Eosinophils orchestrate cancer rejection by normalizing tumor vessels and enhancing infiltration of CD8(+) T cells

Assessment of Tumor-Associated Tissue Eosinophilia (TATE) and Tumor-Associated Macrophages (TAMs) in Canine Transitional Cell Carcinoma of the Urinary Bladder

Transitional cell carcinoma of the urinary bladder is a significant neoplasm in dogs, characterized by a poor prognosis and a high metastatic potential. These canine spontaneous tumors share many characteristics with human transitional cell carcinoma, making them an excellent comparative model. The role of inflammatory infiltration in tumor development and progression is frequently contradictory, especially concerning tumor-associated tissue eosinophils (TATE) and tumor-associated macrophages (TAMs). This study aims to analyze TATE and TAMs in canine transitional cell carcinoma of the urinary bladder. Congo Red staining was used to identify TATE, and immunohistochemistry was performed to detect TAMs in 34 cases of canine transitional cell carcinoma of the bladder carcinomas, categorized into low and high grades. Statistically significant differences were observed between the number of eosinophils and macrophages in the two groups of tumors. The number of TATE was higher in low-grade malignant tumors, but the number of TAMs was higher in high-grade tumors. Our findings suggest the importance of TATEs and TAMs in the aggressiveness of canine transitional cell carcinoma and propose their potential use as therapeutic targets.

Innate Lymphoid Cells in Bladder Cancer: From Mechanisms of Action to Immune Therapies

Bladder tumors have a high mutational burden and tend to be responsive to immune therapies; however, response rates remain modest. To date, immunotherapy in bladder cancer has largely focused on enhancing T-cell immune responses in the bladder tumor microenvironment. It is anticipated that other immune cells, including innate lymphoid cells (ILC), which play an important role in bladder oncogenesis and tumor suppression, could be targeted to improve response to existing therapies. ILCs are classified into five groups: natural killer cells, ILC1s, ILC2s, ILC3s, and lymphoid tissue inducer cells. ILCs are pleiotropic and play dual and sometimes paradoxical roles in cancer development and progression. Here, a comprehensive discussion of the current knowledge and recent advancements in understanding the role of ILCs in bladder cancer is provided. We discuss the multifaceted roles that ILCs play in bladder immune surveillance, tumor protection, and immunopathology of bladder cancer. This review provides a rationale for targeting ILCs in bladder cancer, which is relevant for other solid tumors.

Immuno-genomic analysis reveals eosinophilic feature and favorable prognosis of female non-smoking esophageal squamous cell carcinomas

Most of esophageal squamous cell carcinoma (ESCC) develop in smoking males in Japan, but the genomic etiology and immunological characteristics of rare non-smoking female ECSS remain unclear. To elucidate the genomic and immunological features of ESCC in non-smoking females, we analyzed whole-genome or transcriptome sequencing data from 94 ESCCs, including 20 rare non-smoking female cases. In addition, 31,611 immune cells were extracted from four ESCC tissues and subject to single-cell RNA-seq. We compared their immuno-genomic and microbiome profiles between non-smoking female and smoking ESCCs. Non-smoking females showed much better prognosis. Whole-genome sequencing analysis showed no significant differences in driver genes or copy number alterations depending on smoking status. The mutational signatures specifically observed in non-smoking females ESCC could be attributed to aging. Immune profiling from RNA-seq revealed that ESCC in non-smoking females had high tumor microenvironment signatures and a high abundance of eosinophils with a favorable prognosis. Single-cell RNA-sequencing of intratumor immune cells revealed gender differences of eosinophils and their activation in female cases. ESCCs in non-smoking females have age-related mutational signatures and gender-specific tumor immune environment with eosinophils, which is likely to contribute to their favorable prognosis.

Comparative Study of the Immune Microenvironment in Heterotopic Tumor Models

The tumor microenvironment (TME) is pivotal in cancer progression and the response to immunotherapy. A "hot" tumor typically contains immune cells that promote anti-tumor immunity, predicting positive prognosis. "Cold" tumors lack immune cells, suggesting a poor outlook across various cancers. Recent research has focused on converting "cold" tumors into "hot" tumors to enhance the success of immunotherapy. A prerequisite for the studies of the TME is an accurate knowledge of the cell populations of the TME. This study aimed to describe the immune TME of lung and colorectal cancer and melanoma, focusing on lymphoid and myeloid cell populations. We induced heterotopic immunocompetent tumors in C57BL/6 mice, using KP and LLC (Lewis lung carcinoma) cells for lung cancer, MC38 cells for colorectal cancer, and B16-F10 cells for melanoma. Immune cell infiltration was analyzed using multicolor flow cytometry in single-cell suspensions after tumor excision. KP cell tumors showed an abundance of neutrophils and eosinophils; however, they contained much less adaptive immune cells, while LLC cell tumors predominated in monocytes, neutrophils, and monocyte-derived dendritic cells. Monocytes and neutrophils, along with a significant T cell infiltration, were prevalent in MC38 tumors. Lastly, B16-F10 tumors were enriched in macrophages, while showing only moderate T cell presence. In conclusion, our data provide a detailed overview of the immune TME of various heterotopic tumors, highlighting the variabilities in the immune cell profiles of different tumor entities. Our data may be a helpful basis when investigating new immunotherapies, and thus, this report serves as a helpful tool for preclinical immunotherapy research design.

An increased relative eosinophil count as a predictive dynamic biomarker in non-small cell lung cancer patients treated with immune checkpoint inhibitors

BACKGROUND

An increased relative eosinophil count (REC) has potential as a predictive biomarker for a beneficial clinical response and outcome to cancer immunotherapies. Therefore, the present study investigated the impact of an increased posttreatment REC on the prognosis of non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICIs).

METHODS

We retrospectively reviewed all 151 patients diagnosed with NSCLC and treated with ICI monotherapy and blood test data between March 2016 and August 2021 at National Hospital Organization Kochi Hospital and Tokushima University.

RESULTS

A total of 151 patients with a mean age of 69 years were included. REC after 4 weeks of initial ICI monotherapy was higher than pretreatment REC in 87 patients but not in 64. REC after 4 weeks of the ICI treatment with and without an increased REC were 4.4 and 1.8%, respectively (p < 0.001). Disease control rates (DCR) were significantly higher in patients with than in those without an increased REC (84% vs. 47%, p < 0.001). The median overall survival (OS) of lung cancer patients with or without an increased REC were 674 and 234 days, respectively. A Kaplan-Meier univariate analysis revealed a significant difference in OS between the two groups (p < 0.001). A Cox proportional regression analysis identified an increased REC as an independent predictor of OS (p = 0.003).

CONCLUSION

ICI-treated NSCLC patients with an increased REC after 4 weeks of treatment had a better DCR and prognosis than the other patients examined.

How chemokines organize the tumour microenvironment

For our immune system to contain or eliminate malignant solid tumours, both myeloid and lymphoid haematopoietic cells must not only extravasate from the bloodstream into the tumour tissue but also further migrate to various specialized niches of the tumour microenvironment to functionally interact with each other, with non-haematopoietic stromal cells and, ultimately, with cancer cells. These interactions regulate local immune cell survival, proliferative expansion, differentiation and their execution of pro-tumour or antitumour effector functions, which collectively determine the outcome of spontaneous or therapeutically induced antitumour immune responses. None of these interactions occur randomly but are orchestrated and critically depend on migratory guidance cues provided by chemokines, a large family of chemotactic cytokines, and their receptors. Understanding the functional organization of the tumour immune microenvironment inevitably requires knowledge of the multifaceted roles of chemokines in the recruitment and positioning of its cellular constituents. Gaining such knowledge will not only generate new insights into the mechanisms underlying antitumour immunity or immune tolerance but also inform the development of biomarkers (or 'biopatterns') based on spatial tumour tissue analyses, as well as novel strategies to therapeutically engineer immune responses in patients with cancer. Here we will discuss recent observations on the role of chemokines in the tumour microenvironment in the context of our knowledge of their physiological functions in development, homeostasis and antimicrobial responses.

CD200/CD200R: Bidirectional Role in Cancer Progression and Immunotherapy

As an immune checkpoint molecule, CD200 serves a foundational role in regulating immune homeostasis and promoting self-tolerance. While CD200 expression occurs in various immune cell subsets and normal tissues, its aberrant expression patterns in hematologic malignancies and solid tumors have been linked to immune evasion and cancer progression under pathological conditions, particularly through interactions with its cognate receptor, CD200R. Through this CD200/CD200R signaling pathway, CD200 exerts its immunosuppressive effects by inhibiting natural killer (NK) cell activation, cytotoxic T cell functions, and M1-polarized macrophage activity, while also facilitating expansion of myeloid-derived suppressor cells (MDSCs) and Tregs. Moreover, CD200/CD200R expression has been linked to epithelial-to-mesenchymal transition and distant metastasis, further illustrating its role in cancer progression. Conversely, CD200 has also been shown to exert anti-tumor effects in certain cancer types, such as breast carcinoma and melanoma, indicating that CD200 may exert bidirectional effects on cancer progression depending on the specific tumor microenvironment (TME). Regardless, modulating the CD200/CD200R axis has garnered clinical interest as a potential immunotherapeutic strategy for cancer therapy, as demonstrated by early-phase clinical trials. However, further research is necessary to fully understand the complex interactions of CD200 in the tumor microenvironment and to optimize its therapeutic potential in cancer immunotherapy.

Alleviating hypoxia to improve cancer immunotherapy

Tumor hypoxia resulting from abnormal and dysfunctional tumor vascular network poses a substantial obstacle to immunotherapy. In fact, hypoxia creates an immunosuppressive tumor microenvironment (TME) through promoting angiogenesis, metabolic reprogramming, extracellular matrix remodeling, epithelial-mesenchymal transition (EMT), p53 inactivation, and immune evasion. Vascular normalization, a strategy aimed at restoring the structure and function of tumor blood vessels, has been shown to improve oxygen delivery and reverse hypoxia-induced signaling pathways, thus alleviates hypoxia and potentiates cancer immunotherapy. In this review, we discuss the mechanisms of tumor tissue hypoxia and its impacts on immune cells and cancer immunotherapy, as well as the approaches to induce tumor vascular normalization. We also summarize the evidence supporting the use of vascular normalization in combination with cancer immunotherapy, and highlight the challenges and future directions of this overlooked important field. By targeting the fundamental problem of tumor hypoxia, vascular normalization proposes a promising strategy to enhance the efficacy of cancer immunotherapy and improve clinical outcomes for cancer patients.

Eosinophils-from cradle to grave: An EAACI task force paper on new molecular insights and clinical functions of eosinophils and the clinical effects of targeted eosinophil depletion

Over the past years, eosinophils have become a focus of scientific interest, especially in the context of their recently uncovered functions (e.g. antiviral, anti-inflammatory, regulatory). These versatile cells display both beneficial and detrimental activities under various physiological and pathological conditions. Eosinophils are involved in the pathogenesis of many diseases which can be classified into primary (clonal) and secondary (reactive) disorders and idiopathic (hyper)eosinophilic syndromes. Depending on the biological specimen, the eosinophil count in different body compartments may serve as a biomarker reflecting the underlying pathophysiology and/or activity of distinct diseases and as a therapy-driving (predictive) and monitoring tool. Personalized selection of an appropriate therapeutic strategy directly or indirectly targeting the increased number and/or activity of eosinophils should be based on the understanding of eosinophil homeostasis including their interactions with other immune and non-immune cells within different body compartments. Hence, restoring as well as maintaining homeostasis within an individual's eosinophil pool is a goal of both specific and non-specific eosinophil-targeting therapies. Despite the overall favourable safety profile of the currently available anti-eosinophil biologics, the effect of eosinophil depletion should be monitored from the perspective of possible unwanted consequences.

Eosinophil may be a predictor of immune-related adverse events induced by different immune checkpoint inhibitor types: A retrospective multidisciplinary study

BACKGROUND

Immune checkpoint inhibitors (ICIs) can cause severe immune-related adverse events (irAEs). However, biomarkers for irAEs common to different types of ICIs and cancers have not been reported. This study examined whether eosinophils can be used as a predictor of irAEs.

METHODS

Six hundred fourteen patients with cancer (esophageal, gastric, head and neck, lung, melanoma, renal cell, urothelial, and other cancer) received anti-PD-1, anti-PD-L1, or anti-CTLA-4 plus anti-PD-1 therapy. The patients were divided into two groups depending on whether they experienced irAEs (irAE group) or not (non-irAE group). Eosinophils were examined before the two-course treatment.

RESULTS

Patients in the irAE group who received anti-PD-1 or anti-CTLA-4 plus anti-PD-1 therapy had higher eosinophils before the two-course treatment than those in the non-irAE group (p < 0.05). The eosinophils in the anti-PD-L1 therapy group tended to increase in the irAE group. Furthermore, eosinophils in gastric, head and neck, lung, melanoma, renal, and urothelial cancers were significantly higher in the irAE group than in the non-irAE group (p < 0.05). The optimal cutoff value for eosinophils against irAEs was 3.0% (area under the curve = 0.668). In multivariate analyses, eosinophils of ≥3.0% were an independent factor for irAEs (odds ratio: 2.57, 95% CI: 1.79-3.67).

CONCLUSION

An increased eosinophil before the two-course treatment may be a predictor of irAEs in various cancers treated with different ICIs.

Peripheral blood inflammatory biomarkers dynamics reflect treatment response and predict prognosis in non-small cell lung cancer patients with neoadjuvant immunotherapy

Neoadjuvant immunotherapy has significantly changed the therapeutic approach for treating patients with surgically resectable non-small cell lung cancer (NSCLC). Here, peripheral blood inflammation-based biomarkers as well as previously less focused eosinophil fraction, modified Glasgow prognostic score (mGPS), and prognostic nutritional index (PNI) were systematically included to comprehensively analyze their potential in predicting neoadjuvant immunotherapy efficacy and prognosis. We enrolled 189 patients (94 in training and 95 in validation cohorts) with stage I-III B surgically resectable NSCLC treated with neoadjuvant immunotherapy from the National Cancer Center of China. Baseline and post-treatment eosinophils fraction, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), monocyte-to-lymphocyte ratio (MLR), PNI, mGPS, and their changes were calculated and analyzed for correlation with neoadjuvant immunotherapy efficacy and prognosis. In patients in the major pathological response (MPR) group, the post-treatment eosinophil fraction was significantly high, and NLR, PLR, SII, and MLR were significantly lower compared to the non-MPR group in both the training and validation cohorts. The receiver operating characteristic curve showed that post-treatment, eosinophil fraction and SII and their changing were two of the most important factors. Univariate and multivariate logistic regression analyses showed that post-treatment eosinophil fraction, SII, mGPS, and ΔSII could independently predict MPR in patients treated with neoadjuvant immunotherapy. Survival analysis showed a significant correlation between high post-treatment NLR, PLR, SII, mGPS, and their changes in ΔNLR and ΔSII elevation with poor overall survival and event-free survival of patients. Our results suggest that inflammatory biomarkers could predict the patient's response to neoadjuvant immunotherapy and prognosis.

Exploiting innate immunity for cancer immunotherapy

Immunotherapies have revolutionized the treatment paradigms of various types of cancers. However, most of these immunomodulatory strategies focus on harnessing adaptive immunity, mainly by inhibiting immunosuppressive signaling with immune checkpoint blockade, or enhancing immunostimulatory signaling with bispecific T cell engager and chimeric antigen receptor (CAR)-T cell. Although these agents have already achieved great success, only a tiny percentage of patients could benefit from immunotherapies. Actually, immunotherapy efficacy is determined by multiple components in the tumor microenvironment beyond adaptive immunity. Cells from the innate arm of the immune system, such as macrophages, dendritic cells, myeloid-derived suppressor cells, neutrophils, natural killer cells, and unconventional T cells, also participate in cancer immune evasion and surveillance. Considering that the innate arm is the cornerstone of the antitumor immune response, utilizing innate immunity provides potential therapeutic options for cancer control. Up to now, strategies exploiting innate immunity, such as agonists of stimulator of interferon genes, CAR-macrophage or -natural killer cell therapies, metabolic regulators, and novel immune checkpoint blockade, have exhibited potent antitumor activities in preclinical and clinical studies. Here, we summarize the latest insights into the potential roles of innate cells in antitumor immunity and discuss the advances in innate arm-targeted therapeutic strategies.

Isolated Adrenocorticotropic Hormone Deficiency Associated with Atezolizumab and Bevacizumab Administration for Treating Hepatocellular Carcinoma: A Case Series

Atezolizumab and bevacizumab are currently available as first-line treatments for unresectable hepatocellular carcinoma, but immune-related adverse events are a major concern. We herein report two cases of isolated adrenocorticotropic hormone (ACTH) deficiency. Both patients presented with general fatigue, appetite loss, eosinophilia, and hyponatremia after nine cycles in case 1 and three months after stopping treatment for inflammatory arthritis in case 2. Endocrinological investigations revealed unsatisfactory ACTH and cortisol responses despite the preservation of other anterior pituitary hormones, suggesting isolated ACTH deficiency. As it is rapidly improved by steroid replacement therapy, an early diagnosis and treatment make it possible to resume immunotherapy.

Dopamine Receptor 1 Impedes ILC2-Mediated Antitumor Immunity

Ever-growing evidence has revealed that group 2 innate lymphoid cells (ILC2s) exhibit pleiotropic effects in antihelminth immunity, allergy, tissue protection, and cancer. Currently, the role of ILC2s in cancer is highly controversial regarding the intricate tumor microenvironment (TME), and the tumor-promoting or antitumor immunological mechanisms of ILC2s remain largely unknown. In this study, we report that dopamine receptor 1 (DRD1) restrains ILC2 activity in the TME. DRD1 deficiency promotes ILC2 activation, which irritates eosinophil recruitment and cytotoxic CD8+ T cell expansion during ongoing malignancy. Consequently, DRD1-deficient mice exhibit delayed tumor growth and reduced tumor progression. Furthermore, fenoldopam, a selective DRD1 agonist, restrains the ILC2 response in the TME and aggravates tumor burden in mice. Taken together, our data elaborate that the DRD1 signal acts as an excitatory rheostat in regulating ILC2-dependent antitumor immunity.

Role of eosinophilia in patients with recurrent/metastatic head and neck squamous cell carcinoma treated with nivolumab: Prediction of immune-related adverse events and favorable outcome

INTRODUCTION

Immune-related adverse events (irAEs) are prognostic factors for patients on nivolumab. However, predictors of irAEs have not yet been identified. We aimed to investigate the predictors of irAEs occurrence and nivolumab discontinuation due to irAEs.

METHODS

Sixty-two patients with recurrent/metastatic head and neck squamous cell carcinoma received nivolumab therapy between June 2017 and December 2020. Treatment outcome was compared between the groups with or without irAEs. The irAE (+) group was further divided by nivolumab discontinuation. Progression-free survival (PFS) and overall survival (OS) were compared between the groups. Predictors of irAE occurrence were analyzed.

RESULTS

Twenty-one patients (33.9%) developed irAEs, and six (28.6%) discontinued nivolumab due to severe irAEs. The irAE (+) group had significantly longer PFS and OS than the irAE (-) group (median PFS, 12.7 vs. 1.9 months; median OS, 33.1 vs. 12.8 months). The treatment outcomes in the discontinuation group were comparable to those in the non-discontinuation group. The maximum absolute eosinophil count (AEC) during nivolumab therapy was significantly higher in the irAE (+) group than in the irAE (-) group (548.8 vs. 182) and higher in the discontinuation group than in the non-discontinuation group (729.3 vs. 368.6). The receiver operating characteristic curve showed that the maximum AEC had a moderate-to-high accuracy for predicting irAE occurrence (area under the curve [AUC], 0.757) and nivolumab discontinuation (AUC, 0.893).

DISCUSSION

Monitoring AEC during nivolumab therapy may be useful in predicting irAE occurrence, nivolumab discontinuation, and disease prognosis.

Eosinophils in metastatic melanoma

The potential significance of tissue eosinophils melanomas is unknown. We strove to determine a potential association between the presence of tissue eosinophils and prognosis of patients with metastatic melanoma (MM). A retrospective electronic data base was queried to identify patients (age ≥18 years) evaluated January 1, 2011-October 1, 2022 (inclusive) at our multi-site medical center, who had metastatic melanoma and at least 1 biopsy of melanoma or a melanocytic nevus that was reported to show eosinophils. Patient demographics, histopathological tumor features, AJCC classification parameters, and peripheral blood eosinophilia (PBE) obtained during the patients' routine care were recorded. Seven patients met inclusion criteria had checkpoint inhibitor therapy for MM; 4/7 had prominent eosinophil infiltrates among their melanocytic nevi or/and melanomas, and all had absent or less than predicted tumor progression. In our small cohort of patients undergoing immunotherapy for metastatic melanoma, the presence of tissue eosinophils among nevi or melanomas was associated with a favorable response. While lymphocytes have been considered key in the host response to melanoma, the role of eosinophils may be underappreciated.

OMIP-095: 40-Color spectral flow cytometry delineates all major leukocyte populations in murine lymphoid tissues

High-dimensional immunoprofiling is essential for studying host response to immunotherapy, infection, and disease in murine model systems. However, the difficulty of multiparameter panel design combined with a lack of existing murine tools has prevented the comprehensive study of all major leukocyte phenotypes in a single assay. Herein, we present a 40-color flow cytometry panel for deep immunophenotyping of murine lymphoid tissues, including the spleen, blood, Peyer's patches, inguinal lymph nodes, bone marrow, and thymus. This panel uses a robust set of surface markers capable of differentiating leukocyte subsets without the use of intracellular staining, thus allowing for the use of cells in downstream functional experiments or multiomic analyses. Our panel classifies T cells, B cells, natural killer cells, innate lymphoid cells, monocytes, macrophages, dendritic cells, basophils, neutrophils, eosinophils, progenitors, and their functional subsets by using a series of co-stimulatory, checkpoint, activation, migration, and maturation markers. This tool has a multitude of systems immunology applications ranging from serial monitoring of circulating blood signatures to complex endpoint analysis, especially in pre-clinical settings where treatments can modulate leukocyte abundance and/or function. Ultimately, this 40-color panel resolves a diverse array of immune cells on the axes of time, tissue, and treatment, filling the niche for a modern tool dedicated to murine immunophenotyping.

Neutrophil-to-eosinophil ratio as a biomarker for clinical outcomes in advanced stage melanoma patients treated with anti-PD-1 therapy

Neutrophil-to-lymphocyte ratios (NLR) and eosinophil counts are associated with improved survival in melanoma patients treated with immune checkpoint inhibitors, but no study has investigated neutrophil-to-eosinophil ratios (NER) as a predictive indicator in this population. In this retrospective study evaluating anti-PD-1 treated patients with advanced melanoma, progression-free survival (PFS), overall survival (OS), objective response rates (ORR), and risk of high-grade (grade ≥3) immune-related adverse events (irAEs) were compared between groups defined by median pretreatment NLR and NER as well as median NLR and NER at 1-month post-treatment. Lower baseline NLR and NER were associated with improved OS [HR: 0.504, 95% CI: 0.328-0.773, p = .002 and HR: 0.442, 95% CI: 0.288-0.681, p < .001, respectively] on univariate testing. After accounting for multiple covariates, our multivariate analysis found that lower pretreatment NER was associated with better ORR (by irRECIST) (OR: 2.199, 95% CI: 1.071-4.582, p = .033) and improved OS (HR: 0.480, 95% CI: 0.296-0.777, p = .003). Baseline NLR, 1-month NLR, and 1-month NER were not associated with ORR, PFS, or OS outcomes; but 1-month NER correlated with lower risk of grade ≥3 irAEs (OR: 0.392, 95% CI: 0.165-0.895, p = .029). Our findings suggest baseline NER merits additional investigation as a novel prognostic marker for advanced melanoma patients receiving anti-PD-1-based regimens.

Development of an immunogenic cell death prognostic signature for predicting clinical outcome and immune infiltration characterization in stomach adenocarcinoma

Stomach adenocarcinoma (STAD) is a common gastric histological cancer type with a high mortality rate. Immunogenic cell death (ICD) plays a key factor during carcinogenesis progress, whereas the prognostic value and role of ICD-related genes (ICDRGs) in STAD remain unclear. The MSigDB database collecting ICDRGs were selected by univariate Cox regression analysis and LASSO algorithm to establish a novel risk model. The Kaplan-Meier survival analysis indicated a significant difference of OS rate of patients by risk score stratification. ESTIMATE, CIBERSORT, and single sample gene set enrichment analysis (ssGSEA) algorithms were conducted to estimate the immune infiltration landscape by risk stratification. Subgroup analysis and tumor mutation burden analysis were also analyzed to identify characteristics between groups. Differences in therapeutic responsiveness to chemotherapeutic drugs and targeted drugs were also analyzed between high-risk group and low-risk group. The impact of one ICDRG, GPX1, on the proliferation, migration and invasiveness of was confirmed by in vitro experiments in GC cells to test the reliability of bioinformatics results. This study gives evidence of the involvement of ICD process in STAD and provides a new perspective for further accurate assessment of prognosis and therapeutic efficacy in STAD patients. Stomach adenocarcinoma (STAD) is a common gastric histological cancer type with a high mortality rate. Immunogenic cell death (ICD) plays a key factor during carcinogenesis progress, whereas the prognostic value and role of ICD-related genes (ICDRGs) in STAD remains unclear. The MSigDB database collected ICDRGs were selected by univariate Cox regression analysis and LASSO algorithm to establish a novel risk model. The Kaplan-Meier survival analysis indicated a significant difference of OS rate of patients by risk score stratification. ESTIMATE, CIBERSORT, and single sample gene set enrichment analysis (ssGSEA) algorithms were conducted to estimate the immune infiltration landscape by risk stratification. Subgroup analysis and tumor mutation burden analysis were also analyzed to identify characteristics between groups. Differences in therapeutic responsiveness to chemotherapeutic drugs and targeted drugs were also analyzed between high-risk group and low-risk group. The impact of one ICDRG, GPX1, on the proliferation, migration and invasiveness of was confirmed by in vitro experiments in GC cells to test the reliability of bioinformatics results. This study gives evidence of the involvement of ICD process in STAD and provides a new perspective for further accurate assessment of prognosis and therapeutic efficacy in STAD patients.

Recent research and clinical progress of CTLA-4-based immunotherapy for breast cancer

Breast cancer is characterized by a high incidence rate and its treatment challenges, particularly in certain subtypes. Consequently, there is an urgent need for the development of novel therapeutic approaches. Immunotherapy utilizing immune checkpoint inhibitors (ICIs) is currently gaining momentum for the treatment of breast cancer. Substantial progress has been made in clinical studies employing cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) inhibitors for breast cancer, but the cure rates are relatively low. To improve the efficacy of CTLA-4-based therapy for breast cancer, further research is imperative to explore more effective immune-based treatment strategies. In addition to monotherapy, CTLA-4 inhibitors are also being investigated in combination with other ICIs or alternative medications. However, it should be noted that immune-based treatments may cause adverse events. This review focuses on the mechanisms of CTLA-4 inhibitor monotherapy or combination therapy in breast cancer. We systematically summarize the latest research and clinical advances in CTLA-4-based immunotherapy for breast cancer, providing new perspectives on the treatment of breast cancer. In addition, this review highlights the immune-related adverse events (irAEs) associated with CTLA-4 inhibitors, providing insights into the development of appropriate clinical tumor immunotherapy regimens and intervention strategies.

Elevated eosinophils proportion as predictor of immune-related adverse events after ipilimumab and nivolumab treatment of advanced and metastatic renal cell carcinoma

OBJECTIVES

Ipilimumab and nivolumab treatment against advanced and metastatic renal cell carcinoma (RCC) causes severe and lethal immune-related adverse events (irAEs). Predicting irAEs might improve clinical outcomes, however no practical biomarkers exist. This study examined whether eosinophils could be effective biomarkers for ≥grade 2 irAEs in RCC.

METHODS

We retrospectively analyzed 75 patients with RCC treated with ipilimumab and nivolumab between August 2018 and March 2021 in a multicenter study. Eosinophils were examined before and 2 weeks after treatment, and immediately after irAEs development. The optimal cut-off value for ≥grade 2 irAEs was determined by a receiver operating characteristic (ROC) curve. Univariate and multivariate analyses were undertaken to identify predictors of ≥grade 2 irAEs.

RESULTS

Two weeks after treatment, eosinophils were significantly upregulated in patients who had experienced ≥grade 2 irAEs than in those who had not experienced irAEs (mean, 5.7% vs. 3.2%; p < 0.05). The optimal cut-off value for eosinophils against ≥grade 2 irAEs was 3.0% (area under the curve = 0.69). In multivariate analyses, an eosinophil level ≥ 3.0% was a risk factor for ≥grade 2 irAEs (odds ratio 4.18, 95% confidence interval 1.16-15.1). The eosinophil level 2 weeks after treatment was upregulated by the onset of any type of irAEs including endocrine, gastrointestinal, pulmonary and skin disorders.

CONCLUSIONS

An increased eosinophil level 2 weeks after treatment might be an effective biomarker for ≥grade 2 irAEs in patients with RCC treated with ipilimumab and nivolumab.

Pretreatment eosinophil counts as a predictive biomarker in non-small cell lung cancer patients treated with immune checkpoint inhibitors

BACKGROUND

The peripheral blood eosinophil count prior to treatment has potential as a predictive biomarker for a beneficial clinical response to cancer immunotherapies. Therefore, the present study investigated the impact of the eosinophil count on overall survival (OS) in non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICI).

METHODS

We retrospectively reviewed all patients diagnosed with NSCLC and treated with ICI monotherapy between March 2016 and August 2021 at National Hospital Organization Kochi Hospital and Tokushima University.

RESULTS

A total of 166 patients were included. Fifty-five patients had an eosinophil count of less than 100 cells/μL (Eo < 100). Nighty-eight patients had an eosinophil count of 100 cells/μL or more, but less than 500 cells/μL (100 ≤ Eo < 500). Thirteen patients had an eosinophil count of 500 cells/μL or more (Eo ≥500). The median OS of all lung cancer patients was 476 days. The median OS of lung cancer patients with Eo <100, 100 ≤ Eo <500, and Eo ≥500 was 339, 667, and 143 days, respectively. A Kaplan-Meier univariate analysis showed a significant difference in OS between these three groups (p < 0.001). A Cox proportional regression analysis identified 100 ≤ Eo <500 (p = 0.04), ECOG PS score ≥ 2 (p = 0.02), tumor size ≥5 cm (p = 0.02), and PD-L1 ≥ 1% (p = 0.01) as independent predictors of OS.

CONCLUSION

OS was significantly longer in ICI-treated NSCLC patients with a pretreatment eosinophil count of 100 ≤ Eo <500 than in the other patients and, thus, has potential as a new predictive biomarker.

Comprehensive analysis of ICD-related lncRNAs in predicting risk stratification, clinical prognosis and immune response for breast cancer

BACKGROUND

Breast cancer (BRCA) represents a significant threat with high mortality rates due to relapse, metastasis, and chemotherapy resistance. As a regulated cell death process characterized by the induction of immunogenic signals, immunogenic cell death (ICD) has been identified as an effective anti-tumorigenesis approach. However, the comprehensive study and its clinical value of ICD-related lncRNAs in BRCA is still missing.

METHODS

The transcriptome matrix and corresponding clinical information of BRCA patients were obtained from The Cancer Genome Atlas (TCGA) database. Pearson correlation analysis was performed to identify ICD-related lncRNAs (ICDRLs). To determine the prognostic value of the identified ICDRLs, univariate Cox regression analysis, LASSO algorithm, and multivariate Cox regression analysis were employed to construct a risk model. The prognostic risk model was subsequently evaluated using univariate and multivariate Cox regression analysis, as well as Nomogram analysis. In vitro experiments were also conducted to validate the bioinformatics findings using quantitative real-time PCR (qRT-PCR).

RESULTS

We established a prognostic risk signature consisting of five ICDRLs. The prognostic value of this model was subsequently confirmed in guiding BRCA prognostic stratification. Furthermore, we explored the correlation of the risk score with various clinical characteristics and chemotherapy response. qRT-PCR result confirmed the abnormal expression of ICDRLs, which was consistent with the bioinformatics data.

CONCLUSIONS

Our findings provide evidence of the critical role of ICDRLs in BRCA and offer a novel perspective for exploring precise treatment options for BRCA patients.

Eosinophils in the tumor microenvironment: implications for cancer immunotherapy

Despite being an integral part of the immune response in the tumor microenvironment (TME), few studies have mechanistically elucidated eosinophil functions in cancer outcomes. Eosinophils are a minor population of granulocytes that are mostly explored in asthma and allergic disorders. Their influence on primary and metastatic tumors, however, has recently come to light. Eosinophils' diverse armamentarium of mediators and receptors allows them to participate in innate and adaptive immunity, such as type 1 and type 2 immunity, and shape TME and tumor outcomes. Based on TME cells and cytokines, activated eosinophils drive other immune cells to ultimately promote or suppress tumor growth. Discovering exactly what conditions determine the pro-tumorigenic or anti-tumorigenic role of eosinophils allows us to take advantage of these signals and devise novel strategies to target cancer cells. Here, we first revisit eosinophil biology and differentiation as recognizing eosinophil mediators is crucial to their function in homeostatic and pathological conditions as well as tumor outcome. The bulk of our paper discusses eosinophil interactions with tumor cells, immune cells-including T cells, plasma cells, natural killer (NK) cells-and gut microbiota. Eosinophil mediators, such as IL-5, IL-33, granulocyte-macrophage colony-stimulating factor (GM-CSF), thymic stromal lymphopoietin (TSLP), and CCL11 also determine eosinophil behavior toward tumor cells. We then examine the implications of these findings for cancer immunotherapy approaches, including immune checkpoint blockade (ICB) therapy using immune checkpoint inhibitors (ICIs) and chimeric antigen receptor (CAR) T cell therapy. Eosinophils synergize with CAR T cells and ICB therapy to augment immunotherapies.

Eosinophils Exert Antitumorigenic Effects in the Development of Esophageal Squamous Cell Carcinoma

BACKGROUND AND AIMS

Eosinophils are present in several solid tumors and have context-dependent function. Our aim is to define the contribution of eosinophils in esophageal squamous cell carcinoma (ESCC), as their role in ESCC is unknown.

METHODS

Eosinophils were enumerated in tissues from 2 ESCC cohorts. Mice were treated with 4-NQO for 8 weeks to induce precancer or 16 weeks to induce carcinoma. The eosinophil number was modified by a monoclonal antibody to interleukin-5 (IL5mAb), recombinant IL-5 (rIL-5), or genetically with eosinophil-deficient (ΔdblGATA) mice or mice deficient in eosinophil chemoattractant eotaxin-1 (Ccl11-/-). Esophageal tissue and eosinophil-specific RNA sequencing was performed to understand eosinophil function. Three-dimensional coculturing of eosinophils with precancer or cancer cells was done to ascertain direct effects of eosinophils.

RESULTS

Activated eosinophils are present in higher numbers in early-stage vs late-stage ESCC. Mice treated with 4-NQO exhibit more esophageal eosinophils in precancer vs cancer. Correspondingly, epithelial cell Ccl11 expression is higher in mice with precancer. Eosinophil depletion using 3 mouse models (Ccl11-/- mice, ΔdblGATA mice, IL5mAb treatment) all display exacerbated 4-NQO tumorigenesis. Conversely, treatment with rIL-5 increases esophageal eosinophilia and protects against precancer and carcinoma. Tissue and eosinophil RNA sequencing revealed eosinophils drive oxidative stress in precancer. In vitro coculturing of eosinophils with precancer or cancer cells resulted in increased apoptosis in the presence of a degranulating agent, which is reversed with NAC, a reactive oxygen species scavenger. ΔdblGATA mice exhibited increased CD4 T cell infiltration, IL-17, and enrichment of IL-17 protumorigenic pathways.

CONCLUSION

Eosinophils likely protect against ESCC through reactive oxygen species release during degranulation and suppression of IL-17.

Pathological complete response to neoadjuvant alectinib in unresectable anaplastic lymphoma kinase positive non-small cell lung cancer: A case report

BACKGROUND

The development of anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitors (TKIs) has remarkably improved the prognosis of patients with ALK-positive advanced non-small cell lung cancer (NSCLC). Alectinib, the second-generation ALK-TKI, has been approved as first-line treatment for advanced or metastatic NSCLC patients with ALK rearrangement. Neoadjuvant therapy can achieve tumor downstaging and eradicate occult lesions in patients with potentially resectable disease. Whether neoadjuvant alectinib can be a conversion therapy in ALK-positive advanced NSCLC patients remains unclear.

CASE SUMMARY

A 41-year-old man was pathologically diagnosed with locally advanced ALK-positive stage IIIB NSCLC. Alectinib was prescribed to induce tumor downstaging and facilitate the subsequent surgical resection. The tumor was successfully downstaged and pathological complete response was achieved. Left upper lobectomy with mediastinal lymphadenectomy was performed after tumor downstaging. The patient has continued to receive alectinib as adjuvant therapy during postoperative follow-up with a recurrence-free survival of 29 mo as of writing this report.

CONCLUSION

This case sheds light on the feasibility and safety of alectinib as a neoadjuvant treatment for stage IIIB NSCLC patients with ALK rearrangement. Its efficacy needs to be validated in prospective clinical trials.

T Cells in Colorectal Cancer: Unravelling the Function of Different T Cell Subsets in the Tumor Microenvironment

Therapeutic options for metastatic colorectal cancer (mCRC) are very limited, and the prognosis using combination therapy with a chemotherapeutic drug and a targeted agent, e.g., epidermal growth factor receptor or tyrosine kinase, remains poor. Therefore, mCRC is associated with a poor median overall survival (mOS) of only 25-30 months. Current immunotherapies with checkpoint inhibitor blockade (ICB) have led to a substantial change in the treatment of several cancers, such as melanoma and non-small cell lung cancer. In CRC, ICB has only limited effects, except in patients with microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) tumors, which comprise about 15% of sporadic CRC patients and about 4% of patients with metastatic CRC. The vast majority of sporadic CRCs are microsatellite-stable (MSS) tumors with low levels of infiltrating immune cells, in which immunotherapy has no clinical benefit so far. Immunotherapy with checkpoint inhibitors requires the presence of infiltrating T cells into the tumor microenvironment (TME). This makes T cells the most important effector cells in the TME, as evidenced by the establishment of the immunoscore-a method to estimate the prognosis of CRC patients. The microenvironment of a tumor contains several types of T cells that are anti-tumorigenic, such as CD8⁺ T cells or pro-tumorigenic, such as regulatory T cells (Tregs) or T helper 17 (Th17) cells. However, even CD8⁺ T cells show marked heterogeneity, e.g., they can become exhausted, enter a state of hyporesponsiveness or become dysfunctional and express high levels of checkpoint molecules, the targets for ICB. To kill cancer cells, CD8⁺ T cells need the recognition of the MHC class I, which is often downregulated on colorectal cancer cells. In this case, a population of unconventional T cells with a γδ T cell receptor can overcome the limitations of the conventional CD8⁺ T cells with an αβT cell receptor. γδ T cells recognize antigens in an MHC-independent manner, thus acting as a bridge between innate and adaptive immunity. Here, we discuss the effects of different T cell subsets in colorectal cancer with a special emphasis on γδ T cells and the possibility of using them in CAR-T cell therapy. We explain T cell exclusion in microsatellite-stable colorectal cancer and the possibilities to overcome this exclusion to enable immunotherapy even in these "cold" tumors.

Insight into Cancer Immunity: MHCs, Immune Cells and Commensal Microbiota

Cancer cells circumvent immune surveillance via diverse strategies. In accordance, a large number of complex studies of the immune system focusing on tumor cell recognition have revealed new insights and strategies developed, largely through major histocompatibility complexes (MHCs). As one of them, tumor-specific MHC-II expression (tsMHC-II) can facilitate immune surveillance to detect tumor antigens, and thereby has been used in immunotherapy, including superior cancer prognosis, clinical sensitivity to immune checkpoint inhibition (ICI) therapy and tumor-bearing rejection in mice. NK cells play a unique role in enhancing innate immune responses, accounting for part of the response including immunosurveillance and immunoregulation. NK cells are also capable of initiating the response of the adaptive immune system to cancer immunotherapy independent of cytotoxic T cells, clearly demonstrating a link between NK cell function and the efficacy of cancer immunotherapies. Eosinophils were shown to feature pleiotropic activities against a variety of solid tumor types, including direct interactions with tumor cells, and accessorily affect immunotherapeutic response through intricating cross-talk with lymphocytes. Additionally, microbial sequencing and reconstitution revealed that commensal microbiota might be involved in the modulation of cancer progression, including positive and negative regulatory bacteria. They may play functional roles in not only mucosal modulation, but also systemic immune responses. Here, we present a panorama of the cancer immune network mediated by MHCI/II molecules, immune cells and commensal microbiota and a discussion of prospective relevant intervening mechanisms involved in cancer immunotherapies.

Type 1 and type 2 cytokine-mediated immune orchestration in the tumour microenvironment and their therapeutic potential

Cancer remains the second leading cause of death worldwide despite modern breakthroughs in medicine, and novel treatments are urgently needed. The revolutionary success of immune checkpoint inhibitors in the past decade serves as proof of concept that the immune system can be effectively harnessed to treat cancer. Cytokines are small signalling proteins with critical roles in orchestrating the immune response and have become an attractive target for immunotherapy. Type 1 immune cytokines, including interferon γ (IFNγ), interleukin-12 (IL-12), and tumour necrosis factor α (TNFα), have been shown to have largely tumour suppressive roles in part through orchestrating anti-tumour immune responses mediated by natural killer (NK) cells, CD8⁺ T cells and T helper 1 (Th1) cells. Conversely, type 2 immunity involving group 2 innate lymphoid cells (ILC2s) and Th2 cells are involved in tissue regeneration and wound repair and are traditionally thought to have pro-tumoural effects. However, it is found that the classical type 2 immune cytokines IL-4, IL-5, IL-9, and IL-13 may have conflicting roles in cancer. Similarly, type 2 immunity-related cytokines IL-25 and IL-33 with recently characterised roles in cancer may either promote or suppress tumorigenesis in a context-dependent manner. Furthermore, type 1 cytokines IFNγ and TNFα have also been found to have pro-tumoural effects under certain circumstances, further complicating the overall picture. Therefore, the dichotomy of type 1 and type 2 cytokines inhibiting and promoting tumours respectively is not concrete, and attempts of utilising these for cancer immunotherapy must take into account all available evidence. This review provides an overview summarising the current understanding of type 1 and type 2 cytokines in tumour immunity and discusses the prospects of harnessing these for immunotherapy in light of previous and ongoing clinical trials.

CD200R signaling contributes to unfavorable tumor microenvironment through regulating production of chemokines by tumor-associated myeloid cells

CD200 is overexpressed in many solid tumors and considered as an immune checkpoint molecule dampening cancer immunity. In this study, we found that CD200R-/- mice were significantly more potent in rejecting these CD200+ tumors. scRNA sequencing demonstrated that tumors from CD200R-/- mice had more infiltration of CD4+ and CD8+ T cells, and NK cells but less infiltration of neutrophils. Antibody depletion experiments revealed that immune effector cells are crucial in inhibiting tumor growth in CD200R-/- mice. Mechanistically, we found that CD200R signaling regulates the expression of chemokines in tumor-associated myeloid cells (TAMCs). In the absence of CD200R, TAMCs increased expression of CCL24 and resulted in increased infiltration of eosinophils, which contributes to anti-tumor activity. Overall, we conclude that CD200R signaling contributes to unfavorable TME through chemokine-dependent recruitment of immune suppressive neutrophils and exclusion of anti-cancer immune effectors. Our study has implications in developing CD200-CD200R targeted immunotherapy of solid tumors.

Eosinophils exert direct and indirect anti-tumorigenic effects in the development of esophageal squamous cell carcinoma

Background/Aims

Eosinophils are present in several solid tumors and have context-dependent function. Our aim is to define the contribution of eosinophils in esophageal squamous cell carcinoma (ESCC), since their role in ESCC is unknown.

Methods

Eosinophils were enumerated in tissues from two ESCC cohorts. Mice were treated with 4-nitroquinolone-1-oxide (4-NQO) for 8 weeks to induce pre-cancer or 16 weeks to induce carcinoma. Eosinophil number was modified by monoclonal antibody to IL-5 (IL5mAb), recombinant IL-5 (rIL-5), or genetically with eosinophil-deficient (ΔdblGATA) mice or mice deficient in eosinophil chemoattractant eotaxin-1 ( Ccl11 -/- ). Esophageal tissue and eosinophil specific RNA-sequencing was performed to understand eosinophil function. 3-D co-culturing of eosinophils with pre-cancer or cancer cells was done to ascertain direct effects of eosinophils.

Results

Activated eosinophils are present in higher numbers in early stage versus late stage ESCC. Mice treated with 4-NQO exhibit more esophageal eosinophils in pre-cancer versus cancer. Correspondingly, epithelial cell Ccl11 expression is higher in mice with pre-cancer. Eosinophil depletion using three mouse models ( Ccl11 -/- mice, ΔdblGATA mice, IL5mAb treatment) all display exacerbated 4-NQO tumorigenesis. Conversely, treatment with rIL-5 increases esophageal eosinophilia and protects against pre-cancer and carcinoma. Tissue and eosinophil RNA-sequencing revealed eosinophils drive oxidative stress in pre-cancer. In vitro co-culturing of eosinophils with pre-cancer or cancer cells resulted in increased apoptosis in the presence of a degranulating agent, which is reversed with N-acetylcysteine, a reactive oxygen species (ROS) scavenger. ΔdblGATA mice exhibited increased CD4 T cell infiltration, IL-17, and enrichment of IL-17 pro-tumorigenic pathways.

Conclusion

Eosinophils likely protect against ESCC through ROS release during degranulation and suppression of IL-17.

The Prognostic Role of Baseline Eosinophils in HPV-Related Cancers: a Multi-institutional Analysis of Anal SCC and OPC Patients Treated with Radical CT-RT

BACKGROUND AND AIM

Anal squamous cell carcinoma (SCC) and oropharyngeal cancer (OPC) are rare tumors associated with HPV infection. Bioumoral predictors of response to chemoradiation (CT-RT) are lacking in these settings. With the aim to find new biomarkers, we investigated the role of eosinophils in both HPV-positive anal SCC and HPV-related oropharyngeal cancer (OPC).

METHODS

We retrieved clinical and laboratory data of patients with HPV-positive anal SCC treated with CT-RT in 5 institutions, and patients with locally advanced OPC SCC treated with CT-RT in 2 institutions. We examined the association between baseline eosinophil count (the best cutoff has been evaluated by ROC curve analysis: 100 × 10^9/L) and disease-free survival (DFS). Unadjusted and adjusted hazard ratios by baseline characteristics were calculated using the Cox proportional hazards model.

RESULTS

Three hundred four patients with HPV-positive anal SCCs and 168 patients with OPCs (122 HPV-positive, 46 HPV-negative diseases) were analyzed. In anal SCC, low eosinophil count (< 100 × 10^9/L) correlates to a better DFS (HR = 0.59; p = 0.0392); likewise, in HPV-positive OPC, low eosinophil count correlates to a better DFS (HR = 0.50; p = 0.0428). In HPV-negative OPC, low eosinophil count confers worse DFS compared to high eosinophil count (HR = 3.53; p = 0.0098). After adjustment for age and sex, eosinophils were confirmed to be independent prognostic factors for DFS (HR = 4.55; p = 0.0139).

CONCLUSION

Eosinophil count could be used as a prognostic factor in anal HPV-positive SCC. The worse prognosis showed in HPV-positive patients with high eosinophil count is likely to derive from an unfavorable interaction between the HPV-induced immunomodulation and eosinophils, which may hamper the curative effect of RT.

Eosinophilic esophagitis-associated epithelial remodeling may limit esophageal carcinogenesis

Introduction

Under homeostatic conditions, esophageal epithelium displays a proliferation/differentiation gradient that is generated as proliferative basal cells give rise to suprabasal cells then terminally differentiated superficial cells. This proliferation/differentiation gradient is often perturbed in esophageal pathologies. Basal cell hyperplasia may occur in patients with gastroesophageal reflux disease (GERD), a condition in which acid from the stomach enters the esophagus, or eosinophilic esophagitis (EoE), an emerging form of food allergy. While GERD is a primary risk factor for esophageal cancer, epidemiological data suggests that EoE patients do not develop esophageal cancer.

Methods

In order to investigate the impact of EoE and esophageal cancer specifically on the cellular landscape of esophageal epithelium, we perform single cell RNA-sequencing in murine models of EoE and esophageal cancer, specifically esophageal squamous cell carcinoma (ESCC). We further evaluate modules of co-expressed genes in EoE- and ESCC-enriched epithelial cell clusters. Finally, we pair EoE and ESCC murine models to examine the functional relationship between these pathologies.

Results

In mice with either EoE or ESCC, we find expansion of cell populations as compared to normal esophageal epithelium. In mice with EoE, we detect distinct expansion of 4 suprabasal populations coupled with depletion of 2 basal populations. By contrast, mice with ESCC display unique expansion of 2 basal populations and 1 suprabasal population, as well as depletion of 2 suprabasal populations. Senescence, glucocorticoid receptor signaling, and granulocyte-macrophage colony-stimulating factor pathways are associated with EoE-enriched clusters while pathways associated with cell proliferation and metabolism are identified in ESCC-enriched clusters. Finally, our in vivo data demonstrate that exposure to EoE inflammation limits tumor burden of esophageal carcinogenesis.

Discussion

Our findings provide the first functional investigation of the relationship between EoE and esophageal cancer and suggest that esophageal epithelial remodeling events occurring in response to EoE inflammation may limit esophageal carcinogenesis. This investigation may have future implications for leveraging allergic inflammation-associated alterations in epithelial biology to prevent and/or treat esophageal cancer.

Immunoregulation by resveratrol; implications for normal tissue protection and tumour suppression

Immune reactions are involved in both tumour and normal tissue in response to therapy. Elevated secretion of certain chemokines, exosomes and cytokines triggers inflammation, pain, fibrosis and ulceration among other normal tissue side effects. On the other hand, secretion of tumour-promoting molecules suppresses activity of anticancer immune cells and facilitates the proliferation of malignant cells. Novel anticancer drugs such as immune checkpoint inhibitors (ICIs) boost anticancer immunity via inducing the proliferation of anticancer cells such as natural killer (NK) cells and CD8+ T lymphocytes. Certain chemotherapy drugs and radiotherapy may induce anticancer immunity in the tumour, however, both have severe side effects for normal tissues through stimulation of several immune responses. Thus, administration of natural products with low side effects may be a promising approach to modulate the immune system in both tumour and normal organs. Resveratrol is a well-known phenol with diverse effects on normal tissues and tumours. To date, a large number of experiments have confirmed the potential of resveratrol as an anticancer adjuvant. This review focuses on ensuing stimulation or suppression of immune responses in both tumour and normal tissue after radiotherapy or anticancer drugs. Later on, the immunoregulatory effects of resveratrol in both tumour and normal tissue following exposure to anticancer agents will be discussed.

Efficacy of a Small-Molecule Inhibitor of KrasG12D in Immunocompetent Models of Pancreatic Cancer

Mutations in the KRAS oncogene are found in more than 90% of patients with pancreatic ductal adenocarcinoma (PDAC), with Gly-to-Asp mutations (KRASG12D) being the most common. Here, we tested the efficacy of a small-molecule KRASG12D inhibitor, MRTX1133, in implantable and autochthonous PDAC models with an intact immune system. In vitro studies validated the specificity and potency of MRTX1133. In vivo, MRTX1133 prompted deep tumor regressions in all models tested, including complete or near-complete remissions after 14 days. Concomitant with tumor cell apoptosis and proliferative arrest, drug treatment led to marked shifts in the tumor microenvironment (TME), including changes in fibroblasts, matrix, and macrophages. T cells were necessary for MRTX1133's full antitumor effect, and T-cell depletion accelerated tumor regrowth after therapy. These results validate the specificity, potency, and efficacy of MRTX1133 in immunocompetent KRASG12D-mutant PDAC models, providing a rationale for clinical testing and a platform for further investigation of combination therapies.

SIGNIFICANCE

Pharmacologic inhibition of KRASG12D in pancreatic cancer models with an intact immune system stimulates specific, potent, and durable tumor regressions. In the absence of overt toxicity, these results suggest that this and similar inhibitors should be tested as potential, high-impact novel therapies for patients with PDAC. See related commentary by Redding and Grabocka, p. 260. This article is highlighted in the In This Issue feature, p. 247.

The Combination of Immune Checkpoint Blockade with Tumor Vessel Normalization as a Promising Therapeutic Strategy for Breast Cancer: An Overview of Preclinical and Clinical Studies

Immune checkpoint inhibitors (ICIs) have a modest clinical activity when administered as monotherapy against breast cancer (BC), the most common malignancy in women. Novel combinatorial strategies are currently being investigated to overcome resistance to ICIs and promote antitumor immune responses in a greater proportion of BC patients. Recent studies have shown that the BC abnormal vasculature is associated with immune suppression in patients, and hampers both drug delivery and immune effector cell trafficking to tumor nests. Thus, strategies directed at normalizing (i.e., at remodeling and stabilizing) the immature, abnormal tumor vessels are receiving much attention. In particular, the combination of ICIs with tumor vessel normalizing agents is thought to hold great promise for the treatment of BC patients. Indeed, a compelling body of evidence indicates that the addition of low doses of antiangiogenic drugs to ICIs substantially improves antitumor immunity. In this review, we outline the impact that the reciprocal interactions occurring between tumor angiogenesis and immune cells have on the immune evasion and clinical progression of BC. In addition, we overview preclinical and clinical studies that are presently evaluating the therapeutic effectiveness of combining ICIs with antiangiogenic drugs in BC patients.

The pro-tumorigenic responses in metastatic niches: an immunological perspective

Metastasis is the leading cause of mortality related to cancer. In the course of metastasis, cancer cells detach from the primary tumor, enter the circulation, extravasate at secondary sites, and colonize there. All of these steps are rate limiting and decrease the efficiency of metastasis. Prior to their arrival, tumor cells can modify the secondary sites. These favorable microenvironments increase the probability of successful dissemination and are referred to as pre-metastatic niches. Cancer cells use different mechanisms to induce and maintain these niches, among which immune cells play prominent roles. The immune system, including innate and adaptive, enhances recruitment, extravasation, and colonization of tumor cells at distant sites. In addition to immune cells, stromal cells can also contribute to forming pre-metastatic niches. This review summarizes the pro-metastatic responses conducted by immune cells and the assistance of stromal cells and endothelial cells in the induction of pre-metastatic niches.

Immune-based combination therapy to convert immunologically cold tumors into hot tumors: an update and new insights

As a breakthrough strategy for cancer treatment, immunotherapy mainly consists of immune checkpoint inhibitors (ICIs) and other immunomodulatory drugs that provide a durable protective antitumor response by stimulating the immune system to fight cancer. However, due to the low response rate and unique toxicity profiles of immunotherapy, the strategies of combining immunotherapy with other therapies have attracted enormous attention. These combinations are designed to exert potent antitumor effects by regulating different processes in the cancer-immunity cycle. To date, immune-based combination therapy has achieved encouraging results in numerous clinical trials and has received Food and Drug Administration (FDA) approval for certain cancers with more studies underway. This review summarizes the emerging strategies of immune-based combination therapy, including combinations with another immunotherapeutic strategy, radiotherapy, chemotherapy, anti-angiogenic therapy, targeted therapy, bacterial therapy, and stroma-targeted therapy. Here, we highlight the rationale of immune-based combination therapy, the biomarkers and the clinical progress for these immune-based combination therapies.

IL-5-producing CD4+ T cells and eosinophils cooperate to enhance response to immune checkpoint blockade in breast cancer

Immune checkpoint blockade (ICB) has heralded a new era in cancer therapy. Research into the mechanisms underlying response to ICB has predominantly focused on T cells; however, effective immune responses require tightly regulated crosstalk between innate and adaptive immune cells. Here, we combine unbiased analysis of blood and tumors from metastatic breast cancer patients treated with ICB with mechanistic studies in mouse models of breast cancer. We observe an increase in systemic and intratumoral eosinophils in patients and mice responding to ICB treatment. Mechanistically, ICB increased IL-5 production by CD4⁺ T cells, stimulating elevated eosinophil production from the bone marrow, leading to systemic eosinophil expansion. Additional induction of IL-33 by ICB-cisplatin combination or recombinant IL-33 promotes intratumoral eosinophil infiltration and eosinophil-dependent CD8⁺ T cell activation to enhance ICB response. This work demonstrates the critical role of eosinophils in ICB response and provides proof-of-principle for eosinophil engagement to enhance ICB efficacy.

T cell-eosinophil crosstalk-A new road for effective immune checkpoint blockade in breast cancer?

Immune checkpoint blockade (ICB) has revolutionized the landscape of cancer treatment. Nevertheless, most cancer patients still do not respond to ICB. In this issue of Cancer Cell, Blomberg et al. illustrate a critical cooperation between T cells and eosinophils, which jointly enhance effectiveness of ICB in breast cancer.

Eosinophil and IFN-γ associated with immune-related adverse events as prognostic markers in patients with non-small cell lung cancer treated with immunotherapy

Objectives

Immune checkpoint inhibitors (ICIs) alone or combined with other antitumor agents are largely used in lung cancer patients, which show both positive effects and side effects in particular subjects. Our study aims to identify biomarkers that can predict response to immunotherapy or risk of side effects, which may help us play a positive role and minimize the risk of adverse effects in clinical practice.

Methods

We retrospectively collected data from patients with advanced non-small cell lung cancer (NSCLC) treated with ICIs at our center. Patients who received initial ICI therapy for >1 year without progression of disease were classified as long-term treatment (LT) group, while others were classified as the non-long-term treatment (NLT) group. Multivariate logistic analysis was performed to identify independent risk factors of progression-free survival (PFS) and immune-related adverse events (irAEs).

Results

A total of 83 patients (55.7%) had irAEs. The median PFS for patients in grades 1-2 of irAEs vs. grades 3-4 vs non-irAEs groups was (undefined vs. 12 vs. 8 months; p = 0.0025). The 1-year PFS rate for multisystem vs. single vs. non-irAE groups was 63%, 56%, and 31%, respectively. Signal transduction of inflammatory cytokines improves clinical prognosis through immunomodulatory function, but the benefit is also limited by the resulting organ damage, making it a complex immune balance. Serum biomarkers including EOS% of ≥ 1.15 (HR: 8.30 (95% CI, 2.06 to 33.42); p = 0.003) and IFN-γ of ≥ 3.75 (HR: 5.10 (95% CI, 1.29 to 20.15), p = 0.02) were found to be predictive for irAEs.

Conclusion

EOS% of ≥1.15% and IFN-γ of ≥3.75 ng/L were considered peripheral-blood markers for irAEs and associated with improved clinical outcomes for immunotherapy in patients with advanced NSCLC.

Neoadjuvant immune checkpoint blockade triggers persistent and systemic Treg activation which blunts therapeutic efficacy against metastatic spread of breast tumors

The clinical successes of immune checkpoint blockade (ICB) in advanced cancer patients have recently spurred the clinical implementation of ICB in the neoadjuvant and perioperative setting. However, how neoadjuvant ICB therapy affects the systemic immune landscape and metastatic spread remains to be established. Tumors promote both local and systemic expansion of regulatory T cells (T_regs), which are key orchestrators of tumor-induced immunosuppression, contributing to immune evasion, tumor progression and metastasis. T_regs express inhibitory immune checkpoint molecules and thus may be unintended targets for ICB therapy counteracting its efficacy. Using ICB-refractory models of spontaneous primary and metastatic breast cancer that recapitulate the poor ICB response of breast cancer patients, we observed that combined anti-PD-1 and anti-CTLA-4 therapy inadvertently promotes proliferation and activation of T_regs in the tumor, tumor-draining lymph node and circulation. Also in breast cancer patients, T_reg levels were elevated upon ICB. Depletion of T_regs during neoadjuvant ICB in tumor-bearing mice not only reshaped the intratumoral immune landscape into a state favorable for ICB response but also induced profound and persistent alterations in systemic immunity, characterized by elevated CD8+ T cells and NK cells and durable T cell activation that was maintained after treatment cessation. While depletion of T_regs in combination with neoadjuvant ICB did not inhibit primary tumor growth, it prolonged metastasis-related survival driven predominantly by CD8+ T cells. This study demonstrates that neoadjuvant ICB therapy of breast cancer can be empowered by simultaneous targeting of T_regs, extending metastasis-related survival, independent of a primary tumor response.

Eosinophilia in cancer and its regulation by sex hormones

Gender differences in the functionality of the immune system have been attributed, in part, to direct and indirect effects of sex steroids, especially estrogens, on immune cell repertoire and activity. Notable are studies that have defined roles for estrogens in the regulation of the biology of dendritic cells (DCs), macrophages, T cells and natural killer (NK) cells. Although estrogens can modulate eosinophil function, the mechanisms by which this occurs and how it contributes to the pathobiology of different diseases remains underexplored. Furthermore, although the importance of eosinophils in infection is well established, it remains unclear as to how these innate immune cells, which are present in different tumors, impact the biology of cancer cells and/or response to therapeutics. The observation that eosinophilia influences the efficacy of immune checkpoint blockers (ICBs) is significant considering the role of estrogens as regulators of eosinophil function and recent studies suggesting that response to ICBs is impacted by gender. Thus, in this review, we consider what is known about the roles of estrogen(s) in regulating tissue eosinophilia/eosinophil function and how this influences the pathobiology of breast cancer (in particular). This information provides the context for a discussion of how estrogens/the estrogen receptor (ER) signaling axis can be targeted in eosinophils and how this would be expected to influence the activity of standard-of-care interventions and contemporary immunotherapy regimens in cancer(s).

IL-2/GM-CSF enhances CXCR3 expression in CAR-T cells via the PI3K/AKT and ERK1/2 pathways

OBJECTIVE

To investigate the effects of cytokines IL-2 and GM-CSF on CXCR3 expression and chemotaxis of CAR-T cells.

BACKGROUND

High lymphocyte infiltration within the tumor is a basic requirement for good results in tumor immunotherapy; C-X-C motif chemokine receptor 3 (CXCR3) is an important factor for the chemotaxis of lymphocytes to tumor tissues. The tumor microenvironment can exhibit diverse cytokine suppression or promote antitumor immunity. Both interleukin (IL)-2 and granulocyte macrophage colony-stimulating factor (GM-CSF) contribute to the regulation of immunosuppression in the tumor microenvironment. However, the effects of IL-2 and GM-CSF on CXCR3 expression on the T cell surface and its mechanisms are not well understood. Here, we explored the effects of polycytokines on CXCR3 expression in chimeric antigen receptor T cells (CAR-T cells) and on HuH-7 in situ hepatocellular carcinoma.

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated, followed by purifying using CD3 immunomagnetic beads. Cells were divided into three groups. After 24h of activation using CD3/CD28 antibody, T cells were transfected using lentiviral vector, pGC-SV40-EGFP-GPC3-CAR. Three culture methods were used to amplify the transfected T cells. Method 'A' was to incubate T cells with CD3/CD28 antibody; method 'B' was with CD3/CD28 antibody and IL-2 at a final concentration of 1000 U/ml; method 'C' was with method B in addition of GM-CSF at a final concentration of 1000 U/ml. The phosphorylation of MAPK and PI3K/AKT was determined by western blot. The chemotaxis effect of CAR-T cells on Huh-7 HCCIA in situ was assayed by immunofluorescence and immunohistochemistry.

RESULTS

The CD3/CD28/IL-2/GM-CSF combination is the most potent for stimulating activated CAR-T cell proliferation and CXCR3 expression in vitro; CD3/CD28/IL-2 induces CAR-T cell expression of CXCR3 through the activation of the PI3K/APK pathway and GM-CSF induces CXCR3 expression in CAR-T cells through the activation of ERK1/2 rather than the p38 MAPK signaling pathway. CAR-GPC3-T cells with high CXCR3 expression showed increased chemotaxis ability to HuH in situ hepatocellular carcinoma, and considerably inhibited the growth of in situ tumors in nude mouse livers.

CONCLUSION

A multi-factorial amplification protocol can effectively improve CXCR3 expression on the surface of activated CAR-T cells in vitro, as well as enhance the chemotaxis ability of CAR-T cells in vivo, which significantly inhibit the growth of liver cancer.

Immune-Related Gene Signatures to Predict the Effectiveness of Chemoimmunotherapy in Triple-Negative Breast Cancer Using Exploratory Subgroup Discovery

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited therapeutic options. Although immunotherapy has shown potential in TNBC patients, clinical studies have only demonstrated a modest response. Therefore, the exploration of immunotherapy in combination with chemotherapy is warranted. In this project we identified immune-related gene signatures for TNBC patients that may explain differences in patients' outcomes after anti-PD-L1+chemotherapy treatment. First, we ran the exploratory subgroup discovery algorithm on the TNBC dataset comprised of 422 patients across 24 studies. Secondly, we narrowed down the search to twelve homogenous subgroups based on tumor mutational burden (TMB, low or high), relapse status (disease-free or recurred), tumor cellularity (high, low and moderate), menopausal status (pre- or post) and tumor stage (I, II and III). For each subgroup we identified a union of the top 10% of genotypic patterns. Furthermore, we employed a multinomial regression model to predict significant genotypic patterns that would be linked to partial remission after anti-PD-L1+chemotherapy treatment. Finally, we uncovered distinct immune cell populations (T-cells, B-cells, Myeloid, NK-cells) for TNBC patients with various treatment outcomes. CD4-Tn-LEF1 and CD4-CXCL13 T-cells were linked to partial remission on anti-PD-L1+chemotherapy treatment. Our informatics pipeline may help to select better responders to chemoimmunotherapy, as well as pinpoint the underlying mechanisms of drug resistance in TNBC patients at single-cell resolution.

Association of Pretreatment Neutrophil-to-Eosinophil Ratio with Clinical Outcomes in Patients with Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma Treated with Nivolumab

BACKGROUND

There is a need to develop biomarkers for a more efficient use of immune checkpoint inhibitors (ICIs). Recently, it has been reported that peripheral blood components, including eosinophils, may be effective ICI biomarkers. This study was designed to evaluate the prognostic value of eosinophils for measuring the effects of nivolumab on recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC).

MATERIALS AND METHODS

The study included 47 patients with R/M HNSCC treated with nivolumab. Eosinophil-related biomarkers, such as absolute eosinophil count (AEC), relative eosinophil count (REC), and neutrophil-to-eosinophil ratio (NER), were measured from the peripheral blood of the patients before nivolumab treatment. For each biomarker, the patients were divided into a high- and a low-value group according to their cutoff values, and these groups were compared.

RESULTS

Regarding AEC and REC, no significant improvement in the objective response rate (ORR) was observed between patients with AEC >0.9 × 103/μL and those with AEC <0.9 × 103/μL (p = 0.147) and between patients with REC >2.2% and those with REC <2.2% (p = 0.110). However, patients with NER <32 had improved ORR compared with those with NER >32 (P = 0.0361). Additionally, although patients with AEC >0.9 × 103/μL, REC >2.2%, and NER <32 had longer overall survival (OS) than those with AEC <0.9 × 103/μL, REC <2.2%, and NER >32, only patients with NER <32 showed prolonged progression-free survival (PFS) compared with those with NER >32 according to the Log rank test (p = 0.046, 0.027, and 0.035, respectively). Furthermore, the multivariate analysis revealed that baseline NER >32 (p = 0.027) was an independent prognostic factor for worse OS.

CONCLUSION

A pretreatment feature of low NER (NER <32) may predict better clinical outcomes in patients with R/M HNSCC treated with nivolumab.

Activated Eosinophils Predict Longer Progression-Free Survival under Immune Checkpoint Inhibition in Melanoma

Immune checkpoint inhibition (ICI) has yielded remarkable results in prolonging survival of metastatic melanoma patients but only a subset of individuals treated respond to therapy. Success of ICI treatment appears to depend on the number of tumor-infiltrating effector T-cells, which are known to be influenced by activated eosinophils. To verify the co-occurrence of activated eosinophils and T-cells in melanoma, immunofluorescence was performed in 285 primary or metastatic tumor tissue specimens from 118 patients. Moreover, eosinophil counts and activity markers such as eosinophil cationic protein (ECP) and eosinophil peroxidase (EPX) were measured in the serum before therapy start and before the 4th infusion of ICI in 45 metastatic unresected melanoma patients. We observed a positive correlation between increased tumor-infiltrating eosinophils and T-cells associated with delayed melanoma progression. High baseline levels of eosinophil count, serum ECP and EPX were linked to prolonged progression-free survival in metastatic melanoma. Our data provide first indications that activated eosinophils are related to the T-cell-inflamed tumor microenvironment and could be considered as potential future prognostic biomarkers in melanoma.

Manipulation of the crosstalk between tumor angiogenesis and immunosuppression in the tumor microenvironment: Insight into the combination therapy of anti-angiogenesis and immune checkpoint blockade

Immunotherapy has been recognized as an effective and important therapeutic modality for multiple types of cancer. Nevertheless, it has been increasing recognized that clinical benefits of immunotherapy are less than expected as evidenced by the fact that only a small population of cancer patients respond favorably to immunotherapy. The structurally and functionally abnormal tumor vasculature is a hallmark of most solid tumors and contributes to an immunosuppressive microenvironment, which poses a major challenge to immunotherapy. In turn, multiple immune cell subsets have profound consequences on promoting neovascularization. Vascular normalization, a promising anti-angiogenic strategy, can enhance vascular perfusion and promote the infiltration of immune effector cells into tumors via correcting aberrant tumor blood vessels, resulting in the potentiation of immunotherapy. More interestingly, immunotherapies are prone to boost the efficacy of various anti-angiogenic therapies and/or promote the morphological and functional alterations in tumor vasculature. Therefore, immune reprograming and vascular normalization appear to be reciprocally regulated. In this review, we mainly summarize how tumor vasculature propels an immunosuppressive phenotype and how innate and adaptive immune cells modulate angiogenesis during tumor progression. We further highlight recent advances of anti-angiogenic immunotherapies in preclinical and clinical settings to solidify the concept that targeting both tumor blood vessels and immune suppressive cells provides an efficacious approach for the treatment of cancer.

Estrogen-induced immune changes within the normal mammary gland

Breast cancer (BCa) incidence increases following aberrant hormone exposure, which has been linked to direct effects on estrogen receptor (ER)⁺ mammary epithelium. While estrogen exposure during mammary involution has been shown to drive tumour growth via neutrophils, the potential for the ER + immune microenvironment to mediate part (in addition to mammary epithelial cells) of hormonally controlled BCa risk during normal development has not been assessed. We collected mammary tissue, lymph nodes and blood from tumour naïve mice treated with, oophorectomy, estrogen (17β estradiol) or Fulvestrant. Flow cytometry was used to examine the impact on the frequency of innate and adaptive immune cells. Oophorectomy and fulvestrant decreased the proportion of macrophages, particularly pro-tumour polarized M2 macrophages and neutrophils. Conversely, dendritic cells were increased by these therapies, as were eosinophils. Estrogen increased the proportion of M2 macrophages and to a lesser extent CD4-CD8- double negative and FoxP3⁺ regulatory T cells but decreased CD8 + T cells and B cells. Excluding eosinophils, these changes were restricted to the mammary tissue. This suggests that inhibiting estrogen action lowers the immune suppressive myeloid cells, increases in antigen presentation and eosinophil-mediated direct or indirect cytotoxic effects. In contrast, estrogen exposure, which drives BCa risk, increases the suppressive myeloid cells and reduces anti-tumour cytotoxic T cells. The impact of hormonal exposure on BCa risk, may in part be linked to its immune modulatory activity.