr705) and induced cleaved caspase 3 and cleaved poly (ADP-ribose) polymerase-1 (PARP-1) molecules in an IL-23R-dependent manner and caused apoptosis. Thus, we provided a mechanism showing that T-bet is required to recruit pathogenic Th17 cells to the CNS and RORγt-mediated inflammatory response to drive the apoptosis of IL-23R+ neurons in the CNS and cause EAE. Understanding detailed molecular mechanisms will help to design better strategies to control neuroinflammation and autoimmunity. ONE SENTENCE SUMMARY: IL-23-IL-23R signaling promotes apoptosis of CNS neurons.

Glutaminolysis of CD4+ T Cells: A Potential Therapeutic Target in Viral Diseases

CD4+ T cells play a critical role in the pathogenesis of viral diseases, which are activated by the internal metabolic pathways encountering with viral antigens. Glutaminolysis converts glutamine into tricarboxylic acid (TCA) circulating metabolites by α-ketoglutaric acid, which is essential for the proliferation and differentiation of CD4+ T cells and plays a central role in providing the energy and structural components needed for viral replication after the virus hijacks the host cell. Changes in glutaminolysis in CD4+ T cells are accompanied by changes in the viral status of the host cell due to competition for glutamine between immune cells and host cells. More recently, attempts have been made to treat tumours, autoimmune diseases, and viral diseases by altering the breakdown of glutamine in T cells. In this review, we will discuss the current knowledge of glutaminolysis in the CD4+ T cell subsets from viral diseases, not only increasing our understanding of immunometabolism but also providing a new perspective for therapeutic target in viral diseases.

Notch signaling regulates Th17 cells differentiation through PI3K/AKT/mTORC1 pathway and involves in the thyroid injury of autoimmune thyroiditis

PURPOSE

Autoimmune Thyroiditis (AIT) is the most common thyroid disease; however, there were no measures to prevent the progression of the disease. The present study attempts to identify that Notch signaling regulates the differentiation of T helper 17 (Th17) cells by activating downstream Phosphatidylinositol-3 kinase/protein kinase/mechanistic target of rapamycin complex 1 (PI3K/AKT/mTORC1) pathway participating in the thyroid injury of the experimental autoimmune thyroiditis (EAT).

METHODS

In vivo experiments, mice were randomly divided into 4 groups: a control group, an EAT group, and two groups with LY294002 treatment (pTg plus 25 mg/kg or 50 mg/kg LY294002, respectively). The degrees of thyroiditis were evaluated, and the percentage of Th17 cells, expression of interleukin-17A (IL-17A), and the main components of the Notch-PI3K signaling pathway were detected in different groups. In vitro experiments, two different dosages of LY294002 (25 and 50 μM) were used to intervene splenic mononuclear cells (SMCs) from EAT mice to further evaluate the regulatory effect of Notch-PI3K pathway on Th17 cells.

RESULTS

Our data demonstrate that the infiltration of Th17 cells and the expressions of IL-17A, Notch, hairy and split 1 (Hes1), p‑AKT (Ser473), p‑AKT (Thr308), p‑mTOR (Ser2448), S6K1, and S6K2 increased remarkably in EAT mice. After PI3K pathway was blocked, the degrees of thyroiditis were significantly alleviated, and the proportion of Th17 cells, the expression of IL-17A, and the above Notch-PI3K pathway-related molecules decreased in a dose-dependent manner. Additionally, the proportion of Th17 cells was positively correlated with the concentration of serum thyroglobulin antibody (TgAb), IL-17A, and Notch-PI3K pathway-related molecules mRNA levels.

CONCLUSIONS

Notch signal promotes the secretion of IL-17A from Th17 cells by regulating the downstream PI3K/AKT/mTORC1 pathway through Hes-Phosphatase and tensin homolog (PTEN) and participates in thyroid autoimmune damage, and the PI3K pathway inhibitor may play important effects on AIT by affecting Th17 cells differentiation.

The brain cytokine orchestra in multiple sclerosis: from neuroinflammation to synaptopathology

The central nervous system (CNS) is finely protected by the blood-brain barrier (BBB). Immune soluble factors such as cytokines (CKs) are normally produced in the CNS, contributing to physiological immunosurveillance and homeostatic synaptic scaling. CKs are peptide, pleiotropic molecules involved in a broad range of cellular functions, with a pivotal role in resolving the inflammation and promoting tissue healing. However, pro-inflammatory CKs can exert a detrimental effect in pathological conditions, spreading the damage. In the inflamed CNS, CKs recruit immune cells, stimulate the local production of other inflammatory mediators, and promote synaptic dysfunction. Our understanding of neuroinflammation in humans owes much to the study of multiple sclerosis (MS), the most common autoimmune and demyelinating disease, in which autoreactive T cells migrate from the periphery to the CNS after the encounter with a still unknown antigen. CNS-infiltrating T cells produce pro-inflammatory CKs that aggravate local demyelination and neurodegeneration. This review aims to recapitulate the state of the art about CKs role in the healthy and inflamed CNS, with focus on recent advances bridging the study of adaptive immune system and neurophysiology.

Regulated Cell Death in Endometriosis

Regulated cell death (RCD) represents a distinct mode of cell demise, differing from accidental cell death (ACD), characterized by specific signaling cascades orchestrated by diverse biomolecules. The regular process of cell death plays a crucial role in upholding internal homeostasis, acting as a safeguard against biological or chemical damage. Nonetheless, specific programmed cell deaths have the potential to activate an immune-inflammatory response, potentially contributing to diseases by enlisting immune cells and releasing pro-inflammatory factors. Endometriosis, a prevalent gynecological ailment, remains incompletely understood despite substantial progress in unraveling associated signaling pathways. Its complexity is intricately tied to the dysregulation of inflammatory immune responses, with various RCD processes such as apoptosis, autophagic cell death, pyroptosis, and ferroptosis implicated in its development. Notably, limited research explores the association between endometriosis and specific RCD pathways like pyroptosis and cuproptosis. The exploration of regulated cell death in the context of endometriosis holds tremendous potential for further advancements. This article thoroughly reviews the molecular mechanisms governed by regulated cell death and their implications for endometriosis. A comprehensive understanding of the regulated cell death mechanism in endometriosis has the potential to catalyze the development of promising therapeutic strategies and chart the course for future research directions in the field.

Pathological and Therapeutical Implications of Pyroptosis in Psoriasis and Hidradenitis Suppurativa: A Narrative Review

This manuscript explores the role of pyroptosis, an inflammatory programmed cell death, in the pathogenesis of two chronic dermatoses, psoriasis and hidradenitis suppurativa (HS). The diseases, though clinically diverse, share common pathogenetic pathways involving the unbalanced interaction between the adaptive and innate immune systems. This review focuses on the molecular changes in psoriatic and HS skin, emphasizing the activation of dendritic cells, secretion of interleukins (IL-17, IL-22, and TNF-α), and the involvement of inflammasomes, particularly NLRP3. This manuscript discusses the role of caspases, especially caspase-1, in driving pyroptosis and highlights the family of gasdermins (GSDMs) as key players in the formation of pores leading to cell rupture and the release of proinflammatory signals. This study delves into the potential therapeutic implications of targeting pyroptosis in psoriasis and HS, examining existing medications like biologics and Janus kinase inhibitors. It also reviews the current limitations and challenges in developing therapies that selectively target pyroptosis. Additionally, the manuscript explores the role of pyroptosis in various inflammatory disorders associated with psoriasis and HS, such as inflammatory bowel disease, diabetes mellitus, and cardiovascular disorders. The review concludes by emphasizing the need for further research to fully elucidate the pathomechanisms of these dermatoses and develop effective, targeted therapies.

Interleukin (IL)-23, IL-31, and IL-33 Play a Role in the Course of Autoimmune Endocrine Diseases

BACKGROUND

Interleukins (IL)-23, 31, and 33 are involved in the regulation of T helper 17 (Th17)/regulatory T (Treg) cells balance. The role of IL-23, 31 and 33 in non-endocrine autoimmune diseases has been confirmed. Data on the involvement of these cytokines in endocrine autoimmune diseases are limited.

OBJECTIVE

This study aimed to determine the involvement of cytokines regulating the T helper 17 (Th17)/regulatory T (Treg) cells axis in the course of autoimmune endocrine diseases.

METHODS

A total number of 80 participants were divided into 4 groups: the autoimmune polyendocrine syndrome (APS) group consisting of APS type 2 (APS-2) and type 3 (APS-3) subgroups, the Hashimoto's thyroiditis (HT) group, the Graves' disease (GD) group and the control (C) group. Fifteen cytokines related to Th17 and Treg lymphocytes were determined in the serum of all participants.

RESULTS

Higher levels of IL-23 and IL-31 were found in the APS, GD, and HT groups compared to the C group. Higher levels of IL-23 and IL-31 were also observed in the APS-2 group, in contrast to the APS-3 group. Correlation analysis of variables in the groups showed a statistically significant correlation between the cytokines IL-23, IL-31, and IL-33 in the APS and APS-2 groups, but no correlation in the APS-3 and C groups.

CONCLUSION

IL-23 and IL-31 are independent factors in the course of HT, GD, and APS-2, in contrast to APS-3. The positive correlation between IL-23 and IL-31, IL-23 and IL-33, and between IL-31 and IL-33 in the APS, APS-2 groups, but the lack of correlation in the APS-3 and C groups may further suggest the involvement of these cytokines in the course of Addison's disease.

Transforming growth factor-β, Interleukin-23 and interleukin-1β modulate TH22 response during active multidrug-resistant tuberculosis

We previously reported that patients with multidrug-resistant tuberculosis (MDR-TB) showed low systemic and Mtb-induced Th22 responses associated to high sputum bacillary load and severe lung lesions suggesting that Th22 response could influence the ability of these patients to control bacillary growth and tissue damage. In MDR-TB patients, the percentage of IL-22+ cells inversely correlates with the proportion of senescent PD-1+ T cells. Herein, we aimed to evaluate the pathways involved on the regulation of systemic and Mtb-induced Th22 response in MDR-TB and fully drug-susceptible TB patients (S-TB) and healthy donors. Our results show that while IL-1β and IL-23 promote Mtb-induced IL-22 secretion and expansion of IL-22+ cells, TGF-β inhibits this response. Systemic and in vitro Mtb-induced Th22 response inversely correlates with TGF-β amounts in plasma and in PBMC cultures respectively. The number of circulating PD-1+ T cells directly correlates with plasmatic TGF-β levels and blockade of PD-1/PD-L1 signalling enhances in vitro Mtb-induced expansion of IL-22+ cells. Thus, TGF-β could also inhibit Th22 response through upregulation of PD-1 expression in T cells. Higher percentage of IL-23+ monocytes was observed in TB patients. In contrast, the proportion of IL-1β+ monocytes was lower in TB patients with bilateral lung cavities (BCC) compared to those patients with unilateral cavities (UCC). Interestingly, TB patients with BCC showed higher plasmatic and Mtb-induced TGF-β secretion than patients with UCC. Thus, high TGF-β secretion and subtle differences in IL-23 and IL-1β expression could diminish systemic and in vitro Mtb-induced Th22 response along disease progression in TB patients.

Targeting IL-12 family cytokines: A potential strategy for type 1 and type 2 diabetes mellitus

Diabetes is a common metabolic disease characterized by an imbalance in blood glucose levels. The pathogenesis of diabetes involves the essential role of cytokines, particularly the IL-12 family cytokines. These cytokines, which have a similar structure, play multiple roles in regulating the immune response. Recent studies have emphasized the importance of IL-12 family cytokines in the development of both type 1 and type 2 diabetes mellitus. As a result, they hold promise as potential therapeutic targets for the treatment of these conditions. This review focuses on the potential of targeting IL-12 family cytokines for diabetes therapy based on their roles in the pathogenesis of both types of diabetes. We have summarized various therapies that target IL-12 family cytokines, including drug therapy, combination therapy, cell therapy, gene therapy, cytokine engineering therapy, and gut microbiota modulation. By analyzing the advantages and disadvantages of these therapies, we have evaluated their feasibility for clinical application and proposed possible solutions to overcome any challenges. In conclusion, targeting IL-12 family cytokines for diabetes therapy provides updated insights into their potential benefits, such as controlling inflammation, preserving islet β cells, reversing the onset of diabetes, and impeding the development of diabetic complications.

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.

Intestinal microbiota-specific Th17 cells possess regulatory properties and suppress effector T cells via c-MAF and IL-10

Commensal microbes induce cytokine-producing effector tissue-resident CD4+ T cells, but the function of these T cells in mucosal homeostasis is not well understood. Here, we report that commensal-specific intestinal Th17 cells possess an anti-inflammatory phenotype marked by expression of interleukin (IL)-10 and co-inhibitory receptors. The anti-inflammatory phenotype of gut-resident commensal-specific Th17 cells was driven by the transcription factor c-MAF. IL-10-producing commensal-specific Th17 cells were heterogeneous and derived from a TCF1+ gut-resident progenitor Th17 cell population. Th17 cells acquired IL-10 expression and anti-inflammatory phenotype in the small-intestinal lamina propria. IL-10 production by CD4+ T cells and IL-10 signaling in intestinal macrophages drove IL-10 expression by commensal-specific Th17 cells. Intestinal commensal-specific Th17 cells possessed immunoregulatory functions and curbed effector T cell activity in vitro and in vivo in an IL-10-dependent and c-MAF-dependent manner. Our results suggest that tissue-resident commensal-specific Th17 cells perform regulatory functions in mucosal homeostasis.

A Narrative Review of Cytokine Networks: Pathophysiological and Therapeutic Implications for Inflammatory Bowel Disease Pathogenesis

Inflammatory bowel disease (IBD) is a lifelong inflammatory immune mediated disorder, encompassing Crohn's disease (CD) and ulcerative colitis (UC); however, the cause and specific pathogenesis of IBD is yet incompletely understood. Multiple cytokines produced by different immune cell types results in complex functional networks that constitute a highly regulated messaging network of signaling pathways. Applying biological mechanisms underlying IBD at the single omic level, technologies and genetic engineering enable the quantification of the pattern of released cytokines and new insights into the cytokine landscape of IBD. We focus on the existing literature dealing with the biology of pro- or anti-inflammatory cytokines and interactions that facilitate cell-based modulation of the immune system for IBD inflammation. We summarize the main roles of substantial cytokines in IBD related to homeostatic tissue functions and the remodeling of cytokine networks in IBD, which may be specifically valuable for successful cytokine-targeted therapies via marketed products. Cytokines and their receptors are validated targets for multiple therapeutic areas, we review the current strategies for therapeutic intervention and developing cytokine-targeted therapies. New biologics have shown efficacy in the last few decades for the management of IBD; unfortunately, many patients are nonresponsive or develop therapy resistance over time, creating a need for novel therapeutics. Thus, the treatment options for IBD beyond the immune-modifying anti-TNF agents or combination therapies are expanding rapidly. Further studies are needed to fully understand the immune response, networks of cytokines, and the direct pathogenetic relevance regarding individually tailored, safe and efficient targeted-biotherapeutics.

Th17 cytokines and factors modulating their activity in patients with pernicious anemia

The effects of specific cytokines produced by T cell subsets (such as Th1, Th2, and newly discovered Th17, Treg, Tfh, or Th22) are diverse, depending on interactions with other cytokines, distinct signaling pathways, phase of the disease, or etiological factor. The immunity equilibrium of the immune cells, such as the Th1/Th2, the Th17/Treg, and the Th17/Th1 balance is necessary for the maintenance of the immune homeostasis. If the balance of the T cells subsets is damaged, the autoimmune response becomes enhanced which leads to autoimmune diseases. Indeed, both the Th1/Th2 and the Th17/Treg dichotomies are involved in the pathomechanism of autoimmune diseases. The aim of the study was to determine the cytokines of Th17 lymphocytes as well as the factors modulating their activity in patients with pernicious anemia. The magnetic bead-based immunoassays used (Bio-Plex) allow simultaneous detection of multiple immune mediators from one serum sample. In our study, we showed that patients suffering from pernicious anemia develop the Th1/Th2 imbalance with a quantitative advantage of cytokines participating in Th1-related immune response, the Th17/Treg imbalance with a quantitative advantage of cytokines participating in Treg-related response, as well as the Th17/Th1 imbalance with a quantitative predominance of cytokines participating in Th1-related immune response. Our study results indicate that T lymphocytes and their specific cytokines play an role in the course of pernicious anemia. The observed changes may indicate the immune response to pernicious anemia or be an element of the pernicious anemia pathomechanism.

cAMP responsive element modulator α promotes effector T cells in systemic autoimmune diseases

T lymphocytes play a crucial role in adaptive immunity. Dysregulation of T cell-derived inflammatory cytokine expression and loss of self-tolerance promote inflammation and tissue damage in several autoimmune/inflammatory diseases, including systemic lupus erythematosus (SLE) and psoriasis. The transcription factor cAMP responsive element modulator α (CREMα) plays a key role in the regulation of T cell homeostasis. Increased expression of CREMα is a hallmark of the T cell-mediated inflammatory diseases SLE and psoriasis. Notably, CREMα regulates the expression of effector molecules through trans-regulation and/or the co-recruitment of epigenetic modifiers, including DNA methyltransferases (DNMT3a), histone-methyltransferases (G9a) and histone acetyltransferases (p300). Thus, CREMα may be used as a biomarker for disease activity and/or target for future targeted therapeutic interventions.

The role of transcription factors in shaping regulatory T cell identity

Forkhead box protein 3-expressing (FOXP3+) regulatory T cells (Treg cells) suppress conventional T cells and are essential for immunological tolerance. FOXP3, the master transcription factor of Treg cells, controls the expression of multiples genes to guide Treg cell differentiation and function. However, only a small fraction (<10%) of Treg cell-associated genes are directly bound by FOXP3, and FOXP3 alone is insufficient to fully specify the Treg cell programme, indicating a role for other accessory transcription factors operating upstream, downstream and/or concurrently with FOXP3 to direct Treg cell specification and specialized functions. Indeed, the heterogeneity of Treg cells can be at least partially attributed to differential expression of transcription factors that fine-tune their trafficking, survival and functional properties, some of which are niche-specific. In this Review, we discuss the emerging roles of accessory transcription factors in controlling Treg cell identity. We specifically focus on members of the basic helix-loop-helix family (AHR), basic leucine zipper family (BACH2, NFIL3 and BATF), CUT homeobox family (SATB1), zinc-finger domain family (BLIMP1, Ikaros and BCL-11B) and interferon regulatory factor family (IRF4), as well as lineage-defining transcription factors (T-bet, GATA3, RORγt and BCL-6). Understanding the imprinting of Treg cell identity and specialized function will be key to unravelling basic mechanisms of autoimmunity and identifying novel targets for drug development.

Th17 Cells, Glucocorticoid Resistance, and Depression

Depression is a severe mental disorder that disrupts mood and social behavior and is one of the most common neuropsychological symptoms of other somatic diseases. During the study of the disease, a number of theories were put forward (monoamine, inflammatory, vascular theories, etc.), but none of those theories fully explain the pathogenesis of the disease. Steroid resistance is a characteristic feature of depression and can affect not only brain cells but also immune cells. T-helper cells 17 type (Th17) are known for their resistance to the inhibitory effects of glucocorticoids. Unlike the inhibitory effect on other subpopulations of T-helper cells, glucocorticoids can enhance the differentiation of Th17 lymphocytes, their migration to the inflammation, and the production of IL-17A, IL-21, and IL-23 in GC-resistant disease. According to the latest data, in depression, especially the treatment-resistant type, the number of Th17 cells in the blood and the production of IL-17A is increased, which correlates with the severity of the disease. However, there is still a significant gap in knowledge regarding the exact mechanisms by which Th17 cells can influence neuroinflammation in depression. In this review, we discuss the mutual effect of glucocorticoid resistance and Th17 lymphocytes on the pathogenesis of depression.

Characterisation of IL-1 family members in Sweet syndrome highlights the overexpression of IL-1β and IL-1R3 as possible therapeutic targets

Sweet syndrome (SS) as a prototypic neutrophilic dermatosis (NDs) shares certain clinical and histologic features with monogenic auto-inflammatory disorders in which interleukin (IL)-1 cytokine family members play an important role. This has led to the proposal that NDs are polygenic auto-inflammatory diseases and has fuelled research to further understand the role of IL-1 family members in the pathogenesis of NDs. The aim of this study was to characterise the expression of the IL-1 family members IL-1β, IL-36γ, IL-33 and IL-1R3 (IL-1RaP) in SS. The expression profile of IL-1β, IL-33, IL-36γ and their common co-receptor IL-1R3 was analysed by immunohistochemistry, in situ hybridisation and double immunofluorescence (IF) in healthy control skin (HC) and lesional skin samples of SS. Marked overexpression of IL-1β in the dermis of SS (p < 0.001), and a non-significant increase in dermal (p = 0.087) and epidermal (p = 0.345) IL-36γ expression compared to HC was observed. Significantly increased IL-1R3 expression within the dermal infiltrate of SS skin samples (p = 0.02) was also observed, whereas no difference in IL-33 expression was found between SS and HC (p = 0.7139). In situ hybridisation revealed a good correlation between gene expression levels and the above protein expression levels. Double IF identifies neutrophils and macrophages as the predominant sources of IL-1β. This study shows that IL-1β produced by macrophages and neutrophils and IL-1R3 are significantly overexpressed in SS, thereby indicating a potential pathogenic role for this cytokine and receptor in SS.

STAT3 Signaling Heterogeneity Underlies Cytokine-Expressing Fate in Th17 Cultures

The polarization of naive Th cells into differentiated subsets in vitro was a powerful approach to define the development and function of Th cells in vivo. Th cell cultures identified cytokines that promote polarization and defined the phenotype and stability of differentiated cells. One of the limitations of this approach is the heterogeneity of the differentiated culture, essentially with regard to what proportion of the culture is secreting the hallmark cytokine of interest. This heterogeneity has always been puzzling because all cells in the culture have been exposed to identical culture conditions. We examined this phenomenon using an Il17f lineage-tracing allele (Cost, Cre on seventeen transcript) crossed to stop-flox Rosa-YFP (yellow fluorescent protein) mice. We found that less than half of the cells in a Th17 culture become lineage-positive during a differentiation culture and that it is primarily cells that are lineage-positive that produce cytokines when cultures are restimulated after differentiation. We sorted and analyzed YFP-positive and YFP-negative cells and found similar expression of many Th17 transcription factors, although YFP-negative cells had increased expression of other lineage-defining transcription factors. We observed that YFP-negative cells had diminished expression of Stat3 and Il6ra, as well as decreased STAT3 activation. YFP-negative cells transduced with active STAT3 had significant increases in IL-17A expression, without increases in Th17 transcription factors. Taken together, these data suggest that there is a threshold of STAT3 activation that is required for efficient Th17 differentiation, and that even in a culture of homogeneous naive T cells there is heterogeneity in the receipt of early cytokine signals.

T-helper cells flexibility: the possibility of reprogramming T cells fate

Various disciplines cooperate to find novel approaches to cure impaired body functions by repairing, replacing, or regenerating cells, tissues, or organs. The possibility that a stable differentiated cell can reprogram itself opens the door to new therapeutic strategies against a multitude of diseases caused by the loss or dysfunction of essential, irreparable, and specific cells. One approach to cell therapy is to induce reprogramming of adult cells into other functionally active cells. Understanding the factors that cause or contribute to T cell plasticity is not only of clinical importance but also expands the knowledge of the factors that induce cells to differentiate and improves the understanding of normal developmental biology. The present review focuses on the advances in the conversion of peripheral CD4+ T cells, the conditions of their reprogramming, and the methods proposed to control such cell differentiation.

Th2/Th17 cell associated cytokines found in seroma fluids after breast cancer surgery

PURPOSE

The development of a seroma after breast cancer surgery is a common postoperative complication seen after simple mastectomy and axillary surgery. We could recently demonstrate that breast cancer patients undergoing a simple mastectomy with subsequent seroma formation developed a T-helper cell increase within the aspirated fluid measured by flow cytometry. The same study revealed a Th2 and/or a Th17 immune response in peripheral blood and seroma fluid of the same patient. Based on these results and within the same study population, we now analyzed the Th2/Th17 cell associated cytokine content as well as the best known clinical important cytokine IL-6.

METHODS

Multiplex cytokine measurements (IL-4, IL-5, IL-13, IL-10, IL-17, and IL-22) were done on 34 seroma fluids (Sf) after fine needle aspiration of patients who developed a seroma after a simple mastectomy. Serum of the same patient (Sp) and that of healthy volunteers (Sc) were used as controls.

RESULTS

We found the Sf to be highly cytokine rich. Almost all analyzed cytokines were significantly higher in abundance in the Sf compared to Sp and Sc, especially IL-6, which promotes Th17 differentiation as well as suppresses Th1 differentiation in favor of Th2 development.

CONCLUSION

Our Sf cytokine measurements reflect a local immune event. In contrast, former study results on T-helper cell populations in both Sf and Sp tend to demonstrate a systemic immune process.

TGF-β1 signaling and Smad7 control T-cell responses in health and immune-mediated disorders

Transforming growth factor (TGF)-β1, a member of the TGF-β superfamily, is produced by many immune and nonimmune cells and has pleiotropic effects on both innate and adaptive immunity, especially in the control of T-cell differentiation and function. Consistently, loss of TGF-β1 function is associated with exacerbated T-cell-dependent inflammatory responses that culminate in pathological processes in allergic and immune-mediated diseases. In this review, we highlight the roles of TGF-β1 in immunity, focusing mainly on its ability to promote differentiation of regulatory T cells, T helper (Th)-17, and Th9 cells, thus contributing to amplifying or restricting T-cell responses in health and human diseases (e.g., inflammatory bowel diseases, type 1 diabetes, asthma, and MS). In addition, we discuss the involvement of Smad7, an inhibitor of TGF-β1 signaling, in immune-mediated disorders (e.g., psoriasis, rheumatoid arthritis, MS, and inflammatory bowel diseases), as well as the discordant results of clinical trials with mongersen, an oral pharmaceutical compound containing a Smad7 antisense oligonucleotide, in patients with Crohn's disease. Further work is needed to ascertain the reasons for such a discrepancy as well as to identify better candidates for treatment with Smad7 inhibitors.

Mettl3 induced miR-338-3p expression in dendritic cells promotes antigen-specific Th17 cell response via regulation of Dusp16

Pathogenic Th17 cells are critical drivers of multiple autoimmune diseases, including uveitis and its animal model, experimental autoimmune uveitis (EAU). However, how innate immune signals modulate pathogenic Th17 responses remains largely unknown. Here, we showed that miR-338-3p endowed dendritic cells (DCs) with an increased ability to activate interphotoreceptor retinoid-binding protein (IRBP)1-20 -specific Th17 cells by promoting the production of IL-6, IL-1β, and IL-23. In vivo administration of LV-miR-338-infected DCs promoted pathogenic Th17 responses and exacerbated EAU development. Mechanistically, dual-specificity phosphatase 16 (Dusp16) was a molecular target of miR-338-3p. miR-338-3p repressed Dusp16 and therefore strengthened the mitogen-activated protein kinase (MAPK) p38 signaling, resulting in increased production of Th17-polarizing cytokines and subsequent pathogenic Th17 responses. In addition, methyltransferase like 3 (Mettl3), a key m6A methyltransferase, mediated the upregulation of miR-338-3p in activated DCs. Together, our findings identify a vital role for Mettl3/miR-338-3p/Dusp16/p38 signaling in DCs-driven pathogenic Th17 responses and suggest a potential therapeutic avenue for uveitis and other Th17 cell-related autoimmune disorders.

Critical Roles of SRC-3 in the Development and Progression of Breast Cancer, Rendering It a Prospective Clinical Target

Breast cancer (BCa) is the most frequently diagnosed malignant tumor in women and is also one of the leading causes of cancer-related death. Most breast tumors are hormone-dependent and estrogen signaling plays a critical role in promoting the survival and malignant behaviors of these cells. Estrogen signaling involves ligand-activated cytoplasmic estrogen receptors that translocate to the nucleus with various co-regulators, such as steroid receptor co-activator (SRC) family members, and bind to the promoters of target genes and regulate their expression. SRC-3 is a member of this family that interacts with, and enhances, the transcriptional activity of the ligand activated estrogen receptor. Although SRC-3 has important roles in normal homeostasis and developmental processes, it has been shown to be amplified and overexpressed in breast cancer and to promote malignancy. The malignancy-promoting potential of SRC-3 is diverse and involves both promoting malignant behavior of tumor cells and creating a tumor microenvironment that has an immunosuppressive phenotype. SRC-3 also inhibits the recruitment of tumor-infiltrating lymphocytes with effector function and promotes stemness. Furthermore, SRC-3 is also involved in the development of resistance to hormone therapy and immunotherapy during breast cancer treatment. The versatility of SRC-3 in promoting breast cancer malignancy in this way makes it a good target, and methodical targeting of SRC-3 probably will be important for the success of breast cancer treatment.

Human IL-17A protein production is controlled through a PIP5K1α-dependent translational checkpoint

The cytokine interleukin-17 (IL-17) is secreted by T helper 17 (TH17) cells and is beneficial for microbial control; however, it also causes inflammation and pathological tissue remodeling in autoimmunity. Hence, TH17 cell differentiation and IL-17 production must be tightly regulated, but, to date, this has been defined only in terms of transcriptional control. Phosphatidylinositols are second messengers produced during T cell activation that transduce signals from the T cell receptor (TCR) and costimulatory receptors at the plasma membrane. Here, we found that phosphatidylinositol 4,5-bisphosphate (PIP2) was enriched in the nuclei of human TH17 cells, which depended on the kinase PIP5K1α, and that inhibition of PIP5K1α impaired IL-17A production. In contrast, nuclear PIP2 enrichment was not observed in TH1 or TH2 cells, and these cells did not require PIP5K1α for cytokine production. In T cells from people with multiple sclerosis, IL-17 production elicited by myelin basic protein was blocked by PIP5K1α inhibition. IL-17 protein was affected without altering either the abundance or stability of IL17A mRNA in TH17 cells. Instead, analysis of PIP5K1α-associating proteins revealed that PIP5K1α interacted with ARS2, a nuclear cap-binding complex scaffold protein, to facilitate its binding to IL17A mRNA and subsequent IL-17A protein production. These findings highlight a transcription-independent, translation-dependent mechanism for regulating IL-17A protein production that might be relevant to other cytokines.

The role of inflammation in autoimmune disease: a therapeutic target

Autoimmune diseases (AIDs) are immune disorders whose incidence and prevalence are increasing year by year. AIDs are produced by the immune system's misidentification of self-antigens, seemingly caused by excessive immune function, but in fact they are the result of reduced accuracy due to the decline in immune system function, which cannot clearly identify foreign invaders and self-antigens, thus issuing false attacks, and eventually leading to disease. The occurrence of AIDs is often accompanied by the emergence of inflammation, and inflammatory mediators (inflammatory factors, inflammasomes) play an important role in the pathogenesis of AIDs, which mediate the immune process by affecting innate cells (such as macrophages) and adaptive cells (such as T and B cells), and ultimately promote the occurrence of autoimmune responses, so targeting inflammatory mediators/pathways is one of emerging the treatment strategies of AIDs. This review will briefly describe the role of inflammation in the pathogenesis of different AIDs, and give a rough introduction to inhibitors targeting inflammatory factors, hoping to have reference significance for subsequent treatment options for AIDs.

Distinct inflammatory Th17 subsets emerge in autoimmunity and infection

Th17 cells play a critical role in both tissue homeostasis and inflammation during clearance of infections as well as autoimmune and inflammatory disorders. Despite numerous efforts to distinguish the homeostatic and inflammatory roles of Th17 cells, the mechanism underlying the divergent functions of inflammatory Th17 cells remains poorly understood. In this study, we demonstrate that the inflammatory Th17 cells involved in autoimmune colitis and those activated during colitogenic infection are distinguishable populations characterized by their differential responses to the pharmacological molecule, clofazimine (CLF). Unlike existing Th17 inhibitors, CLF selectively inhibits proautoimmune Th17 cells while preserving the functional state of infection-elicited Th17 cells partially by reducing the enzyme ALDH1L2. Overall, our study identifies two distinct subsets within the inflammatory Th17 compartment with distinct regulatory mechanisms. Furthermore, we highlight the feasibility to develop disease-promoting Th17 selective inhibitor for treating autoimmune diseases.