IL-13 Signaling Research Articles

Dupilumab aggravates Sézary syndrome: The importance of accurate pathological diagnosis

We report a case of Sézary syndrome aggravated by dupilumab. Although a diagnosis of atopic dermatitis was made previously, our retrospective diagnosis was cutaneous T-cell lymphoma. A 72-year-old woman was referred for evaluation of erythema over her entire body. She had received a diagnosis of atopic dermatitis (AD) based on skin biopsy elsewhere 7 years earlier. Since her symptoms were resistant to topical corticosteroids and oral antihistamines, dupilumab was started. She noticed peripheral lymph node enlargement 11 months after the commencement of dupilumab. Physical examination revealed generalized erythroderma with desquamation (Figure 1A,B) and lymphadenopathy in the neck, axilla, and inguinal region. A biopsy from her abdomen showed dense infiltrations of atypical lymphoid cells in the upper dermis with epidermotropism (Figure 1C,D). Immunohistochemically, the infiltrating cells were positive for CD3 and CD4; CD8 was almost negative. There was a 50% deletion of CD7 (Figure 1E–H). Her peripheral blood (PB) white blood cell count was 7660/μL, with 35% abnormal lymphocytes (2681/μL). Although CD4+/CD26− or CD4+/CD7− cells were not assessed, CD4/CD8 ratio was 10.59.1, 2 Human T-lymphotropic virus-1 antibody was negative. Monoclonal gene rearrangement of T-cell receptor β-chain was identified in her PB by Southern blot analysis. Inguinal lymph node biopsy showed partial effacement by atypical lymphocytes. The diagnosis was Sézary syndrome (SS), stage IVA2 (T4N3MXB2). Taking into account the risk of tumor lysis syndrome due to high tumor burden, we selected conventional multiagent chemotherapy as an initial therapy before using a molecular-targeted drug. Dupilumab was discontinued; cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) were started. After two cycles of CHOP, biweekly intravenous mogamulizumab was introduced. Her skin lesions gradually improved. The PB abnormal lymphocyte count decreased. Her disease was well controlled with mogamulizumab for 17 months. We reviewed the previous biopsy specimen. Dense dermal infiltrates with atypical cells and epidermotropism were seen (Figure 1I,J). These infiltrates were positive for CD3 and CD4. CD8-positive cells were sparse. There was a 30% deletion of CD7 (Figure 1K–N). The atypical cells were CCR4+ and CD68−. Although a diagnosis of AD was made previously, our retrospective diagnosis was cutaneous T-cell lymphoma (CTCL). Dupilumab is a monoclonal antibody which inhibits both IL-4 and IL-13 signaling pathways by binding specifically to the α subunit of the IL-4 receptor. Several cases of CTCL that developed or worsened after dupilumab use have been reported. A proposed mechanism of CTCL due to dupilumab is the involvement of IL-13 receptor α2 (IL-13Rα2), which is expressed on CTCL cells and promotes tumor progression. When dupilumab blocks IL-4 and IL-13 receptors, serum IL-13 levels increase. Because dupilumab inhibits IL-13Rα1 but not IL-13Rα2 signaling, increased IL-13 levels due to dupilumab stimulate IL-13Rα2, leading to the activation and proliferation of lymphoma cells.3 To our knowledge, there are 36 cases3-19 of CTCL worsened by dupilumab based on the diagnosis of AD or eczema have been reported. Of these 36 patients, 18 underwent skin biopsy prior to dupilumab therapy; no evidence of CTCL was described in 16 patients.3-10 In one remaining patient, the authors re-evaluated the biopsy specimen taken before dupilumab treatment and revised the diagnosis to early CTCL-not otherwise specified.10 In another patient, the first skin biopsy taken before dupilumab was compatible with AD; however, the diagnosis of mycosis fungoides was made by the second biopsy taken on the first day of dupilumab treatment. After 6 months of dupilumab treatment, the third biopsy turned out CD30-positive anaplastic large-cell lymphoma.11 When using dupilumab for AD, clinicians should be alert to the development or worsening of CTCL. Skin biopsy with immunohistochemical examination is strongly recommended before dupilumab therapy, especially in patients with erythroderma and elderly patients. The authors declare no conflict of interest. Approval of the research protocol: N/A. Informed Consent: N/A. Registry and the Registration No.: N/A. Animal Studies: N/A.

Use of Dupilumab in HyperIgE syndrome with ERBIN-deficiency: case report

HyperIgE Syndromes (HIES) are rare primary immunodeficiencies characterized by recurrent infections and Th2 clinical signature (elevated IgE, eosinophilia, asthma, and atopic dermatitis). The major genetic alterations concern loss of function mutations of the STAT3/ERBIN/SMAD2/3 complex. Patients with ERBIN-deficiency have a higher number of Treg and greater IL-4Rα expression on naïve lymphocytes, due to increased activation of the TGF-ß pathway. Dupilumab is an anti-IL-4Rα monoclonal antibody that inhibits IL-4 and IL-13 signalling and the expression of type 2 cytokines. We here discuss a case of Dupilumab treatment in a ERBB2IP mutated patient. At our Rare Diseases referral Centre, we have been following a 20-year-old patient with severe atopic dermatitis, history of recurrent sinopulmonary infections, asthma and IgE level of 8818kU/L. On physical examination, the patient presented diffuse eczema with areas of lichenization, Eczema Area and Severity Index 29, Numeric Rating Scale of itch 9/10, Dermatology Life Quality Index 28/30, saddle nose, prognathism and severe left-convex scoliosis with NIH-HIES score equal to 37. CD4T lymphocytes were mainly Th2 (52%); Th17 were 13%, with normal IgG, IgA and IgM levels. The NGS genetic study found the following mutation of ERBB2IP, which encodes for ERBIN protein, likely pathogenic for HIES, together with a TMC8 and a CASP10 variant, all in heterozygosis. Given the underlying immunodeficiency and the non-response to topical and systemic corticosteroids, therapy with cyclosporine was not considered. Dupilumab was instead started with an induction dose of 600 mg and maintenance of 300 mg every 15 days. At last follow-up (14 months after dupilumab initiation) the patient presents: subjective well-being, skin free from manifestations, EASI score 0, NRS 0/10, DLQI 0/30, normal lung function with optimal control of asthma, IgE still>5000 kU/L. Of note, no more infectious episodes were reported. In our patient, given the anamnestic context of immunodeficiency, the use of target therapy on IL-4/IL-13R signalling proved to be particularly effective and safe in the treatment of skin manifestations related to the loss of function mutation of the ERBIN gene, known for the functional relationship with STAT3 in the regulation of IL-4Rα expression on naïve lymphocytes and of the Th2 response.

Abstract 6620: Identification of crosstalk signaling between brain-tumor niche and reactive human cytomegalovirus in brain metastases

Abstract Purpose: Human cytomegalovirus (HCMV) is a common neurotropic herpes virus although its DNA was confirmed highly prevalent in various peripheral cancers. HCMV is also a major cause of neuropathology in immune-compromised patients. Since HCMV reactivation frequently causes encephalopathy during chemotherapy or radiation therapy in brain tumor patients, understanding the brain niche-HCMV crosstalk signaling may pinpoint effective strategies in managing brain metastases. Methods: We collected nine pairs of primary breast and brain metastatic tumor samples from our institution and analyzed their RNA-Seq data. Pairwise differential gene expression analysis and gene set enrichment analysis (GSEA) were conducted. TCGA-BRCA (n=1,222) dataset was used for clinical and immune-infiltration correlation analysis. GSE12276 (n=204) dataset was used for brain-metastasis free survival correlation. Immunohistochemistry staining of HCMV was conducted on sixteen primary breast and brain metastatic tumor sections and an 86-core tissue microarray (TMA) of human brain metastasis tissue. CCCExplorer software was used to explore molecular crosstalk signaling between the secretome proteins from HCMV-infected cells and brain metastatic niche cells. Results: Reactome Human cytomegalovirus (HCMV) early and late events was the top enriched pathway for the 371 brain metastasis up-regulated genes while Reactome IL4 and IL5 signaling was the top enriched pathway for the 2,153 primary breast tumor up-regulated genes. Among the 371 brain metastasis up-regulated genes, 287 genes are also up-regulated in primary breast cancer vs. normal breast in the TCGA 1222 cohort (P<0.05). High expression of 19 out of the 287 genes are significantly associated with poor brain metastasis-free survival in the GSE12276 cohort (Logrank P<0.05). We further identified that elevated expression of 12 out of the 19 genes are consistently associated with Th2 cell activation and NK cell deactivation in the TCGA 1,222 cohort, for which immunosuppressive Th2 cells are defined by secretion of IL4 and IL5 signature cytokines. Immunoreactive HCMV reactivation proteins were examined in the paired breast tumor and brain metastatic specimens, and most of the TMA tumors. Preventive treatment of an anti-HCMV drug, ganciclovir, by suppressing viral DNA replication inhibited tumor colonization in the mouse brains of the two HCMV-positive PDX models. Several HCMV cell-entry co-receptors are highly expressed in brain metastatic niche. Furthermore, from the secretome of HCMV-infected cells, we identified 89 paired receptors that potentially regulate niche cell behaviors. Conclusions: Our systemic analysis revealed a causal relationship between HCMV reactivation and brain metastatic outgrowth. Targeting the key brain-tumor niche-HCMV crosstalk signaling may benefit the management of brain metastases. Citation Format: Xin Wang, Puri Akshjot, Kun Han, Amna Irfan, Liliana Guzman, Wei Qian, Roberto Rosato, Hong Zhao, Jenny Chang, Stephen Wong. Identification of crosstalk signaling between brain-tumor niche and reactive human cytomegalovirus in brain metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6620.

Molecular analysis of duodenal eosinophilia

Eosinophilic duodenitis (EoD), characterized by nonspecific gastrointestinal symptoms and increased numbers of duodenal eosinophils, may be in the eosinophilic gastrointestinal disease spectrum. However, diagnostic thresholds and pathogenic processes of duodenal tissue eosinophilia are inadequately characterized. We aimed to define an EoD transcriptome and pathologic pathways. RNA sequencing and histologic features of human duodenal biopsy samples were analyzed as a function of duodenal eosinophils levels. For analyses, we defined EoD as more than 52 peak eosinophils/hpf (n= 8), duodenal eosinophilia as 30 to 52 eosinophils/hpf (n= 11), and normal controls as fewer than 30 eosinophils/hpf (n= 8). Associations between gene expression and histologic features were analyzed with Spearman correlation. We identified 382 differentially expressed genes (EoD transcriptome) between EoD and normal controls (>2-fold change [adjusted P< .05]). The EoD transcriptome distinguished EoD from controls (duodenal eosinophilia and normal controls). The duodenal eosinophil count was correlated with a distinct EoD transcriptome when 50 to 60 peak eosinophils/hpf were present. The EoD transcriptome was enriched in genes involved in IL-4/IL-13 signaling, mast cells, and myeloid progenitor cells. Among duodenal histologic features, lamina propria eosinophil sheets was the most associated with transcriptomic changes (r= 0.66; P< .01). EoD gene signatures were shared with eosinophilic esophagitis and eosinophilic gastritis but not with eosinophilic colitis or celiac disease. We have identified an EoD transcriptomic signature that emerges at 50 to 60 peak eosinophils/hpf and established EoD as part of a spectrum of upper eosinophilic gastrointestinal disorder associated with type 2 immunity and distinct from eosinophilic colitis and celiac disease. These findings provide a basis for improving diagnosis and treatment.

Elarekibep (PRS-060/AZD1402), a new class of inhaled Anticalin medicine targeting IL-4Ra for type 2 endotype asthma

T2 endotype asthma is driven by IL-4 and IL-13 signaling via IL-4Ra, which is highly expressed on airway epithelium, airway smooth muscle and immunocytes in the respiratory mucosa, suggesting potential advantages of an inhalable antagonist. Lipocalin 1 (Lcn1), a 16kD protein abundant in human periciliary fluid, has a robust drug-like structure well-suited to protein engineering, but has never been used to make an inhaled "Anticalin" protein therapeutic. To re-engineer Lcn1 into an inhalable IL-4Ra antagonist and assess its pharmacodynamic/kinetic profile. Lcn1 was systematically modified by directed protein mutagenesis yielding a high affinity, slowly dissociating, long-acting full antagonist of IL-4Ra designated 'PRS-060' with properties analogous to dupilumab, competitively antagonizing IL-4Ra dependent cell proliferation, mucus induction and eotaxin expression in vitro. As PRS-060 displayed exquisite specificity for human IL-4Ra, with no cross-reactivity to rodents or higher primates, we created a new triple-humanized mouse model substituting hIL-4Ra, hIL-4, and hIL-13 at their correct syntenic murine loci to model clinical dosing. Inhaled PRS-060 strongly suppressed acute allergic inflammation indices in triple humanized mice with a duration of action longer than its bulk clearance suggesting it may act locally in the lung. Lcn1 can be re-engineered into the Anticalin antagonist PRS-060, exemplifying a new class of inhaled topical, long-acting therapeutic with potential to treat T2 endotype asthma.

Improvement of Suspected Eosinophilic Otitis Media with Targeted Biologic Therapy.

To compare the responses of suspected eosinophilic otitis media to treatment with or without a targeted biologic therapy against interleukin-4 (IL-4), IL-5, or IL-13 signaling. Retrospective review. Tertiary referral center. Subjects with type 2 chronic rhinosinusitis with nasal polyposis (CRSwNP), asthma, and otitis media who underwent treatment between 2005 and 2021. Treatment with targeted biologic therapy. Pre- and posttreatment nasal endoscopy, ear examination, and audiologic evaluation. Four hundred seventy-seven subjects with type 2 CRSwNP were treated between 2005 and 2021. Sixty-two had otitis media with pre- and posttreatment evaluation. Retrospective chart review assessed pre- and posttreatment exam findings, nasal endoscopy, audiometry, and tympanometry. Nineteen subjects received a biologic therapy, whereas 43 did not. Exam, endoscopy, and tympanometry were graded for severity and compared pre- and posttreatment. Subjective ear exam and tympanometry were significantly improved with biologic therapy (control = 0.05, biologic = 0.84, p = 9.3 × 10 -5 ; control = -0.1, biologic = 0.62, p = 0.0002). Conductive hearing loss as assessed by air-bone gaps did not change between groups (control = 1.2 dB better, biologic = 1.2 dB worse, p = 0.32). Nasal endoscopy findings improved with biologic therapy relative to the control group, although not statistically significant (control = 1.04, biologic = 1.36, p = 0.22). Biologic therapies targeting interleukin-4 (IL-4), IL-5, and IL-13 signaling are potential new treatments for eosinophilic otitis media. This is the largest study demonstrating improvement in subjects with suspected eosinophilic otitis media in response to biologic therapy, and immune modulation represents a novel treatment strategy for this challenging condition. Current treatment strategies for otologic symptoms in eosinophilic disease are not tremendously effective or durable, resulting in a need for improved treatment options. To determine if targeted biologic therapy, often used for eosinophilic asthma and type 2 chronic rhinosinusitis with nasal polyposis, improves coexistent suspected eosinophilic otitis media. Treatment of suspected eosinophilic otitis media with targeted biologic therapy will result in improvement of otologic symptoms with a durable response compared with current treatment options. Level IV. Exempt. HUM00182703.

Study of the shared gene signatures of polyarticular juvenile idiopathic arthritis and autoimmune uveitis.

To explore the shared gene signatures and potential molecular mechanisms of polyarticular juvenile idiopathic arthritis (pJIA) and autoimmune uveitis (AU). The microarray data of pJIA and AU from the Gene Expression Omnibus (GEO) database were downloaded and analyzed. The GEO2R tool was used to identify the shared differentially expressed genes (DEGs) and genes of extracellular proteins were identified among them. Then, weighted gene co-expression network analysis (WGCNA) was used to identify the shared immune-related genes (IRGs) related to pJIA and AU. Moreover, the shared transcription factors (TFs) and microRNAs (miRNAs) in pJIA and AU were acquired by comparing data from HumanTFDB, hTFtarget, GTRD, HMDD, and miRTarBase. Finally, Metascape and g: Profiler were used to carry out function enrichment analyses of previously identified gene sets. We found 40 up-regulated and 15 down-regulated shared DEGs via GEO2R. Then 24 shared IRGs in positivity-related modules, and 18 shared IRGs in negatively-related modules were found after WGCNA. After that, 3 shared TFs (ARID1A, SMARCC2, SON) were screened. And the constructed TFs-shared DEGs network indicates a central role of ARID1A. Furthermore, hsa-miR-146 was found important in both diseases. The gene sets enrichment analyses suggested up-regulated shared DEGs, TFs targeted shared DEGs, and IRGs positivity-correlated with both diseases mainly enriched in neutrophil degranulation process, IL-4, IL-13, and cytokine signaling pathways. The IRGs negatively correlated with pJIA and AU mainly influence functions of the natural killer cell, cytotoxicity, and glomerular mesangial cell proliferation. The down-regulated shared DEGs and TFs targeted shared DEGs did not show particular functional enrichment. Our study fully demonstrated the flexibility and complexity of the immune system disorders involved in pJIA and AU. Neutrophil degranulation may be considered the shared pathogenic mechanism, and the roles of ARID1A and MiR-146a are worthy of further in-depth study. Other than that, the importance of periodic inspection of kidney function is also noteworthy.

A1 TARGETING IL-4 AND IL-13 TO TREAT CROHN’S DISEASE-ASSOCIATED INTESTINAL FIBROSIS IN SHIP DEFICIENT MICE

Abstract Background Crohn’s disease (CD) is an immune-mediated disease characterized by chronic, relapsing and remitting, or progressive inflammation of the digestive tract. One in 3 people with CD will develop intestinal fibrosis requiring surgery within 10 years of diagnosis. Biological therapy is effective at reducing inflammation in CD and early and aggressive treatment with biologics will reduce the incidence of fibrosis. However, in children, for whom a step-up approach to therapy is used, and populations that are refractory to biological therapy; fibrosis remains a serious concern. Treatments for intestinal fibrosis are needed as currently, there are no treatment that target intestinal fibrosis directly. Mice deficient in the Src homology 2 domain-containing inositolpolyphosphate 5’-phosphatase (SHIP-/-) develop spontaneous CD-like ileal inflammation and fibrosis. Fibrosis is dependent on PI3Kp110d activity, leading to induction of the enzyme arginase I (argI). Genetic ablation or pharmacologic inhibition of PI3Kp110δ or inhibition of arginase activity block the development of intestinal fibrosis in SHIP-/- mice. IL-4 and IL-13 can activate PI3Kp110δ and IL-4 concentrations are elevated systemically in SHIP-/- mice. Thus, we hypothesize that SHIP-/- mice develop CD-like intestinal fibrosis due to increased IL-4 and/or IL-13 signalling. Purpose Aim 1: To determine whether genetic ablation of IL-4 prevents ileal fibrosis in SHIP-/- mice Aim 2: To determine whether a blocking antibody directed against IL-4 or IL-13 Method SHIP-/- mice were crossed with IL-4 deficient mice (IL-4-/-) to generate wild type, SHIP+/+IL-4-/- SHIP-/-IL-4+/+, and SHIP-/-IL4-/- mice. SHIP-/- mice (6-week-old) were treated with an anti-IL-4 antibody or an anti-IL-13 antibody, IgG isotype control, or PBS (injection control), for 2 weeks. Ileal fibrosis was assessed in SHIP-/- mice comparing mice treated with anti-IL-4 antibody or anti-IL-13 antibody to IgG controls. Measurements of ileal fibrosis included gross and histopathology, muscle thickening, and collagen accumulation (Masson’s trichrome staining for fibrosis). Result(s) SHIP-/-IL-4-/- mice did not have less ileal fibrosis than their SHIP-/- littermates and blocking IL-4 in SHIP-/- mice did not reduce ileal fibrosis. However, blocking IL-13 in SHIP-/- mice reduced ileal fibrosis. Conclusion(s) Blocking IL-4 genetically or with a blocking antibody is insufficient to reduce ileal fibrosis in SHIP-/- mice. Blocking IL-13 with a blocking antibody is sufficient to block the development of ileal fibrosis in SHIP-/- mice. In future experiments, we will cross SHIP-/- mice with IL-13-/- mice to determine whether targeting IL-13 genetically also reduces fibrosis in SHIP-/- mice. We will also determine which receptor IL-13 is signalling through to indue fibrotic pathology in SHIP deficient mice. Our data suggest that an antibody-based biologic targeting IL-13 may be an effective strategy to prevent fibrosis in people with Crohn’s disease. Disclosure of Interest None Declared

Abstract PD2-11: Human Cytomegalovirus Reactivation in Immunosuppressive Th2 Tumor Microenvironment Facilitates Brain Metastatic Outgrowth

Abstract Background Brain metastases is a fatal consequence of advanced breast cancer with a poor prognosis. Both tumor intrinsic molecular underpinning of the primary tumor and microenvironmental brain niche factors have been reported to allow invading cancer cells to colonize and outgrow into the brain. A systemic investigation of these tumor intrinsic and microenvironmental factors using same patient paired primary breast and brain metastatic tumor samples are warranted. Methods Nine pairs of primary breast and brain metastatic tumor samples were collected for RNA sequencing. Pairwise differential gene expression analysis and gene set enrichment analysis (GSEA) were conducted. TCGA-BRCA (n=1222) dataset and a combined breast cancer cohort (n=2,765) were used for clinical and immune-infiltration correlation analysis. GSE12276 (n=204) dataset was used for brain-metastasis free survival correlation. Immunohistochemistry staining of HCMV was conducted on a total of 16 primary breast and brain metastatic tumor sections including 2 pairs. Two patient-derived xenograft (PDX) models were used for antiviral treatment and mechanism investigation. Results 371 up-regulated and 2,153 down-regulated genes in the 9 paired brain metastatic tumors vs. breast tumors (P&amp;lt; 0.05; log2 FC&amp;gt;1 or ←1) were identified from the RNAseq data. Reactome Human cytomegalovirus (HCMV) early and late events was the top enriched pathway for the 371 brain metastasis up-regulated genes, and Reactome IL4 and IL5 signaling was the top enriched pathway for the 2,153 primary breast tumor up-regulated genes. Among the 371 brain metastasis up-regulated genes, 287 genes are also up-regulated in primary breast cancer vs. normal breast in the TCGA 1222 cohort (P&amp;lt; 0.05). High expression of 23 out of the 287 genes are significantly associated with shorter distant metastasis-free survival (DMFS) in a combined breast cancer cohort of 2,765 patients (Logrank P&amp;lt; 0.05), and 19 of the 23 genes are associated with poor brain metastasis-free survival (BMFS) in the GEO dataset GSE12276 (n=204)(Logrank P&amp;lt; 0.05). We further identified that elevated expression of 12 out of the 19 genes are consistently associated with Th2 cell activation and NK cell deactivation in the TCGA 1222 cohort, for which the immunosuppressive Th2 cells are defined by secretion of IL4 and IL5 signature cytokines. Immunoreactive HCMV immediate early proteins indicating virus infection were examined in all the 16 patient tumor tissues, and strong positive signals were seen in both the paired breast tumor and brain metastatic specimens. Preventive treatment of anti-HCMV drug ganciclovir by suppressing viral DNA replication inhibited tumor colonization in the mouse brain in the two HCMV-positive PDX models. Conclusions Our systemic analysis of paired primary breast and brain metastatic tumor tissues identified a causal relationship between HCMV infection and reactivation, immunosuppressive Th2 cell activation and NK cell deactivation, and brain metastatic outgrowth. Since HCMV reactivation frequently induce encephalopathy during chemotherapy or radiation therapy, anti-HCMV agents may represent an effective strategy in preventing and controlling brain metastases. Citation Format: Xin Wang, Akshjot Puri, Amna Irfan, Kun Han, Wei Qian, Liliana Guzman, Roberto Rosato, Hong Zhao, Jenny Chang, Stephen Wong. Human Cytomegalovirus Reactivation in Immunosuppressive Th2 Tumor Microenvironment Facilitates Brain Metastatic Outgrowth [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD2-11.

IL-4 And IL-13 Have Distinct And Overlapping Effects On Key Cell Types Involved In The Pathobiology Of Atopic Dermatitis

Dupilumab, a human monoclonal antibody that binds to IL-4Ra and inhibits IL-4 and IL-13 signaling, improves inflammation and itch in patients with atopic dermatitis (AD). IL-4 signals through the type I (IL-4Ra and IL-2Rg) and type II receptors (IL-4Ra and IL-13Ra1), while IL-13 signaling is restricted to the type II receptor. By binding to shared receptor chain, IL-4Ra, dupilumab prevents the action of both cytokines. To deconstruct the individual roles of IL-4 and IL-13 in the context of AD, we evaluated receptor expression and cytokine-dependent effects in relevant cell types implicated in disease pathobiology.

Crosstalk between Aryl Hydrocarbon Receptor (AHR) Pathway and IL-13 Signaling in Human Keratinocytes and Implications for Atopic Dermatitis

Atopic dermatitis (AD) is an allergic skin disease mediated by skin barrier dysfunction and an IL-13-driven immune response. The aryl hydrocarbon receptor (AHR) is a sensor molecule that is activated by numerus environmental ligands, some of which have shown promise in clinical trials of AD. Therefore, we hypothesized that the AHR pathway can attenuate IL-13-induced responses.

Interleukin 4 directly activates olfactory neurons and induces loss of smell in mice

Anosmia is common in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Dupilumab, a human IL-4Rα monoclonal antibody that blocks both IL-4 and IL-13 signaling, provides rapid and sustained improvements in sense of smell in patients with CRSwNP via mechanisms not clearly understood. Therefore, we investigated the effects of IL-4 and IL-13 on the mouse olfactory system in vitro and in vivo.

Allergic bronchopulmonary aspergillosis in identical twins: Effectiveness of dupilumab

Allergic bronchopulmonary aspergillosis in identical twins: Effectiveness of dupilumab

Ocular Adverse Events in Patients With Atopic Dermatitis Treated With Upadacitinib: A Real-Life Experience.

Background: Dupilumab, an interleukin (IL)-4 receptor-α inhibitor that blocks IL-4 and IL-13 signaling pathways, is an effective and well-tolerated therapy for moderate-to-severe atopic dermatitis (AD). However, an increased incidence of dupilumab-associated conjunctivitis has been reported in patients treated with dupilumab. In contrast, upadacitinib, a selective Janus kinase 1 inhibitor, is reported to have lower incidence of conjunctivitis than dupilumab. Objective: The aim of this retrospective study was to investigate ocular adverse events in adult patients with moderate-to-severe AD treated with upadacitinib after discontinuing treatment with dupilumab. Methods: In total, 33 patients were examined at the start of treatment with upadacitinib after discontinuation of dupilumab, then again after 4 weeks and every 12 weeks up to a maximum of 72 weeks. Results: Among the patients in the study, 14 had developed dupilumab-associated conjunctivitis during dupilumab treatment and had complete resolution of ocular symptoms after the switch to upadacitinib within the 1-month follow-up visit. In addition, only 1 patient treated with upadacitinib developed an episode of conjunctivitis. This condition was of mild severity and it spontaneously resolved quickly. Interestingly, this patient had no history of dupilumab-associated conjunctivitis. Conclusions: All patients who developed dupilumab-associated conjunctivitis experienced complete remission on upadacitinib and only 3% of the patients in our sample developed conjunctivitis after the start of treatment with upadacitinib. In light of this, upadacitinib appears to be a prudent and safe treatment option for AD patients with uncontrolled ocular symptoms associated with dupilumab therapy.

Solithromycin inhibits IL-13-induced goblet cell hyperplasia and MUC5AC, CLCA1, and ANO1 in human bronchial epithelial cells.

Solithromycin is a novel fluoroketolide antibiotic belonging to the class of macrolide antibiotics. Activation of the interleukin (IL)-13 receptor leads to STAT6 activation and subsequent induction of SAM pointed domain containing ETS transcription factor (SPDEF), chloride channel accessory 1 (CLCA1), and anoctamin-1 (ANO1), all of which are associated with the induction of MUC5AC. We examined the effects of solithromycin on mucin production led by IL-13 signaling. Normal human bronchial epithelial cells were grown at the air-liquid interface with IL-13 with/without solithromycin for 14 days. Histochemical analysis was performed using hematoxylin and eosin staining and MUC5AC immunostaining. MUC5AC, SPDEF, CLCA1, and ANO1 mRNA expressions were examined using real-time polymerase chain reaction. Western blot analysis was performed to assess CLCA1 and ANO1 proteins, and phosphorylation of STAT6 and ERK. Solithromycin attenuated IL-13 induction of goblet cell hyperplasia and MUC5AC, CLCA1 and ANO1 mRNA and protein expression induced by IL-13, but had no effect on the phosphorylation of STAT6 and ERK. Our results indicate that solithromycin could attenuate goblet cell hyperplasia and MUC5AC induced by IL-13 through inhibition of CLCA1 and ANO1 mRNA and protein expression. However, much more information is required to clarify the molecular mechanisms underlying the inhibition of CLCA1 and ANO1 by solithromycin.

Analysis of ferroptosis-associated genes in Crohn's disease based on bioinformatics.

Ferroptosis, a novel mode of apoptosis has recently been shown to be associated with fibrosis, tumor, cardiovascular, and other diseases. In this study, using bioinformatic analysis, we identified ferroptosis genes associated with Crohn's disease (CD) and performed biological function analysis, identified potential drug targets, and provided new directions for the future treatment of CD. Differential expression analysis was performed using the GSE186582 dataset from the Gene Expression Omnibus (GEO) database. Ferroptosis-associated genes were downloaded from the FerrDB database, and overlapping genes associated with CD and ferroptosis were extracted. Then, we performed functional enrichment analysis, constructed a protein-protein interaction network (PPI), identified the correlation between hub genes and immune infiltration, performed external validation using a second and third dataset (GSE102133, GSE95095), and identified potential therapeutic agents. Finally, we validated the protein expression levels of the identified hub genes by immunohistochemical staining in the colon tissues from CD and healthy participants. A total of 28 ferroptosis-associated genes associated with CD were identified in our analysis, which included 22 up-regulated and 6 down-regulated genes. Gene Ontology (GO) analysis showed that these genes are essential for the apical plasma membrane and amide transport, and Metascape analysis showed that these genes mainly act on IL-4 and IL-13 signaling pathways. Five hub genes, PTGS2, IL6, IL1B, NOS2, and IDO1, were identified by a protein interaction network, and external validation of these hub genes showed statistically significant differences in expression between the CD patients and normal participants (p < 0.05), and all AUC values were greater than 0.8. Further, we predicted the top 10 drugs used to treat CD. Immune infiltration results suggest that Hub gene is related to T cells, macrophages, dendritic cells, and other immune cells. Finally, the results of immunohistochemical experiments showed that the protein expression of the hub gene was higher in CD colon tissue than in normal subjects (p < 0.05). Bioinformatics analysis showed that ferroptosis is closely related to the development of CD, and the prediction of potential drugs provides new targets for the treatment of CD. Moreover, five hub genes identified are potentially new and effective markers for the diagnosis of CD.

IL-4Rα signalling in B cells and T cells play differential roles in acute and chronic atopic dermatitis

Atopic dermatitis (AD) is a common pruritic inflammatory skin disease with complex environmental and genetic predisposing factors. Primary skin barrier dysfunction and aberrant T helper 2 (TH2) responses to common allergens, together with increased serum IgE antibodies, characterise the disease. B and T cells are essential in the disease manifestation, however, the exact mechanism of how these cells is involved is unclear. Targeting interleukin 4 receptor alpha (IL-4Rα), an IL-4/IL-13 signalling axis, with dupilumab shows efficacy in AD. We investigated the importance of IL-4Rα signalling specifically on B and T cells during acute and chronic models of AD. We used House dust mite (HDM) and Ovalbumin (OVA) in chronic models and a low-calcemic analog of vitamin D (MC903) for acute models of AD. We used mb1creIL-4Rα−/lox, iLCKcreIL-4Rα−/lox, LCKcreIL-4Rα−/lox, CD4creIL-4Rα−/lox, Foxp3creIL-4Rα−/lox and IL-4Rα−/lox littermate controls. IL-4Rα-responsive B cells were essential in serum IgE levels, but not in epidermal thickening in both chronic and acute models. IL-4Rα-responsive T cells were essential in epidermal thickening in the pan-T cell, but not CD4 or CD8 T cells suggesting the importance of γδT cells during acute AD. Our results suggest that IL-4Rα responsiveness on innate T cells regulates acute atopic dermatitis, while on B cells it regulates IgE.

Co-expression of fibrotic genes in inflammatory bowel disease; A localized event?

Extracellular matrix turnover, a ubiquitous dynamic biological process, can be diverted to fibrosis. The latter can affect the intestine as a serious complication of Inflammatory Bowel Diseases (IBD) and is resistant to current pharmacological interventions. It embosses the need for out-of-the-box approaches to identify and target molecular mechanisms of fibrosis. In this study, a novel mRNA sequencing dataset of 22 pairs of intestinal biopsies from the terminal ileum (TI) and the sigmoid of 7 patients with Crohn's disease, 6 with ulcerative colitis and 9 control individuals (CI) served as a validation cohort of a core fibrotic transcriptomic signature (FIBSig), This signature, which was identified in publicly available data (839 samples from patients and healthy individuals) of 5 fibrotic disorders affecting different organs (GI tract, lung, skin, liver, kidney), encompasses 241 genes and the functional pathways which derive from their interactome. These genes were used in further bioinformatics co-expression analyses to elucidate the site-specific molecular background of intestinal fibrosis highlighting their involvement, particularly in the terminal ileum. We also confirmed different transcriptomic profiles of the sigmoid and terminal ileum in our validation cohort. Combining the results of these analyses we highlight 21 core hub genes within a larger single co-expression module, highly enriched in the terminal ileum of CD patients. Further pathway analysis revealed known and novel inflammation-regulated, fibrogenic pathways operating in the TI, such as IL-13 signaling and pyroptosis, respectively. These findings provide a rationale for the increased incidence of fibrosis at the terminal ileum of CD patients and highlight operating pathways in intestinal fibrosis for future evaluation with mechanistic and translational studies.

Human JAK1 gain of function causes dysregulated myelopoeisis and severe allergic inflammation.

Primary atopic disorders are a group of inborn errors of immunity that skew the immune system toward severe allergic disease. Defining the biology underlying these extreme monogenic phenotypes reveals shared mechanisms underlying common polygenic allergic disease and identifies potential drug targets. Germline gain-of-function (GOF) variants in JAK1 are a cause of severe atopy and eosinophilia. Modeling the JAK1GOF (p.A634D) variant in both zebrafish and human induced pluripotent stem cells (iPSCs) revealed enhanced myelopoiesis. RNA-Seq of JAK1GOF human whole blood, iPSCs, and transgenic zebrafish revealed a shared core set of dysregulated genes involved in IL-4, IL-13, and IFN signaling. Immunophenotypic and transcriptomic analysis of patients carrying a JAK1GOF variant revealed marked Th cell skewing. Moreover, long-term ruxolitinib treatment of 2 children carrying the JAK1GOF (p.A634D) variant remarkably improved their growth, eosinophilia, and clinical features of allergic inflammation. This work highlights the role of JAK1 signaling in atopic immune dysregulation and the clinical impact of JAK1/2 inhibition in treating eosinophilic and allergic disease.

Deep Crypt Secretory Cell Differentiation in the Colonic Epithelium Is Regulated by Sprouty2 and Interleukin 13

Deep crypt secretory (DCS) cells are a critical component of the colonic stem cell niche. However, the regulatory mechanisms controlling DCS cell numbers and function are not well understood. Sprouty2 is an inflammation-responsive regulator of intracellular signaling that influences colonic secretory cell numbers in colitis via an epithelial-stromal interleukin (IL)33/IL13 signaling loop. Here, we tested the hypothesis that IL13, induced by epithelial Sprouty2 down-regulation, promotes DCS cell differentiation and function. Distal colons from mice with an intestinal epithelial-specific Sprouty2 deletion (Spry2ΔIE) and littermate controls were analyzed by in situ hybridization for Reg4+ DCS cells. Single-cell RNA sequencing and immunostaining were used to identify DCS cell-derived host defense peptides (HDPs) and localization of IL13 and IL13 receptor; bulk RNA sequencing and quantitative polymerase chain reaction were used to quantify changes in expression of identified HDPs. Cytokine-treated colonoids were assessed for DCS cells. A requirement for an IL33/IL13 signaling loop in the regulation of DCS cells was assessed invivo using IL13 null mice. Reg4+ DCS cell numbers were increased 2-fold in distal colons of Spry2ΔIE mice with a concomitant overall increase in DCS cell marker expression (Reg4, Spink4, and Agr2). Single-cell transcriptomics showed the HDP Retnlb/Resistin Like Beta (RELMβ) is highly enriched in DCS cells. Retnlb/RELMβ expression was increased in Spry2ΔIE colons. IL13, but not IL33, induced Reg4 and Retnlb expression in colonic epithelial organoids, and IL33-mediated expansion of the DCS cell population invivo was dependent on IL13, which was expressed predominantly by type II innate lymphoid cells in the colonic mucosa. Sprouty2 limits colonic DCS cell differentiation through suppression of IL13 signaling. At homeostasis, DCS cells are marked by high levels of the HDP RELMβ. Loss of epithelial Sprouty2 activates type II innate lymphoid cells to release IL13, promoting expansion of the DCS cell population and increased colonic RELMβ levels.