Innate lymphoid cells (ILCs) are long-lived, tissue-resident cell analogs to T helper subsets that lack antigen-specific receptors. Understanding the roles of specific ILCs in chronic inflammation and fibrosis has been limited by inadequate tools for selective targeting. Here, we used Il17rb-CreERT2-eGFP and Rorc-Cre strains to selectively delete RORα in ILC2s and ILC3/Th17 cells, respectively. RORα deletion in ILC2s caused significant loss of gastrointestinal ILC2s, increased ILC3 abundance, elevated Th17-type responses, and heightened susceptibility to Crohn's disease-like fibrosis. Conversely, RORα deletion in ILC3/Th17 cells reduced IL-17 production, protecting against fibrosis. Using isolithocholic acid (isoLCA), a microbial secondary bile acid and RORγt inverse agonist, we confirmed the role of ILC3s/Th17 cells in fibrosis. In RORγt reporter and Th17-deficient Rag1-/- mice, isoLCA reduced IL-17 production by ILC3s and attenuated intestinal fibrosis by dampening RORγt-dependent ILC3/Th17 responses. These findings reveal a novel interplay between ILC2s and ILC3s in gut homeostasis and demonstrate the therapeutic potential of targeting RORγt in ILC3s as a strategy for preventing fibrosis.

To investigate the role of lncRNA PVT1 in modulating CD4+ T cell subsets and its contribution to systemic lupus erythematosus (SLE) pathogenesis in human patients and MRL/lpr mice.

Measured PVT1 and miR-30e-5p expression in SLE patients (n = 65) and healthy controls (HCs) using qRT-PCR. Analyzed Th1/Th2/Th17/Treg cell frequencies by flow cytometry and cytokine levels (IL-2, IL-4, IL-6, IL-17, TGF-β) via ELISA. Constructed lentiviral vectors to silence (SLE + si-Pvt1) or overexpress Pvt1 (SLE + lenti-Pvt1) in MRL/lpr mice (n = 40).

PVT1 was upregulated (p = 0.0488) and miR-30e-5p downregulated (p = 0.0095) in SLE patients. Th2 (p = 0.0165) and Th17 (p = 0.0017) cells exhibited a significant increase, while Th1 and Treg cells decreased. Pvt1 silencing reversed SLE phenotypes, increasing Th1 and Treg cells, reducing Th2 and Th17 cells, restoring IL-2 and TGF-β levels and reducing levels of IL-6 and IL-17. Overexpression of Pvt1 exacerbated disease severity. Pvt1 acted as a ceRNA to sponge miR-30e-5p, modulating T-bet/GATA3/RORγt/Foxp3 expression.

PVT1 dysregulation disrupts CD4+ T cell homeostasis in SLE. Targeting the PVT1/miR-30e-5p axis may restore immune balance and represent a novel therapeutic strategy. Key Points • Our data confirm the imbalance of CD4+ T cell subsets in SLE patients and demonstrate specific upregulation of lncRNA PVT1 expression in female SLE patients. • Targeting lncRNA PVT1 affects Th1/Th2 and Th17/Treg homeostasis in MRL/lpr mice. • Offers fresh insight into the dysregulation of lymphocyte subsets in SLE.

Autoimmune toxicity affects up to 60 % of patients receiving immune checkpoint inhibitor (ICI) therapy for cancer, presenting a notable clinical obstacle that constrains its wider application. Hence, there is an imperative demand to develop novel strategies to manage immune-related adverse events (irAEs). Ifosfamide (IFO) shares structural and functional resemblances with cyclophosphamide (CPA). Despite the acknowledged dual anti-tumor and immunomodulatory effects of CPA, the specific effect of IFO on autoimmune conditions remains elusive. Here, we evaluated the efficacy of IFO on experimental autoimmune uveitis (EAU) mouse models and explored the cell-specific effects of IFO under autoimmune conditions using single-cell RNA sequencing. Our data indicated that IFO effectively alleviated inflammatory infiltration and reversed pathological alterations of EAU. Subsequent single-cell data analysis and in vivo experiments suggested IFO exerted broad suppressive effects on autoimmune responses, concurrently restoring the balance between Th17 and Treg populations. In addition, we observed that IFO enhanced CD8+ T cell activation and its cytotoxic immune responses, highlighting the cell-type-specific immunomodulatory effects of IFO. Moreover, we constructed EAU models on tumor-bearing mice under ICI treatment, and found that ICI exacerbated EAU symptoms. IFO not only possessed anti-tumor effects as monotherapy, but also augmented ICI efficacy by promoting CD8+ T cell-mediated immunity. Furthermore, we found that IFO alleviated EAU symptoms exacerbated by ICI treatment and effectively restored Th17/Treg balance. Our results elucidated the immunomodulatory effects of IFO treatment, providing evidence for the application of IFO in managing autoimmune conditions and irAEs.

The intestinal immune system maintains tolerance to harmless food proteins and gut microbiota through peripherally derived RORγt+ Tregs (pTregs), which prevent food intolerance and inflammatory bowel disease. Recent studies suggested that RORγt+ antigen-presenting cells (APCs), which encompass rare dendritic cell (DC) subsets and type 3 innate lymphoid cells (ILC3s), are key to pTreg induction. Here, we developed a mouse with reduced RORγt+ APCs by deleting a specific cis-regulatory element of Rorc encoding RORγt. Single-cell RNA sequencing and flow cytometry analyses confirmed the depletion of a RORγt+ DC subset and ILC3s. These mice showed a secondary reduction in pTregs, impaired tolerance to oral antigens, and an increase in T helper (Th)2 cells. Conversely, ILC3-deficient mice showed no pTregs or Th2 cell abnormalities. Lineage tracing revealed that RORγt+ DCs share a lymphoid origin with ILC3s, consistent with their similar phenotypic traits. These findings highlight the role of lymphoid RORγt+ DCs in maintaining intestinal immune balance and preventing conditions like food allergies.

Th17 cells can perform either regulatory or inflammatory functions depending on the cytokine microenvironment. These plastic cells can transdifferentiate into Tregs during inflammation resolution, in allogenic heart transplantation models, or in cancer through mechanisms that remain poorly understood. Here, we demonstrated that NLRP3 expression in Th17 cells is essential for maintaining their immunosuppressive functions through an inflammasome-independent mechanism. In the absence of NLRP3, Th17 cells produce more inflammatory cytokines (IFNγ, Granzyme B, TNFα) and exhibit reduced immunosuppressive activity toward CD8+ cells. Moreover, the capacity of NLRP3-deficient Th17 cells to transdifferentiate into Treg-like cells is lost. Mechanistically, NLRP3 in Th17 cells interacts with the TGF-β receptor, enabling SMAD3 phosphorylation and thereby facilitating the acquisition of immunosuppressive functions. Consequently, the absence of NLRP3 expression in Th17 cells from tumor-bearing mice enhances CD8 + T-cell effectiveness, ultimately inhibiting tumor growth.

Over-proliferation, activation, or aberrant CD4+ T cell differentiation causes various immune-related diseases. DCs are significant professional APCs that regulate the differentiation of CD4+ T cells to participate in an inflammatory response. IOP is an edible fungal polysaccharide with immunoregulatory and anti-inflammatory bioactivities, however, the cellular mechanisms by which they regulate the immune system to exert their anti-inflammatory effects remain unclear. The present study aimed to investigate the effects of IOP on the regulation of CD4+ T cell differentiation and the correlative mechanisms related to DCs. IOP did not regulate the proliferation and activation of CD4+ T cells. However, it inhibited the differentiation of Th1 and Th17 cells and promoted the differentiation of Treg cells. IOP maintained the immature phenotype of BMDCs, which induces immune tolerance and promotes the differentiation of CD4+ T cells into Treg cells. Transfusion of IOPL-BMDC into colitis mice markedly alleviated colitis-associated inflammation and maintained the colon's integrity. IOPL-BMDCs inhibited the differentiation of CD4+ T cells into inflammatory effective Th1 cells in the spleen and MLN while promoting their differentiation into immune-tolerant, anti-inflammatory Treg cells. In conclusion, this research demonstrated that IOP strongly regulates the polarization of CD4+ T cells to Treg subsets with inflammatory suppressive effects by inducing immature tolerant DCs, which provides strategic evidence for the therapeutic application of IOP in colitis, and IOP-induced tolerant DCs provide a new therapeutic approach to the development of a DC vaccine for colitis.

Much remains unknown regarding T follicular helper 17 (TFH17) cells commonly found in autoimmune patients. We previously showed that (and here ask why) egress of gut segmented filamentous bacteria (SFB)-induced TFH cells from Peyer's patches (PP) to systemic sites promotes arthritis. We found splenic TFH17 cells are gut derived. Functional analyses using fate-mapping mice revealed a c-Maf-dependent and SFB-induced TH17-to-TFH cell reprogramming that dominantly occurs in PPs. Unlike conventional TFH cells, TH17-derived TFH cells are highly migratory and atypically concentrated in the dark zone of germinal centers (GCs). Compared to conventional TFH cells, TH17-derived TFH cells express higher levels of TFH-associated functional molecules and more robustly conjugate with B cells. Gain- and loss-of-function studies demonstrated their dominance in promoting GC B cells and arthritis. Notably, murine gut TH17-derived TFH signatures exist in rheumatoid arthritis patients. Thus, gut T cell plasticity generates atypical, potent TFH cells promoting systemic autoimmunity.

Commencing with the breakdown of the intestinal barrier, various pathogenic factors, such as dysbiosis of the gut microbiota, harmful inflammatory cytokines, and immune system imbalance, collectively contribute to the development of colitis. Numerous interventions focusing on single factors have been developed to provide short-term therapeutic benefits, but the continued existence of unresolved pathogenic factors can lead to disease exacerbation. Here we have designed a multicomponent system-inulin microspheres encapsulating selenium-containing nanomicelles, aiming to tackle the multiple factors associated with colitis. This micro-nano drug delivery platform achieves sequential release of drugs in the inflamed colon, with each component of the system functioning independently and jointly. The outer layer of inulin supplies nutrients for probiotics. The inner core comprises selenocystamine and 3-oxolithocholic acid, which polarize macrophages towards an anti-inflammatory phenotype and regulate adaptive immunity by inhibiting TH17-cell differentiation, respectively. In an acute colitis mouse model, this therapeutic system ameliorates colonic inflammation, enhances the abundance of gut microbiota, and modulates the mucosal immune system, showing potential in preventing colitis.

Psoriasis is a chronic inflammatory skin disorder affecting approximately 125 million people. IL-17 A secreted from Th17 cells plays a major role in elucidating psoriasis. Dihydromyricetin (DHM) is plant derived flavonoid isolated from leaves and stems of Rattan tea (Ampelopsis grossedentata). Reports indicate anti-inflammatory property of DHM but no information is currently available on its mechanism of action or effect on IL17 producing Th17 cells and exact role in psoriasis.

DHM shows strong anti-inflammatory properties in vitro, DHM reduced LPS-induced ROS generation, and pro-inflammatory cytokines in macrophages. The efficacy of DHM against chronic inflammatory disorder in vivo was investigated in imiquimod-induced psoriasis established in male BALB/C mice as this model closely resembles human psoriasis. Immunophenotyping and cytokine production were observed by flow cytometry, the status of gene expression was determined by real-time PCR, and nuclear co-localization and immunofluorescence of skin tissue were studied using confocal microscopy.

We observed increased inflammatory parameters in imiquimod treated diseased animals and the application of DHM topically and orally reduced the inflammatory parameters and improved indicators of cardiac damage prominent in psoriatic conditions. In our study, we found that the application of DHM dose-dependently reduced the percentage of IL-17 A-producing T cell population and reduced the nuclear co-translocation of RORγt in psoriatic T cells and possibly also influenced upstream IL-6 signaling.

Our study suggests that DHM effectively alleviates psoriatic symptoms, and its mechanism of action involves the regulation of RORγt pathway in T cells.

The regulation of inflammatory balance is central to immune homeostasis, with disruptions contributing to autoimmune diseases. As representatives of early vertebrates, lampreys offer a valuable model for investigating the evolutionary foundations of immune regulation. This study examines the dual role of L-TGF-β2 in modulating inflammation in lampreys, providing insights into the evolutionary origins of immune homeostasis mechanisms. Using lipopolysaccharide (LPS)-induced inflammation models, recombinant L-TGF-β2 was found to enhance leukocyte chemotaxis in quiescent states while inhibiting excessive migration during activation. Quantitative PCR revealed that L-TGF-β2 stimulates pro-inflammatory cytokine expression during early inflammatory phases and attenuates it during resolution. Tissue-specific expression patterns of TGF-β receptors indicated their potential role in mediating the distinct regulatory effects of L-TGF-β2 across diverse immune environments. These findings align with the biphasic functions of TGF-β observed in higher vertebrates, underscoring the evolutionary conservation of this signaling pathway. This research enhances understanding the functional versatility of TGF-β signaling and its pivotal role in vertebrate immune evolution, providing insights into ancient mechanisms of immune homeostasis and their modern implications for inflammatory disease research.

Epigenetic modifications are critical for the regulation of CD4+ T cell differentiation and function. Previously, we identified Acyl-CoA Synthetase Bubble Gum 1 (Acsbg1), a gene involved in fatty acid metabolism, as part of an epigenetic signature that was selectively demethylated in ex vivo isolated T helper 17 (TH17) cells. However, its functional relevance for CD4+ T cells remains incompletely understood. Here, we used in vitro differentiation assays and the adoptive transfer colitis model to investigate the role of Acsbg1 in the differentiation and function of TH1, TH17, and regulatory T (Treg) cells. In vitro, Acsbg1 was expressed in both TH17 and in vitro-induced Treg (iTreg) cells, whereas TH1 cells lacked Acsbg1 expression. Accordingly, Acsbg1 deficiency resulted in impaired TH17 and iTreg differentiation, whereas TH1 differentiation was unaffected. In vivo, upon adoptive transfer of Acsbg1⁻/⁻ Tnaïve cells, immunodeficient recipient mice exhibited an exacerbated colitis, characterized by an altered balance of TH17 and Treg cells, indicating that Acsbg1 expression is essential for optimal TH17 and Treg cell differentiation and function. Our findings highlight the importance of fatty acid (FA) metabolism in maintaining immune homeostasis by regulating T cell differentiation and provide novel insights into the metabolic targeting of inflammatory diseases.

The retinoic acid-related orphan receptor gamma (RORγt) acts as the major transcriptional activator in Th17 cell development and function to mediate adaptive immune defenses against pathogenic infection. RORγt engages accessible DNA response elements in the genome and interplays with coactivator proteins and accessory transcription factors to drive gene expression. However, how the chromatin environment mediates RORγt structure, dynamics, and function remains unclear. Here, we profile how the nucleosome promotes or restricts access to the main RORγt DNA response elements found in native enhancers and promoters, revealing preferential binding in regions of free DNA and nucleosomal entry/exit sites, with single base-pair resolution. Solution phase measurements using hydrogen deuterium exchange coupled to mass spectrometry identify novel allosteric effects that influence RORγt binding and mediate chromatin dynamics. A high-resolution structure of RORγt bound to the nucleosome reveals how structured elements assemble to confer binding specificity and avidity to chromatin substrates. The observations suggest an activation model where RORγt binding to chromatinized DNA promotes coregulator recruitment and chromatin decompaction.

Diabetic retinopathy (DR) is a major complication of diabetes, leading to vision impairment and blindness. The pathogenesis of DR involves multiple factors, including hyperglycemia-induced vascular damage, hypertension, obesity, anemia, immune dysregulation, and disruption of the blood-retinal barrier (BRB). Th17 and Treg cells, two types of CD4+ T cells, play opposing roles in inflammation. Th17 cells are pro-inflammatory, producing cytokines such as IL-17A, while Treg cells help suppress immune responses and promote anti-inflammatory effects. Recent studies highlight the importance of the Th17/Treg balance in retinal inflammation and disease progression in DR. Our literature review reveals an imbalance in DR, with increased Th17 activity and reduced Treg function. This shift creates a pro-inflammatory environment in the retina, worsening vascular leakage, neovascularization, and vision loss. The limited infiltration of Treg cells suggests that Th17 cells may uniquely infiltrate the retina by overwhelming or outnumbering Tregs or increasing the expression of recruiting chemokines, rather than only taking advantage of a damaged BRB. Therapeutic strategies, such as neutralizing IL-17A and enhancing Treg function with compounds like IL-35 or curcumin, may reduce inflammation and retinal damage. Restoring the balance between Th17 and Treg cells could provide new approaches for treating DR by controlling inflammation and preventing further retinal damage.

The RORγt (nuclear receptor retinoid-related orphan receptor γt) has been identified as a master transcription factor critical for the differentiation of T helper 17 cells, the primary source of IL-17A (interleukin-17A). We previously demonstrated that IL-17A promotes neuroinflammation and sympathetic excitation, contributing to cardiac dysfunction in heart failure and angiotensin II (ANG II)-induced hypertension. The present study sought to determine whether inhibiting RORγt, thereby reducing IL-17A production, could attenuate microglial activation, neuroinflammation, and sympathetic excitation by preserving the integrity of the blood-brain barrier (BBB) in ANG II-induced hypertensive rats.

Rats underwent a 2-week subcutaneous infusion of ANG II, with concurrent daily subcutaneous administration of the RORγt inhibitor digoxin or vehicle.

Compared with controls, ANG II-infused rats exhibited elevated IL-17A levels in both the periphery and brain, along with increased blood pressure and sympathetic tone-effects that were significantly attenuated by inhibiting RORγt with digoxin. ANG II-infused rats also displayed heightened BBB permeability, decreased expression of the BBB regulator Mfsd2a (major facilitator superfamily domain-containing protein 2a), increased caveolar transcytosis, and degradation of tight junction proteins in BBB endothelial cells within the hypothalamic paraventricular nucleus, a key autonomic regulatory brain center, all of which were alleviated by digoxin. Additionally, ANG II-infused rats showed marked microglial activation and elevated expression of proinflammatory cytokines within the paraventricular nucleus, both of which were mitigated by digoxin.

These findings suggest that RORγt inhibition reduces neuroinflammation and sympathetic activation to ameliorate ANG II-induced hypertension, likely by mitigating IL-17A-induced BBB disruption and microglial activation in the paraventricular nucleus.

The HECT E3 ubiquitin ligase Nedd4 has been shown to positively regulate T cell responses, but its role in T helper (Th) cell differentiation and autoimmunity is unknown. Th17 cells are believed to play a pivotal role in the development and pathogenesis of autoimmune diseases. Nevertheless, the regulation of RORγt activation during Th17 cell differentiation by TCR signaling is yet to be elucidated. These uncharted aspects inspire us to explore the potential role of Nedd4 in Th17-mediated autoimmunity.

We evaluated the impact of Nedd4 deficiency on mouse T cell development and differentiation using flow cytometry and siRNA transfection, and subsequently validated these findings in T cells from patients with multiple sclerosis (MS). Furthermore, we investigated the influence of Nedd4 deficiency on Th17-mediated autoimmunity through experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. Subsequently, we elucidated the molecular mechanism underlying the interaction between Nedd4 and RORgt through immunoprecipitation, mass spectrometry analysis, and lentiviral transduction. Additionally, we identified Nedd4 as an E3 ubiquitin ligase for RORγt. Moreover, we characterized the tyrosine residue sites and polyubiquitination patterns involved in RORγt ubiquitination.

In this study, we report that loss of Nedd4 in T cells specifically impairs pathogenic and non-pathogenic Th17 responses, and Th17-mediated EAE development. At the molecular level, Nedd4 binds to the PPLY motif within the ligand binding domain of RORγt, and targets RORγt at K112 for K27-linked polyubiquitination, thus augmenting its activity.

Nedd4 is a crucial E3 ubiquitin ligase for RORγt in the regulating Th17 cell development and offers potential therapeutic benefits for treating Th17-mediated autoimmune diseases.

Pathogenic Th17 cells play crucial roles in CNS autoimmune diseases such as multiple sclerosis (MS), but their regulation by endogenous mechanisms remains unknown. Through RNA-seq analysis of primary brain glial cells, we identified immuno-responsive gene 1 (Irg1) as one of the highly upregulated gene under inflammatory conditions. Validation in the spinal cord of animals with experimental autoimmune encephalomyelitis (EAE), an MS model, confirmed elevated Irg1 levels in myeloid, CD4, and B cells in the EAE group raising the concern if Irg1 is detrimental or protective. Irg1 knockout (KO) mice exhibited severe EAE disease, increased mononuclear cell infiltration, and increased levels of triple-positive CD4+ T cells expressing IL17a, GM-CSF, and IFNγ. A lack of Irg1 in macrophages elevates Class II expression, promoting the polarization of myelin-primed CD4+ T cells into pathogenic Th17 cells via the NLRP3/IL-1β axis. Adoptive transfer in Rag-1 KO and single-cell RNA sequencing highlighted the crucial role of Irg1 in shaping pathogenic Th17 cells. Moreover, bone marrow chimeras revealed that immune cells lacking Irg1 maintained pathogenic and inflammatory phenotypes, suggesting its protective role in autoimmune diseases, including MS.

T helper 17 (Th17) cells are effector cells that mediate inflammatory responses to bacterial and fungal pathogens. While the cytokine signaling inputs required to generate Th17s are established, less is known about intracellular pathways that drive Th17 differentiation. Our previously published phosphoproteomic screen identifies that PIKFYVE, a lipid kinase that generates the phosphatidylinositol PtdIns(3,5)P2, is activated during Th17 differentiation. Herein, we discovered that PIKFYVE regulates kinase and transcription factor networks to promote Th17 differentiation. As a specific example, PtdIns(3,5)P2 directly stimulates mTORC1 kinase activity to promote cell division and differentiation pathways. Furthermore, PIKFYVE promotes STAT3 phosphorylation, which is required for Th17 differentiation. Chemical inhibition or CD4-specific deletion of PIKFYVE reduces Th17 differentiation and autoimmune pathology in the experimental autoimmune encephalomyelitis murine model of multiple sclerosis. Our findings identify molecular mechanisms by which PIKFYVE promotes Th17 differentiation and suggest that PIKFYVE is a potential therapeutic target in Th17-driven autoimmune diseases.

The term "circadian rhythm" refers to the 24-h oscillations found in various physiological processes in organisms, responsible for maintaining bodily homeostasis. Many neurological diseases mainly involve the process of demyelination, and remyelination is crucial for the treatment of neurological diseases. Current research mainly focuses on the key role of circadian clocks in the pathophysiological mechanisms of multiple sclerosis. Various studies have shown that the circadian rhythm regulates various cellular molecular mechanisms and signaling pathways involved in remyelination. The process of remyelination is primarily mediated by oligodendrocyte precursor cells (OPCs), oligodendrocytes, microglia, and astrocytes. OPCs are activated, proliferate, migrate, and ultimately differentiate into oligodendrocytes after demyelination, involving many key signaling pathway and regulatory factors. Activated microglia secretes important cytokines and chemokines, promoting OPC proliferation and differentiation, and phagocytoses myelin debris that inhibits remyelination. Astrocytes play a crucial role in supporting remyelination by secreting signals that promote remyelination or facilitate the phagocytosis of myelin debris by microglia. Additionally, cell-to-cell communication via gap junctions allows for intimate contact between astrocytes and oligodendrocytes, providing metabolic support for oligodendrocytes. Therefore, gaining a deeper understanding of the mechanisms and molecular pathways of the circadian rhythm at various stages of remyelination can help elucidate the fundamental characteristics of remyelination and provide insights into treating demyelinating disorders.

This 2-part, double-blinded trial assessed the RORγt inhibitor BI 730357 in plaque psoriasis.

In part 1, patients were randomized 2:2:2:2:1 to 25, 50, 100, and 200 mg BI 730357 or placebo once daily (fasting conditions); nonresponders were switched to higher doses. In part 2, a separate patient set was randomized 4:4:1 to receive BI 730357 (400 mg once daily, 200 mg twice daily) or a placebo (fed conditions). Patients from parts 1 and 2 could enter a long-term extension trial. Coprimary endpoints included ≥75% reduction from baseline in PASI75 and static Physician's Global Assessment score of 0/1 (clear/almost clear) at week 12.

In total, 274 patients were treated (178 [part 1] and 96 [part 2]). In part 1, 12 (30.0%) patients achieved PASI75 (P = .0062), and 11 (27.5%) achieved static Physician's Global Assessment of 0/1 (P = .0095) with BI 730357 200 mg versus none receiving placebo. Exposure-response relationship plateaued at ≥200 mg once daily BI 730357. Drug-related adverse events occurred in ≤15.8% of patients. Of 165 patients who entered the long-term extension, 93 (56.4%) achieved PASI75 during treatment, and ≤18.5% experienced a drug-related adverse event.

BI 730357 was well tolerated, with moderate efficacy versus placebo in plaque reduction (clinicaltrials.gov: NCT03635099 and NCT03835481).

Limosilactobacillus reuteri, a recognized probiotic, improves intestinal health in animals, but the mechanism remains unclear. This study investigates the mechanisms by which L. reuteri ZY15, isolated from healthy pig feces, mitigates intestinal barrier damage and inflammation caused by oxidative stress in Enterotoxigenic Escherichia coli (ETEC) K88-challenged mice. The results indicated that L. reuteri ZY15 increased antioxidant capacity by reducing serum reactive oxygen species (ROS) and superoxide dismutase (SOD) levels. L. reuteri ZY15 enhanced the intestinal barrier by upregulating mucin 1, mucin 2, occludin, zonula occludens-1 (ZO-1), and claudin-1 expressions in protein and mRNA levels. It significantly alleviated intestinal inflammation by reducing the proinflammatory cytokines interleukin-1β (IL-1β), interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and interleukin-17 (IL-17) mRNA and protein levels. Notably, L. reuteri ZY15 suppressed intestinal inflammation by inhibiting AKT/mTOR/HIF-1α/RORγt/IL-17 pathway activation. Additionally, it significantly altered the structure of gut microorganisms by enriching Akkermansia and Clostridia_UCG.014, and thereby re-establishing colonization resistance and alleviating ETEC K88-induced intestinal barrier damage and inflammation in mice. Taken together, our findings reveal the protective mechanism of L. reuteri ZY15 in mice challenged with ETEC K88 by regulating AKT/mTOR/HIF-1α/RORγt/IL-17 signaling and microbial imbalance. Leveraging these properties, live L. reuteri ZY15 offers a promising alternative treatment for Escherichia coli-induced diarrhea in weaned piglets.

One vision-threatening side effect of systematic diabetes mellitus is diabetic retinopathy (DR). Recent studies have revealed that the development and progression of DR depend critically on inflammation resulting from diabetes. By attracting leukocytes to endothelium, the higher production of the inflammatory mediators induces degeneration of retinal capillaries, hence increasing vascular permeability and thrombosis probability. The leukocytes that are recruited eventually generate additional proinflammatory and proangiogenic substances, resulting in the increased infiltration of leukocytes in the retina. This process also leads to changes in the blood retinal barrier and the formation of new blood vessels, which helps to counteract the damage caused by the blockage of blood flow. IL-12 family members, IL-12, IL-23, IL-27, and IL-35, play a crucial role in regulating the responses of T helper (Th)1 and Th17 cell populations. The collected data from studies investigating the levels of IL-12 family members in the blood and eye tissues suggest that IL-12 is linked to DR, indicating that it may have a role in the development of DR as a sequential component of the immune response. This review specifically examines the possibility of using IL-12 family cytokines as a therapeutic approach for diabetes, taking into consideration their involvement in the development of DR.

We investigated the mechanism whereby double-negative T cells (DNTs) regulate Treg/Th17 balance to promote the progression of liver fibrosis. Liver fibrosis was induced with carbon tetrachloride (CCl4) in mice. Mouse DNTs were isolated, amplified and injected. The proportions of iTreg (CDF4+CD25+Foxp3+) and Th17 (CD4+IL-17A+) in peripheral mononuclear cells, spleen and liver were analyzed by flow cytometry, and the cytokine levels were determined through enzyme-linked immunosorbent assay (ELISA). DNTs could promote the Th17 differentiation and inhibit the iTreg differentiation. The role of DNTs in promoting liver fibrosis progression and tissue inflammation was exerted through activation of IκBa. The use of IL-17A monoclonal antibody enabled suppression of the DNTs effects, reduction of the Th17 proportion and alleviation of liver fibrosis. Hal could suppress the Th17 differentiation and the effect of DNTs. DNTs can promote the Th17 differentiation through IL-17A and inhibit iTreg differentiation, thereby facilitating the liver fibrosis progression and microenvironmental inflammation. DNTs are a kind of important immunocytes that promote the liver fibrosis progression.

Retinoic acid-related orphan receptors (RORs) serve as transcription factors that play a pivotal role in a myriad of physiological processes within the body. Their involvement extends to critical biological processes that confer protective effects in the heart, immune system, and nervous system, as well as contributing to the mitigation of several aggressive cancer types. These protective functions are attributed to ROR's regulation of key proteins and the management of various cellular processes, including autophagy, mitophagy, inflammation, oxidative stress, and glucose metabolism, highlighting the emerging need for pharmacological approaches to modulate ROR expression. Thus, the modulation of RORs is a rapidly growing area of research aimed not only at comprehending these receptors, but also at manipulating them to attain the desired physiological response. Despite the presence of natural ROR ligands, the development of synthetic agonists with high selectivity for these receptors holds substantial therapeutic potential. The exploration and advancement of such compounds can effectively target diseases associated with ROR dysregulation, thereby providing avenues for therapeutic interventions. Herein, we provide a comprehensive examination of the multifaceted role of ROR in diverse physiological and pathophysiological conditions, accompanied by an in-depth exploration of a spectrum of ROR agonists, inverse agonists, and antagonists.

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

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

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

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

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

Retinoic-acid-related orphan receptors (RORs) are transcription factors belonging to the nuclear receptor subfamily consisting of RORα, RORβ, and RORγ. By binding to the ROR response elements (ROREs) on target gene promoters, RORs regulate a wide variety of cellular processes, including autophagy, mitophagy, oxidative stress, and inflammation. The regulatory roles of RORs are observed in cardiac cells, hepatocytes, pulmonary epithelial cells, renal cells, immune cells, and cancer cells. A growing body of clinical and experimental evidence suggests that ROR expression levels are markedly reduced under different pathological and stress conditions, suggesting that RORs may play a critical role in the pathogenesis of a variety of disease states, including myocardial infarction, immune disorders, cancer, and metabolic syndrome. Reductions in RORs are also associated with inhibition of autophagy, increased reactive oxygen species (ROS), and increased cell death, underscoring the importance of RORs in the regulation of these processes. Herein, we highlight the relationship between RORs and homeostatic processes that influence cell viability. Understanding how these intricate processes are governed at the cellular level is of high scientific and clinical importance to develop new therapeutic strategies that modulate ROR expression and disease progression.

This study aimed to construct genome-wide genetic and epigenetic networks (GWGENs) of atopic dermatitis (AD) and healthy controls through systems biology methods based on genome-wide microarray data. Subsequently, the core GWGENs of AD and healthy controls were extracted from their real GWGENs by the principal network projection (PNP) method for Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation. Then, we identified the abnormal signaling pathways by comparing the core signaling pathways of AD and healthy controls to investigate the pathogenesis of AD. Then, IL-1β, GATA3, Akt, and NF-κB were selected as biomarkers for their important roles in the abnormal regulation of downstream genes, leading to cellular dysfunctions in AD patients. Next, a deep neural network (DNN)-based drug-target interaction (DTI) model was pre-trained on DTI databases to predict molecular drugs that interact with these biomarkers. Finally, we screened the candidate molecular drugs based on drug toxicity, sensitivity, and regulatory ability as drug design specifications to select potential molecular drugs for these biomarkers to treat AD, including metformin, allantoin, and U-0126, which have shown potential for therapeutic treatment by regulating abnormal immune responses and restoring the pathogenic signaling pathways of AD.

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are chronic disorders characterized by dysregulated immune response and persistent inflammation. Recent studies suggest that bile acid receptors, particularly GPBAR1, and the transcription factor RORγt play critical roles in modulating intestinal inflammation. This study evaluates the therapeutic potential of PBT002, a dual GPBAR1 agonist and RORγt inverse agonist, in IBD models. The effects of PBT002 were assessed through in vitro and in vivo experiments. Macrophages and T lymphocytes obtained from the buffy coat were exposed to PBT002 to evaluate its immunomodulatory activity. The beneficial effects in vivo were evaluated in mouse models of colitis induced by TNBS, DSS or DSS + IL-23 using also a Gpbar1 knock-out male mice. PBT002 exhibited an EC50 of 1.2 µM for GPBAR1 and an IC50 of 2.8 µM for RORγt. In in vitro, PBT002 modulated macrophage polarization towards an anti-inflammatory M2 phenotype and reduced Th17 cell markers while increasing Treg markers. In the TNBS-induced colitis model, PBT002 reduced weight loss, CDAI, and colon damage, while it modulated cytokine gene expression towards an anti-inflammatory profile. In GPBAR1-/-, the anti-inflammatory effects of PBT002 were attenuated, indicating partial GPBAR1 dependence. RNA sequencing revealed significant modulation of inflammatory pathways by PBT002. In DSS+IL-23 induced colitis, PBT002 mitigated disease exacerbation, reducing pro-inflammatory cytokine levels and immune cell infiltration. In conclusion, PBT002, a GPBAR1 agonist and RORγt inverse agonist, modulates both the innate and adaptive immune responses to reduce inflammation and disease severity in models of IBD.

Evidence shows that CD4+ T cells are altered in obesity and play a significant role in the systemic inflammation in adults with the disease.

Because the profile of these cells is poorly understood in the pediatric population, this study aims to investigate the profile of CD4+ T lymphocytes and the plasma levels of cytokines in this population.

Using flow cytometry, we compared the expression profile of lymphocyte markers, master transcription factors, cytokines, and molecules involved in the regulation of the immune response in CD4+ T cells from children and adolescents with obesity (OB group, n = 20) with those with eutrophy group (EU group, n = 16). Plasma levels of cytokines in both groups were determined by cytometric bead array (CBA).

The OB group presents a lower frequency of CD3+ T cells, as well as a decreased frequency of CD4+ T cells expressing CD28, IL-4, and FOXP3, but an increased frequency of CD4+IL-17A+ cells compared with the EU group. The frequency of CD28 is increased in Th2 and Treg cells in the OB group, whereas CTLA-4 is decreased in all subpopulations compared with the EU group. Furthermore, Th2, Th17, and Treg profiles can differentiate the EU and OB groups. IL-10 plasma levels are reduced in the OB group and negatively correlated with adiposity and inflammatory parameters.

CD4+ T cells have an altered pattern of expression in children and adolescents with obesity, contributing to the inflammatory state and clinical characteristics of these patients.

Zika virus (ZIKV) is an arbovirus with maternal, sexual, and TORCH-related transmission capabilities. After 2015, Brazil had the highest number of ZIVK-infected pregnant women who lost their babies or delivered them with Congenital ZIKV Syndrome (CZS). ZIKV triggers an immune defense in the placenta. This immune response counts with the participation of interleukins and transcription factors. Additionally, it has the potential involvement of human endogenous retroviruses (HERVS). Interleukins are immune response regulators that aid immune tolerance and support syncytial structure development in the placenta, where syncytin receptors facilitate vital cell-to-cell fusion events. HERVs are remnants of ancient viral infections that integrate into the genome and produce syncytin proteins crucial for placental development. Since ZIKV can infect trophoblast cells, we analyzed the relationship between ZIKV infection, HERV, interleukin, and transcription factor modulations in the placenta. To investigate the impact of ZIKV on trophoblast cells, we examined two cell types (BeWo and HTR8) infected with ZIKV-MR766 (African) and ZIKV-IEC-Paraíba (Asian-Brazilian) using Taqman and RT2 Profiler PCR Array assays. Our results indicate that early ZIKV infection (24-72 h) does not induce differential interleukins, transcription factors, and HERV expression. However, we show that the expression of a few of these host defense genes appears to be linked independently of ZIKV infection. Future studies involving additional trophoblastic cell lineages and extended infection timelines will illuminate the dynamic interplay between ZIKV, HERVs, interleukins, and transcription factors in the placenta.

Recent advances in measurement technologies, particularly single-cell RNA sequencing (scRNA-seq), have revolutionized our ability to acquire large amounts of omics-level data on cellular states. As measurement techniques evolve, there has been an increasing need for data analysis methodologies, especially those focused on cell-type identification and inference of gene regulatory networks (GRNs). We have developed a new method named BootCellNet, which employs smoothing and resampling to infer GRNs. Using the inferred GRNs, BootCellNet further infers the minimum dominating set (MDS), a set of genes that determines the dynamics of the entire network. We have demonstrated that BootCellNet robustly infers GRNs and their MDSs from scRNA-seq data and facilitates unsupervised identification of cell clusters using scRNA-seq datasets of peripheral blood mononuclear cells and hematopoiesis. It has also identified COVID-19 patient-specific cells and their potential regulatory transcription factors. BootCellNet not only identifies cell types in an unsupervised and explainable way but also provides insights into the characteristics of identified cell types through the inference of GRNs and MDS.

Atropisomerism, an expression of axial chirality caused by limited bond rotation, is a prominent aspect within the field of medicinal chemistry. It has been shown that atropisomers of a wide range of compounds, including established FDA-approved drugs and experimental molecules, display markedly different biological activities. The time-dependent reversal of chirality in atropisomers poses complexity and obstacles in the process of drug discovery and development. Nonetheless, recent progress in understanding atropisomerism and enhanced characterization methods have greatly assisted medicinal chemists in the effective development of atropisomeric drug molecules. This article provides a comprehensive review of their special design thoughts, synthetic routes, and biological activities, serving as a reference for the synthesis and biological evaluation of bioactive atropisomers in the future.

Cholestatic liver diseases, such as primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), lead to inflammation and severe hepatic damage with limited therapeutic options. This study assessed the efficacy of the inverse RORγt agonist, GSK805, both in vitro using the hepatic stellate cell-line LX-2 and in vivo using male bile duct-ligated BALB/c mice. In vitro, 0.3 μM GSK805 reduced alpha-smooth muscle actin expression in LX-2 cells. In vivo, GSK805 significantly decreased IL-23R, TNF-α, and IFN-γ expression in cholestatic liver. Despite high concentrations of GSK805 in the liver, no significant reduction in fibrosis was noticed. GSK805 significantly increased aspartate aminotransferase and alanine aminotransferase activity in the blood, while levels of glutamate dehydrogenase, alkaline phosphatase, and bilirubin were not substantially increased. Importantly, GSK805 did neither increase an animal distress score nor substantially reduce body weight, burrowing activity, or nesting behavior. These results suggest that a high liver concentration of GSK805 is achieved by daily oral administration and that this drug modulates inflammation in cholestatic mice without impairing animal well-being.

Parkinson's disease (PD) is the second most common neurodegenerative disease, and its hallmark pathological features are the loss of dopaminergic (DA) neurons in the midbrain substantia nigra pars compacta (SNpc) and the accumulation of alpha-synuclein (α-syn). It has been shown that the integrity of the blood-brain barrier (BBB) is damaged in PD patients, and a large number of infiltrating T cells and inflammatory cytokines have been detected in the cerebrospinal fluid (CSF) and brain parenchyma of PD patients and PD animal models, including significant change in the number and proportion of different CD4+ T cell subsets. This suggests that the neuroinflammatory response caused by CD4+ T cells is an important risk factor for the development of PD. Here, we systematically review the differentiation of CD4+ T cell subsets, and focus on describing the functions and mechanisms of different CD4+ T cell subsets and their secreted cytokines in PD. We also summarize the current immunotherapy targeting CD4+ T cells with a view to providing assistance in the diagnosis and treatment of PD.