Interleukin-2 and STAT5 in regulatory T cell development and function

Regulatory T Cells in Tumor Microenvironment: Therapeutic Approaches and Clinical Implications

Regulatory T cells (Tregs), previously referred to as suppressor T cells, represent a distinct subset of CD4+ T cells that are uniquely specialized for immune suppression. They are characterized by the constitutive expression of the transcription factor FoxP3 in their nuclei, along with CD25 (the IL-2 receptor α-chain) and CTLA-4 on their cell surface. Tregs not only restrict natural killer cell-mediated cytotoxicity but also inhibit the proliferation of CD4+ and CD8+ T-cells and suppress interferon-γ secretion by immune cells, ultimately impairing an effective antitumor immune response. Treg cells are widely recognized as a significant barrier to the effectiveness of tumor immunotherapy in clinical settings. Extensive research has consistently shown that Treg cells play a pivotal role in facilitating tumor initiation and progression. Conversely, the depletion of Treg cells has been linked to a marked delay in tumor growth and development.

STAT Signature Dish: Serving Immunity with a Side of Dietary Control

Immunity is a fundamental aspect of animal biology, defined as the host's ability to detect and defend against harmful pathogens and toxic substances to preserve homeostasis. However, immune defenses are metabolically demanding, requiring the efficient allocation of limited resources to balance immune function with other physiological and developmental needs. To achieve this balance, organisms have evolved sophisticated signaling networks that enable precise, context-specific responses to internal and external cues. These networks are essential for survival and adaptation in multicellular systems. Central to this regulatory architecture is the STAT (signal transducer and activator of Transcription) family, a group of versatile signaling molecules that govern a wide array of biological processes across eukaryotes. STAT signaling demonstrates remarkable plasticity, from orchestrating host defense mechanisms to regulating dietary metabolism. Despite its critical role, the cell-specific and context-dependent nuances of STAT signaling remain incompletely understood, highlighting a significant gap in our understanding. This review delves into emerging perspectives on immunity, presenting dynamic frameworks to explore the complexity and adaptability of STAT signaling and the underlying logic driving cellular decision-making. It emphasizes how STAT pathways integrate diverse physiological processes, from immune responses to dietary regulation, ultimately supporting organismal balance and homeostasis.

VI-VS: calibrated identification of feature dependencies in single-cell multiomics

Unveiling functional relationships between various molecular cell phenotypes from data using machine learning models is a key promise of multiomics. Existing methods either use flexible but hard-to-interpret models or simpler, misspecified models. VI-VS (Variational Inference for Variable Selection) balances flexibility and interpretability to identify relevant feature relationships in multiomic data. It uses deep generative models to identify conditionally dependent features, with false discovery rate control. VI-VS is available as an open-source Python package, providing a robust solution to identify features more likely representing genuine causal relationships.

STATs, promising targets for the treatment of autoimmune and inflammatory diseases

Cytokines play a crucial role in the pathophysiology of autoimmune and inflammatory diseases, with over 50 cytokines undergoing signal transduction through the Signal Transducers and Activators of Transcription (STAT) signaling pathway. Recent studies have solidly confirmed the pivotal role of STATs in autoimmune and inflammatory diseases. Therefore, this review provides a detailed summary of the immunological functions of STATs, focusing on exploring their mechanisms in various autoimmune and inflammatory diseases. Additionally, with the rapid advancement of structural biology in the field of drug discovery, many STAT inhibitors have been identified using structure-based drug design strategies. In this review, we also examine the structures of STAT proteins and compile the latest research on STAT inhibitors currently being tested in animal models and clinical trials for the treatment of immunological diseases, which emphasizes the feasibility of STATs as promising therapeutic targets and provides insights into the design of the next generation of STAT inhibitors.

Unveiling the link between arsenic toxicity and diabetes: an in silico exploration into the role of transcription factors

Arsenic-induced diabetes, despite being a relatively newer finding, is now a growing area of interest, owing to its multifaceted nature of development and the diversity of metabolic conditions that result from it, on top of the already complicated manifestation of arsenic toxicity. Identification and characterization of the common and differentially affected cellular metabolic pathways and their regulatory components among various arsenic and diabetes-associated complications may aid in understanding the core molecular mechanism of arsenic-induced diabetes. This study, therefore, explores the effects of arsenic on human cell lines through 14 transcriptomic datasets containing 160 individual samples using in silico tools to take a systematic, deeper look into the pathways and genes that are being altered. Among these, we especially focused on the role of transcription factors due to their diverse and multifaceted roles in biological processes, aiming to comprehensively investigate the underlying mechanism of arsenic-induced diabetes as well as associated health risks. We present a potential mechanism heavily implying the involvement of the TGF-β/SMAD3 signaling pathway leading to cell cycle alterations and the NF-κB/TNF-α, MAPK, and Ca2+ signaling pathways underlying the pathogenesis of arsenic-induced diabetes. This study also presents novel findings by suggesting potential associations of four transcription factors (NCOA3, PHF20, TFDP1, and TFDP2) with both arsenic toxicity and diabetes; five transcription factors (E2F5, ETS2, EGR1, JDP2, and TFE3) with arsenic toxicity; and one transcription factor (GATA2) with diabetes. The novel association of the transcription factors and proposed mechanism in this study may serve as a take-off point for more experimental evidence needed to understand the in vivo cellular-level diabetogenic effects of arsenic.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-024-00255-y.

Therapeutic inhibition of the JAK-STAT pathway in the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) encompasses a group of non-specific chronic intestinal inflammatory conditions of unclear etiology. The current treatment and long-term management primarily involve biologics. Nevertheless, some patients experience treatment failure or intolerance to biologics [1], making these patients a primary focus of IBD research. The Janus kinase (JAK)-Signal Transducers and Activator of Transcription (STAT) signal transduction pathway is crucial to the regulation of immune and inflammatory responses [2], and plays an important role in the pathogenesis of IBD. JAK inhibitors alleviate IBD by suppressing the transmission of JAK-STAT signaling pathway. As the first small-molecule oral inhibitor for IBD, JAK inhibitors greatly improved the treatment of IBD and have demonstrated significant efficacy, with tofacitinib and upadacitinib being approved for the treatment of ulcerative colitis (UC) [3]. JAK inhibitors can effectively alleviate intestinal inflammation in IBD patients who have failed to receive biologics, which may bring new treatment opportunities for refractory IBD patients. This review aims to elucidate the crucial roles of JAK-STAT signal transduction pathway in IBD pathogenesis, examine its role in various cell types within IBD, and explore the research progress of JAK inhibitors as therapeutic agents, paving the road for new IBD treatment strategies.

Increased Frequency of Circulating Activated FOXP3+ Regulatory T Cell Subset in Patients with Chronic Lymphocytic Leukemia Is Associated with the Estimate of the Size of the Tumor Mass, STAT5 Signaling and Disease Course during Follow-Up of Patients on Therapy

INTRODUCTION

Advanced chronic lymphocytic leukemia (CLL) is accompanied by increased circulating regulatory T cells (Tregs) and increased susceptibility to severe infections, which were also shown to entail a striking induction of FOXP3 expression in Tregs. As homeostasis of the most suppressive CD45RA-FOXP3high activated Treg (aTreg) subset differs, it is critical to analyse homeostatic signalling in Treg subsets.

MATERIALS AND METHODS

In this study, by using conventional and imaging flow cytometry, we monitored STAT5 signalling/phosphorylation (pSTAT5) and investigated Treg subsets in relation to the Binet stage, the total tumor mass score (TTM) and the disease course during a follow-up of 37 patients with CLL.

RESULTS

The aTreg percentage was significantly increased among CD4+ T cells from patients with advanced disease and significantly correlated with the TTM. A subgroup of patients with higher aTreg percentages among CD4+FOXP3+ T cells at the start of therapy was characterised by more frequent episodes of severe infections during follow-up.

CONCLUSIONS

The results suggesting that an aTreg fraction could represent a possible marker of a severe disease course with infectious complications. Augmented homeostatic STAT5 signalling could support aTreg expansion, as higher pSTAT5 levels were significantly correlated with an increased aTreg frequency among CD4+FOXP3+ T cells during the follow-up of patients on therapy, as well as following SARS-CoV-2 antigen-specific stimulation in vitro.

Peroxynitrite reduces Treg cell expansion and function by mediating IL-2R nitration and aggravates multiple sclerosis pathogenesis

T-helper 17 cells and regulatory T cells (Treg) are critical regulators in the pathogenesis of multiple sclerosis (MS) but the factors affecting Treg/Th17 balance remains largely unknown. Redox balance is crucial to maintaining immune homeostasis and reducing the severity of MS but the underlying mechanisms are unclear yet. Herein, we tested the hypothesis that peroxynitrite, a representative molecule of reactive nitrogen species (RNS), could inhibit peripheral Treg cells, disrupt Treg/Th17 balance and aggravate MS pathology by inducing nitration of interleukin-2 receptor (IL-2R) and down-regulating RAS/JNK-AP-1 signalling pathway. Experimental autoimmune encephalomyelitis (EAE) mouse model and serum samples of MS patients were used in the study. We found that the increases of 3-nitrotyrosine and IL-2R nitration in Treg cells were coincided with disease severity in the active EAE mice. Mechanistically, peroxynitrite-induced IL-2R nitration down-regulated RAS/JNK signalling pathway, subsequently impairing peripheral Treg expansion and function, increasing Teff infiltration into the central nerve system (CNS), aggravating demyelination and neurological deficits in the EAE mice. Those changes were abolished by peroxynitrite decomposition catalyst (PDC) treatment. Furthermore, transplantation of the PDC-treated-autologous Treg cells from donor EAE mice significantly decreased Th17 cells in both axillary lymph nodes and lumbar spinal cord, and ameliorated the neuropathology of the recipient EAE mice. Those results suggest that peroxynitrite could disrupt peripheral Treg/Th17 balance, and aggravate neuroinflammation and neurological deficit in active EAE/MS pathogenesis. The underlying mechanisms are related to induce the nitration of IL-2R and inhibit the RAS/JNK-AP-1 signalling pathway in Treg cells. The study highlights that targeting peroxynitrite-mediated peripheral IL-2R nitration in Treg cells could be a novel therapeutic strategy to restore Treg/Th17 balance and ameliorate MS/EAE pathogenesis. The study provides valuable insights into potential role of peripheral redox balance in maintaining CNS immune homeostasis.

A review of CD4+ T cell differentiation and diversity in dogs

CD4+ T cells are an integral component of the adaptive immune response, carrying out many functions to combat a diverse range of pathogenic challenges. These cells exhibit remarkable plasticity, differentiating into specialized subsets such as T helper type 1 (TH1), TH2, TH9, TH17, TH22, regulatory T cells (Tregs), and follicular T helper (TFH) cells. Each subset is capable of addressing a distinct immunological need ranging from pathogen eradication to regulation of immune homeostasis. As the immune response subsides, CD4+ T cells rest down into long-lived memory phenotypes-including central memory (TCM), effector memory (TEM), resident memory (TRM), and terminally differentiated effector memory cells (TEMRA) that are localized to facilitate a swift and potent response upon antigen re-encounter. This capacity for long-term immunological memory and rapid reactivation upon secondary exposure highlights the role CD4+ T cells play in sustaining both adaptive defense mechanisms and maintenance. Decades of mouse, human, and to a lesser extent, pig T cell research has provided the framework for understanding the role of CD4+ T cells in immune responses, but these model systems do not always mimic each other. Although our understanding of pig immunology is not as extensive as mouse or human research, we have gained valuable insight by studying this model. More akin to pigs, our understanding of CD4+ T cells in dogs is much less complete. This disparity exists in part because canine immunologists depend on paradigms from mouse and human studies to characterize CD4+ T cells in dogs, with a fraction of available lineage-defining antibody markers. Despite this, every major CD4+ T cell subset has been described to some extent in dogs. These subsets have been studied in various contexts, including in vitro stimulation, homeostatic conditions, and across a range of disease states. Canine CD4+ T cells have been categorized according to lineage-defining characteristics, trafficking patterns, and what cytokines they produce upon stimulation. This review addresses our current understanding of canine CD4+ T cells from a comparative perspective by highlighting both the similarities and differences from mouse, human, and pig CD4+ T cell biology. We also discuss knowledge gaps in our current understanding of CD4+ T cells in dogs that could provide direction for future studies in the field.

Microneedle-Mediated Delivery of Immunomodulators Restores Immune Privilege in Hair Follicles and Reverses Immune-Mediated Alopecia

Disorders in the regulatory arm of the adaptive immune system result in autoimmune-mediated diseases. While systemic immunosuppression is the prevailing approach to manage them, it fails to achieve long-lasting remission due to concomitant suppression of the regulatory arm and carries the risk of heightened susceptibility to infections and malignancies. Alopecia areata is a condition characterized by localized hair loss due to autoimmunity. The accessibility of the skin allows local rather than systemic intervention to avoid broad immunosuppression. It is hypothesized that the expansion of endogenous regulatory T cells (Tregs) at the site of antigen encounter can restore the immune balance and generate a long-lasting tolerogenic response. A hydrogel microneedle (MN) patch is therefore utilized for delivery of CCL22, a Treg-chemoattractant, and IL-2, a Treg survival factor to amplify them. In an immune-mediated murine model of alopecia, local bolstering of Treg numbers is shown, leading to sustained hair regrowth and attenuation of inflammatory pathways. In a humanized skin transplant mouse model, expansion of Tregs within human skin is confirmed without engendering peripheral immunosuppression. The patch offers high-loading capacity and shelf-life stability for prospective clinical translation. By harmonizing immune responses locally, the aim is to reshape the landscape of autoimmune skin disease management.

The role of regulatory T cells in vitiligo and therapeutic advances: a mini-review

BACKGROUND

Regulatory T cells (Tregs) play vital roles in controlling immune reactions and maintaining immune tolerance in the body. The targeted destruction of epidermal melanocytes by activated CD8+T cells is a key event in the development of vitiligo. However, Tregs may exert immunosuppressive effects on CD8+T cells, which could be beneficial in treating vitiligo.

METHODS

A comprehensive search of PubMed and Web of Science was conducted to gather information on Tregs and vitiligo.

RESULTS

In vitiligo, there is a decrease in Treg numbers and impaired Treg functions, along with potential damage to Treg-related signaling pathways. Increasing Treg numbers and enhancing Treg function could lead to immunosuppressive effects on CD8+T cells. Recent research progress on Tregs in vitiligo has been summarized, highlighting various Treg-related therapies being investigated for clinical use. The current status of Treg-related therapeutic strategies and potential future directions for vitiligo treatment are also discussed.

CONCLUSIONS

A deeper understanding of Tregs will be crucial for advancing Treg-related drug discovery and treatment development in vitiligo.

Low-dose IL-2 therapy in autoimmune diseases: An update review

Regulatory T (Treg) cells are essential for maintaining self-immune tolerance. Reduced numbers or functions of Treg cells have been involved in the pathogenesis of various autoimmune diseases and allograft rejection. Therefore, the approaches that increase the pool or suppressive function of Treg cells in vivo could be a general strategy to treat different autoimmune diseases and allograft rejection. Interleukin-2 (IL-2) is essential for the development, survival, maintenance, and function of Treg cells, constitutively expressing the high-affinity receptor of IL-2 and sensitive response to IL-2 in vivo. And low-dose IL-2 therapy in vivo could restore the imbalance between autoimmune response and self-tolerance toward self-tolerance via promoting Treg cell expansion and inhibiting follicular helper T (Tfh) and IL-17-producing helper T (Th17) cell differentiation. Currently, low-dose IL-2 treatment is receiving extensive attention in autoimmune disease and transplantation treatment. In this review, we summarize the biology of IL-2/IL-2 receptor, the mechanisms of low-dose IL-2 therapy in autoimmune diseases, the application in the progress of different autoimmune diseases, including Systemic Lupus Erythematosus (SLE), Type 1 Diabetes (T1D), Rheumatoid Arthritis (RA), Autoimmune Hepatitis (AIH), Alopecia Areata (AA), Immune Thrombocytopenia (ITP) and Chronic graft-versus-host-disease (GVHD). We also discuss the future directions to optimize low-dose IL-2 treatments.

Insufficient phosphorylation of STAT5 in Tregs inhibits the expression of BLIMP-1 but not IRF4, reduction the proportion of Tregs in pediatric aplastic anemia

Deficiency in regulatory T cells (Tregs) is an important mechanism underlying the pathogenesis of pediatric aplastic anemia, but its specific mechanism is unclear. In our study, we aimed to investigate whether IL-2/STAT5 can regulate the proliferation of Tregs in aplastic anemia (AA) by regulating their expression of B lymphocyte-induced mature protein-1 (BLIMP-1) or interferon regulatory factor 4 (IRF4). Through clinical research and animal experiments, we found that poor activation of the IL-2/STAT5 signaling pathway may leads to low expression of BLIMP-1 in Tregs of children with AA, which leads to defects in the differentiation and proliferation of Tregs in AA. In AA model mice, treatment with IL-2c reversed the decrease in Treg proportions and reduction in Blimp-1 expression in Tregs by increasing the phosphorylation of Stat5 in Tregs. In AA, deficiency of IRF4 expression in Tregs is closely related to the deficiency of Tregs, but is not regulated by the IL-2/STAT5 pathway.

CD81 and CD82 expressing tumor-infiltrating lymphocytes in the NSCLC tumor microenvironment play a crucial role in T-cell activation and cytokine production

Introduction

To understand the immune system within the tumor microenvironment (TME) of non-small cell lung cancer (NSCLC), it is crucial to elucidate the characteristics of molecules associated with T cell activation.

Methods

We conducted an in-depth analysis using single-cell RNA sequencing data obtained from tissue samples of 19 NSCLC patients. T cells were classified based on the Tumor Proportion Score (TPS) within the tumor region, and molecular markers associated with activation and exhaustion were analyzed in T cells from high TPS areas.

Results

Notably, tetraspanins CD81 and CD82, belonging to the tetraspanin protein family, were found to be expressed in activated T cells, particularly in cytotoxic T cells. These tetraspanins showed strong correlations with activation and exhaustion markers. In vitro experiments confirmed increased expression of CD81 and CD82 in IL-2-stimulated T cells. T cells were categorized into CD81highCD82high and CD81lowCD82low groups based on their expression levels, with CD81highCD82high T cells exhibiting elevated activation markers such as CD25 and CD69 compared to CD81lowCD82low T cells. This trend was consistent across CD3+, CD8+, and CD4+ T cell subsets. Moreover, CD81highCD82high T cells, when stimulated with anti-CD3, demonstrated enhanced secretion of cytokines such as IFN-γ, TNF-α, and IL-2, along with an increase in the proportion of memory T cells. Bulk RNA sequencing results after sorting CD81highCD82high and CD81lowCD82low T cells consistently supported the roles of CD81 and CD82. Experiments with overexpressed CD81 and CD82 showed increased cytotoxicity against target cells.

Discussion

These findings highlight the multifaceted roles of CD81 and CD82 in T cell activation, cytokine production, memory subset accumulation, and target cell cytolysis. Therefore, these findings suggest the potential of CD81 and CD82 as promising candidates for co-stimulatory molecules in immune therapeutic strategies for cancer treatment within the intricate TME.

Langerhans cells shape postnatal oral homeostasis in a mechanical-force-dependent but microbiota and IL17-independent manner

The postnatal interaction between microbiota and the immune system establishes lifelong homeostasis at mucosal epithelial barriers, however, the barrier-specific physiological activities that drive the equilibrium are hardly known. During weaning, the oral epithelium, which is monitored by Langerhans cells (LC), is challenged by the development of a microbial plaque and the initiation of masticatory forces capable of damaging the epithelium. Here we show that microbial colonization following birth facilitates the differentiation of oral LCs, setting the stage for the weaning period, in which adaptive immunity develops. Despite the presence of the challenging microbial plaque, LCs mainly respond to masticatory mechanical forces, inducing adaptive immunity, to maintain epithelial integrity that is also associated with naturally occurring alveolar bone loss. Mechanistically, masticatory forces induce the migration of LCs to the lymph nodes, and in return, LCs support the development of immunity to maintain epithelial integrity in a microbiota-independent manner. Unlike in adult life, this bone loss is IL-17-independent, suggesting that the establishment of oral mucosal homeostasis after birth and its maintenance in adult life involve distinct mechanisms.

Expression and prognostic role of STAT5a across cancer types

Studies examining the role of signal transducer and activator of transcription 5 (STAT5) in various cancers have produced controversial results. To address this controversy, we examined the prognostic role of STAT5a in cancer patients across multiple cancers. Transcription levels of STAT5a between tumors and normal tissues, obtained from public databases, were analyzed for statistical differences using Cox regression analysis with the outcome as overall survival and covariate of interest as high STAT5a expression. Meta-analysis was then conducted to summarize the hazard ratio estimate from the Cox regression analyses. We found that STAT5a was significantly under-expressed in breast, lung, and ovarian cancers, while STAT5a was significantly overexpressed in lymphoid neoplasm diffuse large B-cell lymphoma, glioblastoma, and glioma. High STAT5a expression was significantly associated with favorable survival in bladder cancer (lnHR = -0.8689 [-1.4087, -0.3292], P-value = 0.0016), breast cancer (lnHR = -0.7805 [-1.1394, -0.4215], P-value < 0.0001) and lung cancer (lnHR = -0.3255 [-0.6427, -0.0083], P-value = 0.0443). After adjusting for clinicopathological factors, high STAT5a expression remained significantly associated with favorable survival in breast cancer (lnHR = -0.6091 [-1.0810, -0.1372], P-value = 0.0114). These results suggest that higher STAT5a expression is associated with favorable overall survival in breast cancer, and therefore might have protective effects, and that STAT5a expression could be a potential prognostic biomarker, especially in breast cancer. However, the prognostic role of STAT5a is dependent on cancer type.

A synthetic glycodendropeptide induces methylation changes on regulatory T cells linked to tolerant responses in anaphylactic-mice

Introduction

Lipid transfer proteins (LTPs) are allergens found in a wide range of plant-foods. Specifically, Pru p 3, the major allergen of peach, is commonly responsible for severe allergic reactions. The need for new alternatives to conventional food allergy treatments, like restrictive diets, suggests allergen immunotherapy as a promising option. It has been demonstrated that sublingual immunotherapy (SLIT) with synthetic glycodendropeptides, such as D1ManPrup3, containing mannose and Pru p 3 peptides induced tolerance in mice and that the persistence of this effect depends on treatment dose (2nM or 5nM). Moreover, it produces changes associated with differential gene expression and methylation profile of dendritic cells, as well as phenotypical changes in regulatory T cells (Treg). However, there are no works addressing the study of epigenetic changes in terms of methylation in the cell subsets that sustain tolerant responses, Treg. Therefore, in this work, DNA methylation changes in splenic-Treg from Pru p 3 anaphylactic mice were evaluated.

Methods

It was performed by whole genome bisulphite sequencing comparing SLIT-D1ManPrup3 treated mice: tolerant (2nM D1ManPrup3), desensitized (5nM D1ManPrup3), and sensitized but not treated (antigen-only), with anaphylactic mice.

Results

Most of the methylation changes were found in the gene promoters from both SLIT-treated groups, desensitized (1,580) and tolerant (1,576), followed by the antigen-only (1,151) group. Although tolerant and desensitized mice showed a similar number of methylation changes, only 445 genes were shared in both. Remarkably, interesting methylation changes were observed on the promoter regions of critical transcription factors for Treg function like Stat4, Stat5a, Stat5b, Foxp3, and Gata3. In fact, Foxp3 was observed exclusively as hypomethylated in tolerant group, whereas Gata3 was only hypomethylated in the desensitized mice.

Discussion

In conclusion, diverse D1ManPrup3 doses induce different responses (tolerance or desensitization) in mice, which are reflected by differential methylation changes in Tregs.

Hypoxia Is Associated with Increased Immune Infiltrates and Both Anti-Tumour and Immune Suppressive Signalling in Muscle-Invasive Bladder Cancer

Hypoxia and a suppressive tumour microenvironment (TME) are both independent negative prognostic factors for muscle-invasive bladder cancer (MIBC) that contribute to treatment resistance. Hypoxia has been shown to induce an immune suppressive TME by recruiting myeloid cells that inhibit anti-tumour T cell responses. Recent transcriptomic analyses show hypoxia increases suppressive and anti-tumour immune signalling and infiltrates in bladder cancer. This study sought to investigate the relationship between hypoxia-inducible factor (HIF)-1 and -2, hypoxia, and immune signalling and infiltrates in MIBC. ChIP-seq was performed to identify HIF1α, HIF2α, and HIF1β binding in the genome of the MIBC cell line T24 cultured in 1% and 0.1% oxygen for 24 h. Microarray data from four MIBC cell lines (T24, J82, UMUC3, and HT1376) cultured under 1%, 0.2%, and 0.1% oxygen for 24 h were used. Differences in the immune contexture between high- and low-hypoxia tumours were investigated using in silico analyses of two bladder cancer cohorts (BCON and TCGA) filtered to only include MIBC cases. GO and GSEA were used with the R packages "limma" and "fgsea". Immune deconvolution was performed using ImSig and TIMER algorithms. RStudio was used for all analyses. Under hypoxia, HIF1α and HIF2α bound to ~11.5-13.5% and ~4.5-7.5% of immune-related genes, respectively (1-0.1% O₂). HIF1α and HIF2α both bound to genes associated with T cell activation and differentiation signalling pathways. HIF1α and HIF2α had distinct roles in immune-related signalling. HIF1 was associated with interferon production specifically, whilst HIF2 was associated with generic cytokine signalling as well as humoral and toll-like receptor immune responses. Neutrophil and myeloid cell signalling was enriched under hypoxia, alongside hallmark pathways associated with Tregs and macrophages. High-hypoxia MIBC tumours had increased expression of both suppressive and anti-tumour immune gene signatures and were associated with increased immune infiltrates. Overall, hypoxia is associated with increased inflammation for both suppressive and anti-tumour-related immune signalling and immune infiltrates, as seen in vitro and in situ using MIBC patient tumours.

Hedgehog Signaling Regulates Treg to Th17 Conversion Through Metabolic Rewiring in Breast Cancer

The tumor immune microenvironment dynamically evolves to support tumor growth and progression. Immunosuppressive regulatory T cells (Treg) promote tumor growth and metastatic seeding in patients with breast cancer. Deregulation of plasticity between Treg and Th17 cells creates an immune regulatory framework that enables tumor progression. Here, we discovered a functional role for Hedgehog (Hh) signaling in promoting Treg differentiation and immunosuppressive activity, and when Hh activity was inhibited, Tregs adopted a Th17-like phenotype complemented by an enhanced inflammatory profile. Mechanistically, Hh signaling promoted O-GlcNAc modifications of critical Treg and Th17 transcription factors, Foxp3 and STAT3, respectively, that orchestrated this transition. Blocking Hh reprogramed Tregs metabolically, dampened their immunosuppressive activity, and supported their transdifferentiation into inflammatory Th17 cells that enhanced the recruitment of cytotoxic CD8+ T cells into tumors. Our results demonstrate a previously unknown role for Hh signaling in the regulation of Treg differentiation and activity and the switch between Tregs and Th17 cells in the tumor microenvironment.

Breast cancer tumor microenvironment affects Treg/IL-17-producing Treg/Th17 cell axis: Molecular and therapeutic perspectives

The tumor microenvironment (TME) comprises a variety of immune cells, among which T cells exert a prominent axial role in tumor development or anti-tumor responses in patients with breast cancer (BC). High or low levels of anti-inflammatory cytokines, such as transforming growth factor β, in the absence or presence of proinflammatory cytokines, such as interleukin-6 (IL-6), delineate the fate of T cells toward either regulatory T (Treg) or T helper 17 (Th17) cells, respectively. The transitional state of RORγt⁺Foxp3⁺ Treg (IL-17-producing Treg) resides in the middle of this reciprocal polarization, which is known as Treg/IL-17-producing Treg/Th17 cell axis. TME secretome, including microRNAs, cytokines, and extracellular vesicles, can significantly affect this axis. Furthermore, immune checkpoint inhibitors may be used to reconstruct immune cells; however, some of these novel therapies may favor tumor development. Therefore, understanding secretory and cell-associated factors involved in their differentiation or polarization and functions may be targeted for BC management. This review discusses microRNAs, cytokines, and extracellular vesicles (as secretome), as well as transcription factors and immune checkpoints (as cell-associated factors), which influence the Treg/IL-17-producing Treg/Th17 cell axis in BC. Furthermore, approved or ongoing clinical trials related to the modulation of this axis in the TME of BC are described to broaden new horizons of promising therapeutic approaches.

Transcriptomic landscape of TIMP3 oncosuppressor activity in thyroid carcinoma

BACKGROUND

Papillary thyroid cancer (PTC) is the most frequent thyroid tumor. The tissue inhibitor of metalloproteinase-3 (TIMP3) gene encodes a matrix metalloproteinases inhibitor that exerts a tumor suppressor role in several tumor types. TIMP3 is frequently downregulated in PTC by promoter methylation. We have previously functionally demonstrated that TIMP3 exerts an oncosuppressor role in PTC: TIMP3 restoration in the PTC-derived NIM1 cell line affects in vitro migration, invasion and adhesive capability, while reduces tumor growth, angiogenesis and macrophage recruitment in vivo. To get a deeper insight on the mediators of TIMP3 oncosuppressor activity in thyroid tumors, here we focused on the TIMP3 related transcriptome.

METHODS

TCGA database was used for investigating the genes differentially expressed in PTC samples with low and high TIMP3 expression. Genome wide expression analysis of clones NIM1-T23 (expressing a high level of TIMP3 protein) and NIM1-EV (control empty vector) was performed. Gene sets and functional enrichment analysis with clusterProfiler were applied to identify the modulated biological processes and pathways. CIBERSORT was used to evaluate the distribution of different immunological cell types in TCGA-PTC tumor samples with different TIMP3 expression levels. Real time PCR was performed for the validation of selected genes.

RESULTS

Thyroid tumors with TIMP3-high expression showed a down-modulation of inflammation-related gene sets, along with a reduced protumoral hematopoietic cells fraction; an enrichment of cell adhesion functions was also identified. Similar results were obtained in the TIMP3-overexpessing NIM1 cells in vitro model, where a down-regulation of immune-related function gene sets, some of which also identified in tumor samples, was observed. Interestingly, through enrichment analysis, were also recognized terms related to cell adhesion, extracellular matrix organization, blood vessel maintenance and vascular process functions that have been found modulated in our previous in vitro and in vivo functional studies.

CONCLUSIONS

Our results highlight the correlation of TIMP3 expression levels with the regulation of inflammatory functions and the immune infiltration composition associated with different PTC prognosis, thus providing a broader view on the oncosuppressor role of TIMP3 in PTC.

Longitudinal transcriptome analysis of cattle infected with Theileria parva

The apicomplexan cattle parasite Theileria parva is a major barrier to improving the livelihoods of smallholder farmers in Africa, killing over one million cattle on the continent each year. Although exotic breeds not native to Africa are highly susceptible to the disease, previous studies have illustrated that such breeds often show innate tolerance to infection by the parasite. The mechanisms underlying this tolerance remain largely unclear. To better understand the host response to T. parva infection we characterised the transcriptional response over 15 days in tolerant and susceptible cattle (n = 29) naturally exposed to the parasite. We identify key genes and pathways activated in response to infection as well as, importantly, several genes differentially expressed between the animals that ultimately survived or succumbed to infection. These include genes linked to key cell proliferation and infection pathways. Furthermore, we identify response expression quantitative trait loci containing genetic variants whose impact on the expression level of nearby genes changes in response to the infection. These therefore provide an indication of the genetic basis of differential host responses. Together these results provide a comprehensive analysis of the host transcriptional response to this under-studied pathogen, providing clues as to the mechanisms underlying natural tolerance to the disease.

Direct AKT activation in tumor-infiltrating lymphocytes markedly increases interferon-γ (IFN-γ) for the regression of tumors resistant to PD-1 checkpoint blockade

PD-1 immune checkpoint blockade against inhibitory receptors such as receptor programmed cell death-1 (PD-1), has revolutionized cancer treatment. Effective immune reactivity against tumour antigens requires the infiltration and activation of tumour-infiltrating T-cells (TILs). In this context, ligation of the antigen-receptor complex (TCR) in combination with the co-receptor CD28 activates the intracellular mediator AKT (or PKB, protein kinase B) and its downstream targets. PD-1 inhibits the activation of AKT/PKB. Given this, we assessed whether the direct activation of AKT might be effective in activating the immune system to limit the growth of tumors that are resistant to PD-1 checkpoint blockade. We found that the small molecule activator of AKT (SC79) limited growth of a B16 tumor and an EMT-6 syngeneic breast tumor model that are poorly responsive to PD-1 immunotherapy. In the case of B16 tumors, direct AKT activation induced (i) a reduction of suppressor regulatory (Treg) TILs and (ii) an increase in effector CD8+ TILs. SC79 in vivo therapy caused a major increase in the numbers of CD4+ and CD8+ TILs to express interferon-γ (IFN-γ). This effect on IFN-γ expression distinguished responsive from non-responsive anti-tumor responses and could be recapitulated ex vivo with human T-cells. In CD4+FoxP3+Treg TILs, AKT induced IFN-γ expression was accompanied by a loss of suppressor activity, the conversation to CD4⁺ helper Th1-like TILs and a marked reduction in phospho-SHP2. In CD8+ TILs, we observed an increase in the phospho-activation of PLC-γ. Further, the genetic deletion of the transcription factor T-bet (Tbx21) blocked the increased IFN-γ expression on all subsets while ablating the therapeutic benefits of SC79 on tumor growth. Our study shows that AKT activation therapy acts to induce IFN-γ on CD4 and CD8 TILs that is accompanied by the intra-tumoral conversation of suppressive Tregs into CD4⁺Th1-like T-cells and augmented CD8 responses.

Decreased GZMB, NRP1, ITPR1, and SERPINB9 Transcripts Lead to Reduced Regulatory T Cells Suppressive Capacity in Generalized Vitiligo Patients

Generalized vitiligo (GV) is an autoimmune skin disease characterized by bilateral white patches over the entire body. Regulatory T cells (Tregs) maintain peripheral tolerance; however, they are found to be reduced in numbers and function in vitiligo patients. The exact mechanism for reduced Treg suppressive capacity is unknown. Therefore, we aimed to assess transcript levels of Tregs-associated immunosuppressive genes (GZMB, NRP1, PDCD1, FASLG, and TNFRS18), regulatory molecules of Tregs suppressive function (SERPINB9, ITPR1, and UBASH3A), and Treg-associated transcription factors (GATA2, GATA3, RUNX1, STAT3, and STAT5) in 52 GV patients and 48 controls by real-time PCR (qPCR). We found significantly reduced GZMB, NRP1, SERPINB9, and ITPR1 transcripts in GV Tregs compared to controls (p = 0.03, p = 0.023, p = 0.0045, and p < 0.0001, respectively). There were 0.44-, 0.45-, 0.32-, and 0.54-fold decrease in GZMB, NRP1, SERPINB9, and ITPR1 transcripts in GV Tregs. Additionally, disease activity and severity-based analyses revealed significantly decreased GZMB (p = 0.019 and 0.034), SERPINB9 (p = 0.031 and p = 0.035), and ITPR1 (p = 0.0003 and p = 0.034) transcripts in active vitiligo and severe GV patients' Tregs. Interestingly, we found a positive correlation for ITPR1 with GZMB (r = 0.45, p = 0.0009) and SERPINB9 (r = 0.52, p = 0.001) transcripts in GV Tregs. Moreover, we found positive correlation for percentage Treg mediated suppression of CD4+ and CD8+T cells with ITPR1 (r = 0.54; r = 0.49), GZMB (r = 0.61; r = 0.58), NRP1 (r = 0.55; r = 0.52), and SERPINB9 (r = 0.56; r = 0.48) in GV Tregs. Further, calcium treatment of Tregs resulted into significantly increased ITPR1, SERPINB9, and GZMB transcripts in GV Tregs (p = 0.023, p = 0.0345, p = 0.02). Overall, our results for the first time revealed the crucial role of GZMB, NRP1, SERPINB9, and ITPR1 transcripts in decreased Treg suppressive capacity leading to GV pathogenesis, progression, and severity. In addition, our study highlighted that ITPR1 might be linked with decreased GZMB and NRP1 expression in GV Tregs. Moreover, our study for the first time suggest that increased SERPINB9 transcripts may lead to endogenous granzyme B-mediated Tregs apoptosis, and calcium treatment of Tregs may improve the Treg suppressive capacity. These findings may further aid in development of Treg-based therapeutics for GV.

An overview of JAK/STAT pathways and JAK inhibition in alopecia areata

Alopecia Areata (AA) is a common autoimmune disease characterized by non-scarring hair loss ranging from patches on the scalp to complete hair loss involving the entire body. Disease onset is hypothesized to follow the collapse of immune privilege of the hair follicle, which results in an increase in self-peptide/MHC expression along the follicular epithelium. Hair loss is associated with infiltration of the hair follicle with putatively self-reactive T cells. This process is thought to skew the hair follicle microenvironment away from a typically homeostatic immune state towards one of active inflammation. This imbalance is mediated in part by the dominating presence of specific cytokines. While interferon-γ (IFNγ) has been identified as the key player in AA pathogenesis, many other cytokines have also been shown to play pivotal roles. Mechanistic studies in animal models have highlighted the contribution of common gamma chain (γ_c) cytokines such as IL-2, IL-7, and IL-15 in augmenting disease. IFNγ and γ_c cytokines signal through pathways involving receptor activation of Janus kinases (JAKs) and signal transducers and activators of transcription (STATs). Based on these findings, JAK/STAT pathways have been targeted for the purposes of therapeutic intervention in the clinical setting. Case reports and series have described use of small molecule JAK inhibitors leading to hair regrowth among AA patients. Furthermore, emerging clinical trial results show great promise and position JAK inhibitors as a treatment strategy for patients with severe or recalcitrant disease. Demonstrated efficacy from large-scale clinical trials of the JAK inhibitor baricitinib led to the first-in-disease FDA-approved treatment for AA in June of 2022. This review aims to highlight the JAK/STAT signaling pathways of various cytokines involved in AA and how targeting those pathways may impact disease outcomes in both laboratory and clinical settings.

The ADP-Ribosylation Factor 4d Restricts Regulatory T-Cell Induction via Control of IL-2 Availability

Interleukin-2 is central to the induction and maintenance of both natural (nT_reg) and induced Foxp3-expressing regulatory T cells (iT_reg). Thus, signals that modulate IL-2 availability may, in turn, also influence T_reg homeostasis. Using global knockout and cell-specific knockout mouse models, we evaluated the role of the small GTPase ADP-ribosylation factor 4d (Arl4d) in regulatory T-cell biology. We show that the expression of Arl4d in T cells restricts both IL-2 production and responsiveness to IL-2, as measured by the phosphorylation of STAT5. Arl4d-deficient CD4 T cells converted more efficiently into Foxp3⁺ iT_reg in vitro in the presence of αCD3ε and TGFβ, which was associated with their enhanced IL-2 secretion. As such, Arl4d^−/− CD4 T cells induced significantly less colonic inflammation and lymphocytic infiltration in a model of transfer colitis. Thus, our data reveal a negative regulatory role for Arl4d in CD4 T-cell biology, limiting iT_reg conversion via the restriction of IL-2 production, leading to reduced induction of T_reg from conventional CD4 T cells.

Single-Cell RNA Sequencing Analysis for Oncogenic Mechanisms Underlying Oral Squamous Cell Carcinoma Carcinogenesis with Candida albicans Infection

Oral squamous cell carcinoma (OSCC) carcinogenesis involves heterogeneous tumor cells, and the tumor microenvironment (TME) is highly complex with many different cell types. Cancer cell-TME interactions are crucial in OSCC progression. Candida albicans (C. albicans)-frequently pre-sent in the oral potentially malignant disorder (OPMD) lesions and OSCC tissues-promotes malignant transformation. The aim of the study is to verify the mechanisms underlying OSCC car-cinogenesis with C. albicans infection and identify the biomarker for the early detection of OSCC and as the treatment target. The single-cell RNA sequencing analysis (scRNA-seq) was performed to explore the cell subtypes in normal oral mucosa, OPMD, and OSCC tissues. The cell composi-tion changes and oncogenic mechanisms underlying OSCC carcinogenesis with C. albicans infec-tion were investigated. Gene Set Variation Analysis (GSVA) was used to survey the mechanisms underlying OSCC carcinogenesis with and without C. albicans infection. The results revealed spe-cific cell clusters contributing to OSCC carcinogenesis with and without C. albicans infection. The major mechanisms involved in OSCC carcinogenesis without C. albicans infection are the IL2/STAT5, TNFα/NFκB, and TGFβ signaling pathways, whereas those involved in OSCC carcinogenesis with C. albicans infection are the KRAS signaling pathway and E2F target down-stream genes. Finally, stratifin (SFN) was validated to be a specific biomarker of OSCC with C. albicans infection. Thus, the detailed mechanism underlying OSCC carcinogenesis with C. albicans infection was determined and identified the treatment biomarker with potential precision medicine applications.

Analysis of Faecal Microbiota and Small ncRNAs in Autism: Detection of miRNAs and piRNAs with Possible Implications in Host-Gut Microbiota Cross-Talk

Intestinal microorganisms impact health by maintaining gut homeostasis and shaping the host immunity, while gut dysbiosis associates with many conditions, including autism, a complex neurodevelopmental disorder with multifactorial aetiology. In autism, gut dysbiosis correlates with symptom severity and is characterised by a reduced bacterial variability and a diminished beneficial commensal relationship. Microbiota can influence the expression of host microRNAs that, in turn, regulate the growth of intestinal bacteria by means of bidirectional host-gut microbiota cross-talk. We investigated possible interactions among intestinal microbes and between them and host transcriptional modulators in autism. To this purpose, we analysed, by "omics" technologies, faecal microbiome, mycobiome, and small non-coding-RNAs (particularly miRNAs and piRNAs) of children with autism and neurotypical development. Patients displayed gut dysbiosis related to a reduction of healthy gut micro- and mycobiota as well as up-regulated transcriptional modulators. The targets of dysregulated non-coding-RNAs are involved in intestinal permeability, inflammation, and autism. Furthermore, microbial families, underrepresented in patients, participate in the production of human essential metabolites negatively influencing the health condition. Here, we propose a novel approach to analyse faeces as a whole, and for the first time, we detected miRNAs and piRNAs in faecal samples of patients with autism.

Immunosuppressive Signaling Pathways as Targeted Cancer Therapies

Immune response has been shown to play an important role in defining patient prognosis and response to cancer treatment. Tumor-induced immunosuppression encouraged the recent development of new chemotherapeutic agents that assists in the augmentation of immune responses. Molecular mechanisms that tumors use to evade immunosurveillance are attributed to their ability to alter antigen processing/presentation pathways and the tumor microenvironment. Cancer cells take advantage of normal molecular and immunoregulatory machinery to survive and thrive. Cancer cells constantly adjust their genetic makeup using several mechanisms such as nucleotide excision repair as well as microsatellite and chromosomal instability, thus giving rise to new variants with reduced immunogenicity and the ability to continue to grow without restrictions. This review will focus on the central molecular signaling pathways involved in immunosuppressive cells and briefly discuss how cancer cells evade immunosurveillance by manipulating antigen processing cells and related proteins. Secondly, the review will discuss how these pathways can be utilized for the implementation of precision medicine and deciphering drug resistance.

Immunosuppressive Signaling Pathways as Targeted Cancer Therapies

Immune response has been shown to play an important role in defining patient prognosis and response to cancer treatment. Tumor-induced immunosuppression encouraged the recent development of new chemotherapeutic agents that assists in the augmentation of immune responses. Molecular mechanisms that tumors use to evade immunosurveillance are attributed to their ability to alter antigen processing/presentation pathways and the tumor microenvironment. Cancer cells take advantage of normal molecular and immunoregulatory machinery to survive and thrive. Cancer cells constantly adjust their genetic makeup using several mechanisms such as nucleotide excision repair as well as microsatellite and chromosomal instability, thus giving rise to new variants with reduced immunogenicity and the ability to continue to grow without restrictions. This review will focus on the central molecular signaling pathways involved in immunosuppressive cells and briefly discuss how cancer cells evade immunosurveillance by manipulating antigen processing cells and related proteins. Secondly, the review will discuss how these pathways can be utilized for the implementation of precision medicine and deciphering drug resistance.

Syntaxin 4 Enrichment in β-Cells Prevents Conversion to Autoimmune Diabetes in Non-Obese Diabetic (NOD) Mice

Syntaxin 4 (STX4), a plasma membrane-localized SNARE protein, regulates human islet β-cell insulin secretion and preservation of β-cell mass. We found that human type 1 diabetes (T1D) and NOD mouse islets show reduced β-cell STX4 expression, consistent with decreased STX4 expression, as a potential driver of T1D phenotypes. To test this hypothesis, we generated inducible β-cell-specific STX4-expressing NOD mice (NOD-iβSTX4). Of NOD-iβSTX4 mice, 73% had sustained normoglycemia vs. <20% of control NOD (NOD-Ctrl) mice by 25 weeks of age. At 12 weeks of age, before diabetes conversion, NOD-iβSTX4 mice demonstrated superior whole-body glucose tolerance and β-cell glucose responsiveness than NOD-Ctrl mice. Higher β-cell mass and reduced β-cell apoptosis were also detected in NOD-iβSTX4 pancreata compared with pancreata of NOD-Ctrl mice. Single-cell RNA sequencing revealed that islets from NOD-iβSTX4 had markedly reduced interferon-γ signaling and tumor necrosis factor-α signaling via nuclear factor-κB in islet β-cells, including reduced expression of the chemokine CCL5; CD4+ regulatory T cells were also enriched in NOD-iβSTX4 islets. These results provide a deeper mechanistic understanding of STX4 function in β-cell protection and warrant further investigation of STX4 enrichment as a strategy to reverse or prevent T1D in humans or protect β-cell grafts.

A DAP5/eIF3d alternate mRNA translation mechanism promotes differentiation and immune suppression by human regulatory T cells

Regulatory T cells (Treg cells) inhibit effector T cells and maintain immune system homeostasis. Treg cell maturation in peripheral sites requires inhibition of protein kinase mTORC1 and TGF-beta-1 (TGF-beta). While Treg cell maturation requires protein synthesis, mTORC1 inhibition downregulates it, leaving unanswered how Treg cells achieve essential mRNA translation for development and immune suppression activity. Using human CD4+ T cells differentiated in culture and genome-wide transcription and translation profiling, here we report that TGF-beta transcriptionally reprograms naive T cells to express Treg cell differentiation and immune suppression mRNAs, while mTORC1 inhibition impairs translation of T cell mRNAs but not those induced by TGF-beta. Rather than canonical mTORC1/eIF4E/eIF4G translation, Treg cell mRNAs utilize the eIF4G homolog DAP5 and initiation factor eIF3d in a non-canonical translation mechanism that requires cap-dependent binding by eIF3d directed by Treg cell mRNA 5' noncoding regions. Silencing DAP5 in isolated human naive CD4+ T cells impairs their differentiation into Treg cells. Treg cell differentiation is mediated by mTORC1 downregulation and TGF-beta transcriptional reprogramming that establishes a DAP5/eIF3d-selective mechanism of mRNA translation.

Evaluation of Anticancer Potential of Flavones from Rhamnus alaternus against B16F10 Melanoma Cells

Melanoma has become an important health problem and new treatment have become an imperative medical need. Therefore, the finding and identification of natural product with less toxic effects, capable of promoting melanoma cell death have become an important goal of research in oncotherapy. In this study, we want to investigate the anticancer activity of an enriched total oligomers flavonoids (TOF) extract of R. alaternus in melanoma cells. First, TOF was exhibited to be rich in flavones. We revealed that this extract reduced proliferation and increased of sub-G1 and S phase cells built-up in B16-F10 cells in a dose-related manner. Moreover, In Vivo, TOF reduced tumor volume and weight with percentages of inhibition of 92.4% and 92.9%, respectively. R. alaternus was also found to be effective in reducing the level of pro-inflammatory cytokine IL-6 during metastasis. Level of TH1 cytokine, such as IL-2, was significantly enhanced by TOF treatment. Indeed, the histological examination of the tumor revealed the absence of mitoses and the presence of numerous melanin pigmented macrophage cells in the R. alaternus extract-treated group that could be explained by the induction of macrophage activation and by the arrest of the cell cycle in the Sub-G1 and S phases.

Construction of a Ferroptosis-Related Nine-lncRNA Signature for Predicting Prognosis and Immune Response in Hepatocellular Carcinoma

Ferroptosis is an iron-dependent cell death process that plays important regulatory roles in the occurrence and development of cancers, including hepatocellular carcinoma (HCC). Moreover, the molecular events surrounding aberrantly expressed long non-coding RNAs (lncRNAs) that drive HCC initiation and progression have attracted increasing attention. However, research on ferroptosis-related lncRNA prognostic signature in patients with HCC is still lacking. In this study, the association between differentially expressed lncRNAs and ferroptosis-related genes, in 374 HCC and 50 normal hepatic samples obtained from The Cancer Genome Atlas (TCGA), was evaluated using Pearson's test, thereby identifying 24 ferroptosis-related differentially expressed lncRNAs. The least absolute shrinkage and selection operator (LASSO) algorithm and Cox regression model were used to construct and validate a prognostic risk score model from both TCGA training dataset and GEO testing dataset (GSE40144). A nine-lncRNA-based signature (CTD-2033A16.3, CTD-2116N20.1, CTD-2510F5.4, DDX11-AS1, LINC00942, LINC01224, LINC01231, LINC01508, and ZFPM2-AS1) was identified as the ferroptosis-related prognostic model for HCC, independent of multiple clinicopathological parameters. In addition, the HCC patients were divided into high-risk and low-risk groups according to the nine-lncRNA prognostic signature. The gene set enrichment analysis enrichment analysis revealed that the lncRNA-based signature might regulate the HCC immune microenvironment by interfering with tumor necrosis factor α/nuclear factor kappa-B, interleukin 2/signal transducers and activators of transcription 5, and cytokine/cytokine receptor signaling pathways. The infiltrating immune cell subtypes, such as resting memory CD4(+) T cells, follicular helper T cells, regulatory T cells, and M0 macrophages, were all significantly different between the high-risk group and the low-risk group as indicated in Spearman's correlation analysis. Moreover, a substantial increase in the expression of B7H3 immune checkpoint molecule was found in the high-risk group. Our findings provided a promising insight into ferroptosis-related lncRNAs in HCC and a personalized prediction tool for prognosis and immune responses in patients.

Immune and Metabolic Dysregulated Coding and Non-coding RNAs Reveal Survival Association in Uterine Corpus Endometrial Carcinoma

Uterine corpus endometrial carcinoma (UCEC) is one of the most common gynecologic malignancies, but only a few biomarkers have been proven to be effective in clinical practice. Previous studies have demonstrated the important roles of non-coding RNAs (ncRNAs) in diagnosis, prognosis, and therapy selection in UCEC and suggested the significance of integrating molecules at different levels for interpreting the underlying molecular mechanism. In this study, we collected transcriptome data, including long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and messenger RNAs (mRNAs), of 570 samples, which were comprised of 537 UCEC samples and 33 normal samples. First, differentially expressed lncRNAs, miRNAs, and mRNAs, which distinguished invasive carcinoma samples from normal samples, were identified, and further analysis showed that cancer- and metabolism-related functions were enriched by these RNAs. Next, an integrated, dysregulated, and scale-free biological network consisting of differentially expressed lncRNAs, miRNAs, and mRNAs was constructed. Protein-coding and ncRNA genes in this network showed potential immune and metabolic functions. A further analysis revealed two clinic-related modules that showed a close correlation with metabolic and immune functions. RNAs in the two modules were functionally validated to be associated with UCEC. The findings of this study demonstrate an important clinical application for improving outcome prediction for UCEC.

Biocompatibility Evolves: Phenomenology to Toxicology to Regeneration

The word "biocompatibility," is inconsistent with the observations of healing for so-called biocompatible biomaterials. The vast majority of the millions of medical implants in humans today, presumably "biocompatible," are walled off by a dense, avascular, crosslinked collagen capsule, hardly suggestive of life or compatibility. In contrast, one is now seeing examples of implant biomaterials that lead to a vascularized reconstruction of localized tissue, a biological reaction different from traditional biocompatible materials that generate a foreign body capsule. Both the encapsulated biomaterials and the reconstructive biomaterials qualify as "biocompatible" by present day measurements of biocompatibility. Yet, this new generation of materials would seem to heal "compatibly" with the living organism, where older biomaterials are isolated from the living organism by the dense capsule. This review/perspective article will explore this biocompatibility etymological conundrum by reviewing the history of the concepts around biocompatibility, today's standard methods for assessing biocompatibility, a contemporary view of the foreign body reaction and finally, a compendium of new biomaterials that heal without the foreign body capsule. A new definition of biocompatibility is offered here to address advances in biomaterials design leading to biomaterials that heal into the body in a facile manner.

Chronic E-Cigarette Aerosol Inhalation Alters the Immune State of the Lungs and Increases ACE2 Expression, Raising Concern for Altered Response and Susceptibility to SARS-CoV-2

Conventional smoking is known to both increase susceptibility to infection and drive inflammation within the lungs. Recently, smokers have been found to be at higher risk of developing severe forms of coronavirus disease 2019 (COVID-19). E-cigarette aerosol inhalation (vaping) has been associated with several inflammatory lung disorders, including the recent e-cigarette or vaping product use-associated lung injury (EVALI) epidemic, and recent studies have suggested that vaping alters host susceptibility to pathogens such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To assess the impact of vaping on lung inflammatory pathways, including the angiotensin-converting enzyme 2 (ACE2) receptor known to be involved in SARS-CoV-2 infection, mice were exposed to e-cigarette aerosols for 60 min daily for 1-6 months and underwent gene expression analysis. Hierarchical clustering revealed extensive gene expression changes occurred in the lungs of both inbred C57BL/6 mice and outbred CD1 mice, with 2,933 gene expression changes in C57BL/6 mice, and 2,818 gene expression changes in CD1 mice (>abs 1.25-fold change). Particularly, large reductions in IgA and CD4 were identified, indicating impairment of host responses to pathogens via reductions in immunoglobulins and CD4 T cells. CD177, facmr, tlr9, fcgr1, and ccr2 were also reduced, consistent with diminished host defenses via decreased neutrophils and/or monocytes in the lungs. Gene set enrichment (GSE) plots demonstrated upregulation of gene expression related to cell activation specifically in neutrophils. As neutrophils are a potential driver of acute lung injury in COVID-19, increased neutrophil activation in the lungs suggests that vapers are at higher risk of developing more severe forms of COVID-19. The receptor through which SARS-CoV-2 infects host cells, ACE2, was found to have moderate upregulation in mice exposed to unflavored vape pens, and further upregulation (six-fold) with JUUL mint aerosol exposure. No changes were found in mice exposed to unflavored Mod device-generated aerosols. These findings suggest that specific vaping devices and components of e-liquids have an effect on ACE2 expression, thus potentially increasing susceptibility to SARS-CoV-2. In addition, exposure to e-cigarette aerosols both with and without nicotine led to alterations in eicosanoid lipid profiles within the BAL. These data demonstrate that chronic, daily inhalation of e-cigarette aerosols fundamentally alters the inflammatory and immune state of the lungs. Thus, e-cigarette vapers may be at higher risk of developing infections and inflammatory disorders of the lungs.

Key molecules involved in the Th17/Treg balance are associated with the pathogenesis of reflux esophagitis and Barrett's esophagus

BACKGROUND

Reflux esophagitis (RE) impairs the squamous epithelium that normally lines the esophagus, and contributes to the replacement of the damaged squamous lining by the intestinal metaplasia of Barrett's esophagus (BE), which is considered as a precursor of esophageal adenocarcinoma. This study aimed to investigate the changes in the balance of Th17/Treg and the related key molecules in the pathogenesis of RE and BE and evaluate the diagnostic and predictive value of the molecules in patients with these diseases.

METHODS

The proportions of Th17 and Treg in RE and BE patients were estimated using flow cytometric analysis. Key molecules involving in the Th17/Treg balance, including RORγt, Foxp3, IL-17, IL-6, IL-10, and TGF-β, were measured using quantitative real-time PCR (qRT-PCR) and ELISA analyses. The diagnostic and predictive value of the Th17/Treg ratio and its key regulators was evaluated using a receiver operating characteristic assay (ROC). In addition, the Spearman correlation analysis explored the relationship between the Th17/Treg ratio and the clinical characteristics.

RESULTS

An increased ratio of Th17/Treg was observed in RE and BE compared with the normal controls, and the proportion of Th17/Treg in BE was further increased compared with RE patients. Moreover, the expression levels of RORγt, IL-17, IL-6, and TGF-β were elevated, while the levels of Foxp3 and IL-10 were reduced in patients when compared to the controls. Compared with the RE groups, the levels of IL-17 were significantly higher in BE patients, while the Foxp3 levels were significant decreased. In addition, the Th17/Treg ratio also showed high diagnostic significance and considerable predictive value for the clinical outcomes in patients with RE and BE.

CONCLUSION

The balance of Th17/Treg was impaired in patients with RE and BE. Th17/Treg may be involved in the development of both RE and BE through regulating the release of inflammatory cytokines, but the concrete mechanisms maybe different in the two diseases. The imbalance of Th17/Treg ratio and the related key molecules had a certain clinical diagnosis and prediction potential for RE and BE.

Stat5B is required for IgE-Mediated mast cell function in vitro and in vivo

Mast cells are found primarily at interfaces with the external environment, where they provide protection from pathogens but also elicit allergic inflammation. Mast cell activation by antigen-induced aggregation of IgE bound to the high affinity receptor, FcεRI, is a critical factor leading to inflammation and bronchoconstriction. We previously found that Stat5 is activated by FcεRI and that Stat5B suppression decreased IgE-induced cytokine production in vitro, but in vivo responses have not been assessed. We now show that Stat5B-deficient (KO) mice have reduced responses to IgE-mediated anaphylaxis, despite normal mast cell tissue distribution. Similarly, Stat5B KO mast cells have diminished IgE-induced degranulation and cytokine secretion in vitro. These mice have elevated IgE production that is not correlated with an intrinsic B cell defect. The current work demonstrates that the Stat5B isoform is required for normal mast cell function and suggests it limits IgE production in vivo.

Geranylgeranyl pyrophosphate amplifies Treg differentiation via increased IL-2 expression to ameliorate DSS-induced colitis

Blocking the mevalonate pathway for cholesterol reduction by using statin may have adverse effects including statin-induced colitis. Moreover, one of the predisposing factors for colitis is an imbalanced CD4⁺ T cell, which can be observed on the complete deletion of HMG-CoA reductase (HMGCR), a target of statins. In this study, we inquired geranylgeranyl pyrophosphate (GGPP) is responsible for maintaining the T-cell homeostasis. Following dextran sulfate sodium (DSS)-induced colitis, simvastatin increased the severity of disease, while cotreatment with GGPP, but not with cholesterol, reversed the disease magnitude. GGPP ameliorated DSS-induced colitis by increasing T_reg cells. GGPP amplified T_reg differentiation through increased IL-2/STAT 5 signaling. GGPP prenylated Ras protein, a prerequisite for extracellular signal-regulated kinase (ERK) pathway activation, leading to increased IL-2 production. Higher simvastatin dose increased the severity of colitis. GGPP ameliorated simvastatin-increased colitis by increasing T_reg cells. T_reg cells, which have the capacity to suppress inflammatory T cells and were generated through IL-2/STAT5 signaling, increased IL-2 production through prenylation and activation of the Ras/ERK pathway.

T-regulatory cells from patients with rheumatoid arthritis retain suppressor functions in vitro

Rheumatoid arthritis (RA) is a chronic disease of connective tissue caused by intolerance to self-antigens. Regulatory T cells (Tregs) are key players in maintaining autotolerance through a variety of suppressor mechanisms. RA is generally believed to develop due to disorders in Tregs; however, there is no consensus on this issue. Thus, the present study focused on phenotypical analysis of Treg cells and their ability to suppress CD4⁺ and CD8⁺ cell proliferation. The present study used peripheral blood samples from 21 patients with RA and 22 healthy donors. The CD25⁺FoxP3⁺ subpopulation of Tregs was analyzed using flow cytometry to evaluate the expression of CTLA-4, PD-L1, HLA-DR, CCR4, CD86 and RORyt. Tregs suppressor activity was calculated in terms of suppression of the proliferation of CD4⁺ and CD8⁺ lymphocytes in vitro. Suppressor activity of the total Treg population did not differ between patients with RA and healthy donors. However, the patients had elevated CD25^loFoxP3⁺ levels and lower CD25^hiFoxP3⁺ levels; in addition, they had more activated Tregs expressing PD-L1, HLA-DR, CCR4 and CD86. The surface expression of CTLA-4 was below the reference level. The patients also had transitional FoxP3⁺RORyt⁺ cells and elevated CD4⁺RORyt⁺ levels, which were highly correlated with disease activity. These results show that in RA, Treg cells are activated and have an immunosuppressive activity. However, it is the transitional FoxP3⁺RORyt⁺ cells and increased CD4⁺RORyt⁺ percentages in peripheral blood that appear to be associated with the pathological conversion of some Treg cells into Th-17. This process appears to be key in RA pathogenesis.

Treg cell therapy: How cell heterogeneity can make the difference

CD4⁺ CD25^high CD127^low/- FOXP3⁺ T regulatory cells are responsible for maintaining immune tolerance and controlling excessive immune responses. Treg cell use in pre-clinical animal models showed the huge therapeutic potential of these cells in immune-mediated diseases and laid the foundations for their applications in therapy in humans. Currently, there are several clinical trials utilizing the adoptive transfer of Treg cells to reduce the morbidity in autoimmune disorders, allogeneic HSC transplantation, and solid organ transplantation. However, a large part of them utilizes total Treg cells without distinction of their biological variability. Many studies on the heterogeneity of Treg cell population revealed distinct subsets with different functions in the control of the immune response and induction of peripheral tolerance. Some of these subsets also showed a role in controlling the general homeostasis of non-lymphoid tissues. All these Treg cell subsets and their peculiar properties can be therefore exploited to develop novel therapeutic approaches. This review describes these functionally distinct subsets, their phenotype, homing properties and functions in lymphoid and non-lymphoid tissues. In addition, we also discuss the limitations in using Treg cells as a cellular therapy and the strategies to enhance their efficacy.

Inactivated STAT5 pathway underlies a novel inhibitory role of EBF1 in chronic lymphocytic leukemia

B-cell chronic lymphocytic leukemia (CLL) is a disease caused by gradual accumulation of functionally incompetent lymphocytes. The majority of CLL cases are accompanied by chemoresistance. Early B cell factor 1 (EBF1) is a crucial contributor to B-cell lymphopoiesis. This study is to explore the effect of EBF1 on CLL cell progression and its involvement in regulating the signal transducers and activators of transcription 5 (STAT5) pathway. We conducted a correlation analysis between EBF1 and the clinical characteristics of CLL patients. Subsequently, EBF1 was overexpressed by transfection with EBF1 overexpression plasmid and the STAT5 pathway was also blocked by treatment with SH-4-54 in isolated CD20⁺ B lymphocytes to investigate their roles in the regulation of cellular functions. STAT5, Janus kinase 2 (JAK2) expression and their phosphorylation levels were determined by quantitative PCR and Western blot analyses. The in vivo effects of EBF1 on tumor growth were evaluated using a xenotransplant model. Downregulation of EBF1 was observed in CD20⁺ B lymphocytes of CLL patients. EBF1 overexpression disrupted the activation of STAT5 pathway, as evidenced by decreased expression and phosphorylation levels of STAT5 and JAK2. Furthermore, overexpression of EBF1 repressed viability and cell cycle entry, and increased apoptosis of CD20⁺ B lymphocytes by inhibiting the STAT5 pathway. Finally, EBF1 exerted antitumor effects in nude mice. Overall, our study elucidates the inhibitory role of EBF1 in CLL through inactivation of the STAT5 pathway, which may provide new targets for CLL treatment.

Maresin1 ameliorates acute lung injury induced by sepsis through regulating Th17/Treg balance

The disturbance of the immune homeostasis caused by infection is decisive for multiple organ dysfunction caused by sepsis. Both the th17 cell and the regulatory cell(Tregs) are important components of the immune system and play a crucial role in maintaining immune homeostasis. In this study, we explored the effect of Maresin1, an emerging specific pro-inflammatory mediator, on the balance of Th17/Treg in sepsis, and investigated the underlying mechanism. We used the male C57BL/6 mice to establish the model of sepsis-induced lung injury by cecal ligation and puncture to verify the protective effect of Maresin1. Our study showed that Maresin1 could significantly inhibit the excessive inflammatory response and promote the inflammation regression in the process of sepsis-induced acute lung injury, thereby reducing lung damage and improving lung function. These effects were accompanied with the regulation of Maresin1 on the Th17/Treg balance in the early stages of sepsis. We demonstrated that Maresin1 has a certain effect on increasing the number of Treg and decreasing the number of Th17 cells in the early stages of sepsis, which is consistent with its effect on STAT3/RORγt and STAT5/Foxp3 signal pathways. Our study elucidated for the first time the relationship between Maresin1 and Th17/Treg balance in sepsis-induced acute lung injury.

miRNA Regulation of T Cells in Islet Autoimmunity and Type 1 Diabetes

PURPOSE OF REVIEW

Regulatory T cells (Tregs) are critical contributors to immune homeostasis and their dysregulation can lead to the loss of immune tolerance and autoimmune diseases like type 1 diabetes (T1D). Recent studies have highlighted microRNAs (miRNAs) as important regulators of the immune system, by fine-tuning relevant genes in various immune cell types. In this review article, we discuss recent insights into miRNA regulation of immune tolerance and activation. Specifically, we discuss how the dysregulation of miRNAs in T cells contributes to their aberrant function and the onset of islet autoimmunity, as well as their potential as targets of novel intervention strategies to interfere with autoimmune activation.

RECENT FINDINGS

Several studies have shown that the dysregulation of individual miRNAs in T cells can contribute to impaired immune tolerance, contributing to onset and progression of islet autoimmunity. Importantly, the targeting of these miRNAs, including miR-92a, miR-142-3p and miR-181a, resulted in relevant effects on downstream pathways, improved Treg function and reduced islet autoimmunity in murine models. miRNAs are critical regulators of immune homeostasis and the dysregulation of individual miRNAs in T cells contributes to aberrant T cell function and autoimmunity. The specific targeting of individual miRNAs could improve Treg homeostasis and therefore limit overshooting T cell activation and islet autoimmunity.

MKL-1 is a coactivator for STAT5b, the regulator of Treg cell development and function

Background

Foxp3⁺CD4⁺ regulatory T cells (Treg) constitutes a key event in autoimmune diseases. STAT5b is the critical link between the IL-2/15 and FOXP3, the master regulator of Treg cells.

Methods

The CD3⁺T cell and Foxp3⁺CD4⁺ regulatory T cells were overexpressioned or knockdown MKL-1 and STAT5a and tested for Treg cell development and function. Direct interaction of MKL-1 and STAT5a were analyzed by coimmunoprecipitation assays, Luciferase assay, Immunofluoresence Staining and Yeast two-hybrid screening. The effect of MKL-1 and STAT5a on the Treg genes expression was analyzed by qPCR and western blotting and Flow cytometry.

Results

However, the molecular mechanisms mediating STAT5b-dependent Treg genes expression and Treg cell phenotype and function in autoimmune diseases are not well defined. Here, we report that the MKL-1 is a coactivator for the major Treg genes transcription factor STAT5b, which is required for human Treg cell phenotype and function. The N terminus of STAT5b, which contains a basic coiled-coil protein–protein interaction domain, binds the C-terminal activation domain of MKL-1 and enhances MKL-1 mediated transcriptional activation of Treg-specific, CArG containing promoters, including the Treg-specific genes Foxp3. Suppression of endogenous STAT5b expression by specific small interfering RNA attenuates MKL-1 transcriptional activation in cultured human cells. The STAT5b–MKL-1 interaction identifies a role of Treg-specific gene regulation and regulated mouse Treg cell development and function and suggests a possible mechanism for the protective effects of autoimmune disease Idiopathic Thrombocytopenic Purpura (ITP).

Conclusions

Our studies demonstrate for the first time that MKL-1 is a coactivator for STAT5b, the regulator of Treg cell development and function.

Analysis of Single Nucleotide Polymorphisms in HLA-DRA, IL2RA , and HMGB1 Genes in Multiple Sclerosis

BACKGROUND

Multiple sclerosis (MS) is a common demyelinating neurodegenerative disorder with significant heritability. Previous studies have associated genetic variants in human leukocyte antigen (HLA) complex, IL2RA , and HMGB1 genes with the pathophysiology of MS.

METHODS

In order to investigate the gene association in the Iranian population, we performed a genotyping study of 36 variants in the mentioned genes using Sanger sequencing in 102 MS patients and 113 healthy controls.

RESULTS

Our results identified significant associations as well as significant allele frequency differences in some of the studied single-nucleotide polymorphisms including rs4935356, rs3177928, and rs7197 from HLA-DRA gene, and rs12722489 and rs12722490 variants from IL2RA gene (p< 0.05). Moreover, the strong linkage disequilibrium of two common haplotypes was estimated from the HLA-DRA gene.

CONCLUSION

This association study may suggest the role of these polymorphisms in the genetic susceptibility of MS in the Iranian population and would facilitate the recognition of causative variants in this disease.

An Integrative Network Modeling Approach to T CD4 Cell Activation

The adaptive immune response is initiated by the interaction of the T cell antigen receptor/CD3 complex (TCR) with a cognate peptide bound to a MHC molecule. This interaction, along with the activity of co-stimulatory molecules and cytokines in the microenvironment, enables cells to proliferate and produce soluble factors that stimulate other branches of the immune response for inactivation of infectious agents. The intracellular activation signals are reinforced, amplified and diversified by a complex network of biochemical interactions, and includes the activity of molecules that modulate the activation process and stimulate the metabolic changes necessary for fulfilling the cell energy demands. We present an approach to the analysis of the main early signaling events of T cell activation by proposing a concise 46-node hybrid Boolean model of the main steps of TCR and CD28 downstream signaling, encompassing the activity of the anergy factor Ndrg1, modulation of activation by CTLA-4, and the activity of the nutrient sensor AMPK as intrinsic players of the activation process. The model generates stable states that reflect the overcoming of activation signals and induction of anergy by the expression of Ndrg1 in the absence of co-stimulation. The model also includes the induction of CTLA-4 upon activation and its competition with CD28 for binding to the co-stimulatory CD80/86 molecules, leading to stable states that reflect the activation arrest. Furthermore, the model integrates the activity of AMPK to the general pathways driving differentiation to functional cell subsets (Th1, Th2, Th17, and Treg). Thus, the network topology incorporates basic mechanism associated to activation, regulation and induction of effector cell phenotypes. The model puts forth a conceptual framework for the integration of functionally relevant processes in the analysis of the T CD4 cell function.

CCL11 increases the proportion of CD4+CD25+Foxp3+ Treg cells and the production of IL‑2 and TGF‑β by CD4+ T cells via the STAT5 signaling pathway

CD4⁺ regulatory T (Treg) cells are associated with immune tolerance and antitumor immunosuppression. The aim of the present study was to investigate the role and molecular mechanism of C-C motif chemokine ligand 11 (CCL11) in the regulation of Treg cells from patients with breast cancer (BC) and healthy individuals in vitro, and from tumor-bearing mice in vivo. CD4⁺ T cells isolated from patients with BC or healthy individuals were incubated with anti-CCL11 neutralizing antibodies or recombinant human CCL11 protein, in the presence or absence of a STAT5 inhibitor. The serum CCL11 level and proportion of Treg cells characterized as CD4⁺CD25⁺forkhead box P3⁺ (Foxp3) among the CD4⁺ T cells in patients with BC and healthy individuals were analyzed by ELISA and flow cytometry, respectively. CCL11, C-C motif chemokine receptor 3 (CCR3), Foxp3, phosphorylated-STAT5 and STAT5 expression levels were determined by western blotting. The serum CCL11 level and the proportion of CD4⁺CD25⁺Foxp3⁺ Treg cells were significantly increased in patients with BC compared with healthy individuals. CCL11 blockade reduced the proportion of CD4⁺CD25⁺Foxp3⁺ Treg cells, the expression of CCR3 and Foxp3, and the level of STAT5 activation in tumor-associated CD4⁺ T cells, in a dose-dependent manner. CCL11 blockade also reduced the proportion of CD4⁺CD25⁺Foxp3⁺ Treg cells and the serum levels of interleukin (IL)-2 and transforming growth factor (TGF)-β1 in tumor-bearing mice. The recombinant human CCL11 protein increased the proportion of CD4⁺CD25⁺Foxp3⁺ Treg cells, the expression of CCR3 and Foxp3, and the release of IL-2 and TGF-β1 in non-tumor-associated CD4⁺ T cells via the STAT5 signaling pathway. The results of the present study may aid in identifying therapeutics that could further modulate the immune system during BC.