IL-7Rα Expression Research Articles

MicroRNA-155-5p Differentially Regulates IL-13Rα1 and IL-13Rα2 Expression and Signaling Driving Abnormal Lung Epithelial Cell Phenotype in Severe Asthma.

MicroRNA (miR)-155-5p increases in innate and adaptive immune cells in response to IL-13 and is associated with the severity of asthma. However, little is known about its role in airway structural cells. Bronchial epithelial cells (BECs) isolated from healthy donors and patients with severe asthma were stimulated with IL-13. miR-155-5p expression and release were measured by real-time (RT)-PCR in BECs and in their derived exosomes. Modulation of miR-155-5p in BECs was performed using transfection of miR-155-5p inhibitor and mimic. IL-13 receptor α1 (IL-13Rα1), IL-13Rα2, MUC5AC, IL-8, and eotaxin-1 expression was measured by RT-PCR and Western blot analysis. The BEC repair process was assessed by a wound-healing assay. IL-13Rα1 and IL-13Rα2 expression and downstream pathways were evaluated by Western blot analysis. A dual luciferase assay was used to identify miR-155-5p target genes associated with IL-13R signaling. BECs from patients with severe asthma showed increased expression and exosomal release of miR-155-5p at baseline with amplification by IL-13 stimulation. BECs from patients with asthma expressed more IL-13Rα1 and less IL-13Rα2 than those from healthy donors, and IL-13Rα1 but not IL-13Rα2 induced miR-155-5p expression under IL-13 stimulation. miR-155-5p overexpression favored MUC5AC, IL-8, and Eotaxin-1 through the IL-13Rα1/SOCS1/STAT6 pathway while delaying the repair process by downregulating IL-13Rα2/MAPK14/c-Jun/c-fos signaling. The dual luciferase assay confirmed that miR-155-5p modulates both IL-13R pathways by directly targeting SOCS1, c-fos, and MAPK14. miR-155-5p is overexpressed in BECs from patients with severe asthma and regulates IL-13Rα1 and IL-13Rα2 expression and signaling, favoring expression of mucin- and eosinophil-related genes to the detriment of airway repair. These results show that miR-155-5p may contribute to airway epithelial cell dysfunction in patients with severe asthma.

Combination therapy of systemic and local metformin improves imiquimod-induced psoriasis-like lesions with type 2 diabetes: the role of AMPK/KGF/STAT3 axis.

Insulin resistance and a disturbed lipid profile are common associations with type 2 diabetes mellitus (T2DM) and different skin diseases, particularly psoriasis (PsO). We investigated potential therapeutic mechanisms of metformin in a murine animal model of psoriasiform lesions in T2DM. Forty-two rats were randomly divided into control, PsO, and type II DM (T2DM) groups. After confirmation of DM, the type II diabetic rats were allocated into T2DM+ PsO, T2DM+ PsO+ systemic metformin (S. met), T2DM+ PsO+ topical metformin (T. met)), and T2DM+ PsO + combined metformin (C. met). PsO was induced by topical imiquimod. Systemic administration of the cornerstone antidiabetic drug, metformin, was able to improve insulin resistance and lipid profile. At molecular levels, both topical and systemic metformin significantly increased AMP-activated protein kinase (AMPK), and lowered keratinocyte growth factor (KGF) / "Signal transducer and activator of transcription" (STAT)3 protein levels, and the IL-17RA and IL-17RC gene expression. Although its glucose-controlling effect was not optimum, T.met gel served anti-psoriatic and anti-inflammatory effects.

IL-7Rα on CD4+ T cells is required for their survival and the pathogenesis of experimental autoimmune encephalomyelitis

BackgroundThe IL-7 receptor alpha (IL-7Rα) binds both IL-7 and thymic stromal lymphopoietin (TSLP). IL-7Rα is essential for the development and survival of naive CD4+ T cells and their differentiation to effector/memory CD4+ T cells. Mice lacking IL-7Rα have severe lymphopenia and are resistant to experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis. However, it has been reported that IL-7Rα on peripheral CD4+ T cells is disposable for their maintenance and EAE pathogenesis, which does not align with the body of knowledge on the role of IL-7Rα in the biology of CD4+ T cells. Given that a definitive study on this important topic is lacking, we revisited it using a novel approach, an inducible knockout of the IL-7Rα gene in CD4+ T cells.MethodsWe generated Il7rafl/fl/CD4CreERT2 double transgenic mouse line (henceforth CD4ΔIl7ra), susceptible to tamoxifen-induced knockout of the IL-7Rα gene in CD4+ T cells. CD4ΔIl7ra mice were immunized with MOG35 − 55 for EAE induction and monitored for disease development. The expression of IL-7Rα, CD4+ T cell numbers, and MOG35 − 55-specific CD4+ T cell response was evaluated in the central nervous system (CNS) and lymphoid tissues by flow cytometry. Additionally, splenocytes of CD4ΔIl7ra mice were stimulated with MOG35 − 55 to assess their proliferative response and cytokine production by T helper cells.ResultsLoss of IL-7Rα from the surface of CD4+ T cells in CD4ΔIl7ra mice was virtually complete several days after tamoxifen treatment. The loss of IL-7Rα in CD4+ T cells led to a gradual and substantial decrease in their numbers in both non-immunized and immunized CD4ΔIl7ra mice, followed by slow repopulation up to the initial numbers. CD4ΔIl7ra mice did not develop EAE. We found a decrease in the total numbers of TNF-, IFN-γ-, IL-17 A-, and GM-CSF-producing CD4+ T cells and regulatory T cells in the spleens and CNS of immunized CD4ΔIl7ra mice. Tracking MOG35 − 55-specific CD4+ T cells revealed a significant reduction in their numbers in CD4ΔIl7ra mice and decreased proliferation and cytokine production in response to MOG35 − 55.ConclusionOur study demonstrates that IL-7Rα on peripheral CD4+ T cells is essential for their maintenance, immune response, and EAE pathogenesis.

Abstract A051: Innate immune cell dynamics and pancreatic tumor progression in alcoholic pancreatitis

Abstract Introduction: Persistent inflammation due to alcoholic chronic pancreatitis (ACP) is associated with pancreatic ductal adenocarcinoma (PDAC). Myeloid cell infiltration within the pancreas, particularly with oncogenic mutant KrasG12D/+ (*Kras), is crucial for driving PDAC carcinogenesis. Our previous work demonstrated that hyperactivation of cyclic AMP response element binding protein (CREB) accelerates ADM/PanIN progression with heightened fibroinflammation. However, the association between CREB in precursor neoplastic lesions and innate myeloid cells remains unclear. Methods: We established an ACP mouse model using an alcohol diet along with prolonged caerulein administration in Ptf1aCreERTM/+; LSL-KrasG12D/+ (KC), and CREB deleted [Crebfl/fl in KC (KCC-/-)] mice. Single-cell RNA sequencing (scRNA-seq) of the mouse pancreas, multiparametric immunophenotyping of tumor-infiltrating myeloid cells and chromatin immunoprecipitation (ChIP-seq) with CREB pulldown were performed. Cytokine arrays and qPCR studies followed co-culture assays using mouse neutrophils (J774M) and macrophages (RAW 264.7) with epithelial cell lines harboring *Kras with in vitro ACP induction were conducted. Results: ACP induction in KC mice led to increased infiltration of neutrophils and alternatively activated macrophages with the pancreas. Conversely, Creb-deleted mice exhibited significantly reduced myeloid cell infiltration despite ACP induction. ChIP-Seq and qPCR identified CREB-regulated chemokines and immunomodulators as mediators of myeloid cell trafficking. Co-culture of mouse neutrophils and macrophages with KC-ACP conditioned media significantly increased IL-1 receptor antagonist (Il-1ra) expression and secretion. Single-cell transcriptomic analysis revealed heightened Il1rn mRNA levels in neutrophils and macrophages in KC-ACP when compared with KC pancreatic tumors. Creb-deleted PDAC models showed strong downregulation of Il1rn in macrophages, confirming CREB’s role in modulating myeloid cell interactions via epithelial cell signaling. Conclusions: Our findings highlight that CREB activation in epithelial cells under ACP conditions facilitates crosstalk with myeloid cells, promoting IL-1ra upregulation in neutrophils and macrophages. This CREB-driven regulation of IL-1ra in myeloid cells contributes to inflammation-associated tumorigenesis. Targeting this axis may offer a novel therapeutic approach to curb pancreatic cancer progression. Citation Format: Siddharth Mehra, Sudhakar Jinka, Varun Krishnamoorthy, Supriya Srinivasan, Anna Bianchi, Andrew Adams, Haleh Amirian, Manan Patel, Jashodeep Datta, Nipun Merchant, Nagaraj Nagathihalli. Innate immune cell dynamics and pancreatic tumor progression in alcoholic pancreatitis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A051.

Genetic evidence for efficacy of targeting IL-2, IL-6 and TYK2 signalling in the prevention of type 1 diabetes: a Mendelian randomisation study.

We aimed to investigate the genetic evidence that supports the repurposing of drugs already licensed or in clinical phases of development for prevention of type 1 diabetes. We obtained genome-wide association study summary statistics for the risk of type 1 diabetes, whole-blood gene expression and serum protein levels and investigated genetic polymorphisms near seven potential drug target genes. We used co-localisation to examine whether the same genetic variants that are associated with type 1 diabetes risk were also associated with the relevant drug target genetic proxies and used Mendelian randomisation to evaluate the direction and magnitude of the associations. Furthermore, we performed Mendelian randomisation analysis restricted to functional variants within the drug target genes. Co-localisation revealed that the blood expression levels of IL2RA (encoding IL-2 receptor subunit α [IL2RA]), IL6R (encoding IL-6 receptor [IL6R]) and IL6ST (encoding IL-6 cytokine family signal transducer [IL6ST]) shared the same causal variant with type 1 diabetes liability near the corresponding genes (posterior probabilities 100%, 96.5% and 97.0%, respectively). The OR (95% CI) of type 1 diabetes per 1-SD increase in the genetically proxied gene expression of IL2RA, IL6R and IL6ST were 0.22 (0.17, 0.27), 1.98 (1.48, 2.65) and 1.90 (1.45, 2.48), respectively. Using missense variants, genetically proxied TYK2 (encoding tyrosine kinase 2) expression levels were associated with type 1 diabetes risk (OR 0.61 [95% CI 0.54, 0.69]). Our findings support the targeting of IL-2, IL-6 and TYK2 signalling in prevention of type 1 diabetes. The analysis code is available at https://github.com/jkoskenniemi/T1DSCREEN , which also includes instructions on how to download the original GWAS summary statistics.

Does the Uterine Ozone Therapy Alter the Transcript Profile of Anti- and Proinflammatory Genes in Mares With Endometritis?

This study aimed to evaluate the localised effects of intrauterine ozone therapy on endometrial recovery in mares with endometritis. Our investigation assessed changes in gene expression profiles of anti-inflammatory (IL-1RA and IL-10), proinflammatory (IL-R1B3i and TNFα) and pleiotropic (IL-6) cytokines, along with detailed histological measurements of epithelial and endometrial thickness and the glandular area ratio. Twenty mares were assigned to a 2 × 2 factorial design based on endometritis diagnosis and treatment (control or 42 μg/mL ozone insufflation), resulting in four groups: NC (negative for endometritis/control), NO (negative/ozone), PC (positive/control) and PO (positive/ozone). Oestrus was induced with 2 mg of oestradiol benzoate on Days -1, 1 and 3, plus 1 mg on Day 5. Day 0 marked the initial uterine treatment, followed by insufflations on Days 1 and 2 with O3 (ozone) or O2 (control). Uterine biopsies were taken before treatment on Day 0 and Day 6 for histological analysis and gene expression assessment. Data were analysed using a statistical model that included endometritis status, treatment type, biopsy times (D0 and D6) and their interactions, analysed with Proc Glimmix. Regardless of treatment or endometritis status, significant biopsy effects (p < 0.01) indicated increased epithelial height and endometrial thickness in Day 6 samples. Analysis of IL-1 and TNFα revealed a significant interaction (p < 0.05) among endometritis, treatment and biopsy, with higher IL-1B3i expression on Day 6 in the PC group. The treatment effect (p < 0.04) showed a higher frequency (p < 0.01) of animals with positive modulation in the PC group (66.7%) versus the PO group (0.0%). An interaction effect (p = 0.08) between endometritis and treatment resulted from higher IL-1RA expression on Day 6 in the PC group compared to the PO group. Biopsy effect was significant for IL-10 (p < 0.01), indicating higher values in the second sample associated with tissue repair. In the short-term evaluation, ozone therapy did not influence endometrial morphology and may modulate cytokine expression, specifically the reduction in IL-1 and TNFα levels. Therefore, this therapy appears to be a safe and potentially effective treatment for modulating the inflammatory response in mares with endometritis.

Establishment and verification of a TME prognosis scoring model based on the acute myeloid leukemia single-cell transcriptome

The tumor microenvironment (TME) plays an important role in the occurrence and progression of Acute Myeloid Leukemia (AML). Single-cell sequencing has enabled researchers to explore the correlation between TME subgroups and tumor prognosis, distinguish the existence of drug-resistant subgroups of tumor cells, and unravel the complexity of the AML cellular heterogeneity. We used bone marrow immune cell enrichment analysis from public databases to screen prognostic genes, construct prognostic models, and validate their prognostic significance on independent external datasets and patient samples. A total of 18,251 single cells were obtained to establish prognostic scoring models for 10 key genes including CCL5, ETLS2, and IL2RA.The AML cases were divided into two groups: high-risk and low-risk. The low-risk group exhibited a higher survival rate than the high-risk group. The areas under curves (AUC) of 1-, 3- and 5-year survival curves in the TCGA and GEO training sets were greater than 0.8 and 0.6, respectively, indicating effective prediction. The model’s prognostic efficacy was confirmed across multiple validation sets. It demonstrated increased expression of ETS2, CCL5, and IL2RA in AML samples compared to controls, which was associated with decreased overall survival (OS). This prognostic scoring model based on tumor immune infiltration provides a reference for developing novel treatment strategies for recurrent/refractory AML.

Cytokines and chemokines skin gene expression in correlation with immune cells in blood and severity in equine insect bite hypersensitivity.

Insect bite hypersensitivity (IBH) is the most frequent skin allergy of horses and is highly debilitating, especially in the chronic phase. IBH is caused by IgE-mediated hypersensitivity reactions to culicoides midge bites and an imbalanced immune response that reduces the welfare of affected horses. In the present study, we investigated the pathological mechanisms of IBH, aiming to understand the immune cell modulation in acute allergic skin lesions of IBH horses with the goal of finding possible biomarkers for a diagnostic approach to monitor treatment success. By qPCR, we quantified the gene expression of cytokines, chemokines, and immune receptors in skin punch biopsies of IBH with different severity levels and healthy horses simultaneously in tandem with the analysis of immune cell counts in the blood. Our data show an increase in blood eosinophils, monocytes, and basophils with a concomitant, significant increase in associated cytokine, chemokine, and immune cell receptor mRNA expression levels in the lesional skin of IBH horses. Moreover, IL-5Ra, CCR5, IFN-γ, and IL-31Ra were strongly associated with IBH severity, while IL-31 and IL-33 were rather associated with a milder form of IBH. In addition, our data show a strong correlation of basophil cell count in blood with IL-31Ra, IL-5, IL-5Ra, IFN-γ, HRH2, HRH4, CCR3, CCR5, IL-12b, IL-10, IL-1β, and CCL26 mRNA expression in skin punch biopsies of IBH horses. In summary, several cytokines and chemokines have been found to be associated with disease severity, hence contributing to IBH pathology. These molecules can be used as potential biomarkers to monitor the onset and progression of the disease or even to evaluate and monitor the efficacy of new therapeutic treatments for IBH skin allergy. To our knowledge, this is the first study that investigated immune cells together with a large set of genes related to their biological function, including correlation to disease severity, in a large cohort of healthy and IBH horses.

Seasonal Comparative Analysis of Follicular Interleukin Concentration and Expression of IL1RII, IL4 and IL1RA in Cystic Follicles Versus Normal Preovulatory Follicles in Buffalo

Seasonal Comparative Analysis of Follicular Interleukin Concentration and Expression of IL1RII, IL4 and IL1RA in Cystic Follicles Versus Normal Preovulatory Follicles in Buffalo

Combinatorial actions of IL-22 and IL-17 drive optimal immunity to oral candidiasis through SPRRs.

Oropharyngeal candidiasis (OPC) is the most common human fungal infection, arising typically from T cell immune impairments. IL-17 and IL-22 contribute individually to OPC responses, but here we demonstrate that the combined actions of both cytokines are essential for resistance to OPC. Mice lacking IL-17RA and IL-22RA1 exhibited high fungal loads in esophagus- and intestinal tract, severe weight loss, and symptoms of colitis. Ultimately, mice succumbed to infection. Dual loss of IL-17RA and IL-22RA impaired expression of small proline rich proteins (SPRRs), a class of antimicrobial effectors not previously linked to fungal immunity. Sprr2a1 exhibited direct candidacidal activity in vitro, and Sprr1-3a-/- mice were susceptible to OPC. Thus, cooperative actions of Type 17 cytokines mediate oral mucosal anti-Candida defenses and reveal a role for SPRRs.

IL-4 acts on skin-derived dendritic cells to promote the TH2 response to cutaneous sensitization and the development of allergic skin inflammation

Atopic dermatitis is characterized by scratching and a TH2-dominated local and systemic response to cutaneously encountered antigens. Dendritic cells (DCs) capture antigens in the skin and rapidly migrate to draining lymph nodes (dLNs) where they drive the differentiation of antigen-specific naive T cells. We sought to determine whether non-T-cell-derived IL-4 acts on skin-derived DCs to promote the TH2 response to cutaneously encountered antigen and allergic skin inflammation. DCs from dLNs of ovalbumin (OVA)-exposed skin were analyzed by flow cytometry and for their ability to polarize OVA-specific naive CD4+ T cells. Skin inflammation following epicutaneous sensitization of tape-stripped skin was assessed by flow cytometry of skin cells and real-time quantitative PCR of cytokines. Cytokine secretion and antibody levels were evaluated by ELISA. Scratching upregulated IL4 expression in human skin. Similarly, tape stripping caused rapid basophil-dependent upregulation of cutaneous Il4 expression in mouse skin. Invitro treatment of DCs from skin dLNs with IL-4 promoted their capacity to drive TH2 differentiation. DCs from dLNs of OVA-sensitized skin of Il4-/- mice and CD11c-CreIl4rflox/- mice, which lack IL-4Rα expression in DCs (DCΔ/Δll4ra mice), were impaired in their capacity to drive TH2 polarization compared with DCs from controls. Importantly, OVA-sensitized DCΔ/Δll4ra mice demonstrated impaired allergic skin inflammation and OVA-specific systemic TH2 response evidenced by reduced TH2 cytokine secretion by OVA-stimulated splenocytes and lower levels of OVA-specific IgE and IgG1 antibodies, compared with controls. Mechanical skin injury causes basophil-dependent upregulation of cutaneous IL-4. IL-4 acts on skin DCs that capture antigen and migrate to dLNs to promote their capacity for TH2 polarization and drive allergic skin inflammation.

A RORE-dependent Intronic Enhancer in the IL-7 Receptor-α Locus Controls Glucose Metabolism via Vγ4+ γδT17 Cells.

The IL-7R regulates the homeostasis, activation, and distribution of T cells in peripheral tissues. Although several transcriptional enhancers that regulate IL-7Rα expression in αβ T cells have been identified, enhancers active in γδ T cells remain unknown. In this article, we discovered an evolutionarily conserved noncoding sequence (CNS) in intron 2 of the IL-7Rα-chain (IL-7Rα) locus and named this region CNS9. CNS9 contained a conserved retinoic acid receptor-related orphan receptor (ROR)-responsive element (RORE) and exerted RORγt-dependent enhancer activity invitro. Mice harboring point mutations in the RORE in CNS9 (CNS9-RORmut) showed reduced IL-7Rα expression in IL-17-producing Vγ4+ γδ T cells. In addition, the cell number and IL-17A production of Vγ4+ γδ T cells were reduced in the adipose tissue of CNS9-RORmut mice. Consistent with the reduction in IL-17A, CNS9-RORmut mice exhibited decreased IL-33 expression in the adipose tissue, resulting in fewer regulatory T cells and glucose intolerance. The CNS9-ROR motif was partially responsible for IL-7Rα expression in RORγt+ regulatory T cells, whereas IL-7Rα expression was unaffected in RORγt-expressing Vγ2+ γδ T cells, Th17 cells, type 3 innate lymphoid cells, and invariant NKT cells. Our results indicate that CNS9 is a RORΕ-dependent, Vγ4+ γδ T cell-specific IL-7Rα enhancer that plays a critical role in adipose tissue homeostasis via regulatory T cells, suggesting that the evolutionarily conserved RORΕ in IL-7Rα intron 2 may influence the incidence of type 2 diabetes.

Effect of IL-15 on anti-tumor immune response to radio-immunotherapy through systemic immune activation.

e14641 Background: In this study, we propose to investigate the key role of IL-15 in radio-immunotherapy and its mechanism in regulating systemic immune activation by radio-immunotherapy. And further explore the potential of IL-15 combined with radio-immunotherapy. Methods: LLC5 and MC38 cells were used in this study. Mouse model and co-culture model were constructed to analyze the effect of IL-15 after radio-immunotherapy. Anti-IL-15 antibody was used to clarify the role of IL-15 on radio-immunotherapy. Flow cytometry and multiplex immunofluorescence were used to clarify IL-15Rα lever in macrophage after radio-immunotherapy. The effect of IL-15 in tumor and secondary lymphoid organ(SLO) was observed after macrophage removal. Macrophage IL-15 level were tested by ELISA. Tumor growth, TME, and memory effect after IL-15 combined with radio-immunotherapy were observed. In co-culture model, CD8+ T cell function were tested. Clearance macrophage of mice to determine the role of macrophage in combination therapy. After macrophages co-cultured with tumor cells, cytokine microarray was used to analyze the cytokine secretion of macrophages in combination treatment. Results: IL-15 secretion was significantly upregulated in TME after radio-immunotherapy. IL-15 and IL-15Rα were most enriched on macrophages and IL-15Rα was significantly increased after radio-immunotherapy. IL-15 inhibition significantly attenuated tumor killing and systemic immune activation and resulted in decreased IL-15Rα expression on macrophages. Removal of macrophages resulted in a significant reduction of IL-15 in tumor and spleen. Radio-immunotherapy in the co-culture model induced a significant increase of IL-15 secreted by macrophages.IL-15 combined with radio-immunotherapy can significantly controlled tumor growth, stimulated systemic immune activation, and CD8+ T cells and memory T cells were significantly increased in the circulation of long-term survival mice. In co-culture experiments, combination treatment stimulated proliferation and secretion of IFN-γ+CD8+ T cells. And it stimulated macrophages secrete more chemokines, especially CCL5, recruit more CD8+ T cells aggregate around macrophages. Macrophage clearance and co-culture experiments confirm that the synergistic effect of this combination therapy is mainly dependent on macrophages. Conclusions: IL-15 plays a critical role in systemic immune activation induced by radio-immunotherapy. Macrophages are the main cellular site of IL-15 effect in the microenvironment of tumor and SLO after radio-immunotherapy. IL-15 combined with radio-immunotherapy had a synergistic antitumor effect, and this combination treatment induced a further enhancement of memory T-cell-mediated systemic immune activation. Macrophage-secreted chemokines such as CCL5 played an important role in the antitumor effect of this combination therapy strategy.

Interleukin-1 regulates follicular T cells during the germinal center reaction

IntroductionAntibody production and the generation of memory B cells are regulated by T follicular helper (Tfh) and T follicular regulatory (Tfr) cells in germinal centers. However, the precise role of Tfr cells in controlling antibody production is still unclear. We have previously shown that both Tfh and Tfr cells express the IL-1R1 agonist receptor, whereas only Tfr cells express the IL-1R2 decoy and IL-1Ra antagonist receptors. We aimed to investigate the role of IL-1 receptors in the regulation of B cell responses by Tfh and Tfr.MethodsWe generated mice with IL-1 receptors inactivated in Tfh or Tfr and measured antibody production and cell activation after immunisation.ResultsWhile IL-1β levels are increased in the draining lymph node after immunisation, antigen-specific antibody levels and cell phenotypes indicated that IL-1β can activate both Tfh and Tfr cells through IL-1R1 stimulation. Surprisingly, expression of IL-1R2 and IL-1Ra on Tfr cells does not block IL-1 activation of Tfh cells, but rather prevents IL-1/IL-1R1-mediated early activation of Tfr cells. IL-1Rs also regulate the antibody response to autoantigens and its associated pathophysiology in an experimental lupus model.DiscussionCollectively, our results show that IL-1 inhibitory receptors expressed by Tfr cells prevent their own activation and suppressive function, thus licensing IL-1-mediated activation of Tfh cells after immunisation. Further mechanistic studies should unravel these complex interactions between IL-1β and follicular helper and regulatory T cells and provide new avenues for therapeutic intervention.

High common-γ cytokine receptor levels promote expression of Interleukin-2/Interleukin-7 receptor α-chains with implications on T-cell differentiation and function.

Cytokines of the common-γ receptor chain (γc) family are crucial for T-cell differentiation and dysregulation of γc cytokine pathways is involved in the pathogenesis of autoimmune diseases. There is increasing evidence that the availability of the γc receptor (CD132) for the associated receptor chains has implications for T-cell functions. Here we studied the influence of differential γc expression on the expression of the IL-2Rα (CD25), the IL-7Rα (CD127) and the differentiation of activated naïve T cells. We fine-tuned the regulation of γc expression in human primary naïve T cells by lentiviral transduction using small hairpin (sh)RNAs and γc cDNA. Differential γc levels were then analysed for effects on T-cell phenotype and function after activation. Differential γc expression markedly affected IL-2Rα and IL-7Rα expression on activated naïve T cells. High γc expression (γc-high) induced significantly higher expression of IL-2Rα and re-expression of IL-7Rα after activation. Inhibition of γc caused lower IL-2Rα/IL-7Rα expression and impaired proliferation of activated naïve T cells. In contrast, γc-high T cells secreted significantly higher concentrations of effector cytokines (i.e., IFN-γ, IL-6) and showed higher cytokine-receptor induced STAT5 phosphorylation during initial stages as well as persistently higher pSTAT1 and pSTAT3 levels after activation. Finally, accelerated transition towards a CD45RO expressing effector/memory phenotype was seen especially for CD4+ γc-high naïve T cells. These results suggested that high expression of γc promotes expression of IL-2Rα and IL-7Rα on activated naïve T cells with significant effects on differentiation and effector cytokine expression.

Small protein blockers of human IL-6 receptor alpha inhibit proliferation and migration of cancer cells

BackgroundInterleukin-6 (IL-6) is a multifunctional cytokine that controls the immune response, and its role has been described in the development of autoimmune diseases. Signaling via its cognate IL-6 receptor (IL-6R) complex is critical in tumor progression and, therefore, IL-6R represents an important therapeutic target.MethodsAn albumin-binding domain-derived highly complex combinatorial library was used to select IL-6R alpha (IL-6Rα)-targeted small protein binders using ribosome display. Large-scale screening of bacterial lysates of individual clones was performed using ELISA, and their IL-6Rα blocking potential was verified by competition ELISA. The binding of proteins to cells was monitored by flow cytometry and confocal microscopy on HEK293T-transfected cells, and inhibition of signaling function was examined using HEK-Blue IL-6 reporter cells. Protein binding kinetics to living cells was measured by LigandTracer, cell proliferation and toxicity by iCELLigence and Incucyte, cell migration by the scratch wound healing assay, and prediction of binding poses using molecular modeling by docking.ResultsWe demonstrated a collection of protein variants called NEF ligands, selected from an albumin-binding domain scaffold-derived combinatorial library, and showed their binding specificity to human IL-6Rα and antagonistic effect in HEK-Blue IL-6 reporter cells. The three most promising NEF108, NEF163, and NEF172 variants inhibited cell proliferation of malignant melanoma (G361 and A2058) and pancreatic (PaTu and MiaPaCa) cancer cells, and suppressed migration of malignant melanoma (A2058), pancreatic carcinoma (PaTu), and glioblastoma (GAMG) cells in vitro. The NEF binders also recognized maturation-induced IL-6Rα expression and interfered with IL-6-induced differentiation in primary human B cells.ConclusionWe report on the generation of small protein blockers of human IL-6Rα using directed evolution. NEF proteins represent a promising class of non-toxic anti-tumor agents with migrastatic potential.

Revealing the mechanism of Dahuang Huanglian Xiexin Decoction attenuates dysbiosis via IL-17 signaling pathway based on network pharmacology and experimental validation

Ethnopharmacological relevanceDahuang Huanglian Xiexin Decoction (XXD), derived from Zhang Zhongjing's Treatise on Typhoid Fever, has a long history of medicinal use and is widely used for digestive system diseases. It is mainly composed of three natural medicines, including Dahuang (Rheum palmatum L.), Huanglian (Coptis chinensis Franch.), and Huangqin (Scutellaria baicalensis Georgi). Modern pharmacological research shows that the active ingredients of XXD can have a positive effect on intestinal flora regulatory effect, but its mechanism of action is unclear. Aims of this studyClarify the effect of XXD on regulating dysbiosis, and elucidate the mechanism of XXD in alleviating dysbiosis based on network pharmacology, molecular docking and experimental verification. MethodsHistopathological observation and intestinal high-throughput sequencing were used to observe the effect. Preliminary prediction of the mechanism of action of XXD in treating dysbiosis through network pharmacology and molecular docking. Finally, the effect of XXD on the IL-17 signaling pathway was verified through in vivo experiments. ResultsHistopathology and high-throughput sequencing of intestinal flora indicated that XXD has a good regulatory effect on bacterial dysbiosis. At the same time, network pharmacology identified a total of 40 active compounds, 14 of which may be key compounds for XXD to treat dysbiosis. In addition, the study also revealed 14 potential key targets as well as the top 5 therapeutic targets: IL-6, TNF-α, IL-1β, TP53 and PTGS2. GO and KEGG predicted the key pathway for IL-17 signaling pathway to play a role in XXD. In the verification of the prediction results, it was found that the above targets and the IL-17 target showed strong activity in molecular docking. Furthermore, it was found that XXD can reduce the levels of IL-17, IL-6, TNF-α, IL-1β, p53 and COX-2 in serum, while inhibiting the expression of IL-17, IL-17RA, Act-1 and NF-κB protein and the mRNA expression of IL-17, IL-17RA and Act-1 in colon tissue. ConclusionsThis study found that XXD has a good regulatory effect on dysbiosis and its induced symptoms. Network pharmacology was used to predict the key compounds and therapeutic targets of XXD, and preliminary experiments confirmed that XXD may regulate bacterial dysbiosis by inhibiting the IL-17 signaling pathway.

Type B thymomas in patients with myasthenia gravis display a distinctive pattern of αβ TCR and IL-7 receptor α expression on CD4+CD8+ thymocytes

Thymoma is closely associated with myasthenia gravis (MG). However, due to the heterogeneity of thymoma and the intricate pathogenesis of MG, it remains unclear why some patients with thymoma develop MG and others do not. In this study, we conducted a comparative phenotype analysis of thymocytes in type B thymomas in patients with MG (MG (+) thymomas) and without MG (MG (−) thymomas) via fluorescence-activated cell sorting (FACS). Our results show that the developmental stages defined by the expression of CD3, CD4, and CD8 were largely maintained in both MG (+) and MG (−) thymomas, with CD4+CD8+ cells constituting the majority of thymocytes in type B thymoma, and no significant difference between this cell population was observed in MG (+) and MG (−) thymomas.We discovered that CD4+CD8+ thymocytes in MG (+) thymomas expressed low levels of αβ TCR and high levels of IL-7 receptor α (IL-7Rα), whereas in MG (−) thymomas, CD4+CD8+ thymocytes exhibited the opposite pattern of αβ TCR and IL-7Rα expression. These results suggest that the positive and negative selection processes of CD4+CD8+ thymocytes might differ between MG (+) thymomas and MG (−) thymomas. The expression of the Helios transcription factor is induced during negative selection and marks a group of T cells that have undergone negative selection and are likely to be deleted due to strong TCR binding with self-peptides/MHC ligands. We observed that the percentage of Helios-positive CD4SP T cells was greater in MG (−) than in MG (+) thymomas. Thus, the differentially regulated selection process of CD4+CD8+ thymocytes, which involves TCR and IL-7/IL-7Rα signaling, is associated with the presence of MG in type B thymomas.

Lung cancer cell-intrinsic IL-15 promotes cell migration and sensitizes murine lung tumors to anti-PD-L1 therapy

BackgroundIL-15 plays a vital role in enhancing NK cell- and T-cell-mediated antitumor immune responses; however, the direct effect of IL-15 on tumor cells has not been fully elucidated. Herein, we investigated the effect of IL-15 on lung adenocarcinoma cells.MethodsSilencing and overexpression techniques were used to modify endogenous IL-15 expression in tumor cells. Transwell assays were used to assess tumor cell migration and invasion; a live-cell analysis system was used to evaluate cell motility; cellular morphological changes were quantified by confocal fluorescence microscopy; the molecular mechanisms underlying the effect of IL-15 on tumor cells were analyzed by western blotting; and RhoA and Cdc42 activities were evaluated by a pulldown assay. NCG and C57BL/6 mouse models were used to evaluate the functions of IL-15 in vivo.ResultsCancer cell-intrinsic IL-15 promoted cell motility and migration in vitro and metastasis in vivo via activation of the AKT-mTORC1 pathway; however, exogenous IL-15 inhibited cell motility and migration via suppression of the RhoA-MLC2 axis. Mechanistic analysis revealed that both the intracellular and extracellular IL-15-mediated effects required the expression of IL-15Rα by tumor cells. Detailed analyses revealed that the IL-2/IL-15Rβ and IL-2Rγ chains were undetected in the complex formed by intracellular IL-15 and IL-15Rα. However, when exogenous IL-15 engaged tumor cells, a complex containing the IL-15Rα, IL-2/IL-15Rβ, and IL-2Rγ chains was formed, indicating that the differential actions of intracellular and extracellular IL-15 on tumor cells might be caused by their distinctive modes of IL-15 receptor engagement. Using a Lewis lung carcinoma (LLC) metastasis model, we showed that although IL-15 overexpression facilitated the lung metastasis of LLC cells, IL-15-overexpressing LLC tumors were more sensitive to anti-PD-L1 therapy than were IL-15-wild-type LLC tumors via an enhanced antitumor immune response, as evidenced by their increased CD8+ T-cell infiltration compared to that of their counterparts.ConclusionsCancer cell-intrinsic IL-15 and exogenous IL-15 differentially regulate cell motility and migration. Thus, cancer cell-intrinsic IL-15 acts as a double-edged sword in tumor progression. Additionally, high levels of IL-15 expressed by tumor cells might improve the responsiveness of tumors to immunotherapies.

Novel Synonymous Variant in IL7R Causes Preferential Expression of the Soluble Isoform

PurposeThe interleukin-7 receptor (IL-7R) is primarily expressed on lymphoid cells and plays a crucial role in the development, proliferation, and survival of T cells. Autosomal recessive mutations that disrupt IL-7Rα chain expression give rise to a severe combined immunodeficiency (SCID), which is characterized by lymphopenia and a T−B+NK+ phenotype. The objective here was to diagnose two siblings displaying the T−B+NK+ SCID phenotype as initial clinical genetic testing did not detect any variants in known SCID genes.MethodsWhole genome sequencing (WGS) was utilized to identify potential variants causing the SCID phenotype. Splicing prediction tools were employed to assess the deleterious impact of the mutation. Polymerase Chain Reaction (PCR), Sanger sequencing, flow cytometry, and ELISA were then used to validate the pathogenicity of the detected mutation.ResultsWe discovered a novel homozygous synonymous mutation in the IL7R gene. Our functional studies indicate that this variant is pathogenic, causing exon 6, which encodes the transmembrane domain, to be preferentially spliced out.ConclusionIn this study, we identified a novel rare synonymous mutation causing a loss of IL-7Rα expression at the cellular membrane. This case demonstrates the value of reanalyzing genetic data based on the clinical phenotype and highlights the significance of functional studies in determining the pathogenicity of genetic variants.