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Effective tissue response to infection and injury essentially relies on the fine-tuned induction and subsequent resolution of inflammation. Recent research highlighted multiple functions of dermal white adipose tissue (dWAT) beyond its traditional role as an energy reservoir. However, in contrast to other fat depots, there are only limited data about putative immune-regulatory functions of dWAT. Therefore, we investigated the impact of dWAT in the control of an acute skin inflammation. Skin inflammation triggers the activation of dWAT. In turn, soluble mediators of activated dWAT stimulate the expression of numerous genes controlling skin inflammation, including the T helper 2 cell cytokines Il4 and Il13, in myeloid cells in vitro. Consistently, myeloid cells isolated from inflamed skin showed a significant upregulation of Il-4/13 expression compared with those isolated from healthy skin. Mechanistically, we demonstrate that IL-33 released from activated dWAT is responsible for IL-4/13 stimulation in myeloid cells. Interestingly, obesity attenuates IL-33 secretion in dWAT during inflammation, resulting in decreased Il-4 and Il-13 expressions in myeloid cells. Our data reveal an IL-33-IL-4/13 signaling cascade initiated from dWAT in a T helper 2-independent context of inflammation that may contribute to limitation of inflammation. This cascade seems to be disturbed in individuals with obesity with prolonged inflammation., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Blocking IL-13 is highly efficacious in patients with Th2-biased atopic dermatitis (AD), and recent clinical data have highlighted that targeting the T cell costimulatory molecules OX40 and OX40L (TNFSF4) holds promise for future treatment of AD., Aim: We asked whether targeting another T cell costimulatory molecule, CD30L (TNFSF8), might also be a possible treatment option in AD., Methods: Single-cell RNA-seq data from human AD skin lesions was analyzed to identify pathogenic IL-13- or IL-22-producing T cells and assess expression of CD30 and its ligand in comparison to OX40 and its ligand. Additionally, a murine model of AD with repetitive exposure to house dust mite allergen was used to compare neutralizing antibodies against CD30L with those against IL-13 or OX40L., Results: Analysis of several scRNA-seq datasets from skin lesions of AD patients showed that transcripts for CD30 or CD30L were found expressed with OX40 or OX40L in the primary T cell populations that also expressed mRNA for IL13 and/or IL22. Suggesting that this could be therapeutically relevant, mice treated prophylactically with a blocking CD30L antibody were protected from developing maximal allergen-induced AD features, including epidermal and dermal thickening, immune cell infiltration, and expression of AD-related genes, similar to mice treated with a blocking IL-13 antibody. Moreover, therapeutic neutralization of CD30L in mice with experimental AD also reduced all of the pathological skin lesion features to a comparable extent as blocking OX40L., Conclusion: These data suggest that targeting the CD30-CD30L axis might hold promise as a future therapeutic intervention in human AD, similar to targeting the OX40-OX40L axis., (© 2024 European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.)

Background: 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., Methodology: 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., Results: 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., Conclusions: Dupilumab improves the sensorineural pattern of olfactory dysfunction in mice, potentially explaining why olfaction improves more rapidly than polyp reduction in patients with CRSwNP.

The interleukin-33(IL-33) - group 2 innate lymphoid cells (ILC2s) - interleukin-13(IL-13) - monocytic myeloid-derived suppressor cells (M-MDSCs) axis plays a critical role in promoting immune evasion in tumors; however, its specific function in cervical cancer remains poorly understood. In this study, we observed that the proportion of IL-33-ILC2s-IL-13-M-MDSCs were significantly elevated in both cervical cancer patients and the subcutaneous U14 cervical cancer mouse model, compared to normal controls. Our results suggest that IL-33 stimulates ILC2s to secrete IL-13, which, in turn, regulates M-MDSCs to enhance their immune evasion capabilities. Notably, in vitro blockade of IL-33 and IL-13 partially restored the levels and functions of both ILC2s and M-MDSCs. In conclusion, these findings imply that the overactivation of the IL-33-ILC2s-IL-13-M-MDSCs axis may contribute to cervical cancer progression. However, further in vivo blockade studies are required to fully elucidate the precise mechanisms underlying this interaction and to assess its potential therapeutic implications for cervical cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Allergic airway inflammation is a universal airway disease induced by inhaling allergens. Published data show that RNF128, an E3 ligase, promotes Th2 activation in the OVA-induced asthma model. Recent advances have shown that group 2 innate lymphoid cells (ILC2s) produce the cytokines IL-5 and IL-13 to mediate type 2 immune response. However, whether RNF128 regulates ILC2-dependent allergic lung inflammation remains unclear. In this study, we observed greater expression of the E3 ligase RNF128 in ILC2s than in other immune cells. RNF128 deficiency caused a selective increase in the number of peripheral mature ILC2s, and mice with RNF128 deficiency were more susceptible to Alternaria alternata (A. alternata) -induced allergic lung inflammation. Furthermore, RNF128 deficiency increased recruitment of eosinophils and levels of IL-5 and IL-13 in the bronchoalveolar lavage fluid. RNF128 effectively inhibited the expansion of ILC2s and the number of IL-5- and IL-13-producing ILC2s. Specially, RNF128 deficiency promoted the expression of the interleukin-33 (IL-33) receptor ST2 in A. alternata-induced allergic lung inflammation. Above all, our study demonstrated that RNF128 played a key role in A. alternata-induced ILC2 activation and type 2 immune response, suggesting that RNF128 may be an effective therapeutic target for allergic lung inflammation initiated by ILC2s., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Understanding how inflammatory cytokines influence profibrogenic wound healing responses in fibroblasts is important for understanding the pathogenesis of fibrosis. TNF-α and IL-13 are key cytokines in Th1 and Th2 immune responses, respectively, while TGF-β1 is the principal pro-fibrotic mediator. We show that 12-day fibroblast culture with TNF-α or IL-13 induces fibrogenesis, marked by progressively increasing type III and VI collagen formation, and that TGF-β1 co-stimulation amplifies these effects. Tofacitinib substantially reduced the formation of ECM proteins in response to IL-13, while fibrogenesis in response to TNF-α or TGF-β1 was marginally inhibited. The in vitro findings were supported by clinical observations in patients with active rheumatoid arthritis, which had elevated serum type III collagen formation, indicating ongoing fibrogenesis during inflammation. After 48-60 weeks of tofacitinib treatment, type III collagen degradation, aswell as formation, were significantly decreased compared to baseline, highlighting dual anti-inflammatory and anti-fibrogenic effects of tofacitinib. In contrast, other anti-inflammatory treatments including methotrexate, adalimumab and tocilizumab demonstrated anti-inflammatory effects only. Our results highlight fibro-inflammatory profiles associated with TNF-α or IL-13 stimulation, both alone and in combination with TGF-β1, and support the use of tofacitinib as an anti-fibrogenic treatment in chronic inflammatory conditions., Competing Interests: Declarations. Competing interests: Martin Pehrsson, Anne-Christine Bay-Jensen, Morten Karsdal, Peder Frederiksen and Joachim H. Mortensen are employees at Nordic Bioscience, Denmark. Nordic Bioscience is a biotechnology company doing contract research with the pharmaceutical industry. Anne-Christine Bay-Jensen and Morten Karsdal own stock in Nordic Bioscience. The biomarker assays PRO-C1, PRO-C3, PRO-C6, FBN-C and C3M are proprietary intellectual property of Nordic Bioscience. Frederik S. Gillesberg, Bent W. Deleuran, Tue W. Kragstrup, Satoshi Kubo and Yoshiya Tanaka have no competing interests in relation to this work., (© 2025. The Author(s).)

Background: Sepsis is a systemic inflammatory response caused by infection. When this inflammatory response spreads to the lungs, it can lead to acute lung injury (ALI) or more severe acute respiratory distress syndrome (ARDS). Pulmonary fibrosis is a potential complication of these conditions, and the early occurrence of pulmonary fibrosis is associated with a higher mortality rate. The underlying mechanism of ARDS-related pulmonary fibrosis remains unclear., Methods: To evaluate the role of mast cell in sepsis-induced pulmonary fibrosis and elucidate its molecular mechanism. We investigated the level of mast cell and epithelial-mesenchymal transition(EMT) in LPS-induced mouse model and cellular model. We also explored the influence of cromolyn sodium and mast cell knockout on pulmonary fibrosis. Additionally, we explored the effect of MC-derived IL-13 on the EMT and illustrated the relationship between mast cell and pulmonary fibrosis., Results: Mast cell was up-regulated in the lung tissues of the pulmonary fibrotic mouse model compared to control groups. Cromolyn sodium and mast cell knockout decreased the expression of EMT-related protein and IL-13, alleviated the symptoms of pulmonary fibrosis in vivo and in vitro. The PI3K/AKT/mTOR signaling was activated in fibrotic lung tissue, whereas Cromolyn sodium and mast cell knockout inhibited this pathway., Conclusion: The expression level of mast cell is increased in fibrotic lungs. Cromolyn sodium intervention and mast cell knockout alleviate the symptoms of pulmonary fibrosis probably via the PI3K/AKT/mTOR signaling pathway. Therefore, mast cell inhibition is a potential therapeutic target for sepsis-induced pulmonary fibrosis., Competing Interests: Declarations. Ethics approval and consent to participate: This study was approved by the Institutional Animal Care and Use Committee (IACUC) of Nanjing Medical University (No. 2207016). Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: Papillary thyroid cancer (PTC) is among the most prevalent forms of endocrine malignancy with a rapid rise in incidence rates worldwide; however, the composition and characteristics of its immune microenvironment is poorly understand. Here, this work investigated the precise function of Dipeptidyl peptidase 4 (DPP4) in tumor-infiltrated T cells within PTC by investigating its role in cytokine-mediated signaling pathways., Methods: TCGA and GEO data as well as human PTC specimens confirmed the expression of DPP4 in PTC. The CIBERSORT and TIMER tool were used to analyze the distribution of tumor-infiltrating immune cells in PTC. CD8+ T cells from PTC patient's peripheral blood were cultured and used in a three-dimensional model for direct co-culture with PTC tumors to investigate DPP4 function., Results: Bioinformatic analyses has uncovered a significant upregulation of DPP4, which enhances the survival and migration of PTC cells in vitro. DPP4 upregulation significantly correlated with advanced grades, stages, and poor progression-free survival. DPP4 influences immune function and the exhaustion of CD8+ T cells through the IL13-IL13RA2 axis. The inhibition of DPP4 reduces CD8+ T cell exhaustion and IL13 secretion, while also blocking the IL13-IL13RA2 axis, thereby promoting the mesenchymal-to-epithelial transition of PTC cells., Conclusion: Blocking DPP4 leads to the conversion of exhausted CD8+ T cells with decreased IL13 level, resulting in downregulation of IL13RA2 to promote mesenchymal-to-epithelial transition of PTC cells. This highlights DPP4 as a potential therapeutic target, particularly between CD8+ T cells and PTC cells via IL13-IL13RA2 axis, and represents a novel avenue for combined immunotherapy in PTC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The effects of vitamin D and vitamin A in immune cells are mediated through the vitamin D receptor (VDR) and retinoic acid receptor (RAR), respectively. These receptors share the retinoid X receptor (RXR) co-factor for transcriptional regulation. We investigated the effects of active vitamin D 3 (1,25(OH) 2 D 3 ) and 9-cis retinoic acid (9cRA) on T helper (T H )1 and T H 2 cytokines and transcription factors in primary human blood-derived CD4 + T cells. We aimed to address the discrepancies in this field, particularly regarding the effects of 9cRA and the vitamins in combination. 1,25(OH) 2 D 3 upregulated IL-13 and suppressed IFNγ, while 9cRA had the opposite effects. This was largely independent of a T H 1/T H 2 phenotype shift. Combined vitamin supplementation produced intermediate cytokine levels, not only through transcriptional regulation by VDR-RXR and RAR-RXR but also through 1,25(OH) 2 D 3 counteracting the effects of 9cRA on solely 9cRA-responsive genes. Similar results were observed in hereditary vitamin D-resistant rickets (HVDRR) patient T cells, where VDR cannot bind to DNA, indicating that RXR binding to either receptor can limit the other's activity. Additionally, we observed downregulated RAR upon 9cRA supplementation and its re-localization out of the nucleus upon 1,25(OH) 2 D 3 supplementation, suggesting a mechanism of indirect regulation by VDR. VDR protein levels were also upregulated upon 9cRA supplementation, suggesting a novel negative feedback mechanism of 9cRA transcriptional activity, whereby 9cRA promotes its own competitor. This study sets the stage for future research into the combined immunomodulatory mechanisms of 1,25(OH) 2 D 3 and 9cRA, involving both direct transcriptional regulation and indirect regulation via RXR competitive binding., (© 2025 The Scandinavian Foundation for Immunology.)

Mucus hypersecretion and mucus obstruction are pathogenic features in many chronic lung diseases directly linked to disease severity, exacerbation, progression, and mortality. The Jagged-1/Notch pathway is a promising therapeutic target that regulates secretory and ciliated cell trans-differentiation in the lung. However, the Notch pathway is also required in various other organs. Hence, pulmonary delivery of therapeutic agents is a promising approach to target this pathway while minimizing systemic exposure. Using Anticalin technology, Jagged-1 Anticalin binding proteins were generated and engineered to potent and selective inhalable Jagged-1 antagonists. Their therapeutic potential to reduce airway mucus hyperproduction and obstruction was investigated ex vivo and in vivo. In primary airway cell cultures grown at an air-liquid interface and stimulated with inflammatory cytokines, Jagged-1 Anticalin binding proteins reduced both mucin gene expression and mucous cell metaplasia. In vivo, prophylactic and therapeutic treatment with a pulmonary-delivered Jagged-1 Anticalin binding protein reduced mucous cell metaplasia, epithelial thickening, and airway mucus hyperproduction in IL-13 and house dust mite allergen-challenged mice, respectively. Furthermore, in a transgenic mouse model with pathophysiologic features of cystic fibrosis and chronic obstructive pulmonary disease (COPD), pulmonary-delivered Jagged-1 Anticalin binding protein reduced hallmarks of airway mucus obstruction. In all in vivo models, a reduction of mucous cells with a concomitant increase of ciliated cells was observed. Collectively, these findings support Jagged-1 antagonists' therapeutic potential for patients with muco-obstructive lung diseases and the feasibility of targeting the Jagged-1/Notch pathway by inhalation. NEW & NOTEWORTHY Airway mucus drives severity and mortality in diverse chronic lung diseases. The Jagged-1/Notch pathway controls the balance of ciliated versus mucous cells, but targeting the pathway systemically carries the risk of side effects. Here we developed novel, Anticalin-derived, pulmonary-delivered Jagged-1 antagonists, to inhibit airway mucus hyperproduction and obstruction in chronic lung diseases. Our preclinical data demonstrate the effectiveness of these antagonists in diminishing secretory cell and mucus levels and alleviating hallmarks of mucus obstruction.

Idiopathic pulmonary fibrosis (IPF) is fatal interstitial lung disease characterized by excessive scarring of the lung tissue and declining respiratory function. Given its short prognosis and limited treatment options, novel strategies to investigate emerging experimental treatments are urgently needed. Macrophages, as the most abundant immune cell in the lung, have key implications in wound healing and lung fibrosis. However, they are highly plastic and adaptive to their surrounding microenvironment, and thus to maximize translation of research to lung disease, there is a need to study macrophages in multifaceted, complex systems that are representative of the lung. Precision-cut lung slices (PCLS) are living tissue preparations derived from the lung that are cultured ex vivo, which bypass the need for artificial recapitulation of the lung milieu and architecture. Macrophage programming studies are traditionally conducted using isolated cells in vitro, thus our objective was to establish and validate a moderate-throughput, biologically-translational, viable model to study profibrotic polarization of pulmonary-resident macrophages using murine PCLS. To achieve this, we used a polarization cocktail (PC), consisting of IL-4, IL-13, and IL-6, over a 72-h time course. We first demonstrated no adverse effects of the PC on PCLS viability and architecture. Next, we showed that multiple markers of macrophage profibrotic polarization, including Arginase-1, CD206, YM1, and CCL17 were induced in PCLS following PC treatment. Through tissue microarray-based histological assessments, we directly visualized and quantified Arginase-1 and CD206 staining in PCLS in a moderate-throughput manner. We further delineated phenotype of polarized macrophages, and using high-plex immunolabelling with the Iterative Bleaching Extends Multiplexity (IBEX) method, showed that the PC effects both interstitial and alveolar macrophages. Substantiating the profibrotic properties of the system, we also showed expression of extracellular matrix components and fibrotic markers in stimulated PCLS. Finally, we demonstrated that clodronate treatment diminishes the PC effects on profibrotic macrophage readouts. Overall, our findings support a suitable complex model for studying ex vivo profibrotic macrophage programming in the lung, with future capacity for investigating experimental therapeutic candidates and disease mechanisms in pulmonary fibrosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Nociceptor neurons play a crucial role in maintaining the body's homeostasis by detecting and responding to potential environmental dangers. However, this function can be detrimental during allergic reactions, as vagal nociceptors contribute to immune cell infiltration, bronchial hypersensitivity, and mucus imbalance in addition to causing pain and coughing. Despite this, the specific mechanisms by which nociceptors acquire pro-inflammatory characteristics during allergic reactions are not yet fully understood. In this study, we investigate the changes in the molecular profile of airway nociceptor neurons during allergic airway inflammation and identify the signals driving such reprogramming. Using retrograde tracing and lineage reporting, we identify a specific class of inflammatory vagal nociceptor neurons that exclusively innervate the airways. In the ovalbumin mouse model of allergic airway inflammation, these neurons undergo significant reprogramming characterized by the upregulation of the neuropeptide Y (NPY) receptor Npy1r. A screening of cytokines and neurotrophins reveals that interleukin 1β (IL-1β), IL-13, and brain-derived neurotrophic factor (BDNF) drive part of this reprogramming. IL-13 triggers Npy1r overexpression in nociceptors via the JAK/STAT6 pathway. In parallel, NPY is released into the bronchoalveolar fluid of asthmatic mice, which limits the excitability of nociceptor neurons. Single-cell RNA sequencing of lung immune cells reveals that a cell-specific knockout of NPY1R in nociceptor neurons in asthmatic mice altered T cell infiltration. Opposite findings are observed in asthmatic mice in which nociceptor neurons are chemically ablated. In summary, allergic airway inflammation reprograms airway nociceptor neurons to acquire a pro-inflammatory phenotype, while a compensatory mechanism involving NPY1R limits the activity of nociceptor neurons., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Fibrosis drives end-organ damage in many diseases. However, clinical trials targeting individual upstream activators of fibroblasts, such as TGFβ, have largely failed. Here, we target the leukemia inhibitory factor receptor (LIFR) as an "autocrine master amplifier" of multiple upstream activators of lung fibroblasts. In idiopathic pulmonary fibrosis (IPF), the most common fibrotic lung disease, we found that lung myofibroblasts had high LIF expression, and the fibroblasts in fibroblastic foci coexpressed LIF and LIFR. In IPF, fibroblastic foci are the "leading edge" of fibrosis and a key site of disease pathogenesis. TGFβ1, one of the principal drivers of fibrosis, up-regulated LIF expression in IPF fibroblasts. We found that TGFβ1, IL-4, and IL-13 stimulations of fibroblasts require the LIF-LIFR axis to evoke a strong fibrogenic effector response in fibroblasts. In vitro antibody blockade of LIFR on IPF lung fibroblasts reduced the induction of profibrotic genes after TGFβ1 stimulation. Silencing LIF and LIFR reduced profibrotic fibroblast activation following TGFβ1, IL-4, and IL-13 stimulations. We also demonstrated that LIFR amplified profibrotic stimuli in precision-cut lung slices from IPF patients. These LIFR signals were transduced via JAK2, and STAT1 in IPF lung fibroblasts. Together, we find that LIFR drives an autocrine circuit that amplifies and sustains pathogenic activation of IPF fibroblasts. Targeting a single, downstream master amplifier on fibroblasts, like LIFR, is an alternative therapeutic strategy that simultaneously attenuates the profibrotic effects of multiple upstream stimuli., Competing Interests: Competing interests statement:C.P.H. reports consulting fees from AstraZeneca, Sanofi, and Takeda, outside of the submitted work. L.M.S. reports consulting: AstraZeneca, Lilly, Genentech. L.P.H. reports consulting: Boehringer Ingelheim, Pliant Therapeutics, Clario, and Abbvie Therapeutics. J.H.Y. reports consulting fees from Bridge Biotherapeutics and Genentech outside the submitted work. M.B.B. is a founder of Mestag Therapeutics and a consultant to GSK, Moderna, Third Rock Ventures, and 4F0 Ventures. J.W. and I.C. are employed by Abpro Corporation. H.N.N., Y.J., E.Y.K., and M.B.B. (lead) are co-inventors for PCT patent application (US2022/075673) concerning a method to treat fibrosis by targeting LIFR, the subject of this manuscript.

Background: IL-33 is a type 2 inflammatory cytokine that is elevated in the esophageal epithelium of eosinophilic esophagitis (EoE) subjects. We previously developed a mouse model of EoE dependent on constitutive overexpression of IL-33 from the esophageal epithelium (EoE33)., Objective: Our objective was to develop an inducible, IL-33-dependent model of EoE and examine induction of EoE-associated pathology., Methods: We utilized a tetracycline-inducible system to express IL-33 in the esophagus by generating 2 transgenic mice. The first (iSophagus) expresses a reverse tetracycline transactivator from the esophageal epithelium. The second (TRE33) features a tetracycline response element driving expression of IL-33. When crossed, these mice generate an inducible model of EoE (iEoE33). Mice were administered doxycycline-infused chow for up to 2 weeks. Cytokines were assessed by ELISA or bead-based multiplex analysis. T cells were assessed by flow cytometry. Pathology was assessed by histology and immunohistochemistry for IL-33, eosinophil peroxidase, CD4, and Ki-67. iEoE33 was treated with steroids and crossed with IL-13 -/- mice., Results: Doxycycline-treated iEoE33 mice demonstrated expression of IL-33 in the esophageal epithelium, and esophageal pathology including eosinophilia, CD4 + cell infiltrate, basal zone hyperplasia, and dilated intercellular spaces. These findings became pronounced on day 7 of induction, were accompanied by weight loss and esophageal thickening, and were steroid responsive and IL-13 dependent., Conclusion: Inducible IL-33 expression in the esophageal epithelium elicited features pathognomonic of EoE. iEoE33 enables investigation of EoE disease mechanisms as well as initiation, progression, and resolution., Competing Interests: Disclosure statement Supported by the Donald and Kathy Levin Family Foundation, Mayo Clinic Foundation, and Phoenix Children’s Hospital Foundation. M.Y.M. is a member of the Immunology Graduate Program and is supported by the Mayo ClinicGraduate School of Biomedical Sciences. This work was also supported by NIH grants: R01DK114436 (H.N.), R37AI71106 (H.K.), R01AI128729 (H.K.), R01HL117823 (H.K.), and K23AI158813 (B.L.W.). iEoE33 mice were generated and characterized as an EoE model with funding support exclusively from the Donald and Kathy Levin Family Foundation. Disclosure of potential conflict of interest: The authors declare that they have no relevant conflicts of interest., (Copyright © 2024 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

The intricate cooperation between cancer cells and nontumor stromal cells within melanoma microenvironment (MME) enables tumor progression and metastasis. We previously demonstrated that the interplay between tumor-associated macrophages (TAMs) and melanoma cells can be disrupted by using long-circulating liposomes (LCLs) encapsulating prednisolone phosphate (PLP) (LCL-PLP) that inhibited tumor angiogenesis coordinated by TAMs. In this study, our goal was to improve LCL specificity for protumor macrophages (M2-like (i.e., TAMs) macrophages) and to induce a more precise accumulation at tumor site by loading PLP into IL-13-conjugated liposomes (IL-13-LCL-PLP), since IL-13 receptor is overexpressed in this type of macrophages. The IL-13-LCL-PLP liposomal formulation was obtained by covalent attachment of thiolated IL-13 to maleimide-functionalized LCL-PLP. C57BL/6 mice bearing B16.F10  s.c melanoma tumors were used to investigate the antitumor action of LCL-PLP and IL-13-LCL-PLP. Our results showed that IL-13-LCL-PLP formulation remained stable in biological fluids after 24h and it was preferentially taken up by M2 polarized macrophages. IL-13-LCL-PLP induced strong tumor growth inhibition compared to nonfunctionalized LCL-PLP at the same dose, by altering TAMs-mediated angiogenesis and oxidative stress, limiting resistance to apoptosis and invasive features in MME. These findings suggest IL-13-LCL-PLP might become a promising delivery platform for chemotherapeutic agents in melanoma.

The type 2 cytokines, interleukin (IL)-4, IL-13 and IL-5 reside within a multigene cluster. Both innate (ILC2) and adaptive T helper 2 (T H 2) lymphocytes secrete type 2 cytokines with diverse production spectra. Using transcription factor footprint and chromatin accessibility, we systemically cataloged regulatory elements (REs) denoted as SHS-I/II, KHS-I/II, +6.5kb Il13 , 5HS-I(a, b, c, d, e), 5HS-II and 5HS-III(a, b, c) across the extended Il4-Il13-Il5 locus in mice. Physical proximities among REs were coordinately remodeled in three-dimensional space after cell activation, leading to divergent compartmentalization of Il4, Il13 and Il5 with varied combinations of REs. Deletions of REs revealed no single RE solely accounted for selective regulation of a given cytokine in vivo. Instead, individual RE differentially contribute to proper genomic positioning of REs and target genes. RE deletions resulted in context-dependent dysregulation of cytokine expression and immune response in tissue. Thus, signal-dependent remodeling of three-dimensional configuration underlies divergent cytokine outputs from the type 2 loci., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Atopic dermatitis (AD) is a common inflammatory skin disorder characterised by hypersensitivity to allergens, eczematous lesions and pruritus. The aim of this study was to comprehensively characterise a murine model of dermatitis and assess the similarity with the human disease, as well as to profile clinically relevant AD therapies. Four repeated topical administrations of oxazolone in the auricular skin of sensitised mice induced morphological features compatible with AD, including redness and swelling, as well as histological changes typical of spongiotic (eczematous) dermatitis and increased plasmatic IgE. Additionally, key driver Type 2 cytokines involved in the pathophysiology of the disease, IL-4, IL-13 and IL - 31, were upregulated in the skin, along with cytokines related to Type 1, 17 and 22 responses, which have been reported to be relevant in the chronic stages of the disease. RNA-seq studies in OXA model mice samples validate expression changes obtained by q-PCR and suggest a greater significant similarity with the transcriptomic signature of human AD with respect to psoriasis studies. Oral (cyclosporine, prednisolone and baricitinib) and topical treatments (betamethasone, tacrolimus and crisaborole) were effective inhibiting the induced pathology, as well as modulating the cytokine gene signature of AD. In conclusion, our 4 oxazolone challenges model recapitulates many of the key features of the disease and is responsive to AD standard of care therapies in humans., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Dietary zinc deficiency is a major risk factor for pneumonia. Acinetobacter baumannii is a leading cause of ventilator-associated pneumonia and a critical public health threat due to increasing rates of multidrug resistance. Patient populations at increased risk for A. baumannii pneumonia are also at increased risk of zinc deficiency. Here we established a mouse model of dietary zinc deficiency and acute A. baumannii pneumonia to test the hypothesis that host zinc deficiency contributes to A. baumannii pathogenesis. We showed that zinc-deficient mice have significantly increased A. baumannii burdens in the lungs, dissemination to the spleen and higher mortality. During infection, zinc-deficient mice produce more pro-inflammatory cytokines, including IL-13. Administration of IL-13 promotes A. baumannii dissemination in zinc-sufficient mice, while antibody neutralization of IL-13 protects zinc-deficient mice from A. baumannii dissemination and mortality during infection. These data highlight the therapeutic potential of anti-IL-13 antibody treatments, which are well tolerated in humans, for the treatment of pneumonia., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: Erythroderma is a dermatologic condition characterized by widespread red and scaly skin. The causes include, but are not limited to, psoriasis, eczema, drug eruptions, pityriasis rubra pilaris (PRP), and cutaneous T-cell lymphoma. Most of these are typified by Type 2 (e.g., eczema) or Type 17 (e.g., psoriasis) immune activation. However, since the clinicopathologic features of erythroderma can be nonspecific, assays that determine the underlying immune activation status are desirable., Methods: IL-13 RNA in situ hybridization and IL-36 immunohistochemistry were performed on 30 specimens of erythroderma, to ascertain Type 2 and Type 17 immune signatures, respectively., Results: Specimens of erythrodermic psoriasis and PRP showed strong expression of IL-36 and less than one IL-13-positive cell per millimeter. Conversely, those of spongiotic dermatitis showed low expression of IL-36 and greater than one IL-13-positive cell per millimeter. Most specimens of spongiotic, psoriasiform dermatitis demonstrated low IL-36 expression and greater than one IL-13-positive cell per millimeter, but a subset showed high IL-36 expression and greater than one IL-13-positive cell per millimeter., Conclusions: We developed a Type 2/17 immune signature classifier based on cytokine profiling, which showed that cases of erythroderma fall within distinct categories of immune activation. This categorization may have utility in guiding clinical decisions., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: The gut microbiota has a profound effect on immunity and metabolic status of the host, which has increasingly attracted research communities. However, the intrinsic mechanism underlying the interplay among these three aspects remains unclear., Results: Different immune states were established via shaping the population structure of gut microbiota with antibacterial agents. The gut microbiota population structures altered with the subtherapeutic level of antibacterial agents facilitated growth phenotype in both piglets and infant mice. Notably, increased colonization of Prevotella copri was observed in the intestinal microbiota, which shifted the immune balance from a CD4 + T cell-dominated population toward a T helper 2 cell (Th2) phenotype, accompanied by a significant elevation of interleukin-13 (IL-13) levels in the portal vein, which was found to display a strong positive correlation with hepatic insulin-like growth factor-1 (IGF-1) levels. Subsequent investigations unveiled that gut-derived IL-13 stimulated the production of hepatic IGF-1 by activating the IL-13R/Jak2/Stat6 pathway in vitro. The IGF-1 levels were increased in the muscles, leading to an upregulation of and resulted the increased genes associated with related to myofibrillar synthesis and differentiation, which ultimately improving the growth phenotype., Conclusions: Our findings highlight the modification of gut immunity states as a central strategy for increasing anabolism of the host, which has significant implications for addressing human undernutrition/stunting, sarcopenia, obesity and related comorbidities. Video Abstract., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Chronic rhinosinusitis with nasal polyps (CRSwNP) is an inflammatory upper airway disease, divided into eosinophilic CRSwNP (eCRSwNP) and noneosinophilic CRSwNP (neCRSwNP) according to eosinophilic levels. Neutrophils are major effector cells in CRSwNP, but their roles in different inflammatory environments remain largely unclear. We performed an integrated transcriptome analysis of polyp-infiltrating neutrophils from patients with CRSwNP, using healthy donor blood as a control. Additional experiments, including flow cytometry and in vitro epithelial cell and fibroblast culture, were performed to evaluate the phenotypic feature and functional role of neutrophils in CRSwNP. Single-cell RNA-sequencing analysis demonstrated that neutrophils could be classified into 5 functional subsets, with GBP5+ neutrophils occurring mainly in neCRSwNP and a high proportion of CXCL8+ neutrophils in both subendotypes. GBP5+ neutrophils exhibited significant IFN-I pathway activity in neCRSwNP. CXCL8+ neutrophils displayed increased neutrophil activation scores and mainly secreted oncostatin M (OSM), which facilitates communication with other cells. In vitro experiments showed that OSM enhanced IL-13- or IL-17-mediated immune responses in nasal epithelial cells and fibroblasts. Our findings indicate that neutrophils display transcriptional plasticity and activation when exposed to polyp tissue, contributing to CRSwNP pathogenesis by releasing OSM, which interacts with epithelial cells and fibroblasts depending on the inflammatory environment.

Levodopa (L-DOPA) treatment is a clinically effective strategy for improving motor function in patients with ischemic stroke. However, the mechanisms by which modulating the dopamine system relieves the pathology of the ischemic brain remain unclear. Emerging evidence from an experimental mouse model of ischemic stroke, established by middle cerebral artery occlusion (MCAO), suggested that L-DOPA has the potential to modulate the inflammatory and immune response that occurs during a stroke. Here, we aimed to demonstrate the therapeutic effect of L-DOPA in regulating the systemic immune response and improving functional deficits in mice with ischemia. Transient MCAO led to progressive degeneration of nigrostriatal dopamine neurons and significant rotational behavior in mice. Exogenous L-DOPA treatment attenuated the striatonigral degeneration and reversed motor behavioral impairment. Notably, treatment with L-DOPA significantly increased IL-13 but reduced IFN-γ in infarct lesions. To investigate the role of IL-13 in motor behavior, we stereotaxically injected anti-IL-13 antibodies into the infarct area of the mouse brain one week after MCAO, followed by L-DOPA treatment. The intervention reduced dopamine, IL-13, and IL-10 levels and exacerbated motor function. IL-13 is potentially expressed on CD4 T cells, while IL-10 is mainly expressed on microglia rather than astrocytes. Finally, IL-13 activates the phagocytosis of microglia, which may contribute to neuroprotection by eliminating degenerating neurons. Our study provides evidence that the L-DOPA-activated dopamine system modulates peripheral immune cells, resulting in the expression of anti-inflammatory and neuroprotective cytokines in mice with ischemic stroke., Competing Interests: Competing interests: The authors declare no competing interests. Ethics approval: All studies were conducted following the guidelines of the Institutional Animal Care and Use Committee of Inha University in Incheon (INHA170908-513-5; INHA180420-558-4; INHA200518-701-7; INHA230525-875-2; INHA240723-939)., (© 2024. The Author(s).)

Objectives: Allergic rhinitis (AR) is a complex disorder with variable pathogenesis. Increasing evidence suggests that the LRRC8A is involved in maintaining cellular stability, regulating immune cell activation and function, and playing significant roles in inflammation. However, the involvement of LRRC8A in AR inflammation and its underlying mechanisms remain unclear., Methods: LRRC8A expression in AR patients, confirmed by qRT-PCR and Western blotting, was analyzed to investigate its relationship with the clinical characteristics of AR patients. In vitro, IL-13 stimulated HNEpCs to establish a Th2 inflammation model, with subsequent LRRC8A knockout or overexpression. NOX1/NOX4 inhibitor (GKT137831) and chloride channel inhibitor (DCPIB) were utilized to investigate AR development mechanisms during LRRC8A overexpression. An OVA-induced AR model with nasal mucosa LRRC8A knockdown confirmed LRRC8A's regulatory role in AR inflammation., Results: LRRC8A mRNA and protein levels were significantly elevated in AR patients, positively correlating with NADPH oxidase subunits and Th2 inflammatory markers. In vitro, IL-13 stimulation of HNEpCs resulted in upregulation of LRRC8A and increased expression of NOX1, NOX4, and p22 phox , along with mitochondrial dysfunction and NF-κB pathway activation. The knockout of LRRC8A reversed these effects. In nasal mucosal epithelial cells, DCPIB and GKT137831 completely blocked mitochondrial dysfunction caused by the overexpression of LRRC8A, which led to up-regulation of NOX1, NOX4, and p22 phox . In vivo, knocking down LRRC8A reduced eosinophil infiltration, downregulated the expression of NOX1, NOX4, p22 phox IL-4, IL-5, and IL-13, and decreased NF-κB pathway activation., Conclusion: LRRC8A drives the upregulation of NOX1, NOX4, and p22 phox , leading to ROS overproduction and mitochondrial dysfunction. It also activates NF-κB, ultimately leading to nasal mucosal epithelial inflammation. LRRC8A may be a potential target for the treatment of AR., Competing Interests: Declarations Ethics approval and consent to participate This study was approved by the Ethics Review Committee of Shandong Provincial ENT Hospital. Informed consent was obtained from all participants. All animal experiments were conducted in accordance with the regulations for the management of experimental animals and were approved by the Animal Ethics Committee of Shandong Provincial ENT Hospital. Consent for publication Not applicable. Competing interests No competing interests exists between any of the authors., (© 2024. The Author(s).)

Infecting humans with controlled doses of small intestinal helminths, such as human hookworm, is proposed as a therapy for the colonic inflammatory disease ulcerative colitis. Strengthening the colonic mucus barrier is a potential mechanism by which small intestinal helminths could treat ulcerative colitis. In this study, we compare C57BL/6 mice infected with the small intestinal helminth Heligmosomoides polygyrus and uninfected controls to investigate changes in colonic mucus. Histology, gene expression, and immunofluorescent analysis demonstrate that this helminth induces goblet cell hyperplasia, and an upregulation of mucin sialylation, and goblet-cell-derived functional proteins resistin-like molecule-beta (RELM-β) and trefoil factors (TFFs), in the colon. Using IL-13 knockout mice, we reveal that these changes are predominantly IL-13-dependent. The assessment of the colonic mucus microbiome demonstrates that H. polygyrus infection increases the abundance of Ruminococcus gnavus , a commensal bacterium capable of utilising sialic acid as an energy source. This study also investigates a human cohort experimentally challenged with human hookworm. It demonstrates that TFF blood levels increase in individuals chronically infected with small intestinal helminths, highlighting a conserved mucus response between humans and mice. Overall, small intestinal helminths modify colonic mucus, highlighting this as a plausible mechanism by which human hookworm therapy could treat ulcerative colitis.

Distinct subsets of eosinophils are reported in inflammatory and healthy tissues, yet the functions of uniquely specialized eosinophils and the signals that elicit them, particularly in eosinophilic esophagitis, are not well understood. Herein, we report an ex vivo system wherein freshly isolated human eosinophils were cocultured with esophageal epithelial cells and disease-relevant proinflammatory (IL-13) or profibrotic (TGF-β) cytokines. Compared with untreated cocultures, IL-13 increased expression of CD69 on eosinophils, whereas TGF-β increased expression of CD81, CD62L, and CD25. Eosinophils from IL-13-treated cocultures demonstrated increased secretion of GRO-α, IL-8, and macrophage colony-stimulating factor and also generated increased extracellular peroxidase activity following activation. Eosinophils from TGF-β-treated cocultures secreted increased IL-6 and exhibited increased chemotactic response to CCL11 compared with eosinophils from untreated or IL-13-treated coculture conditions. When eosinophils from TGF-β-treated cocultures were cultured with fibroblasts, they upregulated SERPINE1 expression and fibronectin secretion by fibroblasts compared with eosinophils that were cultured with granulocyte macrophage colony-stimulating factor alone. Translational studies revealed that CD62L was heterogeneously expressed by eosinophils in patient biopsy specimens. Our results demonstrate that disease-relevant proinflammatory and profibrotic signals present in the esophagus of patients with eosinophilic esophagitis cause distinct profiles of eosinophil activation and gene expression., Competing Interests: Conflict of interest statement. M.E.R. is a consultant for Pulm One, Spoon Guru, ClostraBio, Serpin Pharm, Allakos, Celldex, Nexstone One, Santa Ana Bio, EnZen Therapeutics, Bristol Myers Squibb, Astra Zeneca, Pfizer, GlaxoSmith Kline, Regeneron/Sanofi, Revolo Biotherapeutics, and Guidepoint and has an equity interest in the first 9 listed and royalties from reslizumab (Teva Pharmaceuticals), PEESSv2 (Mapi Research Trust), and UpToDate. M.E.R. is an inventor of patents owned by Cincinnati Children's Hospital., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for Leukocyte Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Introduction: Colorectal cancer (CRC) is a third  cause of death worldwide. The immune system plays a significant role in the tumor microenvironment and identifying its components involved in cancer development can aid in finding new biomarkers for prognosis, treatment monitoring, and immune-based therapies. Interleukin 13 (IL-13) is a cytokine produced by immune cells that has been implicated in tumor invasion, proliferation, and metastasis. Previous studies have shown that IL-13 causes the phosphorylation of Tyrosine kinase 2 (TYK2), which may contribute to the development and progression of cancer. This study investigated the levels expression of IL-13 and TYK2 in the tissue and serum of CRC patients and explored their possible association with pathological and clinical factors., Methods: 105 patients with CRC and 105 healthy individuals were involved in the study. Tissue and blood samples were collected. The quantitative Real-Time PCR (qRT-PCR) technique was used to assess the expression levels of the IL-13 and TYK2 CRC tissue samples in comparison with the adjacent control tissue., Result: The expression levels of IL-13 were lower and TYK2 were found to be higher in CRC tissue compared to normal tissue. Additionally, serum levels of IL-13 were decreased in CRC patients while TYK2 levels were elevated. A significant negative correlation was found between the expression levels of IL-13 in both serum and tissue and the cancer stage., Conclusion: These results suggest that IL-13 and TYKMay 2 play essential roles in CRC development and progression and may serve as potential biomarkers for early detection and treatment.

The interplay between genetic and environmental factors during pregnancy can predispose to inflammatory diseases postnatally, including eosinophilic esophagitis (EoE), a chronic allergic disease triggered by food. Herein, we examined the effects of amniotic fluid (AF) on esophageal epithelial differentiation and responsiveness to proallergic stimuli. Multiplex analysis of AF revealed the expression of 66 cytokines, whereas five cytokines including IL-4 and thymic stromal lymphopoietin (TSLP) were not detected. Several proinflammatory cytokines including TNFα and IL-12 were highly expressed in the AF from women who underwent preterm birth, whereas EGF was the highest in term birth samples. Exposure of esophageal epithelial cells to AF resulted in transient phosphorylation of ERK1/2 and the transcription of early response genes, highlighting the direct impact of AF on esophageal epithelial cells. In a three-dimensional spheroid model, AF modified the esophageal epithelial differentiation program and enhanced the transcription of IL-13-target genes, including CCL26 and CAPN14 , which encodes for a major genetic susceptibility locus for eosinophilic esophagitis. Notably, CAPN14 exhibited upregulation in spheroids exposed to preterm but not term AF following differentiation. Collectively, our findings call attention to the role of AF as a potential mediator of the intrauterine environment that influences subsequent esophageal disorders. NEW & NOTEWORTHY The interaction between amniotic fluid and the esophageal epithelium during pregnancy modifies esophageal epithelial differentiation and subsequent responsiveness to inflammatory stimuli, including interleukin 13 (IL-13). This interaction may predispose individuals to inflammatory conditions of the esophagus, such as eosinophilic esophagitis (EoE), in later stages of life.

The innate immune system shapes brain development and is implicated in neurodevelopmental diseases. It is critical to define the relevant immune cells and signals and their impact on brain circuits. In this work, we found that group 2 innate lymphoid cells (ILC2s) and their cytokine interleukin-13 (IL-13) signaled directly to inhibitory interneurons to increase inhibitory synapse density in the developing mouse brain. ILC2s expanded and produced IL-13 in the developing brain meninges. Loss of ILC2s or IL-13 signaling to interneurons decreased inhibitory, but not excitatory, cortical synapses. Conversely, ILC2s and IL-13 were sufficient to increase inhibitory synapses. Loss of this signaling pathway led to selective impairments in social interaction. These data define a type 2 neuroimmune circuit in early life that shapes inhibitory synapse development and behavior.

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.

Atopic dermatitis (AD) is a common, chronic, and recurrent inflammatory skin condition that affects a considerable portion of the population, and is particularly prevalent among children. The development of AD is influenced by environmental and genetic factors, which cause epidermal barrier dysfunction, immune dysregulation, and dysbiosis. In immune dysregulation, there is excessive production of cytokines. Among the cytokines, interleukin (IL)-13 plays a major role in the pathogenesis of AD. Searching for new and more selective treatments for moderate-to-severe cases is important because of the considerable effect of AD on the quality of life. Tralokinumab and lebrikizumab are selective IL-13 inhibitors that have demonstrated safety and efficacy as treatment options for AD in phase III trials. Tralokinumab is approved for use in Europe and the USA, while lebrikizumab is approved only in Europe. Cendakimab, which is another IL-13 selective inhibitor, has shown promising results in phase II trials, providing safe and effective outcomes. Eblasakimab, which disrupts IL-13 and IL-4 signaling pathways, is currently in phase II trials following well-tolerated administration in phase I studies. This narrative review aims to outline the current state of knowledge regarding the effectiveness and safety of these four biologic agents targeting IL-13 signaling., Competing Interests: Declaration of conflicting interestOrhan Yilmaz, Carlos Teixeira, and Diana Bernardo declare that there is no conflict of interest. Tiago Torres has received consultancy and/or speaker’s honoraria from and/or participated in clinical trials sponsored by AbbVie, Amgen, Almirall, Amgen, Arena Pharmaceuticals, Biocad, Biogen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Fresenius-Kabi, Janssen, LEO Pharma, Eli Lilly, MSD, Mylan, Novartis, Pfizer, Samsung-Bioepis, Sanofi-Genzyme, Sandoz, and UCB.

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease worldwide. However, it is still urgent to develop innovative treatments that can effectively manage refractory patients with unpredictable chronic disease courses. In this study, we evaluated the therapeutic efficacy of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) as a novel agent for AD treatment using a human-like mouse model of AD. PLAG significantly improved 2,4-dinitrochlorobenzene (DNCB)-induced AD skin lesions compared to those in mice treated with DNCB alone. PLAG substantially modulated the AD-induced infiltration of monocytes and eosinophils into skin lesions and humoral systemic responses involving immunoglobulin E (IgE), interleukin (IL)-4, and IL-13, restoring them to a normal state. Next, we compared the therapeutic efficacy of PLAG and abrocitinib for severe AD treatment. PLAG exhibited a significant therapeutic effect on AD skin lesions compared to abrocitinib. Unlike abrocitinib, PLAG significantly reduced AD-induced eosinophil infiltration to a level similar to that observed in untreated negative controls. Notably, both PLAG and abrocitinib downregulated IgE, IL-4, and IL-13 in a similar pattern, reaching levels similar to those in the untreated negative controls. Our findings strongly suggest that PLAG may serve as a therapeutic agent for AD with an efficacy comparable to that of abrocitinib., (© 2024. The Author(s).)

Interleukin-33 (IL-33) is an alarmin released by epithelial cells in response to tissue damage. It activates resident immune sentinel cells, which then produce signals commonly associated with type 2 immune responses, particularly affecting infiltrating antigen-specific T cells. Given that mast cells (MCs) are a primary target of IL-33 and can shape T helper (Th) cell responses, we investigated the effect of IL-33 priming on the ability of MCs to influence Th cell cytokine production. To examine the Th cell/MC interaction, we developed human primary MC/memory CD4 + T-cell coculture systems involving both cognate and non-cognate interactions. Our results demonstrated that IL-33-primed MCs, whether as bystander cells cocultured with activated effector T cells or functioning as antigen-presenting cells, promoted IL-9 and increased IL-13 production in Th cells via an OX40L-dependent mechanism. This indicates that MCs sense IL-33-associated danger, prompting them to direct Th cells to produce the key type 2 effector cytokines IL-9 and IL-13., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Battut, Leveque, Valitutti, Cenac, Dietrich and Espinosa.)

Lung cancer is the leading cause of cancer-related deaths worldwide. Patients with lung cancer usually exhibit poor prognoses and low 5-year survival rates. Idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) are both chronic lung dysfunctions resulting in lung fibrosis and increased risk of lung cancer. Myofibroblasts contribute to the progression of asthma, COPD and IPF, leading to fibrosis in the airway and lungs. A growing body of evidence demonstrates that metabolic reprogramming is a major hallmark of fibrosis, being important in the progression of fibrosis. Using gene expression microarray, we identified and validated that the lipid metabolic pathway was upregulated in lung fibroblasts upon interleukin (IL)-4, IL-13 and tumour necrosis factor (TNF)-α treatment. In this study, we described that prostaglandin E synthase (PTGES) was upregulated in lung fibroblasts after IL-4, IL-13 and TNF-α treatments. PTGES increased α-SMA levels and promoted lung fibroblast cell migration and invasion abilities. Furthermore, PTGES was upregulated in a lung fibrosis rat model in vivo. PTGES increased AKT phosphorylation, leading to activation of the HIF-1α-glycolysis pathway in lung fibroblast cells. HIF-1α inhibitor or 2-DG treatments reduced α-SMA expression in recombinant PTGES (rPTGES)-treated lung fibroblast cells. Targeting PGE 2 signalling in PTGES-overexpressing cells by a PTGES inhibitor reduced α-SMA expression. In conclusion, the results of this study demonstrate that PTGES increases the expression of myofibroblast marker via HIF-1α-dependent glycolysis and contributes to myofibroblast differentiation., (© 2024 The Author(s). Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Basal cells are adult stem cells in the airway epithelium and regenerate differentiated cell populations, including the mucosecretory and ciliated cells that enact mucociliary clearance. Human basal cells can proliferate and produce differentiated epithelium in vitro. However, studies of airway epithelial differentiation mostly rely on immunohistochemical or immunofluorescence-based staining approaches, meaning that a dynamic approach is lacking, and quantitative data are limited. Here, we use a lentiviral reporter gene approach to transduce primary human basal cells with bioluminescence reporter constructs to monitor airway epithelial differentiation longitudinally. We generated three constructs driven by promoter sequences from the TP63 , MUC5AC , and FOXJ1 genes to quantitatively assess basal cell, mucosecretory cell, and ciliated cell abundance, respectively. We validated these constructs by tracking differentiation of basal cells in air-liquid interface and organoid ("bronchosphere") cultures. Transduced cells also responded appropriately to stimulation with interleukin 13 (IL-13; to increase mucosecretory differentiation and mucus production) and IL-6 (to increase ciliated cell differentiation). These constructs represent a new tool for monitoring airway epithelial cell differentiation in primary epithelial and/or induced pluripotent stem cell (iPSC)-derived cell cultures. NEW & NOTEWORTHY Orr et al. generated and validated new lentiviral vectors to monitor the differentiation of airway basal cells, goblet cells, or multiciliated cells using bioluminescence.

Key Points: A persistent type 2 endotype signature exists in recalcitrant chronic rhinosinusitis with nasal polyps mucosa on dupilumab. Revision sinus surgery immediately prior to dupilumab reduces long-term interleukin (IL)-4/IL-13 tissue mRNA. Pre-dupilumab revision surgery is associated with reduced tissue eosinophils and GATA-3+ cells., (© 2024 ARS‐AAOA, LLC.)

In mice, intestinal tuft cells have been described as a long-lived, postmitotic cell type. Two distinct subsets have been identified: tuft-1 and tuft-2 (ref. 1 ). By combining analysis of primary human intestinal resection material and intestinal organoids, we identify four distinct human tuft cell states, two of which overlap with their murine counterparts. We show that tuft cell development depends on the presence of Wnt ligands, and that tuft cell numbers rapidly increase on interleukin-4 (IL-4) and IL-13 exposure, as reported previously in mice 2-4 . This occurs through proliferation of pre-existing tuft cells, rather than through increased de novo generation from stem cells. Indeed, proliferative tuft cells occur in vivo both in fetal and in adult human intestine. Single mature proliferating tuft cells can form organoids that contain all intestinal epithelial cell types. Unlike stem and progenitor cells, human tuft cells survive irradiation damage and retain the ability to generate all other epithelial cell types. Accordingly, organoids engineered to lack tuft cells fail to recover from radiation-induced damage. Thus, tuft cells represent a damage-induced reserve intestinal stem cell pool in humans., (© 2024. The Author(s).)

Background: Intensive care unit-acquired weakness (ICU-AW) is a syndrome characterized by a long-term muscle weakness often observed in sepsis-surviving patients during the chronic phase. Although ICU-AW is independently associated with increased mortality, effective therapies have yet to be established. Programmed death-1 (PD-1) inhibitors have attracted attention as potential treatments for reversing immune exhaustion in sepsis; however, its impact on ICU-AW remains to be elucidated. Here, we study how PD-1 deficiency affects sepsis-induced skeletal muscle dysfunction in a preclinical sepsis model., Methods: Chronic sepsis model was developed by treating wild-type (WT) and PD-1 knockout (KO) mice with caecal slurry, followed by resuscitation with antibiotics and saline. Mice were euthanized on days 15-17. Body weights, muscle weights, and limb muscle strengths were measured. Interleukin 13 (IL-13) and PD-1 expressions were examined by flow cytometry. Messenger RNA (mRNA) expressions of slow-twitch muscles were measured by reverse transcription and quantitative polymerase chain reaction (RT-qPCR). In an in vitro study, C2C12 myotubes were treated with lipopolysaccharide (LPS) and recombinant IL-13 followed by gene expression measurements., Results: WT septic mice exhibited decreased muscle weight (quadriceps, P < 0.01; gastrocnemius, P < 0.05; and tibialis anterior, P < 0.01) and long-term muscle weakness (P < 0.0001), whereas PD-1 KO septic mice did not exhibit any reduction in muscle weights and strengths. Slow-twitch specific mRNAs, including myoglobin (Mb), troponin I type 1 (Tnni1), and myosin heavy chain 7 (Myh7) were decreased in WT skeletal muscle (Mb, P < 0.0001; Tnni1, P < 0.05; and Myh7, P < 0.05) after sepsis induction, but mRNA expressions of Tnni1 and Myh7 were increased in PD-1 KO septic mice (Mb, not significant; Tnni1, P < 0.0001; and Myh7, P < 0.05). Treatment of C2C12 myotube cells with LPS decreased the expression of slow-twitch mRNAs, which was restored by IL-13 (Mb, P < 0.0001; Tnni1, P < 0.001; and Myh7, P < 0.05). IL-13 production was significantly higher in ILC2s compared to T cells in skeletal muscle (P < 0.05). IL-13-producing ILC2s in skeletal muscle were examined and found to increase in PD-1 KO septic mice, compared with WT septic mice (P < 0.05). ILC2-derived IL-13 was increased by PD-1 KO septic mice and thought to protect the muscles from experimental ICU-AW., Conclusions: Long-term muscle weakness in experimental ICU-AW was ameliorated in PD-1 KO mice. ILC2-derived IL-13 production in skeletal muscles was increased in PD-1 KO mice, thereby suggesting that IL-13 alleviates muscle weakness during sepsis. This study demonstrates the effects of PD-1 blockade in preserving muscle strength during sepsis through an increase in ILC2-derived IL-13 and may be an attractive therapeutic target for sepsis-induced ICU-AW., (© 2024 The Author(s). Journal of Cachexia, Sarcopenia and Muscle published by Wiley Periodicals LLC.)

Dysfunction of group 2 innate lymphoid cells (ILC2s) plays an important role in the development of type 2 inflammation-related diseases such as asthma and pulmonary fibrosis. Notably, neural signals are increasingly recognized as pivotal regulators of ILC2s. However, how ILC2s intrinsically modulate their responsiveness to these neural signals is still largely unknown. Here, using single-cell RNA-Seq, we found that the immune-regulatory molecule phosphatase of activated cells 1 (PAC1) selectively promoted the signaling of the neuropeptide calcitonin gene-related peptide (CGRP) in ILC2s in a cell-intrinsic manner. Genetic ablation of PAC1 in ILC2s substantially impaired the inhibitory effect of CGRP on proliferation and IL-13 secretion. PAC1 deficiency significantly exacerbated allergic airway inflammation induced by Alternaria alternata or papain in mice. Moreover, in human circulating ILC2s, the expression level of PAC1 was also significantly negatively correlated with the number of ILC2s and their expression level of IL13. Mechanistically, PAC1 was necessary for ensuring the expression of CGRP response genes by influencing chromatin accessibility. In summary, our study demonstrated that PAC1 is an important regulator of ILC2 responses, and we propose that PAC1 is a potential target for therapeutic interventions in type 2 inflammation-related diseases.

Calcitriol, the bioactive form of vitamin D, exerts its biological functions by binding to its cognate receptor, the vitamin D receptor (VDR). The indicators of the severity of allergies and asthma have been linked to low vitamin D levels. However, the role of calcitriol in regulating IL-4 and IL-13, two cytokines pivotal to allergic inflammation, remained unclear. Our study observed diminished IL-4 and IL-13 secretion in murine and human Th2 cells treated with calcitriol. In murine Th2 cells, Gata3 expression was attenuated by calcitriol. However, the expression of the transcriptional repressor Gfi1, too, was attenuated in the presence of calcitriol. Ectopic expression of either Gfi1 or VDR impaired the secretion of IL-13 in Th2 cells. In murine Th2 cells, VDR interacted with Gata3 but not Gfi1. Gfi1 significantly impaired Il13 promoter activation, which calcitriol failed to restore. Conversely, calcitriol augmented Gfi1 recruitment to the Il13 promoter. Ecr, a conserved region between these two genes, which enhanced the transactivation of Il4 and Il13 promoters, is essential for calcitriol-mediated suppression of both the genes. Calcitriol augmented the recruitment of VDR to the Il13 promoter and Ecr regions. Gata3 recruitment was significantly impaired at the Il13 and Ecr loci in the presence of calcitriol but increased at the Il4 promoter. Furthermore, the recruitment of the histone deacetylase HDAC1 was universally increased at the promoters of Il4, Il13, and Ecr when calcitriol was present. Together, our data clearly elucidate that calcitriol modulates VDR, Gata3, and Gfi1 to suppress IL-4 and IL-13 production in Th2 cells., (Copyright © 2024 by The American Association of Immunologists, Inc.)

The airway surface liquid (ASL) plays a crucial role in lung defense mechanisms, and its composition and volume are regulated by the airway epithelium. The cystic fibrosis transmembrane conductance regulator (CFTR) is abundantly expressed in a rare airway epithelial cell type called an ionocyte. Recently, we demonstrated that ionocytes can increase liquid absorption through apical CFTR and basolateral barttin/chloride channels, while airway secretory cells mediate liquid secretion through apical CFTR channels and basolateral NKCC1 transporters. Th2-driven (IL-4/IL-13) airway diseases, such as asthma, cause goblet cell metaplasia, accompanied by increased mucus production and airway secretions. In this study, we investigate the effect of IL-13 on chloride and liquid transport performed by ionocytes. IL-13 treatment of human airway epithelia was associated with reduced epithelial liquid absorption rates and increased ASL volume. Additionally, IL-13 treatment reduced the abundance of CFTR-positive ionocytes and increased the abundance of CFTR-positive secretory cells. Increasing ionocyte abundance attenuated liquid secretion caused by IL-13. Finally, CFTR-positive ionocytes were less common in asthma and chronic obstructive pulmonary disease and were associated with airflow obstruction. Our findings suggest that loss of CFTR in ionocytes contributes to the liquid secretion observed in IL-13-mediated airway diseases.

Immune memory has been expanded to group 2 innate lymphoid cells (ILC2s), but the cellular and molecular bases remain incompletely understood. Based on house dust mite (HDM)-induced mice asthma models and human samples, we applied flow cytometry, parabiosis, in vivo imaging and adoptive transplantation to confirm the persistence, migration and function of CD45 + lineage - CD90.2 + NK1.1 - NKp46 - ST2 - KLRG1 + IL-17RB + memory-like ILC2s (ml-ILC2s). Regulated by CCR9/CCL25 and S1P signaling, ml-ILC2s reside in the lamina propria of small intestines (siLP) in asthma remission, and subsequently move to airway upon re-encountering antigens or alarmins. Furthermore, ml-ILC2s possess properties of longevity, potential of rapid proliferation and producing IL-13, and display transcriptional characteristics with up-regulation of Tox and Tcf-7. ml-ILC2s transplantation restore the asthmatic changes abrogated by Tox and Tcf7 knockdown. Our data identify siLP ml-ILC2s as a memory-like subset, which promotes asthma relapse. Targeting TCF-1 and TOX might be promising for preventing asthma recurrence., (© 2024. The Author(s).)

Glioblastoma multiforme (GBM) is one of the most aggressive and deadly forms of brain cancer, which has a very complex tumor microenvironment (TME) promoting tumor growth, immune evasion, and resistance to therapy. The main players within this environment are represented by cytokines such as Interleukin-4, Interleukin-6, and Interleukin-13, along with the costimulatory molecule CD40. The paper draws back the curtain on the complex interactions played out by these molecules in contributing to the formation of a TME within GBM. IL-4 and IL-13 induce an immunosuppressive environment through the polarization of tumor-associated macrophages (TAMs) into a pro-tumoral M2 phenotype. In contrast, IL-6 takes part in the activation of the JAK-STAT3 pathway, enhancing survival and proliferation of tumor cells. In this context, CD40 either induces anti-tumor immunity through APC activation or facilitates tumors by angiogenesis and survival pathways. The synergistic actions of these molecules create feedback loops that keep up the malignancy of GBM and present a big problem for therapy. Knowledge of these interactions opens new ways for the development of multi-targeted therapeutic strategies at the other end. This may result in the interruption of the tumor-supportive environment in GBM, reducing tumor growth and improving patient outcomes by targeting IL-4, IL-6, IL-13, and CD40 simultaneously., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Interleukin-8 (IL8), Interleukin-12 (IL12) and Interleukin-13 (IL13) are cytokines that play regulatory role in cancer pathogenesis. We analysed their expression profile to evaluate as molecular biomarkers of esophageal squamous cell carcinoma (ESCC) and their association with different parameters and patient survival., Methods: Expression analysis was performed by Real time quantitative polymerase chain reaction and receiver operating characteristic (ROC) curve analysis was done. The expression profiles were associated with different clinicopathological and dietary factors. Survival and hazard analysis were also performed., Results: IL8 expression showed upregulation in tissue (p = 0.000) and blood samples (p = 0.481), IL12 expression showed downregulation in tissue samples (p = 0.064) and upregulation in blood samples (p = 0.689) and IL13 expression showed upregulation in tissue (p = 0.000) and blood samples (p = 0.006). IL13 expression in tissue showed the highest area under the curve (AUC) value (0.773) for ESCC diagnosis, followed by IL8 expression in tissue (0.704) and IL13 expression in blood (0.643). This study also reveals the correlation of studied cytokines in tissue and blood level. Different clinicopathological and dietary factors showed significant association (p < 0.05) with IL8, IL12 and IL13 expression and with survival of ESCC patients. IL8 expression in blood and IL12 expression in tissue and blood showed significant association (p < 0.05) with patient survival., Conclusion: Altered expression of IL8, IL12 and IL13 may be associated with ESCC progression. Overexpression of IL8 and IL13 in tissue samples may be potential biomarkers for ESCC screening. Additionally, both survival and hazard analysis data indicate the effects of different parameters on the prognosis of ESCC patients., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Adipose-derived stem cells (ASCs) are multipotent stem cells capable of differentiating into many cell lineages. They play an important role in wound healing by secreting cytokines. Prior studies have demonstrated the presence of proinflammatory cytokines in burn wounds. However, no studies have been performed evaluating the cytokines released by burn wounds with infections. We hypothesized that there is an alteration in the paracrine factors secreted by ASCs in burn wounds with concomitant infections., Methods: Adipose tissue was collected from patients with burn injuries at their index operation. ASCs were extracted and grown under standard tissue culture techniques. The supernatant was extracted. Cytokine analyses were performed with multiplex assays. Infection was determined using a burn sepsis protocol. The cytokine profiles of the two groups were compared using a Mann-Whitney U test., Results: Sixteen patients were enrolled in the study, 50% with bacterial infection (n = 8). There was no significant difference in the baseline demographics of the two groups (P > 0.05). There were significantly lower concentrations of interleukin 13 and interferon gamma (P < 0.05) in burn patients with concomitant infections., Conclusions: ASCs are critical to burn wound healing. This study demonstrated diminished production of interleukin 13, an immunoregulatory cytokine involved in the antiinflammatory pathway by downregulating macrophage activity. This study also demonstrated significantly lower levels of interferon gamma in patient with burns and concomitant infection. This cytokine is crucial for antimicrobial defenses., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Interleukin (IL)-4 and IL-13 are the main effectors of innate lymphoid cells (ILC2) of the type 2 innate immune response, which can carry out specific signal transmission between multiple cells in the tumor immune microenvironment. IL-4 and IL-13 mediate signal transduction and regulate cellular functions in a variety of solid tumors through their shared receptor chain, the transmembrane heterodimer interleukin-4 receptor alpha/interleukin-13 receptor alpha-1 (type II IL-4 receptor). IL-4, IL-13, and their receptors can induce the formation of a variety of malignant tumors and play an important role in their progression, growth, and tumor immunity. In order to explore possible targets for lung cancer prediction and treatment, this review summarizes the characteristics and signal transduction pathways of IL-4 and IL-13, and their respective receptors, and discusses in depth their possible role in the occurrence and development of lung cancer.

Eosinophils play divergent roles in health and disease, contributing to both immunoregulatory and proinflammatory responses. Helminth infection is strongly associated with eosinophilia and the induction of the type 2 cytokines interleukin (IL)-5, IL-4 and IL-13. This study aimed to elucidate the heterogeneity of pulmonary eosinophils in response to helminth infection and the roles of IL-5, IL-4 and IL-13 in driving pulmonary eosinophil responses. Using the murine helminth model Nippostrongylus brasiliensis (Nb), we characterize a subtype of eosinophils, defined by high expression of CD101, that is induced in the lungs of Nb-infected mice and are phenotypically distinct from lung eosinophils that express low levels of CD101. Strikingly, we show that the two eosinophil subtypes have distinct anatomical localization within the lung: CD101 low eosinophils are predominantly localized in the lung vasculature, whereas Nb-induced CD101 hi eosinophils are predominantly localized in the extravascular lung niche. We show that CD101 hi eosinophils are also induced across other models of pulmonary infection and inflammation, including a nonlung-migrating helminth infection, house dust mite-induced allergic inflammation and influenza infection. Furthermore, we demonstrate that the induction of CD101 hi tissue eosinophils is independent of IL-5 and IL-4 signaling, but is dependent on intact IL-13 signaling. These results suggest that IL-13 produced during helminth infection and other disease states promotes a pulmonary tissue-infiltrating program in eosinophils defined by high expression of CD101., (© 2024 The Author(s). Immunology & Cell Biology published by John Wiley & Sons Australia, Ltd on behalf of the Australian and New Zealand Society for Immunology, Inc.)

Intestinal tuft cells are critical for anti-helminth parasite immunity because they produce IL-25, which triggers IL-13 secretion by activated group 2 innate lymphoid cells (ILC2s) to expand both goblet and tuft cells. We show that epithelial Elp3, a tRNA-modifying enzyme, promotes tuft cell differentiation and is consequently critical for IL-25 production, ILC2 activation, goblet cell expansion and control of Nippostrongylus brasiliensis helminth infection in mice. Elp3 is essential for the generation of intestinal immature tuft cells and for the IL-13-dependent induction of glycolytic enzymes such as Hexokinase 1 and Aldolase A. Importantly, loss of epithelial Elp3 in the intestine blocks the codon-dependent translation of the Gator1 subunit Nprl2, an mTORC1 inhibitor, which consequently enhances mTORC1 activation and stabilizes Atf4 in progenitor cells. Likewise, Atf4 overexpression in mouse intestinal epithelium blocks tuft cell differentiation in response to intestinal helminth infection. Collectively, our data define Atf4 as a negative regulator of tuft cells and provide insights into promotion of intestinal type 2 immune response to parasites through tRNA modifications., (© 2024. The Author(s).)

Interleukin (IL)-13 has emerged as one of the recently identified cytokine. Since IL-13 causes the severity of COVID-19 and alters crucial biological processes, it is urgent to explore novel molecules or peptides capable of including IL-13. Computational prediction has received attention as a complementary method to in-vivo and in-vitro experimental identification of IL-13 inducing peptides, because experimental identification is time-consuming, laborious, and expensive. A few computational tools have been presented, including the IL13Pred and iIL13Pred. To increase prediction capability, we have developed PredIL13, a cutting-edge ensemble learning method with the latest ESM-2 protein language model. This method stacked the probability scores outputted by 168 single-feature machine/deep learning models, and then trained a logistic regression-based meta-classifier with the stacked probability score vectors. The key technology was to implement ESM-2 and to select the optimal single-feature models according to their absolute weight coefficient for logistic regression (AWCLR), an indicator of the importance of each single-feature model. Especially, the sequential deletion of single-feature models based on the iterative AWCLR ranking (SDIWC) method constructed the meta-classifier consisting of the top 16 single-feature models, named PredIL13, while considering the model's accuracy. The PredIL13 greatly outperformed the-state-of-the-art predictors, thus is an invaluable tool for accelerating the detection of IL13-inducing peptide within the human genome., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Kurata et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Integrin activation resulting in enhanced adhesion to the extracellular matrix plays a key role in fundamental cellular processes. Although integrin activation has been extensively studied in circulating cells such as leukocytes and platelets, much less is known about the regulation and functional impact of integrin activation in adherent cells such as smooth muscle. Here, we show that two different asthmagenic cytokines, IL-13 and IL-17A, activate type I and IL-17 cytokine receptor families, respectively, to enhance adhesion of airway smooth muscle. These cytokines also induce activation of β1 integrins detected by the conformation-specific antibody HUTS-4. Moreover, HUTS-4 binding is increased in the smooth muscle of patients with asthma compared to nonsmokers without lung disease, suggesting a disease-relevant role for integrin activation in smooth muscle. Indeed, integrin activation induced by the β1-activating antibody TS2/16, the divalent cation manganese, or the synthetic peptide β1-CHAMP that forces an extended-open integrin conformation dramatically enhances force transmission in smooth muscle cells and airway rings even in the absence of cytokines. We demonstrate that cytokine-induced activation of β1 integrins is regulated by a common pathway of NF-κB-mediated induction of RhoA and its effector Rho kinase, which in turn stimulates PIP5K1γ-mediated synthesis of PIP 2 at focal adhesions, resulting in β1 integrin activation. Taken together, these data identify a pathway by which type I and IL-17 cytokine receptor family stimulation induces functionally relevant β1 integrin activation in adherent smooth muscle and help to explain the exaggerated force transmission that characterizes chronic airway diseases such as asthma., Competing Interests: Competing interests statement:The authors declare no competing interest.

Background: Interleukin (IL)-13 is a key driver of inflammation and barrier dysfunction in atopic dermatitis (AD). While there is robust evidence that tralokinumab - a monoclonal antibody that neutralizes IL-13 - reduces inflammation and clinical disease activity, less is known about its effects on barrier function., Objectives: To characterize the effects of tralokinumab treatment on skin barrier function., Methods: Transepidermal water loss (TEWL), stratum corneum hydration (SCH), natural moisturizing factor content, histopathological characteristics, biomarker expression and microbiome composition were evaluated in lesional, nonlesional and sodium lauryl sulfate-irritated skin of 16 patients with AD over the course of 16 weeks of tralokinumab treatment., Results: All clinical severity scores decreased significantly over time. At week 16, mean TEWL in target lesions decreased by 33% (P = 0.01) and SCH increased by 58% (P = 0.004), along with a histological reduction in spongiosis (P = 0.003), keratin 16 expression and epidermal thickness (P = 0.001). In parallel, there was a significant decrease in several barrier dysfunction-associated and proinflammatory proteins such as fibronectin (P = 0.006), CCL17/TARC (P = 0.03) and IL-8 (P = 0.01), with significant changes seen as early as week 8. Total bacterial load and Staphylococcus aureus abundance were significantly reduced from week 2., Conclusions: Tralokinumab treatment improved skin physiology, epidermal pathology and dysbiosis, further highlighting the pleiotropic role of IL-13 in AD pathogenesis., Competing Interests: Conflicts of interest S.W. is has received institutional research grants from LEO Pharma, Pfizer and Sanofi; and has performed consultancies and/or lectures for AbbVie, Almirall, Boehringer, Galderma, GSK, LEO Pharma, Lilly, Pfizer, Regeneron and Sanofi. S.G. has been an advisor and/or has received speakers’ honoraria and/or has received grants and/or has participated in clinical trials for the following companies: AbbVie, ACELYRIN, Affibody, Akari Therapeutics, Almirall-Hermal, Amgen, Argenx, Aristea Therapeutics, Bristol Myers Squibb, Boehringer Ingelheim, Celgene, Dermira, Eli Lilly, Galderma, Hexal, Incyte, Janssen-Cilag, Klinge Pharma, Kymab, LEO Pharma, Medac, MSD, Neubourg Skin Care, Novartis, Pfizer, Pierre Fabre, Principia Biopharma, Regeneron Pharmaceutical, Sandoz Biopharmaceuticals, Sanofi-Aventis, Trevi Therapeutics and UCB Pharma. E.v.d.B. has received funds from the LEO Foundation and Fagron, has performed consultancies and contract research for NIZO Food Research, and has received in kind contributions for research projects from CELLnTEC and TropIQ Health Services. The other authors declare no conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Association of Dermatologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)