Thymic Stromal Lymphopoietin Signaling Research Articles

Thymic stromal lymphopoietin signaling in B cells from progenitors to plasma cells.

Thymic stromal lymphopoietin (TSLP) is an established pleotropic alarmin cytokine that is generated at barrier tissues to induce type 2 immune responses, but its role in regulating the diversity of B cells is poorly understood. Here, we will highlight the key findings that underpin our limited understanding of the role TSLP in modulating different stages of B cell development. We will also provide an overview of how TSLP drives B cell-mediated immune disease and how novel TSLP-blocking biologics could be used to modulate B cell responses. TSLP is critical for the regulation, diversity, and longevity of humoral immunity.

Development of a novel humanized anti-TSLP monoclonal antibody, QX008N, and exploration of combination therapy of anti-TSLP antibody and anti-IL-4R antibody

BackgroundSevere asthma is a complex and chronic respiratory disease, and current conventional treatments are not effective in controlling the patients’ condition. Thymic stromal lymphopoietin (TSLP) is a key regulatory factor in the initiation and maintenance of asthma. Thus, blocking TSLP during allergic inflammation emerges as a promising therapeutic approach; however, novel anti-TSLP therapies remain to be developed. Furthermore, the importance of other signaling molecules, such as IL-4 and IL-13, should be considered. Moreover, to the best of our knowledge, the inhibitory effect of binding upstream and downstream signaling molecules has not been assessed. PurposeThis study aimed to develop a novel, humanized anti-TSLP antibody and explore the enhancement in its efficacy when combined with anti-IL-4R antibodies to treat asthma. ResultsQX008N, derived from a rabbit antibody platform, exhibits a high affinity for TSLP and superior efficacy in blocking TSLP-induced signaling pathways and inflammation in vitro compared with Tezepelumab. In a cynomolgus monkey asthma model, QX008N ameliorated lung function and reduced the levels of eosinophils and IgE. Moreover, the coadministration of QX008N with anti-IL-4R antibodies enhanced the inhibition of inflammatory mediator production triggered via costimulation in vitro. In mouse asthma models, the simultaneous blockade of TSLP and IL-4R using anti-TL4R and anti-TSLP surrogates surpassed the efficacy of monotherapy. To the best of our knowledge, the therapeutic effect of a combination of anti-TSLP and IL-4R antibodies in an asthma model has not yet been reported. ConclusionThese results furnish comprehensive preclinical evidence for QX008N as an innovative anti-TSLP therapeutic agent and provide a preliminary rationale for the development of combination therapies that simultaneously target the TSLP and IL-4R signaling pathways.

Lung Tissue Transcriptomics Reveal Associations between Thymic Stromal Lymphopoietin Signaling, Mast Cells, and Airway Obstruction in Active Smokers

Lung Tissue Transcriptomics Reveal Associations between Thymic Stromal Lymphopoietin Signaling, Mast Cells, and Airway Obstruction in Active Smokers

Thymic stromal lymphopoietin contributes to ozone-induced exacerbations of eosinophilic airway inflammation via granulocyte colony-stimulating factor in mice

BackgroundOzone is one of the triggers of asthma, but its impact on the pathophysiology of asthma, such as via airway inflammation and airway hyperresponsiveness (AHR), is not fully understood. Thymic stromal lymphopoietin (TSLP) is increasingly seen as a crucial molecule associated with asthma severity, such as corticosteroid resistance. MethodsFemale BALB/c mice sensitized and challenged with house dust mite (HDM) were exposed to ozone at 2 ppm for 3 h. Airway inflammation was assessed by the presence of inflammatory cells in bronchoalveolar lavage fluid and concentrations of cytokines including TSLP in lung. Anti-TSLP antibody was administered to mice to block the signal. Survival and adhesion of bone marrow-derived eosinophils in response to granulocyte colony-stimulating factor (G-CSF) were evaluated. ResultsOzone exposure increased eosinophilic airway inflammation and AHR in mice sensitized and challenged with HDM. In addition, TSLP, but not IL-33 and IL-25, was increased in lung by ozone exposure. To confirm whether TSLP signaling is associated with airway responses to ozone, an anti-TSLP antibody was administered, and it significantly attenuated eosinophilic airway inflammation, but not AHR. Interestingly, G-CSF, but not type 2 cytokines such as IL-4, IL-5, and IL-13, was regulated by TSLP signaling associated with eosinophilic airway inflammation, and G-CSF prolonged survival and activated eosinophil adhesion. ConclusionsThe present data show that TSLP contributes to ozone-induced exacerbations of eosinophilic airway inflammation and provide greater understanding of ozone-induced severity mechanisms in the pathophysiology of asthma related to TSLP and G-CSF.

Abstract 4449: The expression and immune regulation of thymic stromal lymphopoietin in non-small cell lung cancer development and progression

Abstract Purpose: Previous studies have shown thymic stromal lymphopoietin (TSLP) to be an important driver of type 2 inflammation. A new and unexpected function for TSLP has been found in the induction and progression of a variety of tumors. This study conducted TSLP performance in lung cancer patients and the correlation of the clinical pathological data. Materials and Methods: The patients with pathological diagnosis of lung cancer were enrolled. The percentage of CD19 + B cells was determined in the lymphocyte gate and counted via flow cytometry. Relevant serum cytokines including TSLP were analyzed using LEGENDplex software. In vitro study was conducted by A549 cell line and the mRNA expression change of TSLP was extracted by Reverse Transcriptase PCR (RT-PCR). Results: When comparing the frequencies of B cell subsets between early-stage (N = 31) and late-stage lung cancer group (N = 29), the frequency of memory B cell (17.3±6.1% vs 23.4±15.1%, p=0.042), CD27+IgM+ B cell (1.8±1.3% vs 2.9±2.3%, p=0.030), class-switched B cell (15.5±5.5% vs 22.2±14.9%, p=0.023), class-switched memory B cell (69.9±11.3% vs 59.9±19.7%, p=0.017) and plasmablast (8.5±7.3% vs 18.0±20.8%, p=0.019) were significantly different between groups. The patients with higher frequency of class-switched B cell had significantly worse prognosis than low frequency (HR 3.054, 95% CI 1.007-9.262, p=0.049). The level of IL-1B, IL-6, IL-10, IL-12, IL-13, and TSLP were significantly higher in the late-stage cancer patients. Simulation in vitro test with human lung A549 cell line was performed, the expression of short-form TSLP (sfTSLP) level decreased with the higher anti-cancer drug as Pemetrexed concentration. Conclusions: The increase proportion of CD27+CD38- (class-switched) B cell could be an independent, poor prognostic factor for NSCLC patients. TSLP signaling is addressed to the anti-cancer therapeutic response. Therefore, TSLP and relevant cytokines may be involved directly and indirectly in shaping the inflammatory status of the tumor microenvironment. Citation Format: Chung-Yu Chen, Ying-Yin Chen, Hung-Chueh Peng, Yi-Ling Ye. The expression and immune regulation of thymic stromal lymphopoietin in non-small cell lung cancer development and progression. [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 4449.

B cell- and T cell-intrinsic regulation of germinal centers by thymic stromal lymphopoietin signaling.

Long-lived and high-affinity antibodies are derived from germinal center (GC) activity, but the cytokines that regulate GC function are still being identified. Here, we show that thymic stromal lymphopoietin (TSLP) signaling regulates the GC and the magnitude of antigen-specific antibody responses. Both GC B cells and T follicular helper (TFH) cells up-regulate the expression of surface TSLP receptor (TSLPR), but cell-specific loss of TSLPR results in distinct effects on GC formation and antibody production. TSLPR signaling on T cells supports the retention of antigen-specific B cells and TFH differentiation, whereas TSLPR in B cells regulates the generation of antigen-specific memory B cells. TSLPR in both cell types promotes interferon regulatory factor 4 (IRF4) expression, which is important for efficient GC activity. Overall, we identified a previously unappreciated cytokine regulator of GCs and identified how this signaling pathway differentially regulates B and T cell responses in the GC.

Keratinocyte-derived cytokine TSLP promotes growth and metastasis of melanoma by regulating the tumor-associated immune microenvironment.

Malignant melanoma is a major public health issue displaying frequent resistance to targeted therapy and immunotherapy. A major challenge lies in better understanding how melanoma cells evade immune elimination and how tumor growth and metastasis is facilitated by the tumor microenvironment. Here, we show that expression of the cytokine thymic stromal lymphopoietin (TSLP) by epidermal keratinocytes is induced by cutaneous melanoma in both mice and humans. Using genetically engineered models of melanoma and tumor cell grafting combined with TSLP-KO or overexpression, we defined a crosstalk between melanoma cells, keratinocytes, and immune cells in establishing a tumor-promoting microenvironment. Keratinocyte-derived TSLP is induced by signals derived from melanoma cells and subsequently acts via immune cells to promote melanoma progression and metastasis. Furthermore, we show that TSLP signals through TSLP receptor-expressing (TSLPR-expressing) DCs to play an unrecognized role in promoting GATA3+ Tregs expressing a gene signature including ST2, CCR8, ICOS, PD-1, CTLA-4, and OX40 and exhibiting a potent suppressive activity on CD8+ T cell proliferation and IFN-γ production. An analogous population of GATA3-expressing Tregs was also identified in human melanoma tumors. Our study provides insights into the role of TSLP in programming a protumoral immune microenvironment in cutaneous melanoma.

Linalyl Acetate Ameliorates Mechanical Hyperalgesia Through Suppressing Inflammation by TSLP/IL-33 Signaling

Neuropathic pain is a debilitating chronic disorder, significantly causing personal and social burdens, in which activated neuroinflammation is one major contributor. Thymic stromal lymphopoietin (TSLP) and interleukin (IL)-33 is important for chronic inflammation. Linalyl acetate (LA) is main component of lavender oil with an anti-inflammatory property through TSLP signaling. The aim of the study is to investigate how LA regulates mechanical hyperalgesia after sciatic nerve injury (SNI). Adult Sprague-Dawley male rats were separated into 3 groups: control group, SNI group and SNI with LA group. LA was administrated intraperitoneally one day before SNI. Pain behavior test was evaluated through calibration forceps testing. Ipsilateral sciatic nerves (SNs), dorsal root ganglions (DRGs) and spinal cord were collected for immunofluorescence staining and Western blotting analyses. SNI rats were more sensitive to hyperalgesia response to mechanical stimulus since operation, which was accompanied by spinal cord glial cells reactions and DRG neuro-glial interaction. LA could relieve the pain sensation, proinflammatory cytokines and decrease the expression of TSLP/TSLPR complex. Also, LA could reduce inflammation through reducing IL-33 signaling. This study is the first to indicate that LA can modulate pain through TSLP/TSLPR and IL-33 signaling after nerve injury.

Downregulation of deubiquitinating enzyme USP25 promotes the development of allergic rhinitis by enhancing TSLP signaling in the nasal epithelium.

Ubiquitin-specific peptidase 25 (USP25) is a key deubiquitylase belonging to the USP superfamily that is primarily involved in inflammation and the immune response. Thymic stromal lymphopoietin (TSLP) is an epithelial-derived cytokine that is regarded as the master switch that initiates and maintains the type 2 immune response in allergic rhinitis (AR). However, the molecular mechanisms by which USP25 regulates TSLP signaling in the nasal epithelium in AR remain unclear. The present study assessed the protein expression levels of USP25 in the nasal epithelium of patients with AR. Moreover, USP25 knockout (KO) and wild-type (WT) mice were treated with ovalbumin (OVA) to establish a model of AR. The results of western blotting and immunohistochemistry in the present study demonstrated that the protein expression levels of USP25 were significantly decreased in the nasal mucosa of patients with AR and AR mice, whereas the protein expression levels of TSLP were significantly increased. Allergic inflammation was more severe in USP25 KO mice compared with WT mice exposed to OVA, as demonstrated by increased nose scratching and sneezing, increased eosinophil infiltration, goblet cell hyperplasia and enhanced T helper type 2 (Th2) cytokine production. The results of in vitro experiments demonstrated that silencing or overexpression of USP25 decreased or increased TNF receptor-associated factor 3 (TRAF3) protein expression levels, respectively, in human nasal epithelial cells, whereas TSLP protein expression levels were negatively associated with the expression of USP25 and TRAF3. In summary, USP25 downregulation enhanced TSLP signaling in the nasal mucosal epithelium via decreased TRAF3 expression, thereby exacerbating inflammation in AR. Therefore, USP25 may act as a novel therapeutic target in AR.

Targeting circNCLN/miR-291a-3p/TSLP signaling axis alleviates lipopolysaccharide-induced acute lung injury

Acute lung injury (ALI) is a life-threatening disease caused by the severe and acute response of the lungs to a variety of direct and indirect insults. Patients with ALI are currently treated mainly with respiratory support due to inadequate understanding of ALI progression. Alveolar epithelial cells produced thymic stromal lymphopoietin (TSLP) has been proved to worsen ALI by triggering airway inflammation. However, the regulation mechanism of TSLP expression remains unclear. In this study, we identified the crucial role played by circNCLN in lipopolysaccharide (LPS)-induced ALI. We demonstrated for the first time that miR-291a-3p could directly bind to the 3′UTR of TSLP and suppress TSLP expression in alveolar epithelial cells. Mechanistically, our data identified that circNCLN acts as a molecular sponge to antagonize miR-291a-3p and thereby maintaining the expression of TSLP in alveolar epithelial cells. Importantly, targeting circNCLN by its antisense oligonucleotide (ASO) markedly alleviated LPS-induced ALI. Therefore, our results suggested that circNCLN/miR-291a-3p/TSLP axis may be an important signaling in LPS-induced ALI and circNCLN inhibition may serve as a potential treatment of ALI.

IL7Rα and TSLPR expression on Langerhans cells in response to inflammatory stimulation

Abstract A key component of immune barriers are innate immune cells localized in the epithelium responsible for sensing local signals such as foreign antigens and cytokines. In the skin, specialized antigen presenting cells (APC) known as Langerhans cells (LC) can integrate these signals influencing downstream T cell activation and polarization. Thymic stromal lymphopoietin (TSLP) is a proinflammatory mediator released by keratinocytes that promotes LC to enhance type 2 immune response (Th2). When Th2 response becomes unbalanced, it induces type 2 inflammation as seen in atopic dermatitis. TSLP signaling is regulated by two cell surface receptor chains: TSLP receptor (TSLPR) and IL7Rα. Interestingly, IL7Rα is not commonly expressed in murine conventional APC such as dendritic cells (DC). Our previous findings have shown that IL7Rα expression regulates TSLP sensitivity of splenic DCs (sDC) ex vivo. However, the receptor expression dynamic in tissue resident LC and its biological implications has not yet been elucidated. In this study we enriched LC from healthy mice B6 mice using MACS magnetic beads. Cytokine surface receptors and pospho-STAT5 activation were assessed using flow cytometry. Moreover, topic administration of vitamin analog MC903 will be used to evaluate TSLPR and IL7Rα dynamic. Our current results indicate that IL7Rα is expressed on unstimulated LC contrary to sDC. Furthermore, TSLPR was not differently expressed between LC and sDC. Functional assessment of p-STAT5 ex vivo and the dynamic of these receptors in the context of MC903 treatment in vivo is yet to be measured. Our results suggest that tissue resident APC regulate differently cytokines receptors enabling spatial-temporal regulation of proinflammatory signals. Academy of Finland (IJ: grants: 25013080481 and 25013142041), The Competitive State Research Financing of the Expert Responsibility Area of Fimlab Laboratories (grant X51409 to IJ), Tampere University Hospital Support Foundation (IJ) and Tampere Tuberculosis Foundation (IJ).

Thymic stromal lymphopoietin (TSLP) receptor signaling controls a tumorigenic Treg to promote colorectal cancer

Abstract Regulatory T cell (Treg) is a hallmark of progression of cancer. However, the subset of Tregs and the factor regulating Tregs in colorectal cancers (CRCs) have not been defined. We identified a novel subset of Tregs expressing TSLP receptor (TSLPR) and ST2 was predominantly associated with CRC in human and mouse. Mef2c, a transcription factor, exclusively expressed on this Treg controlled the expression of CTLA-4 on this Treg under TSLPR signaling. To study the role of TSLP signaling on this Treg, we examined mice lacking TSLPR on Tregs (TSLPRΔTreg) in AOM/DSS-induced CRC model. The results showed that the number and the expression of CTLA-4 on this Treg were lower in TSLPRΔTreg mice and the size and number of tumors were reduced compared to control mice, concomitant with increase of Th1 cells. In addition, in human CRCs, the number of TSLPR+ ST2+ Tregs is negatively correlated with the number of Th1 cells. These findings suggested that TSLPR+ ST2+ Tregs play a pivotal role in progression of CRC through suppression of anti-tumor immunity in CRCs in human and mouse. Furthermore, to address the cure of CRC, we administrated mice with neutralization antibody for TSLP after development of colorectal tumors. Blockage of TSLP signaling reduced size and number of tumors via reduction of TSLPR+ ST2+ Tregs, indicating that neutralization of TSLP inhibits progression of CRCs. Taken together, and TSLP signaling on tumorigenic TSLPR+ ST2+ Treg can be good therapeutic targets for CRC.

B- and T-Cell-Intrinsic Regulation of Germinal Centers by Thymic Stromal Lymphopoietin Signaling

B- and T-Cell-Intrinsic Regulation of Germinal Centers by Thymic Stromal Lymphopoietin Signaling

Dupilumab and tezepelumab in severe refractory asthma: new opportunities.

Bronchial asthma is a chronic inflammatory condition with increasing prevalence worldwide that may present as heterogeneous phenotypes defined by the T2-mediated pattern of airway inflammation T2-high and T2-low asthma. Severe refractory asthma includes a subset of asthmatic patients who fail to control their disease despite maximal therapy and represent a group of patients needing marked resource utilization and hence may be eligible to add-on biological therapies. Among the new biologics, we focused our attention on two monoclonal antibodies: dupilumab, exerting a dual blockade of cytokine (interleukin (IL)-4 and IL-13) signaling; and tezepelumab, acting at a higher level preventing the binding of thymic stromal lymphopoietin (TSLP) to its receptor, thus blocking TSLP, IL-25, and IL-33 signaling, hence modulating airway T2 immune responses. With their different mechanisms of action, these two biologics represent important options to provide an enhanced personalized treatment regimen. Several clinical trials have been conducted testing the efficacy and safety of dupilumab in severe refractory asthmatic patients showing improvements in lung function, asthma control, and reducing exacerbations. Similar results were reported with tezepelumab that, differently from dupilumab, acts irrespectively on eosinophilic or non-eosinophilic phenotype. In this review, we provide an overview of the most important highlights regarding dupilumab and tezepelumab characteristics and mechanism of action with a critical review of the principal results of clinical (Phase II and III) studies concluded and those still in progress.

ASP7266, a Novel Antibody against Human Thymic Stromal Lymphopoietin Receptor for the Treatment of Allergic Diseases.

Thymic stromal lymphopoietin (TSLP), positioned at the top of the inflammatory cascade, is a key regulator that enhances allergic inflammatory responses by activating T helper type 2 cells, Group 2 innate lymphoid cells (ILC2), and myeloid dendritic cells (mDCs) via the TSLP receptor (TSLPR). We evaluated the inhibitory effects of ASP7266, a novel recombinant fully human IgG1 monoclonal antibody against TSLPR, on TSLP signaling and inflammation. The inhibitory effects of ASP7266 and the control antibody tezepelumab on TSLP and TSLPR interactions were investigated using a proliferation assay with TSLP stimulation and a chemokine production assay. The pharmacological effects of ASP7266 were investigated by examining differentiation of naive CD4+ T cells, ILC2 cytokine production, and ascaris extract-induced skin allergic reaction in cynomolgus monkeys. ASP7266 potently inhibited TSLP-induced cell proliferation and C-C motif chemokine ligand 17 production. Furthermore, ASP7266 inhibited TSLP-stimulated mDC-mediated naive CD4+ T-cell differentiation and interleukin 5 production by lineage-negative peripheral blood mononuclear cells, which can be considered ILC2 in vitro. In sensitized monkeys, ASP7266 completely suppressed ascaris extract-induced allergic skin reactions. Based on these results, ASP7266, a novel human therapeutic antibody against TSLPR, is a potential therapy for patients with allergic diseases. SIGNIFICANCE STATEMENT: TSLP, positioned at the top of the inflammatory cascade, plays a key role in various allergic diseases, including asthma, chronic rhinosinusitis with nasal polyposis, and atopic dermatitis. Here we show that the anti-TSLPR antibody ASP7266 exhibited excellent pharmacological activity in preclinical studies. Therefore, ASP7266 has the potential to be a promising treatment option for patients with allergic disorders.

Lignans from Machilus thunbergii as Thymic Stromal Lymphopoietin Inhibitors.

Thymic stromal lymphopoietin (TSLP) plays an important role in the pathophysiology of various allergic diseases that are mediated by T helper cell type-2 (Th2) responses, including asthma and atopic dermatitis. The primary focus of this study was the identification of potent inhibitors of the TSLP signaling pathway for potential therapeutic use. The 80% methanol extract of Machilus thunbergii bark significantly inhibited the signal transducer and activator of transcription 5 (STAT5) phosphorylation in human mast cell (HMC)-1 cells. Through activity-guided isolation, three lignans (1–3) were obtained and identified as (+)-galbelgin (1), meso-dihydroguaiaretic acid (2), and machilin A (3). Among them, two lignans (1 and 2) significantly inhibited STAT5 phosphorylation and TSLP/TSLPR interaction, as determined by ELISA. Our results indicated that lignans isolated from M. thunbergii are a promising resource for the treatment of allergic diseases.

Targeting TSLP-Induced Tyrosine Kinase Signaling Pathways in CRLF2-Rearranged Ph-like ALL.

Philadelphia (Ph)-like acute lymphoblastic leukemia (ALL) is characterized by aberrant activation of signaling pathways and high risk of relapse. Approximately 50% of Ph-like ALL cases overexpress cytokine receptor-like factor 2 (CRLF2) associated with gene rearrangement. Activated by its ligand thymic stromal lymphopoietin (TSLP), CRLF2 signaling is critical for the development, proliferation, and survival of normal lymphocytes. To examine activation of tyrosine kinases regulated by TSLP/CRLF2, phosphotyrosine (P-Tyr) profiling coupled with stable isotope labeling of amino acids in cell culture (SILAC) was conducted using two CRLF2-rearranged (CRLF2r) Ph-like ALL cell lines stimulated with TSLP. As a result, increased P-Tyr was detected in previously reported TSLP-activated tyrosine kinases and substrates, including JAK1, JAK2, STAT5, and ERK1/2. Interestingly, TSLP also increased P-Tyr of insulin growth factor 1 receptor (IGF1R) and fibroblast growth factor receptor 1 (FGFR1), both of which can be targeted with small-molecule inhibitors. Fixed-ratio combination cytotoxicity assays using the tyrosine kinase inhibitors BMS-754807 and ponatinib that target IGF1R and FGFR1, respectively, revealed strong synergy against both cell line and patient-derived xenograft (PDX) models of CRLF2r Ph-like ALL. Further analyses also indicated off-target effects of ponatinib in the synergy, and novel association of the Ras-associated protein-1 (Rap1) signaling pathway with TSLP signaling in CRLF2r Ph-like ALL. When tested in vivo, the BMS-754807/ponatinib combination exerted minimal efficacy against 2 Ph-like ALL PDXs, associated with low achievable plasma drug concentrations. Although this study identified potential new targets in CRLF2r Ph-like ALL, it also highlights that in vivo validation of synergistic drug interactions is essential. IMPLICATION: Quantitative phosphotyrosine profiling identified potential therapeutic targets for high-risk CRLF2-rearranged Ph-like ALL.

Modulation of Signaling Mediated by TSLP and IL-7 in Inflammation, Autoimmune Diseases, and Cancer.

Thymic Stromal Lymphopoietin (TSLP) and Interleukin-7 (IL-7) are widely studied cytokines within distinct branches of immunology. On one hand, TSLP is crucially important for mediating type 2 immunity at barrier surfaces and has been linked to widespread allergic and inflammatory diseases of the airways, skin, and gut. On the other hand, IL-7 operates at the foundations of T-cell and innate lymphoid cell (ILC) development and homeostasis and has been associated with cancer. Yet, TSLP and IL-7 are united by key commonalities in their structure and the structural basis of the receptor assemblies they mediate to initiate cellular signaling, in particular their cross-utilization of IL-7Rα. As therapeutic targeting of TSLP and IL-7 via diverse approaches is reaching advanced stages and in light of the plethora of mechanistic and structural data on receptor signaling mediated by the two cytokines, the time is ripe to provide integrated views of such knowledge. Here, we first discuss the major pathophysiological roles of TSLP and IL-7 in autoimmune diseases, inflammation and cancer. Subsequently, we curate structural and mechanistic knowledge about receptor assemblies mediated by the two cytokines. Finally, we review therapeutic avenues targeting TSLP and IL-7 signaling. We envision that such integrated view of the mechanism, structure, and modulation of signaling assemblies mediated by TSLP and IL-7 will enhance and fine-tune the development of more effective and selective approaches to further interrogate the role of TSLP and IL-7 in physiology and disease.

Overexpression of miR-142-5p inhibits the progression of nonalcoholic steatohepatitis by targeting TSLP and inhibiting JAK-STAT signaling pathway

This study aimed to figure out the underlying mechanism of miR-142-5p in the non-alcoholic steatohepatitis (NASH). Bioinformatics, luciferase assay and Western blot were performed. The NASH mouse model was established through feeding a high fat diet (HFD). Relative expressions of miR-142-5p, thymic stromal lymphopoietin (TSLP), inflammatory factors were detected by qRT-PCR. The injury level of liver was assessed via measurement of serum alanine aminotransferase (ALT) and serum aspartate aminotransferase (AST). H&E staining and Masson’s trichrome staining examine the liver fatty degeneration and fibrosis. MiR-142-5p and TSLP were differentially expressed and JAK-STAT signaling pathway was activated in the NASH group. Luciferase assay identified that TSLP was the downstream target of miR-142-5p. Through overexpression of miR-142-5p, ALT and AST in serum were inhibited, pro-inflammatory factors, liver fatty degeneration and fibrosis in liver tissues were decreased, while anti-inflammatory factors were increased. Overexpression of TSLP and JAK-STAT signaling pathway activation could reverse the effects of miR-142-5p on NASH. Taken together, overexpression of miR-142-5p could attenuate NASH progression via inhibiting TSLP and JAK-STAT pathway. MiR-142-5p might be a novel latent target for NASH therapy.

The role of Thymic Stromal Lymphopoietin (TSLP) in protection from Type II diabetes

Abstract Within the past 30 years, obesity and associated disorders such as Type II diabetes are rapidly becoming world-wide epidemics. Type II diabetes, caused by the loss of insulin sensitivity, accounts for $327 billion annually in the U.S. Recent studies have shown that the immune system plays a critical role in regulating the metabolic function of adipose tissue. Importantly, Type II diabetes is a disease of chronic low-grade inflammation, and adipose T regulatory cells (Tregs) can help maintain insulin sensitivity by suppressing the inflammation caused by monocytes, CD8 T, and Natural Killer (NK) cells. We have previously reported that topical application of the Vitamin D3 analog MC903 induces a two-fold increase in the proportion and absolute number of Tregs systemically. MC903 induces production of the cytokine Thymic Stromal Lymphopoietin (TSLP) from skin keratinocytes, and TSLP stimulates proliferation of Tregs through activation of dendritic cells. In a model of diet-induced Type II diabetes, we found that mice on high fat diet treated with MC903 compared to vehicle demonstrate improved metabolic parameters, including increased glucose tolerance and decreased insulin resistance, decreased fasting glucose and insulin, and lower liver triglycerides. Concordantly, treatment of mice with a TSLP-expressing adeno-associated virus also induced similar results, suggesting that TSLP is sufficient to improve insulin sensitivity. Importantly, there was a robust increase in Tregs and decrease in CD8 T cells and NK cells in the adipose of MC903 and TSLP-treated mice. Together, our results suggest that activation of TSLP signaling may be a therapeutic immunotarget for improving insulin sensitivity and preventing Type II diabetes.