IL-2 Signaling Research Articles

Transcriptional Profiling of Tofacitinib Treatment in Juvenile Idiopathic Arthritis: Implications for Treatment Response Prediction.

To assess changes in gene expression following tofacitinib treatment and investigate transcription patterns as potential predictors of treatment response in patients with active juvenile idiopathic arthritis (JIA). Whole blood samples were collected from JIA patients at baseline and after 18 weeks of open-label tofacitinib treatment (clinical trial NCT02592434). Patients who achieved a JIA-American College of Rheumatology (ACR) response of 70 or above at week 18 were classified as treatment-responders (TR) while those with at most a JIA-ACR30 response were classified as poor-responders (PR). Differential gene expression and gene ontology (GO) over-representation analyses were performed to compare RNA expression between week 18 and baseline samples, as well as between PR and TR samples at baseline. Samples from 67 patients at baseline and 60 at week 18 were analyzed. Following 18 weeks of tofacitinib treatment across all JIA subjects, 883 genes showed significant differential expression (week 18 - baseline). The most strongly downregulated genes were over-represented within IL-7, type I, and type II interferon pathways, while upregulated genes were enriched in ontologies related to neuronal cell processes and cell signaling. Comparing PR and TR at baseline, 663 genes showed differential expression. Upregulated genes were over-represented within ontologies including activation of MAPK activity (p=9.40x10-5), myeloid cell development (p=8.13 x10-5), activation of GTPase activity (p=0.00015), and organelle transport along microtubules (p=0.00021). Tofacitinib treatment in JIA downregulated genes in interferon and IL-7 signaling pathways regardless of effectiveness. Furthermore, baseline upregulation of MAPK signaling may predict poor response to tofacitinib treatment in JIA.

Nrf2 Regulates Inflammation by Modulating Dendritic Cell-T Cell Crosstalk during Viral-Bacterial Superinfection.

Every year millions of people are infected with influenza, which can be complicated by secondary bacterial pneumonia. One factor that may contribute to increased susceptibility to secondary bacterial infection is the modulation of inflammatory cytokines. NF erythroid 2-related factor 2 (Nrf2) has been shown to be a master regulator of the antioxidant response and various inflammatory cytokines. To test the role of Nrf2 during viral-bacterial superinfection, we used a mouse model of influenza-Staphylococcus aureus superinfection with wild-type (WT) or Nrf2-deficient (Nrf2-/-) mice. Loss of Nrf2 reduced influenza burden and increased S. aureus burden during superinfection. Additionally, Nrf2-/- mice had increased abundance of conventional type 1 dendritic cells (DCs). We then tested the interaction between DCs and T cells using an invitro model of bone marrow-derived DCs with OVA and OT-II T cells. In this system, Nrf2-/- DCs promoted a Th2/regulatory T cell response as opposed to a Th1/Th17 response by WT DCs. This was recapitulated invivo with superinfected Nrf2-/- mice having increased regulatory T cell populations. We also observed an increased median survival time of Nrf2-/- superinfected mice, due at least in part to increased IL-10 signaling, as anti-IL-10R Ab treatment reduced median survival time to levels seen in WT mice. Overall, these data suggest that loss of Nrf2 promotes differential T cell skewing mediated by DCs that promote a regulatory phenotype, increasing superinfection survival time, despite increased bacterial burden.

Integrative analysis of gene expression, protein abundance, and metabolomic profiling elucidates complex relationships in chronic hyperglycemia-induced changes in human aortic smooth muscle cells

Type 2 diabetes mellitus (T2DM) is a major public health concern with significant cardiovascular complications (CVD). Despite extensive epidemiological data, the molecular mechanisms relating hyperglycemia to CVD remain incompletely understood. We here investigated the impact of chronic hyperglycemia on human aortic smooth muscle cells (HASMCs) cultured under varying glucose conditions in vitro, mimicking normal (5 mmol/L), pre-diabetic (10 mmol/L), and diabetic (20 mmol/L) conditions, respectively. Normal HASMC cultures served as baseline controls, and patient-derived T2DM-SMCs served as disease controls. Results showed significant increases in cellular proliferation, area, perimeter, and F-actin expression with increasing glucose concentration (p < 0.01), albeit not exceeding the levels in T2DM cells. Atomic force microscopy analysis revealed significant decreases in Young’s moduli, membrane tether forces, membrane tension, and surface adhesion in SMCs at higher glucose levels (p < 0.001), with T2DM-SMCs being the lowest among all the cases (p < 0.001). T2DM-SMCs exhibited elevated levels of selected pro-inflammatory markers (e.g., ILs-6, 8, 23; MCP-1; M-CSF; MMPs-1, 2, 3) compared to glucose-treated SMCs (p < 0.01). Conversely, growth factors (e.g., VEGF-A, PDGF-AA, TGF-β1) were higher in SMCs exposed to high glucose levels but lower in T2DM-SMCs (p < 0.01). Pathway enrichment analysis showed significant increases in the expression of inflammatory cytokine-associated pathways, especially involving IL-10, IL-4 and IL-13 signaling in genes that are up-regulated by elevated glucose levels. Differentially regulated gene analysis showed that compared to SMCs receiving normal glucose, 513 genes were upregulated and 590 genes were downregulated in T2DM-SMCs; fewer genes were differentially expressed in SMCs receiving higher glucose levels. Finally, the altered levels in genes involved in ECM organization, elastic fiber synthesis and formation, laminin interactions, and ECM proteoglycans were identified. Growing literature suggests that phenotypic switching in SMCs lead to arterial wall remodeling (e.g., change in stiffness, calcific deposits formation), with direct implications in the onset of CVD complications. Our results suggest that chronic hyperglycemia is one such factor that leads to morphological, biomechanical, and functional alterations in vascular SMCs, potentially contributing to the pathogenesis of T2DM-associated arterial remodeling. The observed differences in gene expression patterns between in vitro hyperglycemic models and patient-derived T2DM-SMCs highlight the complexity of T2DM pathophysiology and underline the need for further studies.

Mendelian Susceptibility to Mycobacterial Disease with Signal Peptide Peptidase-like 2A (SPPL2A) Deficiency: A Case Report

Mendelian susceptibility to mycobacterial disease (MSMD) is a rare genetic disorder characterized by immunodeficiency, leading to increased susceptibility to mycobacterial infections. Studies have identified several genes that are associated with MSMD in the interferon-gamma/interleukin (IL)-12/IL-23 signaling pathway. One of these genes is signal peptide peptidase-like 2A (SPPL2A), which is very rare, and defects in this gene have been reported only in 3 patients with MSMD. This case report presents the rare SPPL2A deficiency with an abnormal presentation, which adds to the limited number of these genetic defects. This report presents the case of a 1-year-old boy who developed Bacillus Calmette-Guerin infection (BCGitis), lymphadenopathy, and an arm abscess that required surgical drainage following BCG vaccination. The patient had hypogammaglobulinemia, normal B-cell counts, normal CD4 counts, low CD8 counts, and SPPL2A deficiency, which is related to MSMD. The patient received a second line of anti-tuberculosis agents. SPPL2A deficiency is associated with MSMD and can cause severe BCGitis and disruption of immunoglobulin production.

Abstract A031: Unhelpful CD4 help: Removal of conventional CD4+ T cells promotes priming of tumor antigen-specific CD8 T cells in the context of CD4-depletion therapy

Abstract Preclinical and clinical studies have used antibodies to deplete CD4-expressing cells to promote anti-tumor immunity. Specifically, a monoclonal anti-CD4 antibody (anti-CD4) has been employed to remove FOXP3+ CD4+ regulatory T cells (Tregs), which are known to impede anti-tumor immunity. Our previous studies demonstrated that administering anti-CD4 during B16 melanoma tumor growth in mice leads to the generation of tumor Ag-specific CD8 T cells that disseminate and form memory following surgical tumor excision. However, the importance of co-depleting other CD4-expressing cell compartments for anti-CD4 treatment efficacy are unknown. We utilized flow cytometry and single-cell RNA sequencing (scRNAseq) to evaluate the primary response of tumor Ag-specific CD8 T cells (pmel) in B16 melanoma tumor bearing mice treated with anti-CD4. Responses were compared to those induced by anti-PD1 and anti-CTLA4 dual immune checkpoint blockade (ICB). To determine the importance of homeostatic space in priming, homeostatic expansion and priming were decoupled, and neutralizing antibodies were administered. Treg-depleted (Foxp3-DTR) mice were used for comparison, and Batf3-/- mice and IL-2R blocking antibodies were used to determine requirements for CD8 T cell priming. Finally, scRNAseq was conducted on CD4 T cells from human melanoma tumors previously treated with ICB to characterize transcriptional properties of intratumoral CD4 T cells. Compared to ICB, anti-CD4 treatment elicited a more robust, disseminated, and persistent primary tumor Ag-specific CD8 T cell response. ScRNAseq revealed that anti-CD4 treatment induced more stem-like (TCF1+) memory precursor cells, whereas ICB induced more differentiated effector (Gzmb+) cells. Removal of homeostatic space or blockade of IL-7R and IL-15 during priming did not diminish pmel responses in anti-CD4 treated mice, indicating that homeostatic space was not required. Importantly, pmel cells were shown to produce their own IL-2, and pmel priming was significantly lower after IL-2 receptor blockade, suggesting dependence on autocrine IL-2 signals. Using DT-treated FOXP3-DTR mice, we found that targeted Treg depletion was insufficient for the pmel priming that disseminated and formed memory, indicating that total CD4 T cell depletion was required for this systemic response. Depletion of total CD4 T cells uniquely increased cDC1 proportions in tumor-draining LNs as well as their expression of CD86. However, treatment of tumor-bearing RAG-/- mice with anti-CD4 confirmed that depletion of CD4-expressing APC compartments does not contribute to anti-CD4 treatment efficacy. ScRNAseq of CD4 T cells from human melanoma tumors showed dominance of Tr1-like cells and other subsets without transcriptional evidence of helper differentiation, despite prior ICB. In mice, combination of anti-CD4 with dual ICB restored the systemic response of tumor-specific CD8 T cells. This study underscores the importance of eliminating conventional CD4 T cells in tumor-bearing hosts to elicit systemic primary and memory CD8 T cell responses. Citation Format: Christo P. C. Dragnev, Delaney E. Ramirez, Tyler G. Searles, Nathaniel Spicer, TIffany Chen, J. Louise Lines, Aaron R. Hawkes, Wilson L. Davis III, Asmaa Mohamed, Keisuke Shirai, Joesph D. Phillips, Pamela C. Rosato, Yina H. Huang, Mary Jo Turk. Unhelpful CD4 help: Removal of conventional CD4+ T cells promotes priming of tumor antigen-specific CD8 T cells in the context of CD4-depletion therapy [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2024 Oct 18-21; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2024;12(10 Suppl):Abstract nr A031.

Unique transcriptomic profile of peripheral blood monocytes in rheumatoid arthritis-associated interstitial lung disease.

Though interstitial lung disease (ILD) contributes to excess morbidity and mortality in rheumatoid arthritis (RA), RA-ILD pathogenesis remains incompletely defined. As intermediate, non-classical and suppressed CD14+ monocytes are expanded in RA-ILD, this study sought to characterize gene expression profiles of circulating monocytes in RA-ILD. Peripheral blood mononuclear cells were collected from patients with RA without lung disease (N = 5), RA-ILD (N = 5), idiopathic pulmonary fibrosis (IPF; N = 5), and controls without lung and autoimmune disease (N = 4). RNA was extracted from CD14+ isolated monocytes and subjected to transcriptional analysis of 1365 genes. Gene enrichment and pathway analyses were performed. Unsupervised clustering grouped patients with RA-ILD together with IPF for myeloid innate genes. For fibrosis genes, patients with RA-ILD clustered independent of comparator groups. There were 103, 66, and 64 upregulated and 66, 14, and 25 downregulated genes for RA-ILD, RA, and IPF, vs controls, respectively. For RA-ILD, there was increased expression of genes involved in regulating inflammation and fibrosis (SOCS3, CECAM1, LTB4R2, CLEC7A, IRF7, PHYKPL, GBP5, RAPGEF), epigenetic modification (KDM5D, KMT2D, OGT), and macrophage activation. Top canonical pathways included macrophage differentiation-activation, IL-12, neuroinflammatory, glucocorticoid receptor, and IL-27 signalling. Circulating monocytes in RA-ILD patients demonstrate unique gene expression profiles with innate immune gene features more aligned with IPF as opposed to RA in the absence of clinical lung disease with fibrosis gene expression that was distinct from RA and IPF. These studies are important for understanding disease pathogenesis and may provide information for future therapeutic targets in RA-ILD.

Eblasakimab, an Anti-IL‑13Rα1 Antibody, Reduces Atopy-Associated Serum Biomarkers in Moderate‑to‑Severe Atopic Dermatitis.

Eblasakimab, a first-in-class monoclonal antibody with a unique mechanism to target the interleukin (IL)-13 receptor alpha 1 (IL-13Rα1), inhibits IL-4/IL-13 signaling in the pathophysiology of atopic dermatitis (AD). This study investigates the impact of eblasakimab on type 2 inflammatory biomarkers in patients with moderate-to-severe AD. A double‑blind, multiple ascending dose, phase Ib study evaluated the effect of eblasakimab (200, 400, 600mg) or placebo administered subcutaneously once weekly for 8 weeks in patients with moderate‑to‑severe AD. Serum levels of thymus and activation-regulated chemokine (TARC), total immunoglobulin E (IgE), and lactate dehydrogenase (LDH) were assessed. Eblasakimab suppressed TARC, IgE, and LDH in the 400-mg and 600-mg groups over 8 weeks of treatment. Patients in the 400-mg and 600-mg groups experienced a reduction of 72.8% (p=0.004) and 62.9% (p=0.003), respectively, for TARC, 35.1% (p=0.006) and 20.9% (not significant; NS), respectively, for IgE, and 24.6% (NS) and 23.1% (NS), respectively, for LDH between baseline and Week 8. Reduction in serum TARC in the 400-mg group was significantly greater than placebo as early as Week 1, whereas reductions in total IgE were more gradual. Serum TARC and total IgE remained suppressed in the 400-mg and 600-mg eblasakimab groups for 4-6 weeks following the last administered dose. The effect of eblasakimab on circulating AD‑associated biomarker levels was accompanied by improvements in signs and symptoms of AD, consistent with the inhibition of IL-13 and IL-4 signaling via the type 2 receptor. NCT04090229.

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Ebi3 Blocks IFN-γ and IL-10 Signaling See article p. 1115 Thermal Regulation of WSSV Resistance See article p. 1187 ITPK1 Sensitizes Tumor Cells to IgA-Mediated Neutrophil Adcc See article p. 1244

LncRNA SNHG16 Inhibits Intracellular M. tuberculosis Growth Involving Cathelicidin Pathway, Autophagy, and Effector Cytokines Production.

Long noncoding small nucleolar RNA (LncRNA) host gene 16 (SNHG16) is associated with certain diseases, including cancers. However, its role and mechanism in Mycobacterium tuberculosis (Mtb) infection remain unclear. Here, we demonstrated that SNHG16 expression levels were suppressed in peripheral blood mononuclear cells (PBMCs) and CD14+ monocytes of tuberculosis (TB) patients. SNHG16 was up-regulated by acute Mtb infection of PBMCs from healthy control (HC) subjects. Such TB suppression of SNHG16 was consistent with an immunosuppressive-like state driven by IL-10 signaling as seen in TB patients. Notably, SNHG16 limited Mtb growth in macrophages/monocytes through autophagy and vitamin D receptor (VDR)-dependent cathelicidin (CAMP) antimicrobial pathways. Concurrently, SNHG16 was highly expressed in lymphocytes, including CD8+ and Vγ2 Vδ2 T-cell subsets in HCs. SNHG16 overexpression in lymphocytes allowed them to control Mtb infection in macrophages, and SNHG16 epigenetically increased the expression of anti-Mtb effector cytokines in lymphocytes by developing more accessible chromatin states in gene loci encoding IFN-γ, TNF-α, and Granzyme B. Furthermore, the adoptive transfer of SNHG16-overexpressing human PBMCs into Mtb-infected SCID mice conferred protective immunity against Mtb infection. Thus, SNHG16 drove the induction of pleiotropic effector functions that inhibited intracellular Mtb growth in vitro and in vivo, serving as an immunotherapy target in TB.

S1241 Guselkumab Binding to CD64+ IL-23–Producing Myeloid Cells Enhances Potency for Neutralizing IL-23 Signaling

S1241 Guselkumab Binding to CD64+ IL-23–Producing Myeloid Cells Enhances Potency for Neutralizing IL-23 Signaling

Single-cell analysis reveals T cell dysfunction driven by macrophages and differential expression of transposable elements in severe COVID-19 patients

The vastly spreading COVID-19 pneumonia is caused by SARS-CoV-2. Lymphopenia and cytokine levels are tightly associated with disease severity. However, virus-induced immune dysregulation at cellular and molecular levels remains largely undefined. Here, the leukocytes in the pleural effusion, sputum, and peripheral blood biopsies from severe and mild patients were analyzed at single-cell resolution. Drastic T cell hyperactivation accompanying elevated T cell exhaustion was observed, predominantly in pleural effusion. The mechanistic investigation identified a group of CD14+ monocytes and macrophages highly expressing CD163 and MRC1 in the biopsies from severe patients, suggesting M2 macrophage polarization. These M2-like cells exhibited up-regulated IL10, CCL18, APOE, CSF1 (M-CSF), and CCL2 signaling pathways. Further, cell type specific dysregulation of transposable elements was observed in Severe COVID-19 patients. Together, our results suggest that severe SARS-CoV-2 infection causes immune dysregulation by inducing M2 polarization and subsequent T cell exhaustion. This study improves our understanding of COVID-19 pathogenesis.

IL15/IL15Rα complex induces an anti-tumor immune response following radiation therapy only in the absence of Tregs and fails to induce expansion of progenitor TCF1+ CD8 T cells.

This work seeks to understand whether IL15-incorporating treatments improve response to radiotherapy and uncover mechanistic rationale for overcoming resistance to IL15 agonism using novel therapeutic combinations. Orthotopic tumor models of PDAC were used to determine response to treatment. IL15-/- and Rag1-/- mouse models were employed to determine dependence on IL15 and CTLs, respectively. Flow cytometry was used to assess immune cell frequency and activation state. Phospho-proteomic analyses were used to characterize intracellular signaling pathways. We show that the combination of radiation therapy (RT) and an IL15/IL15Ra fusion complex (denoted IL15c) fails to confer anti-tumor efficacy; however, a CD8-driven anti-tumor immune response is elicited with the concurrent administration of an aCD25 Treg-depleting antibody. Using IL15-/- and Rag1-/- mice, we demonstrate that response to RT + IL15c + aCD25 is dependent on both IL15 and CTLs. Furthermore, despite an equivalent survival benefit following treatment with RT + IL15c + aCD25 and combination RT + PD1-IL2v, a novel immunocytokine with PD-1 and IL2Rβγ binding domains, CTL immunophenotyping and phospho-proteomic analysis of intracellular metabolites showed significant upregulation of activation and functionality in CD8 T cells treated with RT + PD1-IL2v. Finally, we show the immunostimulatory response to RT + PD1-IL2v is significantly diminished with a concurrent lack of TCF+ CD8 T cell generation in the absence of functional IL15 signaling. Our results are illustrative of a mechanism wherein unimpeded effector T cell activation through IL2Rβ signaling and Treg inhibition are necessary in mediating an anti-tumor immune response.

Changes in conjunctival mononuclear phagocytes and suppressive activity of regulatory macrophages in desiccation induced dry eye

PurposeTo evaluate the effects of dry eye on conjunctival immune cell number and transcriptional profiles with attention to mononuclear phagocytes. MethodsExpression profiling was performed by single-cell RNA sequencing on sorted conjunctival immune cells from non-stressed and C57BL/6 mice subjected to desiccating stress (DS). Monocle 3 modeled cell trajectory, scATAC-seq assessed chromatin accessibility and IPA identified canonical pathways. Inflammation and goblet cells were measured after depletion of MRC1+ MΦs with mannosylated clodronate liposomes. ResultsMononuclear phagocytes (monocytes, MΦs, DCs) comprised 72 % of immune cells and showed the greatest changes with DS. Distinct DS induced gene expression patterns were seen in phagocytes classified by expression of Ccr2 and [Timd4, Lyve1, Folr2 (TLR)]. Expression of phagocytosis/efferocytosis genes increased in TLF+CCR2- MΦs. Monocytes showed the highest expression of Ace, Cx3cr1, Vegfa, Ifngr1,2, and Stat1 and TLF−CCR2+ cells expressed higher levels of inflammatory mediators (Il1a, Il1b, Il1rn, Nfkb1, Ccl5, MHCII, Cd80, Cxcl10, Icam1). A trajectory from monocyte precursors branched to terminate in regulatory MΦs or in mDCs via transitional MΦ and cDC clusters. Activated pathways in TLF+ cells include phagocytosis, PPAR/RXRα activation, IL-10 signaling, alternate MΦ activation, while inflammatory pathways were suppressed. Depletion of MRC1+ MΦs increased IL-17 and IFN-γ expression and cytokine-expressing T cells, reduced IL-10 and worsened goblet loss. ConclusionsDryness stimulates distinct gene expression patterns in conjunctival phagocytes, increasing expression of regulatory genes in TLF+ cells regulated in part by RXRα, and inflammatory genes in CCR2+ cells. Regulatory MΦs depletion worsens DS induced inflammation and goblet cell loss.

Mechanistic and dynamic insight into novel IL7 receptor activators as immunotherapy for the treatment of tuberculosis

The bacterium that causes tuberculosis (TB), Mycobacterium tuberculosis, is still a significant global public health problem due to its contagious nature and the emergence of drug-resistant variants. This study leverages network pharmacology and computational drug discovery to identify genes linked to TB using the GSE54992 and GSE62525 datasets. In active tuberculosis patients, it identifies 162 DEGs that are not present in healthy people. The research includes an investigation of gene ontology (GO) and protein–protein interaction (PPI) networks to provide a comprehensive understanding of these DEGs. Crucially, it identifies ten hub genes: IL7R, CCR7, CXCR5, CCR6, CCR9, S1PR1, BACH2, CXCL5, SPIB, and EBF. The research suggests IL7R as a potential therapeutic target because of its essential role in FoxO signalling pathways and cytokine-cytokine receptor interaction. IL7 and its receptor (IL7R) are vital for T cell functionality and essential in combating TB. The study explores novel small-molecule activators for IL7R (IL7Rα), aiming to boost the immune response against TB. The following four compounds were found using molecular dynamics simulation, virtual screening, computational pharmacophore modelling, and MM/GBSA analytical techniques: ZINC02131028, ZINC02135418, ZINC46007405, and ZINC59273354. These activators may enhance the IL7 signalling pathway, potentially strengthening the immune fight against M. tuberculosis. Among these ZINC02131028 showed the best results to activate IL7 by binding to its active site, stabilizing its active conformation and enhancing its interaction with the IL7 receptor (IL7R). The findings encourage experimental validation of these IL7 activators, marking a significant step towards innovative TB treatment strategies.

The iNKT cell ligand α-GalCer prevents murine septic shock by inducing IL10-producing iNKT and B cells.

α-galactosylceramide (α-GalCer), a prototypical agonist of invariant natural killer T (iNKT) cells, stimulates iNKT cells to produce various cytokines such as IFNγ and IL4. Moreover, repeated α-GalCer treatment can cause protective or pathogenic outcomes in various immune-mediated diseases. However, the precise role of α-GalCer-activated iNKT cells in sepsis development remains unclear. To address this issue, we employed a lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced murine sepsis model and two alternative models. Sepsis was induced in wild-type (WT) C57BL/6 (B6) mice by three methods (LPS/D-GalN, α-GalCer/D-GalN, and cecal slurry), and these mice were monitored for survival rates. WT B6 mice were intraperitoneally injected with α-GalCer or OCH (an IL4-biased α-GalCer analog) one week prior to the induction of sepsis. To investigate the effects of α-GalCer-mediated iNKT cell activation on sepsis development, immune responses were analyzed by flow cytometry using splenocytes and liver-infiltrating leukocytes. In addition, a STAT6 inhibitor (AS1517499) and an IL10 inhibitor (AS101) were employed to evaluate the involvement of IL4 or IL10 signaling. Furthermore, we performed B cell adoptive transfers to examine the contribution of α-GalCer-induced regulatory B (Breg) cell populations in sepsis protection. In vivo α-GalCer pretreatment polarized iNKT cells towards IL4- and IL10-producing phenotypes, significantly attenuating LPS/D-GalN-induced septic lethality in WT B6 mice. Furthermore, α-GalCer pretreatment reduced the infiltration of immune cells to the liver and attenuated pro-inflammatory cytokine production. Treatment with a STAT6 inhibitor was unable to modulate disease progression, indicating that IL4 signaling did not significantly affect iNKT cell-mediated protection against sepsis. This finding was confirmed by pretreatment with OCH, which did not alter sepsis outcomes. However, interestingly, prophylactic effects of α-GalCer on sepsis were significantly suppressed by treatment with an IL10 antagonist, suggesting induction of IL10-dependent anti-inflammatory responses. In addition to IL10-producing iNKT cells, IL10-producing B cell populations were significantly increased after α-GalCer pretreatment. Overall, our results identify α-GalCer-mediated induction of IL10 by iNKT and B cells as a promising option for controlling the pathogenesis of postoperative sepsis.

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.

Interleukin-27 signaling resists obesity by promoting the accumulation of Treg cells in visceral adipose tissue

The prevalence of obesity and its associated metabolic disorders has emerged as one of the most significant health threats worldwide. The visceral adipose tissue regulatory T cells (VAT Treg) play an essential role in maintaining homeostasis and preventing obesity mainly by secreting Interleikin-10 (IL-10) and Transforming Growth Factor β (TGF-β). However, the mechanism that regulates VAT Treg quantity and function remains unclear. Here we elucidate the pivotal role of IL-27 signaling in sustaining the accumulation of VAT Treg cells, thereby conferring protection against obesity. We found that mice with the deficiency of IL-27 receptor Wsx1 gained more body weight and VAT weight than their wild-type littermates when fed both a normal-fat diet (NFD) and a high-fat diet (HFD). Notably, the population of VAT Treg cells was reduced in Wsx1 knockout (KO) mice, regardless of whether they were fed a normal-fat diet (NFD) or a high-fat diet (HFD). Correspondingly, the expression levels of the transcription factors FOXP3 and PPAR-γ, essential for VAT Treg function, were also diminished in Wsx1 KO mice. Taken together, our findings indicate that IL-27 signaling plays a protective role in obesity by supporting the maintenance and accumulation of VAT Treg cells.

IL-2 delivery to CD8+ T cells during infection requires MRTF/SRF-dependent gene expression and cytoskeletal dynamics

Paracrine IL-2 signalling drives the CD8 + T cell expansion and differentiation that allow protection against viral infections, but the underlying molecular events are incompletely understood. Here we show that the transcription factor SRF, a master regulator of cytoskeletal gene expression, is required for effective IL-2 signalling during L. monocytogenes infection. Acting cell-autonomously with its actin-regulated cofactors MRTF-A and MRTF-B, SRF is dispensible for initial TCR-mediated CD8+ T cell proliferation, but is required for sustained IL-2 dependent CD8+ effector T cell expansion, and persistence of memory cells. Following TCR activation, Mrtfab-null CD8+ T cells produce IL-2 normally, but homotypic clustering is impaired both in vitro and in vivo. Expression of cytoskeletal structural and regulatory genes, most notably actins, is defective in Mrtfab-null CD8+ T cells. Activation-induced cell clustering in vitro requires F-actin assembly, and Mrtfab-null cell clusters are small, contain less F-actin, and defective in IL-2 retention. Clustering of Mrtfab-null cells can be partially restored by exogenous actin expression. IL-2 mediated CD8+ T cell proliferation during infection thus depends on the control of cytoskeletal dynamics and actin gene expression by MRTF-SRF signalling.

Dual blockade of IL-4 and IL-13 with dupilumab ameliorates sensorineural olfactory dysfunction in mice with eosinophilic sinonasal inflammation.

Dupilumab, an antibody that binds IL-4Rα and inhibits IL-4 and IL-13 signals, has demonstrated efficacy in chronic rhinosinusitis with nasal polyps (CRSwNP) primarily characterized by type 2 inflammation. Current evidence suggests that the rate of improvement in olfactory dysfunction with dupilumab exceeds that of nasal polyp reduction, yet the underlying mechanism remains undisclosed. We hypothesize that dupilumab may initially ameliorate sensorineural olfactory dysfunction. Male BALB/c mice were intranasally administered ovalbumin and Aspergillus protease for 12 weeks to induce eosinophilic sinonasal inflammation. Dupilumab treatment was also administered. The mice underwent histological assessment, olfactory behavioural test, and gene expression profiling to identify neuroinflammatory markers within the olfactory bulb. Dupilumab treatment resulted in a reduction in the number of mucosal protruding lesions, as well as decreased infiltration of eosinophils and neutrophils, along with a decrease in olfactory sensory neuron injury. Furthermore, there was a downregulation in the mRNA expression related to microglia activation and neuroinflammation in the olfactory bulb. Dupilumab improves the sensorineural pattern of olfactory dysfunction in mice, potentially explaining why olfaction improves more rapidly than polyp reduction in patients with CRSwNP.

Lung Microbial and Host Genomic Signatures as Predictors of Prognosis in Early-Stage Adenocarcinoma.

Risk of early-stage lung adenocarcinoma recurrence after surgical resection is significant, and the postrecurrence median survival is approximately 2 years. Currently, there are no commercially available biomarkers that predict recurrence. In this study, we investigated whether microbial and host genomic signatures in the lung can predict recurrence. In 91 patients with early-stage (stage IA/IB) lung adenocarcinoma with extensive follow-up, we used 16s rRNA gene sequencing and host RNA sequencing to map the microbial and host transcriptomic landscape in tumor and adjacent unaffected lung samples. Of 91 subjects, 23 had tumor recurrence over 5-year period. In tumor samples, lung adenocarcinoma recurrence was associated with enrichment in Dialister and Prevotella, whereas in unaffected lung samples, recurrence was associated with enrichment in Sphingomonas and Alloiococcus. The strengths of the associations between microbial and host genomic signatures with lung adenocarcinoma recurrence were greater in adjacent unaffected lung samples than in the primary tumor. Among microbial-host features in the unaffected lung samples associated with recurrence, enrichment in Stenotrophomonas geniculata and Chryseobacterium was positively correlated with upregulation of IL2, IL3, IL17, EGFR, and HIF1 signaling pathways among the host transcriptome. In tumor samples, enrichment in Veillonellaceae (Dialister), Ruminococcaceae, Haemophilus influenzae, and Neisseria was positively correlated with upregulation of IL1, IL6, IL17, IFN, and tryptophan metabolism pathways. Overall, modeling suggested that a combined microbial/transcriptome approach using unaffected lung samples had the best biomarker performance (AUC = 0.83). This study suggests that lung adenocarcinoma recurrence is associated with distinct pathophysiologic mechanisms of microbial-host interactions in the unaffected lung rather than those present in the resected tumor.