Thymic Stromal Lymphopoietin Research Articles

Thymic Stromal Lymphopoietin (TSLP) Is Cleaved by Human Mast Cell Tryptase and Chymase.

Thymic stromal lymphopoietin (TSLP), mainly expressed by epithelial cells, plays a central role in asthma. In humans, TSLP exists in two variants: the long form TSLP (lfTSLP) and a shorter TSLP isoform (sfTSLP). Macrophages (HLMs) and mast cells (HLMCs) are in close proximity in the human lung and play key roles in asthma. We evaluated the early proteolytic effects of tryptase and chymase released by HLMCs on TSLP by mass spectrometry. We also investigated whether TSLP and its fragments generated by these enzymes induce angiogenic factor release from HLMs. Mass spectrometry (MS) allowed the identification of TSLP cleavage sites caused by tryptase and chymase. Recombinant human TSLP treated with recombinant tryptase showed the production of 1-97 and 98-132 fragments. Recombinant chymase treatment of TSLP generated two peptides, 1-36 and 37-132. lfTSLP induced the release of VEGF-A, the most potent angiogenic factor, from HLMs. By contrast, the four TSLP fragments generated by tryptase and chymase failed to activate HLMs. Long-term TSLP incubation with furin generated two peptides devoid of activating property on HLMs. These results unveil an intricate interplay between mast cell-derived proteases and TSLP. These findings have potential relevance in understanding novel aspects of asthma pathobiology.

Relevance of Thymic Stromal Lymphopoietin on the Pathogenesis of Glioblastoma: Role of the Neutrophil

Glioblastoma multiforme (GBM) is the most predominant and malignant primary brain tumor in adults. Thymic stromal lymphopoietin (TSLP), a cytokine primarily generated by activated epithelial cells, has recently garnered attention in cancer research. This study was aimed to elucidate the significance of TSLP in GBM cells and its interplay with the immune system, particularly focused on granulocyte neutrophils. Our results demonstrate that the tumor produces TSLP when stimulated with epidermal growth factor (EGF) in both the U251 cell line and the GBM biopsy (GBM-b). The relevance of the TSLP function was evaluated using a 3D spheroid model. Spheroids exhibited increased diameter, volume, and proliferation. In addition, TSLP promoted the generation of satellites surrounding the main spheroids and inhibited apoptosis in U251 treated with temozolomide (TMZ). Additionally, the co-culture of polymorphonuclear (PMN) cells from healthy donors with the U251 cell line in the presence of TSLP showed a reduction in apoptosis and an increase in IL-8 production. TSLP directly inhibited apoptosis in PMN from GBM patients (PMN-p). Interestingly, the vascular endothelial growth factor (VEGF) production was elevated in PMN-p compared with PMN from healthy donors. Under these conditions, TSLP also increased VEGF production, in PMN from healthy donors. Moreover, TSLP upregulated programed death-ligand 1 (PDL-1) expression in PMN cultured with U251. On the other hand, according to our results, the analysis of RNA-seq datasets from Illumina HiSeq 2000 sequencing platform performed with TIMER2.0 webserver demonstrated that the combination of TSLP with neutrophils decreases the survival of the patient. In conclusion, our results position TSLP as a possible new growth factor in GBM and indicate its modulation of the tumor microenvironment, particularly through its interaction with PMN.Graphical Protumoral activity of TSLP. Neutrophils (derived from GBM patients) and GBM cells (under EGF stimulus) not only produce TSLP but also express its receptor. TSLP induces PDL1 expression and decreases apoptosis on both GBM cells and neutrophils. TSLP also increases proliferation and satellite development on GBM cells, whereas favors more neutrophil infiltration by increasing IL8 production.

Airway remodelling in asthma and the epithelium: on the edge of a new era.

Asthma is a chronic, heterogeneous disease of the airways, often characterised by structural changes known collectively as airway remodelling. In response to environmental insults, including pathogens, allergens and pollutants, the epithelium can initiate remodelling via an inflammatory cascade involving a variety of mediators that have downstream effects on both structural and immune cells. These mediators include the epithelial cytokines thymic stromal lymphopoietin, interleukin (IL)-33 and IL-25, which facilitate airway remodelling through cross-talk between epithelial cells and fibroblasts, and between mast cells and airway smooth muscle cells, as well as through signalling with immune cells such as macrophages. The epithelium can also initiate airway remodelling independently of inflammation in response to the mechanical stress present during bronchoconstriction. Furthermore, genetic and epigenetic alterations to epithelial components are believed to influence remodelling. Here, we review recent advances in our understanding of the roles of the epithelium and epithelial cytokines in driving airway remodelling, facilitated by developments in genetic sequencing and imaging techniques. We also explore how new and existing therapeutics that target the epithelium and epithelial cytokines could modify airway remodelling.

A dual computational and experimental strategy to enhance TSLP antibody affinity for improved asthma treatment.

Thymic stromal lymphopoietin is a key cytokine involved in the pathogenesis of asthma and other allergic diseases. Targeting TSLP and its signaling pathways is increasingly recognized as an effective strategy for asthma treatment. This study focused on enhancing the affinity of the T6 antibody, which specifically targets TSLP, by integrating computational and experimental methods. The initial affinity of the T6 antibody for TSLP was lower than the benchmark antibody AMG157. To improve this, we utilized alanine scanning, molecular docking, and computational tools including mCSM-PPI2 and GEO-PPI to identify critical amino acid residues for site-directed mutagenesis. Subsequent mutations and experimental validations resulted in an antibody with significantly enhanced blocking capacity against TSLP. Our findings demonstrate the potential of computer-assisted techniques in expediting antibody affinity maturation, thereby reducing both the time and cost of experiments. The integration of computational methods with experimental approaches holds great promise for the development of targeted therapeutic antibodies for TSLP-related diseases.

Multifactorial Causes and Consequences of TLSP Production, Function, and Release in the Asthmatic Airway.

Disruption of the airway epithelium triggers a defensive immune response that begins with the production and release of alarmin cytokines. These epithelial-derived alarmin cytokines, including thymic stromal lymphopoietin (TSLP), are produced in response to aeroallergens, viruses, and toxic inhalants. An alarmin response disproportionate to the inhaled trigger can exacerbate airway diseases such as asthma. Allergens inhaled into previously sensitized airways are known to drive a T2 inflammatory response through the polarization of T cells by dendritic cells mediated by TSLP. Harmful compounds found within air pollution, microbes, and viruses are also triggers causing airway epithelial cell release of TSLP in asthmatic airways. The release of TSLP leads to the development of inflammation which, when unchecked, can result in asthma exacerbations. Genetic and inheritable factors can contribute to the variable expression of TSLP and the risk and severity of asthma. This paper will review the various triggers and consequences of TSLP release in asthmatic airways.

Interplay of cytokines in the pathophysiology of atopic dermatitis: insights from Murin models and human.

The pathogenesis of atopic dermatitis (AD) is understood to be crucially influenced by three main factors: dysregulation of the immune response, barrier dysfunction, and pruritus. In the lesional skin of AD, various innate immune cells, including Th2 cells, type 2 innate lymphoid cells (ILC2s), and basophils, produce Th2 cytokines [interleukin (IL)-4, IL-5, IL-13, IL-31]. Alarmins such as TSLP, IL-25, and IL-33 are also produced by epidermal keratinocytes, amplifying type 2 inflammation. In the chronic phase, not only Th2 cells but also Th22 and Th17 cells increase in number, leading to suppression of filaggrin expression by IL-4, IL-13, and IL-22, which further deteriorates the epidermal barrier function. Dupilumab, which targets IL-4 and IL-13, has shown efficacy in treating moderate to severe AD. Nemolizumab, targeting IL-31RA, effectively reduces pruritus in AD patients. In addition, clinical trials with fezakinumab, targeting IL-22, have demonstrated promising results, particularly in severe AD cases. Conversely, in murine models of AD, several cytokines, initially regarded as promising therapeutic targets, have not demonstrated sufficient efficacy in clinical trials. IL-33 has been identified as a potent activator of immune cells, exacerbating AD in murine models and correlating with disease severity in human patients. However, treatments targeting IL-33 have not shown sufficient efficacy in clinical trials. Similarly, thymic stromal lymphopoietin (TSLP), integral to type 2 immune responses, induces dermatitis in animal models and is elevated in human AD, yet clinical treatments like tezepelumab exhibit limited efficacy. Therapies targeting IL-1α, IL-5, and IL-17 also failed to achieve sufficient efficacy in clinical trials. It has become clear that for treating AD, IL-4, IL-13, and IL-31 are relevant therapeutic targets during the acute phase, while IL-22 emerges as a target in more severe cases. This delineation underscores the necessity of considering distinct pathophysiological aspects and therapeutic targets in AD between mouse models and humans. Consequently, this review delineates the distinct roles of cytokines in the pathogenesis of AD, juxtaposing their significance in human AD from clinical trials against insights gleaned from AD mouse models. This approach will improve our understanding of interspecies variation and facilitate a deeper insight into the pathogenesis of AD in humans.

Biomarker combination predicting imminent relapse after discontinuation of biological drugs in patients with rheumatoid arthritis in remission.

Compared to conventional disease-modifying antirheumatic drugs (DMARDs), biological DMARDs demonstrate superior efficacy but come with higher costs and increased infection risks. The ability to stop and resume biological DMARD treatment while maintaining remission would significantly alleviate these barriers and anxieties. The objective of this study was to identify biomarkers that can predict an imminent relapse, hopefully enabling the timely resumption of biological DMARDs before relapse occurs. Forty patients with rheumatoid arthritis who had been in remission for more than 12 months were included in the study. The patients discontinued their biological DMARD treatment and were monitored monthly for the next 24 months. Out of the 40 patients, 14 (35%) remained in remission at the end of the 24-month period, while 26 (65%) experienced relapses at different time points. Among the relapse cases, 13 patients experienced early relapse within 6 months, and another 13 patients had late relapse between 6 months and 24 months. Seventy-three cytokines in the sera collected longitudinally from the 13 patients with late relapse were measured by multiplex immunoassay. Using cytokines at two time points, immediately after withdrawal and just before relapse, volcano plot and area under the receiver operating characteristic curves (AUC) were drawn to select cytokines that distinguished imminent relapse. Univariate and multivariate logistic regression analyses were used for the imminent relapse prediction model. IL-6, IL-29, MMP-3, and thymic stromal lymphopoietin (TSLP) were selected as potential biomarkers for imminent relapse prediction. All four cytokines were upregulated at imminent relapse time point. Univariate and multivariate logistic regression showed that a combination model with IL-6, MMP-3, and TSLP yielded an AUC of 0.828 as top predictors of imminent relapse. This methodology allows for the prediction of imminent relapse while patients are in remission, potentially enabling the implementation of on- and off-treatments while maintaining remission. It also helps alleviate patient anxiety regarding the high cost and infection risks associated with biological DMARDs, which are the main obstacles to benefiting from their superb efficacy.

High mobility group box 1 cytokine targeted topical delivery of resveratrol embedded nanoemulgel for the management of atopic dermatitis.

Resveratrol is a polyphenolic compound showing anti-inflammatory activity by inhibition of high mobility group box 1 cytokine responsible for the activation of nuclear factor-κB pathway in atopic dermatitis. To evaluate the efficacy of resveratrol through topical route we have developed resveratrol-loaded nanoemulgel for the effective management of atopic dermatitis in mice model. The resveratrol-loaded nanoemulsion (0.5%, 0.75% and 1% w/w) was optimized by spontaneous nano-emulsification. The optimized resveratrol-loaded nanoemulsions showed average globule size in the 180-230nm range and found to be monodispersed. The resveratrol nanoemulgel was prepared with a SEPINEO™ P 600 gel base and propylene glycol. Ex vivo permeation and retention study resulted in significantly higher skin retention of resveratrol from resveratrol-loaded nanoemulgel than free resveratrol-loaded gel. Preclinical efficacy of resveratrol nanoemulgel displayed promising therapeutic outcomes where, western blotting of skin tissues disclosed a significant reduction in the relative expression of high mobility group box 1, the receptor for advanced glycation end products, toll-like receptor-4 and phosphorylated nuclear factor-κB. Further, real-time polymerase chain reaction also disclosed a significant reduction in pro-inflammatory cytokines such as thymic stromal lymphopoietin, interleukin-4, interleukin-13, interleukin-31, tumor necrosis factor-α and interleukin-6. The histopathological examination of skin sections showed improvement in the skin condition. Collectively, the findings from our study showcased the significant improvement in the atopic dermatitis skin condition in mice model after topical application of resveratrol loaded nanoemulgel.

Endoplasmic reticulum stress enhances the expression of TLR3-induced TSLP by airway epithelium.

Thymic stromal lymphopoietin (TSLP) is an epithelial-derived pleiotropic cytokine that regulates T-helper 2 (Th2) immune responses in the lung and plays a major role in severe uncontrolled asthma. Emerging evidence suggests a role for endoplasmic reticulum (ER) stress in the pathogenesis of asthma. In this study, we determined if ER stress and the unfolded protein response (UPR) signaling are involved in TSLP induction in the airway epithelium. For this, we treated human bronchial epithelial basal cells and differentiated primary bronchial epithelial cells with ER stress inducers and the TSLP mRNA and protein expression was determined. A series of siRNA gene knockdown experiments were conducted to determine the ER stress-induced TSLP signaling pathways. cDNA collected from asthmatic bronchial biopsies was used to determine the gene correlation between ER stress and TSLP. Our results show that ER stress signaling induces TSLP mRNA expression via the PERK-C/EBP homologous protein (CHOP) signaling pathway. AP-1 transcription factor is important in regulating this ER stress-induced TSLP mRNA induction, though ER stress alone cannot induce TSLP protein production. However, ER stress significantly enhances TLR3-induced TSLP protein secretion in the airway epithelium. TSLP and ER stress (PERK) mRNA expression positively correlates in bronchial biopsies from participants with asthma, particularly in neutrophilic asthma. In conclusion, these results suggest that ER stress primes TSLP that is then enhanced further upon TLR3 activation, which may induce severe asthma exacerbations. Targeting ER stress using pharmacological interventions may provide novel therapeutics for severe uncontrolled asthma.NEW & NOTEWORTHY TSLP is an epithelial-derived cytokine and a key regulator in the pathogenesis of severe uncontrolled asthma. We demonstrate a novel mechanism by which endoplasmic reticulum stress signaling upregulates airway epithelial TSLP mRNA expression via the PERK-CHOP signaling pathway and enhances TLR3-mediated TSLP protein secretion.

New Drug for Management of Severe Uncontrolled Asthma: Tezepelumab

Abstract: Tezepelumab is a first-in-class human IgG2λ monoclonal antibody used to treat severe, uncontrolled asthma. Tezepelumab acts by hindering the action of thymic stromal lymphopoietin (TSLP), an epithelial-derived cytokine that triggers an immunological response by binding to TSLP and thereby preventing its binding with the TSLP receptor complex. TSLP has a critical role in Th2 immunity and plays an important role in the pathogenesis of asthma because it stimulates the production of Th2-associated inflammatory mediators, such as interleukin-4, interleukin-5, interleukin-9, and interleukin-13. It is the first biologic with no phenotypic or biomarker restrictions that has been approved for use in severe asthma. Tezepelumab is indicated in severe, uncontrolled asthma patients due to its safety, tolerability, and efficacy. Adults with severe, uncontrolled asthma experienced considerably lower annualised asthma exacerbation rates (AAERs) when administered with tezepelumab compared to a placebo. These preliminary results indicated that the TSLP-induced release of T2 inflammatory mediators may be reduced, and the sustained inhibition was maintained over a 52-week treatment period. In this review, we have summarised various phase III clinical trials and the mechanism of action of tezepelumab in severe, uncontrolled asthma.

Cytokines in Allergic Conjunctivitis: Unraveling Their Pathophysiological Roles.

Allergic conjunctivitis is one of the common immune hypersensitivity disorders that affect the ocular system. The clinical manifestations of this condition exhibit variability contingent upon environmental factors, seasonal dynamics, and genetic predisposition. While our comprehension of the pathophysiological engagement of immune and nonimmune cells in the conjunctiva has progressed, the same cannot be asserted for the cytokines mediating this inflammatory cascade. In this review, we proffer a comprehensive description of interleukins 4 (IL-4), IL-5, IL-6, IL-9, IL-13, IL-25, IL-31, and IL-33, as well as thymic stromal lymphopoietin (TSLP), elucidating their pathophysiological roles in mediating the allergic immune responses on the ocular surface. Delving into the nuanced functions of these cytokines holds promise for the exploration of innovative therapeutic modalities aimed at managing allergic conjunctivitis.

The glucocorticoid dexamethasone alleviates allergic inflammation through a mitogen-activated protein kinase phosphatase-1-dependent mechanism in mice.

Glucocorticoids are widely used in the treatment of allergic and inflammatory diseases. Glucocorticoids have a widespread action on gene expression resulting in their pharmacological actions and also an array of adverse effects which limit their clinical use. It remains, however, to be studied which target gene effects are essential for the anti-allergic activity of glucocorticoids. Mitogen-activated protein kinase phosphatase-1 (MKP-1) inhibits proinflammatory signalling by suppressing the activity of mitogen activated protein kinase (MAP kinase) pathways. MKP-1 is one of the anti-inflammatory genes whose expression is enhanced by glucocorticoids. In the present study, we aimed to investigate the role of MKP-1 in the therapeutic effects of the glucocorticoid dexamethasone in acute allergic reaction. The effects of dexamethasone were studied in wild-type and MKP-1 deficient mice. The mice were first sensitized to ovalbumin, and the allergic reaction was then induced by a subcutaneous ovalbumin injection in the hind paw. Inflammatory edema was quantified with plethysmometer and expression of inflammatory factors was measured by quantitative reverse transcription polymerase chain reaction (RT-PCR). Dexamethasone reduced the ovalbumin-induced paw edema at 1.5, 3 and 6h time points in wild-type mice by 70%, 95% and 89%, respectively. The effect was largely abolished in MKP-1 deficient mice. Furthermore, dexamethasone significantly attenuated the expression of ovalbumin-induced inflammatory factors cyclooxygenase-2 (COX-2); inducible nitric oxide synthase (iNOS); interleukins (IL) 1β, 6 and 13; C-C motif chemokine 11 (CCL-11); tumour necrosis factor (TNF) and thymic stromal lymphopoietin (TSLP) in wild-type mice by more than 40%. In contrast, in MKP-1 deficient mice dexamethasone had no effect or even enhanced the expression of these inflammatory factors. The results suggest that dexamethasone alleviates allergic inflammation through an MKP-1-dependent mechanism. The results also demonstrate MKP-1 as an important conveyor of the favourable glucocorticoid effects in ovalbumin-induced type I allergic reaction. Together with previous findings, the present study supports the concept of MKP-1 enhancing compounds as potential novel anti-inflammatory and anti-allergic drugs.

Skin biomarkers predict the development of food allergy in early life

BackgroundFood allergy (FA) often occurs in early childhood with and without atopic dermatitis (AD). FA can be severe and even fatal. For primary prevention, it is important to find early biomarkers to predict the future onset of FA before any clinical manifestations. ObjectiveTo find early predictors of future onset of FA in the stratum corneum (SC). MethodsSkin tape strips (STS) were collected from the forearm of newborns (n=129) at the age of 2 months before any signs of clinical FA or AD. Children were clinically monitored until they reached 2 years of age to confirm the presence or absence of FA and AD. STS were subjected to lipidomic analyses by the LC-MS/MS and cytokine determination by Meso Scale Discovery U-Plex assay. ResultsOverall, 9/129 (7.0%) infants developed FA alone, and 9/129 (7.0%) infants developed FA concomitantly with AD (ADFA). In the SC of future FA and ADFA children, absolute amounts of unsaturated (N24:1)(C18S)Ceramide and (N26:1)(C18S)Ceramide and their relative percentages within the molecular group were increased in comparison to healthy children with p-values between <0.01 and p<0.05, ANOVA. Future AD children had normal levels of these molecules. Interleukin (IL)-33 was upregulated in future FA but not AD infants, whereas thymic stromal lymphopoietin (TSLP) was upregulated in AD but not FA. Logistic regression analysis revealed strong FA predicting power for the combination of dysregulated lipids and cytokines, with an odds ratio reaching 101.4 (95% CI 5.4 – 1910.6). ConclusionNon-invasive STS analysis at 2 months of age can identify infants at risk of future FA.

Anti-inflammatory control of human skin keratinocytes by targeting nuclear transport checkpoint.

In the two common inflammatory skin diseases, Atopic Dermatitis (AD) and Psoriasis (Ps), keratinocytes (KCs) respond to immune insults through activation of proinflammatory transcription factors (TFs) and their translocation to the cell's nucleus. Therein, the TFs induce expression of genes encoding mediators of skin inflammation. The Nuclear Transport Checkpoint Inhibitors (NTCIs) were developed to regulate nuclear translocation of activated TFs, the essential step of inflammatory response. This new class of cell-penetrating peptide therapeutics controls inflammation caused by allergic, autoimmune, metabolic, and microbial insults. In preclinical model of AD, the treatment with NTCI, cSN50.1 peptide, suppressed the expression of Thymic Stromal Lymphopoietin (TSLP), the key gene in the development of allergic inflammation, among the 15 genes silenced by the NTCI. Here, we report the mechanism of anti-inflammatory action of NTCI in human skin-derived KCs. We aimed to determine whether the NTCI treatment can protect human KCs from harmful inflammatory insults. Human primary KCs were pretreated with NTCI and challenged with the mix of cytokines Tumour Necrosis Factor alpha (TNF-α) and Interleukin (IL)-17A, or with Phorbol 12-Myristate 13-Acetate (PMA), and analysed for nuclear content of TFs and the expression of genes encoding mediators of inflammation. The nuclear import of TFs, Nuclear Factor ĸB (NF-ĸB) and Signal Transduction and Activator of Transcription 3 (STAT3), was inhibited in cells treated with NTCI. The expression of TSLP, along with genes encoding the core mediators of inflammation (TNF, IL1B, and IL6) was suppressed by NTCI. Noteworthy, NTCI silenced genes encoding Granulocyte-Macrophage Colony-Stimulating Factor (CSF2), and chemokine IL-8 (CXCL8), responsible for skin infiltration by the eosinophils and other myelomonocytic cells. The control of inflammatory response in human KCs by NTCI is attributed to the inhibition of nuclear import of proinflammatory TFs. The protection of human KCs by NTCI, adds new perspectives to the completed Phase two clinical trial of the NTCI (AMTX-100 CF) for AD (NCT04313400).

Tezepelumab for Severe Asthma: One Drug Targeting Multiple Disease Pathways and Patient Types.

Asthma is a heterogeneous inflammatory disease of the airways, affecting many children, adolescents, and adults worldwide. Up to 10% of people with asthma have severe disease, associated with a higher risk of hospitalizations, greater healthcare costs, and poorer outcomes. Patients with severe asthma generally require high-dose inhaled corticosteroids and additional controller medications to achieve disease control; however, many patients remain uncontrolled despite this intensive treatment. The treatment of severe uncontrolled asthma has improved with greater understanding of asthma pathways and phenotypes as well as the advent of targeted biologic therapies. Tezepelumab, a monoclonal antibody, blocks thymic stromal lymphopoietin, an epithelial cytokine that has multifaceted effects on the initiation and persistence of asthma inflammation and pathophysiology. Unlike other biologic treatments, tezepelumab has demonstrated efficacy across severe asthma phenotypes, with the magnitude of effects varying by phenotype. Here we describe the anti-inflammatory effects and efficacy of tezepelumab across the most relevant phenotypes of severe asthma. Across clinical studies, tezepelumab reduced annualized asthma exacerbation rates versus placebo by 63-71% in eosinophilic severe asthma, by 58-68% in allergic severe asthma, by 67-71% in allergic and eosinophilic severe asthma, by 34-49% in type 2-low asthma, and by 31-41% in oral corticosteroid-dependent asthma. Furthermore, in all these asthma phenotypes, tezepelumab demonstrated higher efficacy in reducing exacerbations requiring hospitalizations or emergency department visits versus placebo. In patients with severe uncontrolled asthma, who commonly have multiple drivers of inflammation and disease, tezepelumab may modulate airway inflammation more extensively, as other available biologics block only specific downstream components of the inflammatory cascade.

Myelitis associated with COVID-19: clinical, radiological, and laboratory characteristics

Aim: The current study aimed to describe various types of myelitis associated with a novel coronavirus infection [coronavirus disease 2019 (COVID-19)] as well as to analyze cytokine profiles and cerebrospinal fluid (CSF) parameters in affected patients and to compare them to patients with other immune-mediated disorders—multiple sclerosis (MS), in order to identify possible common pathogenetic pathways and consequently treatment targets. Methods: Clinical, radiological, and laboratory characteristics were studied based on patients’ history. CSF from patients with myelitis associated with COVID-19 (11 patients) was compared with CSF of healthy controls (HC) (7 patients) and patients with MS (37 patients) from the non-COVID era. CSF cytological examination, protein levels and oligoclonal bands (OCBs) evaluation, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus detection and cytokine profiling using Bio-Plex Pro Human Inflammation Panel 1, 37-Plex were performed. Results: In total 11 patients with different types of myelitis developed up to 3 months after COVID-19 were enrolled in the study. Radiological findings were diverse: short transverse myelitis (lesion of fewer than 3 segments) (n = 6), longitudinal extensive transverse myelitis (LETM) (n = 2), multifocal spinal cord lesions (n = 1), and myelitis involving dorsal and lateral columns (n = 2). The most pronounced response to treatment was observed in patients with partial transverse myelitis and patients with anti-myelin oligodendrocyte glycoprotein (MOG) antibodies (MOG Abs). Multiple comparisons have demonstrated decreased levels of interleukin-10 (IL-10), interferon-α2 (IFN-α2), IFN-β, and thymic stromal lymphopoietin (TSLP), and increased IL-19 and B cell activating factor (BAFF) in patients with COVID-19 myelitis (CM) compared to the MS group. The highest BAFF and a proliferation-inducing ligand (APRIL) concentrations were found in patients with the most profound neurological disability. Conclusions: Myelitis associated with COVID-19 is clinically and radiologically heterogeneous. Evaluation of cytokine profiles in patients with myelitis associated with COVID-19 revealed their relative similarity with ones of MS patients, except for a few cytokines. BAFF/APRIL system as well as IL-10 is well-known for the role in the development and progression of autoimmune diseases, however, their links with COVID-19 and effects on the development of immune-mediated central nervous system (CNS) disorders after SARS-CoV-2 remain to be further studied.

Oral Administration of Apple Pectin Solution Improves Atopic Dermatitis in a Mouse Model.

The development of atopic dermatitis (AD) involves multiple factors. Three such factors are particularly important in AD onset: immune abnormalities, skin barrier dysfunction, and itching. Many studies report that an imbalance between helper T (Th)1 and Th2 cells causes AD. Apple pectin, a prebiotic, has preventative effects in other allergic diseases (e.g., bronchial asthma and AD), but its potential benefits in AD are unclear. In this study, we investigated the effect of oral apple pectin administration on skin inflammation in an AD mouse model and examined changes in T cells involved in AD. To induce AD, a picryl chloride solution was applied to the shaved back skin of male NC/Nga mice. AD mice then received an oral apple pectin solution (0.4% or 4%) for 35 d. Compared with untreated AD mice, mice in both apple pectin-treated groups showed improvement in AD-induced inflammation and skin symptoms. Histological evaluation showed that apple pectin treatment attenuated epidermal thickening and decreased the number of mast cells and CD4+ cells in AD-induced mice. Apple pectin treatment also reduced serum IgE concentration, as well as expression of the inflammation indicator cyclooxygenase-2 and the Th2-related factors thymic stromal lymphopoietin, interleukin-4, and GATA3. Additionally, increased mRNA expression of the genes that encode interferon-γ and T-bet, which are Th1-related factors, and forkhead box protein P3, were observed in the apple pectin-treated groups. Our findings suggest that apple pectin treatment ameliorates AD by increasing regulatory T cells and improving the Th1/Th2 balance in the skin of AD model mice.

Development of a novel humanized anti-TSLP monoclonal antibody HZ-1127 with anti-allergic diseases and cancer potential.

Thymic stromal lymphopoietin (TSLP) is a member of the IL-2 cytokine family and has been widely recognized as a master regulator of type 2 inflammatory responses at barrier surfaces. Recent studies found dysregulation of the TSLP-TSLP receptor (TSLPR) pathway is associated with the pathogenesis of not only allergic diseases but also a wide variety of cancers including both solid tumors and hematological tumors. Thus, the blockade of TSLP represents an attractive therapeutic strategy for allergic diseases and cancer. In this study, we report the development of a novel humanized anti-TSLP monoclonal antibody (mAb) HZ-1127. Binding affinity, specificity, and ability of HZ-1127 in inhibiting TSLP were tested. HZ-1127 selectively binds to the TSLP cytokine with high affinity and specificity. Furthermore, HZ-1127 dramatically inhibits TSLP-dependent STAT5 activation and is more potent than Tezepelumab, which is an FDA-approved humanized mAb against TSLP for severe asthma treatment in inhibiting TSLP-induced CCL17 and CCL22 chemokines secretion in human peripheral blood mononuclear cells. Our pre-clinical study demonstrates that HZ-1127 may serve as a potential therapeutic agent for allergic diseases and cancer.

Analysis of genetic variant associated with heart failure mortality implicates thymic stromal lymphopoietin as mediator of strain-induced myocardial fibroblast-mast cell crosstalk and fibrosis.

Heart failure (HF) is a leading cause of death and disability globally. Heritable factors and the extent and pattern of myocardial fibrosis are important determinants of outcomes in patients with HF. In a genome-wide association study of mortality in HF, we recently identified a genetic polymorphism on chromosome 5q22 associated with HF mortality. Here, we sought to study the mechanisms by which this variant may influence myocardial disease processes. We find that the risk allele is located in an enhancer motif upstream of the TSLP gene (encoding thymic stromal lymphopoietin), conferring increased binding of the transcription factor nescient helix-loop helix 1 (NHLH1) and increased TSLP expression in human heart. Further, we find that increased strain of primary human myocardial fibroblasts results in increased TSLP expression and that the TSLP receptor is expressed in myocardial mast cells in human single nuclei RNA sequence data. Finally, we show that TSLP overexpression induces increased transforming growth factor β expression in myocardial mast cells and tissue fibrosis. Collectively, our findings based on follow-up of a human genetic finding implicate a novel pathway in myocardial tissue homeostasis and remodeling.

TSLP is localized in and released from human lung macrophages activated by T2-high and T2-low stimuli: relevance in asthma and COPD

BackgroundMacrophages are the predominant immune cells in the human lung and play a central role in airway inflammation, including asthma and chronic obstructive pulmonary disease (COPD). Thymic stromal lymphopoietin (TSLP), a pleiotropic cytokine mainly expressed by bronchial epithelial cells, plays a key role in asthma and COPD pathobiology. TSLP exists in two variants: the long form (lfTSLP) and a shorter TSLP isoform (sfTSLP). We aimed to localize TSLP in human lung macrophages (HLMs) and investigate the mechanisms of its release from these cells. We also evaluated the effects of the two variants of TSLP on the release of angiogenic factor from HLMs. MethodsWe employed immunofluorescence and Western blot to localize intracellular TSLP in HLMs purified from human lung parenchyma. HLMs were activated by T2-high (IL-4, IL-13) and T2-low (lipopolysaccharide: LPS) immunological stimuli. ResultsTSLP was detected in HLMs and subcellularly localized in the cytoplasm. IL-4 and LPS induced TSLP release from HLMs. Preincubation of macrophages with brefeldin A, known to disrupt the Golgi apparatus, inhibited TSLP release induced by LPS and IL-4. lfTSLP concentration-dependently induced the release of vascular endothelial growth factor-A (VEGF-A), the most potent angiogenic factor, from HLMs. sfTSLP neither activated nor interfered with the activating property of lfTSLP on macrophages. ConclusionsOur results highlight a novel immunologic circuit between HLMs and TSLP. Given the central role of macrophages in airway inflammation, this autocrine loop holds potential translational relevance in understanding innovative aspects of the pathobiology of asthma and chronic inflammatory lung disorders.