Thymic stromal lymphopoietin (TSLP) inhibits human colon tumor growth by promoting apoptosis of tumor cells

TSLP enhances progestin response in endometrial cancer via androgen receptor signal pathway

BACKGROUND

The enriched proteins within in vitro fertilisation (IVF)-generated human embryonic microenvironment could reverse progestin resistance in endometrial cancer (EC).

METHODS

The expression of thymic stromal lymphopoietin (TSLP) in EC was evaluated by immunoblot and IHC analysis. Transcriptome sequencing screened out the downstream pathway regulated by TSLP. The role of TSLP, androgen receptor (AR) and KANK1 in regulating the sensitivity of EC to progestin was verified through a series of in vitro and in vivo experiments.

RESULTS

TSLP facilitates the formation of a BMP4/BMP7 heterodimer, resulting in activation of Smad5, augmenting AR signalling. AR in turn sensitises EC cells to progestin via KANK1. Downregulation of TSLP, loss of AR and KANK1 in EC patients are associated with tumour malignant progress. Moreover, exogenous TSLP could rescue the anti-tumour effect of progestin on mouse in vivo xenograft tumour.

CONCLUSIONS

Our findings suggest that TSLP enhances the sensitivity of EC to progestin through the BMP4/Smad5/AR/KANK1 axis, and provide a link between embryo development and cancer progress, paving the way for the establishment of novel strategy overcoming progestin resistance using embryo original factors.

Thymic stromal lymphopoietin (TSLP) is a substrate for tryptase in patients with mastocytosis

Mastocytosis is a heterogeneous disease associated to uncontrolled proliferation and increased density of mast cells in different organs. This clonal disorder is related to gain-of-function pathogenic variants of the c-kit gene that encodes for KIT (CD117) expressed on mast cell membrane. Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine, which plays a key role in allergic disorders and several cancers. TSLP is a survival and activating factor for human mast cells through the engagement of the TSLP receptor. Activated human mast cells release several preformed mediators, including tryptase. Increased mast cell-derived tryptase is a diagnostic biomarker of mastocytosis. In this study, we found that in these patients serum concentrations of TSLP were lower than healthy donors. There was an inverse correlation between TSLP and tryptase concentrations in mastocytosis. Incubation of human recombinant TSLP with sera from patients with mastocytosis, containing increasing concentrations of tryptase, concentration-dependently decreased TSLP immunoreactivity. Similarly, recombinant β-tryptase reduced the immunoreactivity of recombinant TSLP, inducing the formation of a cleavage product of approximately 10 kDa. Collectively, these results indicate that TSLP is a substrate for human mast cell tryptase and highlight a novel loop involving these mediators in mastocytosis.

Integration analysis using bioinformatics and experimental validation on the clinical and biological significance of TSLP in cancers

Thymic stromal lymphopoietin (TSLP) has significantly impacted the development and progression of various neoplastic disorders. To comprehensively evaluate the diverse significance of TSLP in malignant tumors, we first integrative analyze the TSLP expression level in paired and unpaired pan-cancer tissue and cell line, compared against the normal tissue. The correlation between TSLP expression, molecular subtypes, immune subtypes, diagnostic value, and prognostic value in pan-cancer was also investigated. We then explored the impact of TSLP expression on multifaced immune cell infiltration and subsequent clinical outcomes in lung adenocarcinoma (LUAD) patients. and conducted cellular experiments to functionally examine the effect of TSLP on cell proliferation, apoptosis, cell cycle, migration, and invasion in LUAD. The anti-neoplastic mechanism of TSLP was further investigated by qRT-PCR and western blotting. Our findings reveal that TSLP expression is abnormally low in various cancers compared to normal tissue and is associated with different molecular and immune subtypes of cancers. Moreover, ROC and survival analysis results suggest that TSLP expression is correlated with the diagnostic, prognostic, clinical features, and immune cells of LUAD patients. Cell experiments showed that overexpression of TSLP elicited a significant reduction in LUAD cell viability, promoted cell apoptosis, impeded cell cycle progression in the G2/M phase, and inhibited cell migration and invasion. In addition, TSLP inhibited LUAD progression through the JAK1/STAT3 signaling pathway. Therefore, targeting TSLP shows potential as a therapeutic strategy for pan-cancer, particularly for LUAD, and as a biomarker for predicting the prognosis of this malignancy.

EFFECT OF ANTI-TSLPR MONOCLONAL ANTIBODY ON VIABILITY, PROAPOPTOTIC GENES EXPRESSION, AND PRODUCTION OF PRO-INFLAMMATORY CYTOKINES IN MCF-7 AND A549 CELLS

BACKGROUND

Thymic stromal lymphopoietin (TSLP) and its receptor (TSLPR) are expressed in various cancer cells. However, their role in cancer development is not well defined.

AIM

To investigate the effects of anti-TSLPR antibody on the viability, proapoptotic genes expression, and production of pro-inflammatory cytokines in MCF-7 and A549 cancer cells.

MATERIALS AND METHODS

MCF-7 and A549 cells were exposed to anti-TSLPR monoclonal antibody for 24, 48, and 72 h. The effect on cell viability was examined by MTT assay. The expression levels of TP53, BAX, and CASP3 genes were evaluated by the quantitative reverse transcription polymerase chain reaction (qRT-PCR). Levels of interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), and transforming growth factor (TGF-β1) were measured by the enzyme-linked immunosorbent assay (ELISA).

RESULTS

The treatment of MCF-7 cells with anti- TSLPR antibody slightly stimulates cell proliferation after 48 h and 72 h following initial cytotoxicity in 24 h with a significant reduction in IL-6 and TNF-α production. A significant increase in the BAX expression in anti-TSLPR treated cells at a concentration of 2.5 μg/ml at 24-h point was evident. In anti-TSLPR-treated A549 cells, no decrease in cell count was observed, and slight dose-dependent stimulation of cell proliferation was evident in 48 h and 72 h of culture. A significant increase in TP53, BAX, and CASP3 expression upon treatment with 2.5 μg/ml of anti-TSLPR was evident in A549 cells.

CONCLUSION

The effects of anti-TSLPR on cell viability, proapoptotic gene expression, and production of pro-inflammatory cytokines (IL-6 and TNF-α) vary in MCF-7 and A549 cells.

Attenuated Dengue virus PV001-DV induces oncolytic tumor cell death and potent immune responses

BACKGROUND

Viral therapies developed for cancer treatment have classically prioritized direct oncolytic effects over their immune activating properties. However, recent clinical insights have challenged this longstanding prioritization and have shifted the focus to more immune-based mechanisms. Through the potential utilization of novel, inherently immune-stimulating, oncotropic viruses there is a therapeutic opportunity to improve anti-tumor outcomes through virus-mediated immune activation. PV001-DV is an attenuated strain of Dengue virus (DEN-1 #45AZ5) with a favorable clinical safety profile that also maintains the potent immune stimulatory properties characterstic of Dengue virus infection.

METHODS

In this study, we utilized in vitro tumor killing and immune multiplex assays to examine the anti-tumor effects of PV001-DV as a potential novel cancer immunotherapy.

RESULTS

In vitro assays demonstrated that PV001-DV possesses the ability to directly kill human melanoma cells lines as well as patient melanoma tissue ex vivo. Importantly, further work demonstrated that, when patient peripheral blood mononuclear cells (PBMCs) were exposed to PV001-DV, a substantial induction in the production of apoptotic factors and immunostimulatory cytokines was detected. When tumor cells were cultured with the resulting soluble mediators from these PBMCs, rapid cell death of melanoma and breast cancer cell lines was observed. These soluble mediators also increased dengue virus binding ligands and immune checkpoint receptor, PD-L1 expression.

CONCLUSIONS

The direct in vitro tumor-killing and immune-mediated tumor cytotoxicity facilitated by PV001-DV contributes support of its upcoming clinical evaluation in patients with advanced melanoma who have failed prior therapy.

Association between C-reactive protein-albumin-lymphocyte (CALLY) index and overall survival in patients with colorectal cancer: From the investigation on nutrition status and clinical outcome of common cancers study

Background

Colorectal cancer (CRC) is among the most common malignant cancers worldwide, and its development is influenced by inflammation, nutrition, and the immune status. Therefore, we combined C-reactive protein (CRP), albumin, and lymphocyte, which could reflect above status, to be the CRP-albumin-lymphocyte (CALLY) index, and evaluated its association with overall survival (OS) in patients with CRC.

Methods

The clinicopathological and laboratory characteristics of 1260 patients with CRC were collected from the Investigation on Nutrition Status and Clinical Outcome of Common Cancers (INSCOC) study. Cox regression analysis was performed to assess the association between the CALLY index and OS. A nomogram including sex, age, the CALLY index and TNM stage was constructed. The Concordance Index (C-index) was utilized to evaluate the prognostic value of the CALLY index and classical CRC prognostic factors, such as modified Glasgow prognostic score (mGPS), neutrocyte to lymphocyte ratio (NLR), systemic immune inflammation index (SII), and platelet to lymphocyte ratio (PLR), as well as to assess the prognostic value of the nomogram and TNM stage.

Results

Multivariate Cox regression analyses demonstrated that the CALLY index was independently associated with OS in patients with CRC [Hazard ratio (HR) = 0.91, 95% confidence interval (CI) = 0.87-0.95, P<0.001]. The CALLY index showed the highest prognostic value (C-index = 0.666, 95% CI = 0.638-0.694, P<0.001), followed by mGPS, NLR, SII, and PLR. The nomogram demonstrated higher prognostic value (C-index = 0.784, 95% CI = 0.762-0.807, P<0.001) than the TNM stage.

Conclusion

The CALLY index was independently associated with OS in patients with CRC and showed higher prognostic value than classical CRC prognostic factors. The nomogram could provide more accurate prognostic prediction than TNM stage.

Development of an inhaled anti-TSLP therapy for asthma

Thymic stromal lymphopoietin (TSLP), an epithelial cell-derived cytokine, acts as a key mediator in airway inflammation and modulates the function of multiple cell types, including dendritic cells and group 2 innate lymphoid cells. TSLP plays a role in asthma pathogenesis as an upstream cytokine, and data suggest that TSLP blockade with the anti-TSLP monoclonal antibody, tezepelumab, could be efficacious in a broad asthma population. Currently approved asthma biologic therapies target allergic or eosinophilic disease and require phenotyping; therefore, an unmet need exists for a therapy that can address Type 2 (T2)-high and T2-low inflammation in asthma. All currently approved biologic treatments are delivered intravenously or subcutaneously; an inhaled therapy route that allows direct targeting of the lung with reduced systemic impact may offer advantages. Currently in development, ecleralimab (CSJ117) represents the first inhaled anti-TSLP antibody fragment that binds soluble TSLP and prevents TSLP receptor activation, thereby inhibiting further inflammatory signalling cascades. This anti-TSLP antibody fragment is being developed for patients with severe uncontrolled asthma despite standard of care inhaled therapy. A Phase IIa proof of concept study, using allergen bronchoprovocation as a model for asthma exacerbations, found that ecleralimab was well-tolerated and reduced allergen-induced bronchoconstriction in adult patients with mild asthma. These results suggest ecleralimab may be a promising, new therapeutic class for asthma treatment.

The Controversial Role of Intestinal Mast Cells in Colon Cancer

Mast cells are tissue-resident sentinels involved in large number of physiological and pathological processes, such as infection and allergic response, thanks to the expression of a wide array of receptors. Mast cells are also frequently observed in a tumor microenvironment, suggesting their contribution in the transition from chronic inflammation to cancer. In particular, the link between inflammation and colorectal cancer development is becoming increasingly clear. It has long been recognized that patients with inflammatory bowel disease have an increased risk of developing colon cancer. Evidence from experimental animals also implicates the innate immune system in the development of sporadically occurring intestinal adenomas, the precursors to colorectal cancer. However, the exact role of mast cells in tumor initiation and growth remains controversial: mast cell-derived mediators can either exert pro-tumorigenic functions, causing the progression and spread of the tumor, or anti-tumorigenic functions, limiting the tumor's growth. Here, we review the multifaceted and often contrasting findings regarding the role of the intestinal mast cells in colon cancer progression focusing on the molecular pathways mainly involved in the regulation of mast cell plasticity/functions during tumor progression.

Role of thymic stromal lymphopoietin in allergy and beyond

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine that acts on multiple cell lineages, including dendritic cells, T cells, B cells, neutrophils, mast cells, eosinophils and innate lymphoid cells, affecting their maturation, survival and recruitment. It is best known for its role in promoting type 2 immune responses such as in allergic diseases and, in 2021, a monoclonal antibody targeting TSLP was approved for the treatment of severe asthma. However, it is now clear that TSLP has many other important roles in a variety of settings. Indeed, several genetic variants for TSLP are linked to disease severity, and chromosomal alterations in TSLP are common in certain cancers, indicating important roles of TSLP in disease. In this Review, we discuss recent advances in TSLP biology, highlighting how it regulates the tissue environment not only in allergic disease but also in infectious diseases, inflammatory diseases and cancer. Encouragingly, therapies targeting the TSLP pathway are being actively pursued for several diseases.

TSLP as a Potential Therapy in the Treatment of CRLF2 B Cell Acute Lymphoblastic Leukemia

Cytokine receptor-like factor 2 B-cell acute lymphoblastic leukemia (CRLF2 B-ALL) is a high-risk subtype characterized by CRLF2 overexpression with poor survival rates in children and adults. CRLF2 and interleukin-7 receptor alpha (IL-7Rα) form a receptor for the cytokine thymic stromal lymphopoietin (TSLP), which induces JAK/STAT and PI3K/AKT/mTOR pathway signals. Previous studies from our group showed that low TSLP doses increased STAT5, AKT, and S6 phosphorylation and contributed to CRLF2 B-ALL cell survival. Here we investigated the role of TSLP in the survival and proliferation of CRLF2 B-ALL cells in vitro and in vivo. We hypothesized that high doses of TSLP increase CRLF2 signals and contribute to increased proliferation of CRLF2 B-ALL cells in vitro and in vivo. Interestingly, we observed the opposite effect. Specifically, high doses of TSLP induced apoptosis in human CRLF2 B-ALL cell lines in vitro, prevented engraftment of CRLF2 B-ALL cells, and prolonged the survival of +TSLP patient-derived-xenograft mice. Mechanistically, we showed that high doses of TSLP induced loss of its receptor and loss of CRLF2 signals in vitro. These results suggest that high doses of TSLP could be further investigated as a potential therapy for the treatment of CRLF2 B-ALL.

Emerging role for thymic stromal lymphopoietin-responsive regulatory T cells in colorectal cancer progression in humans and mice

Recruitment of regulatory T cells (T_regs) to tumors is a hallmark of cancer progression. Tumor-derived factors, such as the cytokine thymic stromal lymphopoietin (TSLP), can influence T_reg function in tumors. In our study, we identified a subset of T_regs expressing the receptor for TSLP (TSLPR⁺ T_regs) that were increased in colorectal tumors in humans and mice and largely absent in adjacent normal colon. This T_reg subset was also found in the peripheral blood of patients with colon cancer but not in the peripheral blood of healthy control subjects. Mechanistically, we found that this T_reg subset coexpressed the interleukin-33 (IL-33) receptor [suppressor of tumorigenicity 2 (ST2)] and had high programmed cell death 1 (PD-1) and cytotoxic lymphocyte-associated antigen 4 (CTLA-4) expression, regulated in part by the transcription factor Mef2c. T_reg-specific deletion of TSLPR, but not ST2, was associated with a reduction in tumor number and size with concomitant increase in T_H1 cells in tumors in chemically induced mouse models of colorectal cancer. Therapeutic blockade of TSLP using TSLP-specific monoclonal antibodies effectively inhibited the progression of colorectal tumors in this mouse model. Collectively, these data suggest that TSLP controls the progression of colorectal cancer through regulation of tumor-specific T_reg function and represents a potential therapeutic target that requires further investigation.

AllergoOncology: Role of immune cells and immune proteins

Background

Immune cells and immune proteins play a pivotal role in host responses to pathogens, allergens and cancer. Understanding the crosstalk between allergic response and cancer, immune surveillance, immunomodulation, role of immunoglobulin E (IgE)‐mediated functions and help to develop novel therapeutic strategies. Allergy and oncology show two opposite scenarios: whereas immune tolerance is desired in allergy, it is detrimental in cancer.

Aim

The current review provides an update on the role of immune cells and immune proteins in allergy and cancer fields.

Methods

Authors investigated the role of relevant immunological markers and the correlation with cancer progression or cancer suppression.

Results

Activated immune cells such as macrophages ‘M1’, dendritic cells (DCs), innate lymphoid cells (ILC2), NK cells, Th1, follicular T helper cells (TFH), TCD8+, B lymphocytes and eosinophils have inhibitory effects on tumourigenesis, while tolerogenic cells such as macrophages ‘M2,’ tolerogenic DCs, ILC3, T and B regulatory lymphocytes appear to favour carcinogenesis. Mastocytes and alarmins can have both effects. RIgE antibodies and CCCL5 chemokine have an anticancer role, whereas IgG4, free light chains, Il‐10, TGF‐β, lipocalin‐2, CCL1 chemokine promote cancer progression. Fundamental is also the contribution of epigenetic changes regulated by the microRNA in cancer progression.

Conclusion

This knowledge represents the key to developing new anticancer therapies.

Targeting the Epithelium-Derived Innate Cytokines: From Bench to Bedside

When epithelial cells are exposed to potentially threatening external stimuli such as allergens, bacteria, viruses, and helminths, they instantly produce "alarmin" cytokines, namely, IL-33, IL-25, and TSLP. These alarmins alert the immune system about these threats, thereby mobilizing host immune defense mechanisms. Specifically, the alarmins strongly stimulate type-2 immune cells, including eosinophils, mast cells, dendritic cells, type-2 helper T cells, and type-2 innate lymphoid cells. Given that the alarm-raising role of IL-33, IL-25, and TSLP was first detected in allergic and infectious diseases, most studies on alarmins focus on their role in these diseases. However, recent studies suggest that alarmins also have a broad range of effector functions in other pathological conditions, including psoriasis, multiple sclerosis, and cancer. Therefore, this review provides an update on the epithelium-derived cytokines in both allergic and non-allergic diseases. We also review the progress of clinical trials on biological agents that target the alarmins and discuss the therapeutic potential of these agents in non-allergic diseases.

GPC2 deficiency inhibits cell growth and metastasis in colon adenocarcinoma

Glypican-2 (GPC2) has been reported to promote tumor progression through metabolic pathways. However, the role of GPC2 in colon adenocarcinoma (COAD) remains to be further investigated. This study was designed to evaluate the role of GPC2 in COAD. Based on patients with complete clinical information and GPC2 expression from the Cancer Genome Atlas-COAD database, we found that GPC2 mRNA was highly expressed in COAD tissues, which was associated with poor prognosis and tumornode-metastasis (TNM) stage. The predicted survival probability based on GPC2 mRNA expression and TNM stage was in good agreement with the observed survival probability. Furthermore, the genes coexpressed with GPC2 in COAD tissues were significantly enriched in basal cell carcinoma, Notch signaling pathway, and Hedgehog signaling pathway. After GPC2 was decreased through transfecting short hairpin RNA of GPC2 into HCT-8 and SW620 cells, cell cycle was arrested in G0/G1 phase, proliferation was decreased, apoptosis was increased, and migration and invasion were repressed. In conclusion, decreasing GPC2 significantly inhibited proliferation, migration, and invasion, and enhanced apoptosis, which implied that GPC2 can be considered a promising therapeutic target of COAD in the future.

The correlation between single nucleotide polymorphisms of the thymic stromal lymphopoietin receptor and breast cancer in a cohort of female patients in Saudi Arabia

The current study aimed to examine thymic stromal lymphopoietin receptor (TSLPR) genetic variation and breast cancer (BC) susceptibility in women in Saudi Arabia. Therefore, 127 blood samples from female patients diagnosed with BC and 116 blood samples from healthy female controls were studied using a genotyping assay to determine the association between three TSLPR single nucleotide polymorphisms (SNPs)-P196L, X201W, and A238V-and the risk of BC progression. In addition, gene expression was evaluated in 20 matching BC and normal tissues using immunohistochemistry. TSLPR protein levels were higher among BC patients than those with matching normal breast tissue. In addition, TSLPR SNP P196L was found to have a significant protective effect on BC progression (OR = 0.4427), although only the T allele for TSLPR P196L had this protective effect against BC progression in participants who were younger than 48 years old. In contrast, no association was found between the T allele and risk of BC in participants who were older than 48 years old, and the CT and TT genotypes were significantly associated with BC risk protection in the older group. The effects of the TT genotype and the T allele were closely associated with a decreased risk of BC in participants with estrogen receptors (ER+) and without them (ER-). Overall, the findings revealed a significant correlation between SNPs in the TSLPR genes and BC progression among women in Saudi Arabia.

Human Lung-Resident Macrophages Express and Are Targets of Thymic Stromal Lymphopoietin in the Tumor Microenvironment

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine highly expressed by epithelial cells and several innate and adaptive immune cells. TSLP exerts its biological effects by binding to a heterodimeric complex composed of TSLP receptor (TSLPR) and IL-7Rα. In humans, there are two TSLP isoforms: the short form (sfTSLP), constitutively expressed, and the long form (lfTSLP), which is upregulated in inflammation. TSLP has been implicated in the induction and progression of several experimental and human cancers. Primary human lung macrophages (HLMs), monocyte-derived macrophages (MDMs), and peripheral blood monocytes consitutively expressed sfTSLP mRNA. Incubation of HLMs, MDMs, and monocytes with lipopolysaccharide (LPS) or IL-4, but not with IL-13, induced TSLP release from HLMs. LPS, but not IL-4 or IL-13, induced CXCL8 release from HLMs. LPS, IL-4 alone or in combination with IL-13, induced the expression of lfTSLP, but not of sfTSLP from HLMs. Preincubation of HLMs with IL-4, alone or in combination with IL-13, but not IL-13 alone, synergistically enhanced TSLP release from LPS-activated macrophages. By contrast, IL-4, alone or in combination with IL-13, inhibited LPS-induced CXCL8 release from HLMs. Immunoreactive TSLP was detected in lysates of HLMs, MDMs, and monocytes. Incubation of HLMs with TSLP induced the release of proinflammatory (TNF-α), angiogenic (VEGF-A, angiopoietin 2), and lymphangiogenic (VEGF-C) factors. TSLP, TSLPR, and IL-7Rα were expressed in intratumoral and peritumoral areas of human lung cancer. sfTSLP and lfTSLP mRNAs were differentially expressed in peritumoral and intratumoral lung cancer tissues. The TSLP system, expressed in HLMs, MDMs, and monocytes, could play a role in chronic inflammatory disorders including lung cancer.

Data Driven Mathematical Model of Colon Cancer Progression

Every colon cancer has its own unique characteristics, and therefore may respond differently to identical treatments. Here, we develop a data driven mathematical model for the interaction network of key components of immune microenvironment in colon cancer. We estimate the relative abundance of each immune cell from gene expression profiles of tumors, and group patients based on their immune patterns. Then we compare the tumor sensitivity and progression in each of these groups of patients, and observe differences in the patterns of tumor growth between the groups. For instance, in tumors with a smaller density of naive macrophages than activated macrophages, a higher activation rate of macrophages leads to an increase in cancer cell density, demonstrating a negative effect of macrophages. Other tumors however, exhibit an opposite trend, showing a positive effect of macrophages in controlling tumor size. Although the results indicate that for all patients the size of the tumor is sensitive to the parameters related to macrophages, such as their activation and death rate, this research demonstrates that no single biomarker could predict the dynamics of tumors.

Thymic Stromal Lymphopoietin and Cancer: Th2-Dependent and -Independent Mechanisms

The thymic stromal lymphopoietin (TSLP) is an IL-7-like cytokine originally cloned from a murine thymic stromal cell line, and subsequently a human homolog was identified using database search methods. Human TSLP is mostly expressed in epithelial cells, among which are keratinocytes as well as stromal cells such as fibroblasts and immune cells. Human TSLP was first described to activate myeloid dendritic cells, which prime naïve T helper cells to produce high concentrations of Th2 cytokines, thus representing a key cytokine in triggering dendritic cells-mediated allergic Th2 inflammation. TSLP and/or its receptor has been shown to be expressed in several tumor types, where TSLP expression is associated with functional activities that can be associated or not with the induction of a Th2-prone tumor microenvironment, i.e., Th2-dependent and Th2-independent mechanisms. These mechanisms involve tissue- and immune cell target-dependent tumor-promoting or tumor-suppressive functions in different or even the same tumor type. Here we report and discuss the Th2-dependent and Th2-independent roles of TSLP in cancer and possible therapeutic targeting.

Yupingfeng Granule Improves Th2-Biased Immune State in Microenvironment of Hepatocellular Carcinoma through TSLP-DC-OX40L Pathway

The tumor immunological microenvironment in hepatocellular carcinoma (HCC) is the T-helper (Th) 2 dominant inhibition state. Improving the immunosuppressive tumor microenvironment represents an important strategy for HCC treatment. TSLP-OX40L pathway is a target to improve Th2 immunosuppression. Yupingfeng granule (YPF) is clinically used to effectively improve the immune status of HCC. In this study, YPF increased the percentage of mature dendritic cells (DCs) and decreased levels of TSLP, TSLPR, and OX40L in tumor and adjacent tissues of the orthotopic-HCC mice model. This occurs together with the decreased levels of Th2 cytokines and increased levels of Th1 cytokines and Th1/Th2 ratio. In vitro experiment showed that YPF not only increased the percentage of mature DCs and stimulated IL-12 secretion in DCs but also reduced the positive rate of OX40L expression, decreased the proportion of CD4⁺ IL-13⁺ T cells, increased levels of Th1 cytokines, and decreased levels of Th2 cytokines from TSLP-treated DCs. In summary, these findings demonstrated that YPF promoted the maturation of DCs, decreased OX40L in TSLP-induced DCs, and improved the immunosuppressive state of Th2 in HCC microenvironment. Our results suggest that the mechanism underlying the improving effect of YPF on the immunosuppression is related to the DC-mediated TSLP-OX40L pathway.

Tezepelumab: a novel biological therapy for the treatment of severe uncontrolled asthma

Introduction: Thymic stromal lymphopoietin (TSLP) is overexpressed in the airways of severe asthmatics and is an upstream cytokine that orchestrates inflammatory responses in asthma. TSLP exerts its effects by binding to a high affinity heteromeric receptor complex composed of TSLPR and IL-7Rα. An association of polymorphisms in TSLP with airway hyperresponsiveness, IgE, eosinophilia and asthma has been documented. TSLP has been implicated in asthma pathophysiology. Tezepelumab is a first-in-class human monoclonal antibody that binds to TSLP, thus inhibiting its interaction with TSLP receptor complex. Tezepelumab given as an add-on-therapy to patients with severe uncontrolled asthma has shown safety, tolerability and efficacy. Several trials are evaluating the long-term safety and the efficacy of tezepelumab in adults and adolescents with severe uncontrolled asthma.Areas covered: We provide an overview of the monoclonal antibody therapeutics market for severe uncontrolled asthma, examine the underlying pathophysiology that drives TSLP and discuss the use of tezepelumab for the treatment of severe uncontrolled asthma,Expert opinion: TSLP is a promising target for T2-high and perhaps some patients with T2-low asthma. The results of preliminary clinical trials are encouraging. Several unanswered questions concerning basic pathophysiological aspects of TSLP variants, the long-term safety and efficacy of tezepelumab with different phenotypes/endotypes of asthma should be addressed.

Expression and allele frequencies of Thymic stromal lymphopoietin are a key factor of breast cancer risk

Background

Thymic stromal Lymphopoeitin (TSLP) is a key cytokine involved in inflammation and cancer progression. TSLP gene polymorphisms have been associated with increased susceptibility to cancer progression in different organs. We performed a control case study to examine the correlation of expression and polymorphisms of three nucleotides in TSLP with breast cancer (BC) risk in Saudi Arabian females.

Materials and methods

The study was conducted on 116 healthy control subjects and 127 female patients with BC for the purpose of genotyping. Ten matching tissues provided data on immunohistochemistry to evaluate TSLP expression. Three SNPs (rs10043985, rs2289276, and rs3806933) were genotyped with TaqMan allelic discrimination assay. The patients' ages and estrogen receptor statuses were used to investigate the potential correlations between the different variations of TSLP genotypes and BC risk.

Results

BC tissues expressed positive immuno‐staining for TSLP at a high rate compared to normal matching breast tissues. Malignant breast tumors exhibited higher TSLP expression than benign breast tumors. We also found that the rs3806933 (T) allele frequency decreased the risk of developing BC in the study population (OR = 0.356, p = 0.00027) significantly (0.356 times). Interestingly, statistical analysis revealed that the genotype mutant (AC) and the allele mutant (C) of rs10043985 within TSLP were significantly correlated with an increased BC risk (odds ratio [OR] = 4.762, confidence interval [CI] = 1.000–22.666, p = 0.03244; OR = 4.762, CI = 1.000–22.666, p = 0.03244; and OR = 4.575, CI = 0.975–21.464, p = 0.03516, respectively). In addition, the AC and AC + CC genotypes of TSLP rs10043985 were confirmed to be associated with an increased risk of BC risk in women aged above 48 years, compared with the AA genotype (AC and AC + CC vs. AA: OR = 9.468, CI = 0.493–181.768, p = 0.04537).

Conclusion

The results reveal significant correlation between SNPs in TSLP and BC progression in Saudi Arabian female patients.

Thymic stromal lymphopoietin in human pancreatic ductal adenocarcinoma: expression and prognostic significance

Thymic stromal lymphopoietin (TSLP) has emerged as an important, but contradictory, player conditioning tumor growth. In certain contexts, by driving T helper (h) 2 responses via tumor-associated OX40 Ligand (OX40L)⁺ dendritic cells (DCs), TSLP may play a pro-tumorigenic role. The study elucidates the importance of TSPL in pancreatic ductal adenocarcinoma (PDAC), by analyzing: i) TSLP levels in PDAC cell-line supernatants and plasma from patients with locally-advanced/metastatic PDAC, pre- and post-treatment with different chemotherapeutic protocols, in comparison with healthy donors; ii) TSLP and OX40L expression in PDAC and normal pancreatic tissues, by immunohistochemistry; iii) OX40L expression on ex vivo-generated normal DCs in the presence of tumor-derived TSLP, by flow cytometry; iv) clinical relevance in terms of diagnostic and prognostic value and influence on treatment modality and response.

Some PDAC cell lines, such as BxPC-3, expressed both TSLP mRNA and protein. Normal DCs, generated ex vivo in the presence of TSLP-rich-cell supernatants, displayed increased expression of OX40L, reduced by the addition of a neutralizing anti-TSLP polyclonal antibody. OX40L⁺ cells were detected in pancreatic tumor inflammatory infiltrates. Abnormally elevated TSLP levels were detected in situ in tumor cells and, systemically, in locally-advanced/metastatic PDAC patients. Of the chemotherapeutic protocols applied, gemcitabine plus oxaliplatin (GEMOX) significantly increased circulating TSLP levels. Elevated plasma TSLP concentration was associated with shorter overall survival and increased risk of poor outcome. Plasma TSLP measurement successfully discriminated PDAC patients from healthy controls.

These data show that TSLP secreted by pancreatic cancer cells may directly impact PDAC biology and patient outcome.

Thymic Stromal Lymphopoietin Isoforms, Inflammatory Disorders, and Cancer

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine originally isolated from a murine thymic stromal cell line. TSLP exerts its biological effects by binding to a high-affinity heteromeric complex composed of thymic stromal lymphopoietin receptor chain and IL-7Rα. TSLP is primarily expressed by activated lung and intestinal epithelial cells, keratinocytes, and fibroblasts. However, dendritic cells (DCs), mast cells, and presumably other immune cells can also produce TSLP. Different groups of investigators have demonstrated the existence of two variants for TSLP in human tissues: the main isoform expressed in steady state is the short form (sf TSLP), which plays a homeostatic role, whereas the long form (lfTSLP) is upregulated in inflammatory conditions. In addition, there is evidence that in pathological conditions, TSLP can be cleaved by several endogenous proteases. Several cellular targets for TSLP have been identified, including immune (DCs, ILC2, T and B cells, NKT and Treg cells, eosinophils, neutrophils, basophils, monocytes, mast cells, and macrophages) and non-immune cells (platelets and sensory neurons). TSLP has been originally implicated in a variety of allergic diseases (e.g., atopic dermatitis, bronchial asthma, eosinophilic esophagitis). Emerging evidence indicates that TSLP is also involved in chronic inflammatory (i.e., chronic obstructive pulmonary disease and celiac disease) and autoimmune (e.g., psoriasis, rheumatoid arthritis) disorders and several cancers. These emerging observations greatly widen the role of TSLP in different human diseases. Most of these studies have not used tools to analyze the expression of the two TSLP isoforms. The broad pathophysiologic profile of TSLP has motivated therapeutic targeting of this cytokine. Tezepelumab is a first-in-class human monoclonal antibody (1) that binds to TSLP inhibiting its interaction with TSLP receptor complex. Tezepelumab given as an add-on-therapy to patients with severe uncontrolled asthma has shown safety and efficacy. Several clinical trials are evaluating the safety and the efficacy of tezepelumab in different inflammatory disorders. Monoclonal antibodies used to neutralize TSLP should not interact or hamper the homeostatic effects of sf TSLP.

Expression and Regulation of Thymic Stromal Lymphopoietin and Thymic Stromal Lymphopoietin Receptor Heterocomplex in the Innate-Adaptive Immunity of Pediatric Asthma

Asthma is a chronic inflammatory disease affecting the airway, and it is characterized by a wheezing breathing sound, variable airflow obstruction and the presence of inflammatory cells in the submucosa of the bronchi. Viral infection, pollutants and sensitivity to aeroallergens damage the epithelium from childhood, which causes asthma. The pathogenesis of asthma includes pathways of innate stimulation by environmental microbes and irritant pathogens. Damaged epithelial cells produce thymic stromal lymphopoietin (TSLP) and stimulate myeloid dendritic cell maturation through the thymic stromal lymphopoietin receptor (TSLPR) heterocomplex. TSLP-activated myeloid dendritic cells promote naive CD4⁺ T cells to differentiate into T helper type 2 (Th2) phenotype CD4⁺ T cells. Re-exposure to allergens or environmental stimuli causes an adaptive immune response. TSLP-activated dendritic cells expressing the OX40 ligand (OX40L; CD252) trigger naive CD4⁺ T cells to differentiate into inflammatory Th2 effector cells secreting the cytokines interleukin-4, 5, 9, and 13 (IL-4, IL-5, IL-9 and IL-13), and the dendritic cells (DCs) promote the proliferation of allergen-specific Th2 memory cells. Allergen presentation by Th2 cells through its interaction with their receptors in the presence of major histocompatibility complex (MHC) class II on B cells and through costimulation involving CD40 and CD40L interactions results in immunoglobulin class switching from IgM to IgE. DCs and other blood cell subsets express the TSLPR heterocomplex. The regulatory mechanism of the TSLPR heterocomplex on these different cell subsets remains unclear. The TSLPR heterocomplex is composed of the IL-7Rα chain and TSLPR chain. Moreover, two isoforms of TSLP, short isoform TSLP (sfTSLP) and long isoform TSLP (lfTSLP), have roles in atopic and allergic development. Identifying and clarifying the regulation of TSLPR and IL-7Rα in pediatric asthma are still difficult, because the type of blood cell and the expression for each blood cell in different stages of atopic diseases are poorly understood. We believe that further integrated assessments of the regulation mechanism of the TSLP–TSLPR heterocomplex axis in vitro and in vivo can provide a faster and earlier diagnosis of pediatric asthma and promote the development of more effective preventive strategies at the onset of allergies.

A tumor-myeloid cell axis, mediated via the cytokines IL-1α and TSLP, promotes the progression of breast cancer

Tumors actively manipulate the immune response through the production of factors that attract immune cells and subsequently alter their ability to recognize and effectively remove the tumor. While this immune evasion mechanism is an important aspect of tumor survival, the factors that serve as primary growth factors for the tumor are less understood. Here, we demonstrated a novel mechanism by which breast cancer cells manipulate tumor-infiltrating myeloid cells to maintain their survival. Tumor-derived interleukin 1α (IL-1α), acting on infiltrating myeloid cells, induced the expression of a critical tumor survival factor, the cytokine thymic stromal lymphopoietin (TSLP). TSLP promoted the survival of the tumor cells through induction of Bcl-2 expression. TSLP signaling was also required for metastasis to the lung. These studies define a novel IL-1α–TSLP-mediated crosstalk between tumor-infiltrating myeloid cells and tumor cells in the control of metastatic breast cancer.

AllergoOncology - the impact of allergy in oncology: EAACI position paper

Th2 immunity and allergic immune surveillance play critical roles in host responses to pathogens, parasites and allergens. Numerous studies have reported significant links between Th2 responses and cancer, including insights into the functions of IgE antibodies and associated effector cells in both antitumour immune surveillance and therapy. The interdisciplinary field of AllergoOncology was given Task Force status by the European Academy of Allergy and Clinical Immunology in 2014. Affiliated expert groups focus on the interface between allergic responses and cancer, applied to immune surveillance, immunomodulation and the functions of IgE-mediated immune responses against cancer, to derive novel insights into more effective treatments. Coincident with rapid expansion in clinical application of cancer immunotherapies, here we review the current state-of-the-art and future translational opportunities, as well as challenges in this relatively new field. Recent developments include improved understanding of Th2 antibodies, intratumoral innate allergy effector cells and mediators, IgE-mediated tumour antigen cross-presentation by dendritic cells, as well as immunotherapeutic strategies such as vaccines and recombinant antibodies, and finally, the management of allergy in daily clinical oncology. Shedding light on the crosstalk between allergic response and cancer is paving the way for new avenues of treatment.

Thymic Stromal Lymphopoietin: To Cut a Long Story Short

Thymic stromal lymphopoietin (TSLP) was identified more than 20 years ago as a secreted factor of a mouse thymic stromal cell line; later, a human orthologue was also identified. The signaling pathway triggered by TSLP has been extensively studied, and upregulation of the cytokine itself is linked to the pathogenesis of numerous Th2-related diseases, including atopic dermatitis, asthma, allergic responses, as well as certain types of cancers. On the other hand, TSLP mediates several immune homeostatic functions in both the gut and the thymus. Thus, a paradox occurs; why is TSLP homeostatic in certain tissues and a hallmark of exacerbated Th2 responses in the aforementioned pathologies? We and others have recently shown that in humans a novel isoform exists; this is a shorter isoform of TSLP whose expression is constitutive and controlled by a separate promoter. Short TSLP isoform mediates the homeostatic functions, whereas the long isoform is expressed at low/undetectable level at steady state and upregulated during inflammation in several tissues. Here we review the most recent data concerning the differential expression of the 2 isoforms and provide a potential explanation to the paradox. TSLP is regarded as a promising target for treatment of relevant pathologies, with a number of clinical trials already underway. It is important to design new strategies aimed at leaving intact the homeostatic effects of the short isoform while targeting the inflammatory effects of the long isoform.