The role of regulatory T cells in cancer

Guardians and Mediators of Metastasis: Exploring T Lymphocytes, Myeloid-Derived Suppressor Cells, and Tumor-Associated Macrophages in the Breast Cancer Microenvironment

Breast cancers (BCs) are solid tumors composed of heterogeneous tissues consisting of cancer cells and an ever-changing tumor microenvironment (TME). The TME includes, among other non-cancer cell types, immune cells influencing the immune context of cancer tissues. In particular, the cross talk of immune cells and their interactions with cancer cells dramatically influence BC dissemination, immunoediting, and the outcomes of cancer therapies. Tumor-infiltrating lymphocytes (TILs), tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs) represent prominent immune cell populations of breast TMEs, and they have important roles in cancer immunoescape and dissemination. Therefore, in this article we review the features of TILs, TAMs, and MDSCs in BCs. Moreover, we highlight the mechanisms by which these immune cells remodel the immune TME and lead to breast cancer metastasis.

Immunotherapy Innovations in the Fight against Osteosarcoma: Emerging Strategies and Promising Progress

Immunosuppressive elements within the tumor microenvironment are the primary drivers of tumorigenesis and malignant advancement. The presence, as well as the crosstalk between myeloid-derived suppressor cells (MDSCs), osteosarcoma-associated macrophages (OS-Ms), regulatory T cells (Tregs), and endothelial cells (ECs) with osteosarcoma cells cause the poor prognosis of OS. In addition, the consequent immunosuppressive factors favor the loss of treatment potential. Nanoparticles offer a means to dynamically and locally manipulate immuno-nanoparticles, which present a promising strategy for transforming OS-TME. Additionally, chimeric antigen receptor (CAR) technology is effective in combating OS. This review summarizes the essential mechanisms of immunosuppressive cells in the OS-TME and the current immune-associated strategies. The last part highlights the limitations of existing therapies and offers insights into future research directions.

Evaluating CD4 and Foxp3 mRNA Expression in Tissue Specimens of Celiac Disease and Colorectal Cancer Patients

OBJECTIVE

Celiac disease (CD) and colorectal cancer (CRC) are distinct gastrointestinal conditions with a debated association. This study aimed to evaluate the mRNA expression of CD4 and Foxp3 in tissue specimens of CD and CRC patients. The findings can provide valuable insights into the complex connection between these different gastrointestinal conditions.

METHODS

Tissue samples from 100 CRC patients, 50 CD patients, and 50 healthy controls (HCs) were collected. RNA extraction, cDNA synthesis, and quantitative real-time PCR were performed. Statistical analysis was conducted using ANOVA and Pearson's correlation test.

RESULT

CD4 mRNA expression was significantly higher in CRC patients compared to CD patients and HCs (P<0.0001 for both). Foxp3 mRNA expression was significantly higher in CD patients compared to CRC patients and HCs (P<0.0001 for both). Clinicopathological characteristics did not correlate significantly with gene expression levels.

CONCLUSION

This study reveals differential expression patterns of CD4 and Foxp3 mRNA in CRC and CD patients. Upregulated CD4 mRNA suggests its potential role in promoting tumor growth, while increased Foxp3 mRNA expression may reflect an immunosuppressive mechanism in CD pathogenesis. These findings provide insights into the molecular and immunological aspects of CRC and CD, warranting further studies for potential therapeutic strategies.

Integrated Bulk and Single-cell RNA Sequencing Data Constructs and Validates a Prognostic Model for Non-small Cell Lung Cancer

Background: Most of the current research on prognostic model construction for non-small cell lung cancer (NSCLC) only involves in bulk RNA-seq data without integration of single-cell RNA-seq (scRNA-seq) data. Besides, most of the prognostic models are constructed by predictive genes, ignoring other predictive variables such as clinical features. Methods: We obtained scRNA-seq data from GEO database and bulk RNA-seq data from TCGA database. We construct a prognostic model through the Least Absolute Shrinkage and Selection Operator (LASSO) and Cox regression. Furthermore, we performed ESTIMATE, CIBERSORT, immune checkpoint-related analyses and compared drug sensitivity using pRRophetic method judged by IC50 between different risk groups. Results: 14 tumor-related genes were extracted for model construction. The AUC for 1-, 3-, and 5 years overall survival prediction in TCGA and three validation cohorts were almost higher than 0.65, some of which were even higher than 0.7, even 0.8. Besides, calibration curves suggested no departure between model prediction and perfect fit. Additionally, immune-related and drug sensitivity results revealed potential targets and strategies for treatment, which can provide clinical guidance. Conclusion: We integrated traditional bulk RNA-seq and scRNA-seq data, along with predictive clinical features to develop a prognostic model for patients with NSCLC. According to the constructed model, patients in different groups can follow precise and individual therapeutic schedules based on immune characteristics as well as drug sensitivity.

Intricacies of TGF-β signaling in Treg and Th17 cell biology

Balanced immunity is pivotal for health and homeostasis. CD4+ helper T (Th) cells are central to the balance between immune tolerance and immune rejection. Th cells adopt distinct functions to maintain tolerance and clear pathogens. Dysregulation of Th cell function often leads to maladies, including autoimmunity, inflammatory disease, cancer, and infection. Regulatory T (Treg) and Th17 cells are critical Th cell types involved in immune tolerance, homeostasis, pathogenicity, and pathogen clearance. It is therefore critical to understand how Treg and Th17 cells are regulated in health and disease. Cytokines are instrumental in directing Treg and Th17 cell function. The evolutionarily conserved TGF-β (transforming growth factor-β) cytokine superfamily is of particular interest because it is central to the biology of both Treg cells that are predominantly immunosuppressive and Th17 cells that can be proinflammatory, pathogenic, and immune regulatory. How TGF-β superfamily members and their intricate signaling pathways regulate Treg and Th17 cell function is a question that has been intensely investigated for two decades. Here, we introduce the fundamental biology of TGF-β superfamily signaling, Treg cells, and Th17 cells and discuss in detail how the TGF-β superfamily contributes to Treg and Th17 cell biology through complex yet ordered and cooperative signaling networks.

The Immunomodulatory Effect of β-Glucan Depends on the Composition of the Gut Microbiota

This study aimed to elucidate the relationship between the immunomodulatory effects of β-glucan and the composition of gut microbiota in mice. The mice were fed a diet containing β-glucan for 3 weeks, and feces, blood, and tissues were then collected to analyze the immunomodulatory effect and gut microbiota composition. Based on the results of the analysis of the expression level of immune-associated proteins, the high immunomodulatory effect group (HIE) and low immunomodulatory effect group (LIE) were categorized. Before the β-glucan diet, the proportions of the phylum Bacteroidota, family Muribaculaceae, and family Lactobacillaceae were significantly higher in HIE than in LIE. Furthermore, the genus Akkermansia was absent before the β-glucan diet and increased after β-glucan diet. These microbes had the ability to metabolize β-glucan or were beneficial to health. In conclusion, our findings demonstrate that variation in the composition of gut microbiota among individuals can result in varying expressions of β-glucan functionality. This outcome supports the notion that β-glucan may be metabolized through diverse pathways by gut microbes originally possessed by mice, subsequently producing various metabolites, such as short-chain fatty acids. Alternatively, the viscosity of the intestinal mucosa could be enhanced by β-glucan, potentially promoting the growth of certain bacteria (e.g., the genus Akkermansia). This study provides insights into the intricate interplay between β-glucan, gut microbiota, and immunomodulation.

Inhibition of MC38 colon cancer growth by multicomponent chemoimmunotherapy with anti-IL-10R antibodies, HES-MTX nanoconjugate, depends on application of IL-12, IL-15 or IL-18 secreting dendritic cell vaccines

Background

The tumor microenvironment (TME) provides a conducive environment for the growth and survival of tumors. Negative factors present in TME, such as IL-10, may limit the effectiveness of cellular vaccines based on dendritic cells, therefore, it is important to control its effect. The influence of IL-10 on immune cells can be abolished e.g., by using antibodies against the receptor for this cytokine - anti-IL-10R. Furthermore, the anticancer activity of cellular vaccines can be enhanced by modifying them to produce proinflammatory cytokines, such as IL-12, IL-15 or IL-18. Additionally, an immunomodulatory dose of methotrexate and hydroxyethyl starch (HES-MTX) nanoconjugate may stimulate effector immune cells and eliminate regulatory T cells, which should enhance the antitumor action of immunotherapy based on DC vaccines. The main aim of our study was to determine whether the HES-MTX administered before immunotherapy with anti-IL-10R antibodies would change the effect of vaccines based on dendritic cells overproducing IL-12, IL-15, or IL-18.

Methods

The activity of modified DCs was checked in two therapeutic protocols - immunotherapy with the addition of anti-IL10R antibodies and chemoimmunotherapy with HES-MTX and anti-IL10R antibodies. The inhibition of tumor growth and the effectiveness of the therapy in inducing a specific antitumor response were determined by analyzing lymphoid and myeloid cell populations in tumor nodules, and the activity of restimulated splenocytes.

Results and conclusions

Using the HES-MTX nanoconjugate before immunotherapy based on multiple administrations of anti-IL-10R antibodies and cellular vaccines capable of overproducing proinflammatory cytokines IL-12, IL-15 or IL-18 created optimal conditions for the effective action of these vaccines in murine colon carcinoma MC38 model. The applied chemoimmunotherapy caused the highest inhibition of tumor growth in the group receiving DC/IL-15/IL-15Rα/TAg + DC/IL-18/TAg at the level of 72.4%. The use of cellular vaccines resulted in cytotoxic activity increase in both immuno- or chemoimmunotherapy. However, the greatest potential was observed both in tumor tissue and splenocytes obtained from mice receiving two- or three-component vaccines in the course of combined application. Thus, the designed treatment schedule may be promising in anticancer therapy.

Tumor-resident regulatory T cells in pancreatic cancer express the αvβ5 integrin as a targetable activation marker

Pancreatic ductal adenocarcinoma (PDAC) has abundant immunosuppressive regulatory T cells (Tregs), which contribute to a microenvironment resistant to immunotherapy. Here, we report that Tregs in the PDAC tissue, but not those in the spleen, express the αvβ5 integrin in addition to neuropilin-1 (NRP-1), which makes them susceptible to the iRGD tumor-penetrating peptide, which targets cells positive for αv integrin- and NRP-1. As a result, long-term treatment of PDAC mice with iRGD leads to tumor-specific depletion of Tregs and improved efficacy of immune checkpoint blockade. αvβ5 integrin ⁺ Tregs are induced from both naïve CD4 ⁺ T cells and natural Tregs upon T cell receptor stimulation, and represent a highly immunosuppressive subpopulation of CCR8 ⁺ Tregs. This study identifies the αvβ5 integrin as a marker for activated tumor-resident Tregs, which can be targeted to achieve tumor-specific Treg depletion and thereby augment anti-tumor immunity for PDAC therapy.

Investigation on the regulatory T cells signature and relevant Foxp3/STAT3 axis in esophageal cancer

BACKGROUND

Regulatory T cells (Tregs) have an important role in accelerating the immunosuppression of tumor. Tregs regulation is a hopeful strategy to improve the dismal prognosis of Esophageal cancer (EC), while its mechanisms have not yet been fully clarified.

METHODS

To characterize the role of Tregs in EC, we comprehensively explored its prognostic value, clinical pathology partnership, related biological functions and potential mechanisms at transcriptome level. Through the integrated analysis of GEO and TCGA datasets, we comprehensively evaluated the Tregs infiltration patterns in EC patients. The correlation between Tregs infiltration and genomic characteristics, as well as biological functions were analyzed by a variety of computational algorithms.

RESULTS

We observed that Tregs were significantly upregulated in EC and involved in various immune processes. According to TCGA and GEO transcriptional classification schemes, Tregs specific genes were observed to be highly expressed in tumor samples, as well as were closely associated with poor prognosis and worse clinical outcomes. In addition, EC patients can be stratified into high-risk and low-risk immune subgroups according to Tregs/macrophages infiltration level, and the results showed significant differences in tumor development, biological processes and probe gene expression pattern. The multi-variate analysis revealed that the interaction between STAT3 and Foxp3 was a potential prognostic signature of Tregs in EC, especially the modulation effect of STAT3 on Foxp3 expression, which has not been well studied in EC. We also identified that STAT3 and Foxp3 expression presented a high accuracy in predicting Tregs infiltration level in EC patients (AUC: 0.817; 95% CI: 0.756-0.878).

CONCLUSIONS

Our results revealed that Tregs have the potential to predict prognosis and tumor deterioration in EC patients. A comprehensive landscape of Tregs regulation mechanisms will help us interpret the immunosuppression of tumor microenvironment (TME) and novel strategies for EC immunotherapy.

CC Chemokine Receptor 4 (CCR4) as a Possible New Target for Therapy

Chemokines and their receptors participate in many biological processes, including the modulation of neuroimmune interactions. Approximately fifty chemokines are distinguished in humans, which are classified into four subfamilies based on the N-terminal conserved cysteine motifs: CXC, CC, C, and CX3C. Chemokines activate specific receptors localized on the surface of various immune and nervous cells. Approximately twenty chemokine receptors have been identified, and each of these receptors is a seven-transmembrane G-protein coupled receptor. Recent studies provide new evidence that CC chemokine receptor 4 (CCR4) is important in the pathogenesis of many diseases, such as diabetes, multiple sclerosis, asthma, dermatitis, and cancer. This review briefly characterizes CCR4 and its ligands (CCL17, CCL22, and CCL2), and their contributions to immunological and neoplastic diseases. The review notes a significant role of CCR4 in nociceptive transmission, especially in painful neuropathy, which accompanies many diseases. The pharmacological blockade of CCR4 seems beneficial because of its pain-relieving effects and its influence on opioid efficacy. The possibilities of using the CCL2/CCL17/CCL22/CCR4 axis as a target in new therapies for many diseases are also discussed.

Primary central nervous system Hodgkin lymphoma: A case report and review of the literature

Central nervous system (CNS) involvement in the context of relapsed/refractory Hodgkin lymphoma (HL) is a quite rare, but well-known complication. Nevertheless, primary CNS-HL is an exceedingly rare condition, which diagnosis is based on well-defined morphological and immunohistochemical features, in addition to isolated involvement of the CNS. In spite of limited casuistry (just over twenty cases reported in the literature), available data agree that primary and isolated CNS-HL, when treated with a combination of surgery followed by some form of adjuvant therapy (radiotherapy±chemotherapy), carries a better prognosis than those cases with CNS involvement in the context of relapsed/refractory HL or those with CNS non-Hodgkin lymphoma. We herein report a case of a 55-year-old female patient who was diagnosed with primary CNS-HL. The patient was treated with complete surgical resection followed by intrathecal chemotherapy and whole brain radiotherapy (WBRT), showing fourteen months of disease-free survival at the time of this case report. A review of the available literature is also presented.

The Modulatory Effects and Targets Prediction of Herbal Medicines or Phytochemicals on Cancer Immunosurveillance

Cancer is a main life-threatening disease worldwide. Due to the adverse effects of conventional chemotherapies and radiotherapies, immunotherapy has emerged as a potent strategy to treat cancer. In cancer immunotherapy, cancer immune surveillance plays a crucial role in the cancer process, which contains various effector cells from innate and adaptive immunity. This review summarized the functions of innate and adaptive immune cells in cancer immunosurveillance and their main reported targets. Moreover, the potential targets about the modulatory effects of cancer immunosurveillance were predicted using network-based target analysis, with total predicted pathways not only reporting previously reported pathways, but also putative signaling pathways pending for investigation. In addition, the potential use of herbal medicines and their phytochemicals in the modulation of cancer immunosurveillance were also discussed. Taken together, this review paper aims to provide scientific insight into further drug development, particularly herbs, phytochemicals, and TCM formulae, in the modulatory effects of cancer immunosurveillance.

Leukocyte modulation by natural products from herbal medicines and potential as cancer immunotherapy

Cancer constitutes a kind of life-threatening disease that is prevalent throughout the world. In light of limitations in conventional chemotherapies or radiotherapies, cancer immunotherapy has emerged as a potent strategy in treating cancer. In cancer immunotherapy, preliminary studies have demonstrated that cancer immune surveillance serves a crucial role in tumor initiation, progression, and metastasis. Herbal medicines and natural products, which serve as alternative medicines, are involved in the modulation of tumor immunosurveillance to enhance antitumor activity. Accordingly, this review aimed to summarize the modulation function of herbal medicines and natural products on tumor immunosurveillance while providing scientific insight into further research on its molecular mechanism and potential clinical applications.

Clinical analysis and artificial intelligence survival prediction of serous ovarian cancer based on preoperative circulating leukocytes

Circulating leukocytes are an important part of the immune system. The aim of this work is to explore the role of preoperative circulating leukocytes in serous ovarian carcinoma and investigate whether they can be used to predict survival prognosis. Routine blood test results and clinical information of patients with serous ovarian carcinoma were retrospectively collected. And to predict survival according to the blood routine test result the decision tree method was applied to build a machine learning model.

The results showed that the number of preoperative white blood cells (p = 0.022), monocytes (p < 0.001), lymphocytes (p < 0.001), neutrophils (p < 0.001), and eosinophils (p < 0.001) and the monocyte to lymphocyte (MO/LY) ratio in the serous ovarian cancer group were significantly different from those in the control group. These factors also showed a correlation with other clinicopathological characteristics. The MO/LY was the root node of the decision tree, and the predictive AUC for survival was 0.69. The features involved in the decision tree were the MO/LY, differentiation status, CA125 level, neutrophils (NE,) ascites cytology, LY% and age.

In conclusion, the number and percentage of preoperative leukocytes in patients with ovarian cancer is changed significantly compared to those in the normal control group, as well as the MO/LY. A decision tree was built to predict the survival of patients with serous ovarian cancer based on the CA125 level, white blood cell (WBC) count, presence of lymph node metastasis (LNM), MO count, the MO/LY ratio, differentiation status, stage, LY%, ascites cytology, and age.

RNA modification writers influence tumor microenvironment in gastric cancer and prospects of targeted drug therapy

Background: RNA adenosine modifications are crucial for regulating RNA levels. N6-methyladenosine (m6A), N1-methyladenosine (m1A), adenosine-to-inosine RNA editing, and alternative polyadenylation (APA) are four major RNA modification types. Methods: We evaluated the altered mRNA expression profiles of 27 RNA modification enzymes and compared the differences in tumor microenvironment (TME) and clinical prognosis between two RNA modification patterns using unsupervised clustering. Then, we constructed a scoring system, WM_score, and quantified the RNA modifications in patients of gastric cancer (GC), associating WM_score with TME, clinical outcomes, and effectiveness of targeted therapies. Results: RNA adenosine modifications strongly correlated with TME and could predict the degree of TME cell infiltration, genetic variation, and clinical prognosis. Two modification patterns were identified according to high and low WM_scores. Tumors in the WM_score-high subgroup were closely linked with survival advantage, CD4[Formula: see text] T-cell infiltration, high tumor mutation burden, and cell cycle signaling pathways, whereas those in the WM_score-low subgroup showed strong infiltration of inflammatory cells and poor survival. Regarding the immunotherapy response, a high WM_score showed a significant correlation with PD-L1 expression, predicting the effect of PD-L1 blockade therapy. Conclusion: The WM_scoring system could facilitate scoring and prediction of GC prognosis.

Regulatory T Cells in Autoimmune Vasculitis

Blood vessels are indispensable for host survival and are protected from inappropriate inflammation by immune privilege. This protection is lost in patients with autoimmune vasculitides, a heterogeneous group of diseases causing damage to arteries, arterioles, and capillaries. Vasculitis leads to vascular wall destruction and/or luminal occlusion, resulting in hemorrhage and tissue ischemia. Failure in the quantity and quality of immunosuppressive regulatory T cells (Treg) has been implicated in the breakdown of the vascular immune privilege. Emerging data suggest that Treg deficiencies are disease-specific, affecting distinct pathways in distinct vasculitides. Mechanistic studies have identified faulty CD8+ Tregs in Giant Cell Arteritis (GCA), a vasculitis of the aorta and the large aortic branch vessels. Specifically, aberrant signaling through the NOTCH4 receptor expressed on CD8+ Treg cells leads to rerouting of intracellular vesicle trafficking and failure in the release of immunosuppressive exosomes, ultimately boosting inflammatory attack to medium and large arteries. In Kawasaki’s disease, a medium vessel vasculitis targeting the coronary arteries, aberrant expression of miR-155 and dysregulated STAT5 signaling have been implicated in undermining CD4+ Treg function. Explorations of mechanisms leading to insufficient immunosuppression and uncontrolled vascular inflammation hold the promise to discover novel therapeutic interventions that could potentially restore the immune privilege of blood vessels and pave the way for urgently needed innovations in vasculitis management.

Recent advances in immunotherapy for hepatocellular carcinoma

BACKGROUND

Treatment of hepatocellular carcinoma (HCC) is challenging as most patients are diagnosed at advanced stage with underlying chronic liver conditions. Conventional systemic chemotherapy has failed in HCC, and the clinical efficacy of FDA-approved molecular targeted agents such as sorafenib and lenvatinib remains unsatisfactory.

DATA SOURCES

Literature search was conducted in PubMed for relevant articles published before January 2021. The search aimed to identify recent developments in immune-based treatment approaches for HCC. Information of clinical trials was obtained from https://clinicaltrials.gov/.

RESULTS

Two immune checkpoint inhibitors (ICIs), nivolumab and pembrolizumab were approved as monotherapies, which has revolutionized HCC treatment. Besides, combination ICIs have also got accelerated FDA approval recently. Immune-based therapies have challenged targeted drugs owing to their safety, tolerability, and survival benefits. In addition to the significant success in ICIs, other immunotherapeutic strategies such as cancer vaccine, chimeric antigen receptor T-cells, natural killer cells, cytokines, and combination therapy, have also shown promising outcomes in clinical trials. Various diagnostic and prognostic biomarkers have been identified which can help in clinical decision making when starting treatment with ICIs.

CONCLUSIONS

Immunotherapy has emerged as one of the mainstream treatment modalities for advanced HCC in recent years. However, challenges such as low response rate and acquired resistance in previously respondent patients still exist. Further research is needed to understand the unique resistance mechanism to immunotherapy and to discover more predictive biomarkers to guide clinical decision making.

Modulation of T-cell Regulators Associated with Advanced Stage of Prostate Cancer

Background:

Benign prostatic hyperplasia (BPH) and prostate cancer are the most common prostate diseases. The possible role of the immune system in the pathogenesis of BPH and prostate cancer in recent years has begun to be widely studied. Although many studies have focused on T lymphocytes on the development of BPH and prostate cancer, the role of regulatory T-cells in the pathogenesis of BPH and prostate cancer is still not well known.

Objective:

To determine the amount of regulatory T-cells in prostate cancer and BPH so that it can contribute to the concept of understanding the pathogenesis of prostate cancer and BPH.

Methods:

This study used cross-sectional design study. Total samples were 24 patients, with 13 subjects prostate cancer group, and 11 subjects BPH group. Furthermore, peripheral blood samples are taken and then the amount of regulatory T-cells is calculated. After obtaining data on the amount of CD4⁺ CD25⁺ Foxp3⁺ regulatory T-cells in the blood, data analysis was performed between groups of patients diagnosed with prostate cancer and benign prostatic hyperplasia.

Results:

The average amount of regulatory T-cells in the CRPC group was 53.44±29.43, prostate cancer group was 57.02±22.49 and the BPH group 89.71±9.31. One Way ANOVA test results showed that the average amount of regulatory T-cells between treatment groups gave a significant difference in regulatory T-cells with a p-value (0,003) <0.05. It can be concluded that there are differences in the average amount of regulatory T-cells, so we continued the testing with Tukey test. We continue to Pearson correlation study and resulted in significantly correlated with p value = 0.011 (P<0.05) and r = 0.414.

Conclusions:

It can be concluded there was significant difference between the average number of regulator T-cells in the BPH group compared with prostate cancer and CRPC patient. Further research is needed regarding the number of regulator T-cells CD4 + CD25 + FOXP3 + in prostate cancer patients (grouped according to Gleason score) and benign prostatic hyperplasia before and after therapy with bigger samples.

Primary central nervous system Hodgkin Lymphoma: A case discussion and a hypothesis on the etiology

Hodgkin Lymphoma (HL) is a systemic disease with involvement of the cervical, supraclavicular, and mediastinal lymph nodes. It is commonly diagnosed in patients within the second and third decades of their lives. Diagnosis is usually made based on the distinct morphological and immunohistochemical characteristics, with the tissue biopsy being the cornerstone of workup. Extranodal presentation of HL is unusual and seldom encountered. Primary HL of the central nervous system (CNS) is exceedingly rare. We herein report a case of a 38-year-old male patient who was diagnosed with primary CNS-HL. The patient was treated with complete surgical resection followed by radiotherapy and chemotherapy. The patient was disease-free for 7 years postoperatively without any clinical evidence of relapse. We also discussed a possible role of CNS regulatory T-cells (Tregs) in developmental primary CNS-HL.

EVA1C Is a Potential Prognostic Biomarker and Correlated With Immune Infiltration Levels in WHO Grade II/III Glioma

Background

Immunotherapy is an effective therapeutic approach for multiple human cancer types. However, the correlations between EVA1C and patients’ prognosis as well as immune infiltration remain obscure. Herein, we employed transcriptomic and clinical data extracted from two independent databases to systematically investigate the role of EVA1C in the oncological context.

Methods

The differential expression of EVA1C was analyzed via TCGA and Oncomine databases. We evaluated the influence of EVA1C on clinical prognosis using Kaplan-Meier plotter. We then used the expression profiler to calculate stromal score, immune score, and ESTIMATE score based on the ESTIMATE algorithm. The abundance of infiltrating immune cells was calculated via TIMER. The correlations between EVA1C expression and immune infiltration levels were analyzed in two independent cohorts.

Results

In patients with World Health Organization (WHO) grade II/III glioma, high EVA1C expression was associated with malignant clinicopathological features and poor overall survival in both cohorts. EVA1C expression was positively associated with immune infiltration levels of B cell, CD4+ T cell, neutrophil, macrophage, and dendritic cells (DCs). Besides, EVA1C expression strongly correlated with diverse immune marker sets. And the predictive power of EVA1C was better than that of other indicators in predicting high immune infiltration levels in glioma.

Conclusions

For the first time, we identified the overexpression of EVA1C in glioma, which was tightly correlated with the high infiltration levels of multiple immune cells as well as poor prognosis. Meanwhile, EVA1C might be a potential biomarker for predicting high immune infiltration in WHO grade II/III gliomas.

Nomogram based on immune scores for predicting the survival of patients with esophageal squamous cell carcinoma

Objective

To explore the relationship between immune scores and prognosis of patients with esophageal squamous cell carcinoma (ESCC) and construct a corresponding clinical prediction model.

Methods

The present research was a retrospective cohort study. We obtained the clinical information and immune scores of 137 patients with ESCC from The Cancer Genome Atlas database, and a Cox proportional risk model was used to construct the clinical prediction model. The concordance index, receiver operating characteristic curve, calibration curve, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were used to evaluate model performance and prediction accuracy.

Results

Patients with a high immune score (> −121.4) showed a worse prognosis than those with a low immune score (< −645.8; hazard ratio=3.743, 95% confidence interval [CI]=1.385–10.115, P=0.009). The concordance index of the predictive model was 0.733 (95% CI=0.655–0.812). The calibration curve showed that the 3- and 5-year overall survival rates predicted by the model were highly consistent with the observed values. The NRI and IDI for the 3-year overall survival indicated that the model with the immune scores was superior for classifying the risk probability and distinguishing cases.

Conclusion

Immune scores may be an independent predictor of prognosis in patients with ESCC.

Primary central nervous system Hodgkin's lymphoma: a case report

Primary central nervous system Hodgkin's lymphoma (CNS-HL) is extremely rare. This current case report describes a 60-year-old male patient that presented with numbness of the left lower extremity and worsening headache. After a full range of investigations and a partial resection of the right cerebellum, external ventricular drainage reservoir placement and cranioplasty, he was diagnosed with primary CNS-HL. The patient was treated with 3 g/m² methotrexate (intravenous [i.v.], once a day, day 1) and 1 g/m² cytarabine (i.v., every 12 h, days 2 + 3), followed by anti-programmed cell death protein 1 antibodies (200 mg sintilimab, i.v., once a day, day 1, every 3 weeks). After six courses of treatment with intrathecal injections of 50 mg cytarabine (once a day, day 1) and 5 mg dexamethasone (once a day, day 1), there was no residual lesion on cranial magnetic resonance imaging. No significant drug-related adverse events were observed. The patient has been followed up every 3 months and no relapse has occurred.

Interleukin-10: A double-edged sword in breast cancer

Breast cancer (BC) is a frequently diagnosed cancer among women worldwide. Currently, BC can be divided into different subgroups according to the presence of the following hormone receptors: estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. Each of these subgroups has different treatment strategies. However, the presence of new metastatic lesions and patient deterioration suggest resistance to a given treatment. Various lines of evidence had shown that cytokines are one of the important mediators of tumor growth, invasion, metastasis, and treatment resistance. Interleukin-10 (IL-10) is an immunoregulatory cytokine, and acts as a poor prognostic marker in many cancers. The anti-inflammatory IL-10 blocks certain effects of inflammatory cytokines. It also antagonizes the co-stimulatory molecules on the antigen-presenting cells. Here, we review the current knowledge on the function and molecular mechanism of IL-10, and recent findings on how IL-10 contributes to the progression of BC.

Immune System Efficiency in Cancer and the Microbiota Influence

The immune system plays a critical role in preventing cancer development and progression. However, the complex network of cells and soluble factor that form the tumor microenvironment (TME) can dictate the differentiation of tumor-infiltrating leukocytes and shift the antitumor immune response into promoting tumor growth. With the advent of cancer immunotherapy, there has been a reinvigorated interest in defining how the TME shapes the antitumor immune response. This interest brought to light the microbiome as a novel player in shaping cancer immunosurveillance. Indeed, accumulating evidence now suggests that the microbiome may confer susceptibility or resistance to certain cancers and may influence response to therapeutics, particularly immune checkpoint inhibitors. As we move forward into the age of precision medicine, it is vital that we define the factors that influence the interplay between the triad immune system-microbiota-cancer. This knowledge will contribute to improve the therapeutic response to current approaches and will unravel novel targets for immunotherapy.

Myeloid-Derived Suppressor Cell Differentiation in Cancer: Transcriptional Regulators and Enhanceosome-Mediated Mechanisms

Myeloid-derived Suppressor Cells (MDSCs) are a sub-population of leukocytes that are important for carcinogenesis and cancer immunotherapy. During carcinogenesis or severe infections, inflammatory mediators induce MDSCs via aberrant differentiation of myeloid precursors. Although several transcription factors, including C/EBPβ, STAT3, c-Rel, STAT5, and IRF8, have been reported to regulate MDSC differentiation, none of them are specifically expressed in MDSCs. How these lineage-non-specific transcription factors specify MDSC differentiation in a lineage-specific manner is unclear. The recent discovery of the c-Rel−C/EBPβ enhanceosome in MDSCs may help explain these context-dependent roles. In this review, we examine several transcriptional regulators of MDSC differentiation, and discuss the concept of non-modular regulation of MDSC signature gene expression by transcription factors such as c-Rel and C/EBPß.

Immunosuppressive Phenotype of Esophagus Tumors Stroma

Background

Tumor-associated macrophages (TAMs) and tumor-infiltrating lymphocytes (TILs) contribute significantly to the development of immunosuppressive properties of a tumor. In this study, we performed immunohistochemical analysis of immune cells of esophageal tumors stroma.

Methods

Paraffin-embedded tissue specimens from 48 esophageal squamous cell carcinoma (ESCC) patients were retrospectively collected for immunohistochemical analysis of stromal cells. For staining of macrophages, CD68, CD163, CD206, PU.1, and iNOS were used. For T cell detection, CD8, CD3, and FOXP3 were used. Also, we performed staining for PD-L1 that can be expressed on TAMs and tumor cells. Clinicopathological and survival data were collected and analyzed using the χ² and Fisher exact tests, Kaplan–Meier curves, and the log-rank test. The correlation analysis was performed with Spearman's rank correlation coefficient.

Results

We found that FOXP3 expression was associated with age (p = 0.042) and iNOS expression was associated with the disease stage (p = 0.044). In addition, FOXP3 and CD163 appeared to be markers of good prognosis (HR = 0.4420, p = 0.0325, and HR = 0.4447, p = 0.0456, respectively). Significant association between PU.1+ and CD68+ macrophages (r = 0.833; p ≤ 0.001) and between PU.1+ and CD163+ macrophages (r = 0.500; p ≤ 0.001) was established; positive association between PU.1 and CD206 expression was also observed (r = 0.250; p = 0.043).

Conclusions

Large amounts of CD163+ macrophages and FOXP3+ Т cells appear to be markers of good prognosis of ESCC. The number of PU.1+ macrophages strongly correlates with the number of CD68+ macrophages; therefore, usage of PU.1 as a potential macrophage marker can be recommended for esophageal tumors.

From Interconnection between Genes and Microenvironment to Novel Immunotherapeutic Approaches in Upper Gastro-Intestinal Cancers-A Multidisciplinary Perspective

Despite the progress during the last decade, patients with advanced gastric and esophageal cancers still have poor prognosis. Finding optimal therapeutic strategies represents an unmet need in this field. Several prognostic and predictive factors have been evaluated and may guide clinicians in choosing a tailored treatment. Data from large studies investigating the role of immunotherapy in gastrointestinal cancers are promising but further investigations are necessary to better select those patients who can mostly benefit from these novel therapies. This review will focus on the treatment of metastatic esophageal and gastric cancer. We will review the standard of care and the role of novel therapies such as immunotherapies and CAR-T. Moreover, we will focus on the analysis of potential predictive biomarkers such as Modify as: Microsatellite Instability (MSI) and PD-L1, which may lead to treatment personalization and improved treatment outcomes. A multidisciplinary point of view is mandatory to generate an integrated approach to properly exploit these novel antiproliferative agents.

Chinese Herbal Medicine and Its Regulatory Effects on Tumor Related T Cells

Traditional Chinese medicine is an accepted and integral part of clinical cancer management alongside Western medicine in China. However, historically TCM physicians were unaware of the chemical constituents of their formulations, and the specific biological targets in the body. Through HPLC, flow cytometry, and other processes, researchers now have a much clearer picture of how herbal medicine works in conjunction with the immune system in cancer therapy. Among them, the regulation of tumor-related T cells plays the most important role in modulating tumor immunity by traditional Chinese medicine. Encouraging results have been well-documented, including an increase in T cell production along with their associated cytokines, enhanced regulation of Tregs and important T cell ratios, the formation and function of Tregs in tumor microenvironments, and the promotion of the number and function of normal T Cells to reduce conventional cancer therapy side effects. Chinese herbal medicine represents a rich field of research from which to draw further inspiration for future studies. While promising agents have already been identified, the vast majority of Chinese herbal mechanisms remain undiscovered. In this review, we summarize the effects and mechanisms of specific Chinese herbs and herbal decoctions on tumor related T cells.

Duration of Environmental Enrichment Determines Astrocyte Number and Cervical Lymph Node T Lymphocyte Proportions but Not the Microglial Number in Middle-Aged C57BL/6 Mice

Environmental enrichment (EE) has been shown to modulate behavior and immunity. We recently reported that both short and long-term EE enhance baseline locomotion and alleviate depressive-like behavior, but only long-term EE affects locomotion adversely in a threatening environment and enhances anxiety-like behavior in middle-age mice. We have now investigated whether the observed changes in behavior after short- and long-term EE were associated with underlying immune changes. Hence, at the end of behavioral testing, mice were sacrificed, and brains and cervical lymph nodes were collected to investigate the differential effects of the duration of EE (short- and long-term) on the number of immunopositive glial cells in the dentate gyrus, CA1, CA2, and CA3 regions of the hippocampus and proportions of T cell subsets in the cervical lymph nodes using immunohistochemistry and flow cytometry, respectively. EE, regardless of duration, caused an increase in microglia number within the dentate gyrus, CA1 and CA3 hippocampal regions, but only long-term EE increased astrocytes number within the dentate gyrus and CA3 hippocampal regions. A significantly higher proportion of CD8⁺ naive T cells was observed after long-term EE vs. short-term EE. No significant differences were observed in the proportion of central memory and effector memory T cells or early activated CD25⁺ cells between any of the test groups. Our results suggest that EE, irrespective of duration, enhances the numbers of microglia, but long-term EE is required to modify astrocyte number and peripheral T cell proportions in middle-aged mice. Our findings provide new insights into the therapeutic effects of EE on various brain disorders, which may be at least partly mediated by glial and neuroimmune modulation.

Effects of dasatinib on CD8+T, Th1, and Treg cells in patients with chronic myeloid leukemia

OBJECTIVE

To investigate the immunomodulatory effects of the tyrosine kinase inhibitor (TKI) dasatinib on T-cell subtypes in patients with chronic myeloid leukemia (CML).

METHODS

T helper (Th) 1, Th2, regulatory T (Treg), and CD8+T cell levels were detected in patients with CML (n = 9) before and after dasatinib treatment. The corresponding response level at the time of a blood test was evaluated.

RESULTS

After dasatinib treatment, six patients achieved a better response level, while three did not show improved response levels. Among the total nine patients, there were no significant differences in Th1, Th2, and Treg cell levels, whereas CD8+T cell levels were significantly increased after dasatinib treatment compared with before treatment. When we analyzed the six patients who obtained a better response level, Th1 and CD8+T cell levels were significantly increased after dasatinib treatment, but Th2 and Treg cell levels did not change. The other three patients who did not have improved response levels showed decreased Th1 cell levels and increased Treg cell levels after treatment.

CONCLUSIONS

Dasatinib may increase Th1 and CD8+T cell levels, and decrease Treg cell levels in patients with CML. This finding might be associated with a good therapeutic response to this drug.

Low Dose Cyclophosphamide Modulates Tumor Microenvironment by TGF-β Signaling Pathway

The tumor microenvironment has been recently recognized as a critical contributor to cancer progression and anticancer therapy-resistance. Cyclophosphamide (CTX) is a cytotoxic agent commonly used in clinics for the treatment of cancer. Previous reports demonstrated that CTX given at low continuous doses, known as metronomic schedule, mainly targets endothelial cells and circulating Tregs with unknown mechanisms. Here, we investigated the antitumor activity of two different metronomic schedules of CTX along with their corresponding MTD regimen and further explored their effect on immune function and tumor microenvironment. Toxicity evaluation was monitored by overall survival rate, weight loss, and histopathological analysis. A nude mouse model of Lewis lung cancer was established to assess the anti-metastatic effects of CTX in vivo. CD4⁺, CD8⁺, and CD4⁺CD25⁺FoxP3 T cells were selected by flow cytometry analysis. Low and continuous administration of CTX was able to restore immune function via increase of CD4⁺/CD8⁺ T cells and depletion of T regulatory cells, not only in circulatory and splenic compartments, but also at the tumor site. Low-dose CTX also reduced myofibroblasts, accompanied with an increased level of E-cadherin and low N-cadherin, both in the primary tumor and lung through the TGF-β pathway by the downregulated expression of TGF-β receptor 2. Our data may indicate that several other molecular mechanisms of CTX for tumor may be involved in metronomic chemotherapy, besides targeting angiogenesis and regulatory T cells.

Hepatic Stellate Cells in Liver Tumor

Hepatocellular carcinoma and intrahepatic cholangiocarcinoma are the most common types of primary liver cancers. Moreover, the liver is the second most frequently involved organ in cancer metastasis after lymph nodes. The tumor microenvironment is crucial for the development of both primary and secondary liver cancers. The hepatic microenvironment consists of multiple cell types, including liver sinusoidal endothelial cells, Kupffer cells, natural killer cells, liver-associated lymphocytes, and hepatic stellate cells (HSCs). The microenvironment of a normal liver changes to a tumor microenvironment when tumor cells exist or tumor cells migrate to and multiply in the liver. Interactions between tumor cells and non-transformed cells generate a tumor microenvironment that contributes significantly to tumor progression. HSCs play a central role in the tumor microenvironment crosstalk. As this crosstalk is crucial for liver carcinogenesis and liver-tumor development, elucidating the mechanism underlying the interaction of HSCs with the tumor microenvironment could provide potential therapeutic targets for liver cancer.

Regulatory T cells in breast cancer as a potent anti-cancer therapeutic target

Despite marked advances in treatment approaches, breast cancer is still going to be more prevalent, worldwide. High levels of regulatory T (Treg) cells have repeatedly been demonstrated in circulation, lymph nodes, and tumor samples from patients with various cancer types. The transcription factor Forkhead box protein 3 (Foxp3)-expressing Treg cells have the high suppressive potential of the immune system and are fundamental in preserving immune homeostasis and self-tolerance. However, they enhance tumor development by curbing efficient anti-tumor immune mechanisms in malignancies. Moreover, the accumulation of Treg cells in breast tumors is related to the short overall survival of patients. Treg cell frequency has been applied as an independent predicting factor to diagnose patients with a high risk of relapse. Pulling out all populations of Treg cells to promote the efficacy of anticancer treatment methods may potentially lead to hazardous autoimmune disorders. Thus, realizing the exact structure of tumor-infiltrating Treg cells is pivotal to efficiently target Treg cells in tumors. There are exclusive and non-exclusive approaches to lower down and degrade the number/function of Treg cells. These approaches can include inhibiting tumoral migration, depletion, interference with function, and utilizing T cell plasticity. This review article attempts to clarify the implications concerning the involvement of Treg cells in breast cancer progression and discuss the current approaches in the treatment of this cancer via modulation of Treg cells function.

Comparison between tumors in plants and human beings: Mechanisms of tumor development and therapy with secondary plant metabolites

BACKGROUND

Human tumors are still a major threat to human health and plant tumors negatively affect agricultural yields. Both areas of research are developing largely independent of each other. Treatment of both plant and human tumors remains unsatisfactory and novel therapy options are urgently needed.

HYPOTHESIS

The concept of this paper is to compare cellular and molecular mechanisms of tumor development in plants and human beings and to explore possibilities to develop novel treatment strategies based on bioactive secondary plant metabolites. The interdisciplinary discourse may unravel commonalities and differences in the biology of plant and human tumors as basis for rational drug development.

RESULTS

Plant tumors and galls develop upon infection by bacteria (e.g. Agrobacterium tumefaciens and A. vitis, which harbor oncogenic T-DNA) and by insects (e.g. gall wasps, aphids). Plant tumors are benign, i.e. they usually do not ultimately kill their host, but they can lead to considerable economic damage due to reduced crop yields of cultivated plants. Human tumors develop by biological carcinogenesis (i.e. viruses and other infectious agents), chemical carcinogenesis (anthropogenic and non-anthropogenic environmental toxic xenobiotics) and physical carcinogenesis (radioactivity, UV-radiation). The majority of human tumors are malignant with lethal outcome. Although treatments for both plant and human tumors are available (antibiotics and apathogenic bacterial strains for plant tumors, cytostatic drugs for human tumors), treatment successes are non-satisfactory, because of drug resistance and the severe adverse side effects. In human beings, attacks by microbes are repelled by cellular immunity (i.e. innate and acquired immune systems). Plants instead display chemical defense mechanisms, whereby constitutively expressed phytoanticipin compounds compare to the innate human immune system, the acquired human immune system compares to phytoalexins, which are induced by appropriate biotic or abiotic stressors. Some chemical weapons of this armory of secondary metabolites are also active against plant galls. There is a mutual co-evolution between plant defense and animals/human beings, which was sometimes referred to as animal plant warfare. As a consequence, hepatic phase I-III metabolization and excretion developed in animals and human beings to detoxify harmful phytochemicals. On the other hand, plants invented "pro-drugs" during evolution, which are activated and toxified in animals by this hepatic biotransformation system. Recent efforts focus on phytochemicals that specifically target tumor-related mechanisms and proteins, e.g. angiogenic or metastatic inhibitors, stimulators of the immune system to improve anti-tumor immunity, specific cell death or cancer stem cell inhibitors, inhibitors of DNA damage and epigenomic deregulation, specific inhibitors of driver genes of carcinogenesis (e.g. oncogenes), inhibitors of multidrug resistance (i.e. ABC transporter efflux inhibitors), secondary metabolites against plant tumors.

CONCLUSION

The exploitation of bioactive secondary metabolites to treat plant or human tumors bears a tremendous therapeutic potential. Although there are fundamental differences between human and plant tumors, either isolated phytochemicals and their (semi)synthetic derivatives or chemically defined and standardized plant extracts may offer new therapy options to decrease human tumor incidence and mortality as well as to increase agricultural yields by fighting crown galls.

Phenotypic Switching of Naïve T Cells to Immune-Suppressive Treg-Like Cells by Mutant KRAS

Oncogenic (mutant) Ras protein Kirsten rat sarcoma viral oncogene homolog (KRAS) promotes uncontrolled proliferation, altered metabolism, and loss of genome integrity in a cell-intrinsic manner. Here, we demonstrate that CD4⁺ T cells when incubated with tumor-derived exosomes from mutant (MT) KRAS non-small-cell lung cancer (NSCLC) cells, patient sera, or a mouse xenograft model, induce phenotypic conversion to FOXP3⁺ Treg-like cells that are immune-suppressive. Furthermore, transfecting T cells with MT KRAS cDNA alone induced phenotypic switching and mathematical modeling supported this conclusion. Single-cell sequencing identified the interferon pathway as the mechanism underlying the phenotypic switch. These observations highlight a novel cytokine-independent, cell-extrinsic role for KRAS in T cell phenotypic switching. Thus, targeting this new class of Tregs represents a unique therapeutic approach for NSCLC. Since KRAS is the most frequently mutated oncogene in a wide variety of cancers, the findings of this investigation are likely to be of broad interest and have a large scientific impact.

Recent advancements in the study of breast cancer exosomes as mediators of intratumoral communication

Breast cancer is a heterogeneous disease, with a morbidity rate of 27.8% and a mortality rate of 15% among women population worldwide. Understanding how this cancer develops and the mechanisms behind tumor progression and chemoresistance is of utmost importance. Exosomes mediate communication in a population of heterogeneous tumoral cells. They have a cargo composed of oncogenes and oncomiRs which change the transcriptomic scenario of their targeted cells and activate numerous tumor-promoting signaling pathways. Exosomes secreted by breast cancer cells lead to enhanced cell proliferation, replicative immortality, angiogenesis, invasion, migration, and chemoresistance. Studying exosomes from this perspective offers more in depth understanding of breast malignancy and may aid in the future development of early diagnostic, prognostic and therapeutic options. We present the latest findings in this area and offer practical solutions which may further stimulate the much-needed research of exosome in breast cancer.

Lactate modulates CD4+ T-cell polarization and induces an immunosuppressive environment, which sustains prostate carcinoma progression via TLR8/miR21 axis

Leukocyte infiltration plays an active role in controlling tumor development. In the early stages of carcinogenesis, T cells counteract tumor growth. However, in advanced stages, cancer cells and infiltrating stromal components interfere with the immune control and instruct immune cells to support, rather than counteract, tumor malignancy, via cell-cell contact or soluble mediators. In particular, metabolites are emerging as active players in driving immunosuppression. Here we demonstrate that in a prostate cancer model lactate released by glycolytic cancer-associated fibroblasts (CAFs) acts on CD4⁺ T cells, shaping T-cell polarization. In particular, CAFs exposure (i) reduces the percentage of the antitumoral Th1 subset, inducing a lactate-dependent, SIRT1-mediated deacetylation/degradation of T-bet transcription factor; (ii) increases T_reg cells, driving naive T cells polarization, through a lactate-based NF-kB activation and FoxP3 expression. In turn, this metabolic-based CAF-immunomodulated environment exerts a pro-invasive effect on prostate cancer cells, by activating a previously unexplored miR21/TLR8 axis that sustains cancer malignancy.

Au-CGKRK Nanoconjugates for Combating Cancer through T-Cell-Driven Therapeutic RNA Interference

Numerous prior studies on fighting cancer have been based on using inhibitors of JAK-STAT pathway (signal transducer and activator of transcription 3 (STAT3) inhibitor in particular), a signaling pathway responsible for progression of many types of cancer cells. However, recent studies have shown that STAT3 activation leads to upregulation of program death receptor-ligand 1 (PD-L1, an immune checkpoint protein that plays a major role behind evasion of immune systems by growing tumors) expression levels in tumor cells, leading to enhanced immune suppression. This is why global efforts are being witnessed in combating cancer through use of immune checkpoint inhibitors. Herein, we report on the design, synthesis, physicochemical characterizations, and bioactivity evaluation of novel tumor- and tumor-vasculature-targeting noncytotoxic Au-CGKRK nanoconjugates (17-80 nm) for combating tumor. Using a syngeneic mouse tumor model, we show that intraperitoneal (i.p.) administration of the Au-CGKRK nanoparticles (NPs) complexed with both PD-L1siRNA (the immune checkpoint inhibitor) and STAT3siRNA (the JAK-STAT pathway inhibitor) results in significant (>70%) enhancement in overall survivability (OS) in melanoma-bearing mice (n = 5) when compared to the OS in the untreated mice group. The expression levels of CD8 and CD4 proteins in the tumor lysates of differently treated mice groups (by Western blotting) are consistent with the observed OS enhancement being a T-cell-driven process. Biodistribution study using near-infrared dye-loaded Au-CGKRK nanoconjugates revealed selective accumulation of the dye in mouse tumor. Notably, the overall survival benefits were significantly less (∼35%) when melanoma-bearing mice were treated (i.p.) with Au-CGKRK NPs complexed with only PD-L1siRNA or with STAT3siRNA alone. The presently described Au-CGKRK nanoconjugates are expected to find future use in therapeutic RNA-interference-based cancer immunotherapy.

Biomarkers of response to immune checkpoint blockade in cancer treatment

Immune checkpoint inhibitors (ICPis) are emerging as the new corner stone of cancer treatment due to their ability to produce durable responses in patients with various cancers. But, objective responses to ICPis vary among each type of cancer. Further, treatment with ICPis is often associated with risk of developing immune-related adverse event, which are potentially life-threatening if untreated, indicating a need for patient selection. However, given the complexity of the tumor microenvironment and the dynamic interaction between tumor and immune cells, development of robust biomarkers to predict patients who are likely to respond to treatment with ICPis remains a challenge. In this review we present an overview of the immune monitoring strategies that are currently in use to enable appropriate patient selection.

A Small β-Carboline Derivative "B-9-3" Modulates TGF-β Signaling Pathway Causing Tumor Regression in Vivo

Targeting tumor microenvironment (TME) is crucial in order to overcome the anti-cancer therapy resistance. In this study, we report the antitumor activity of a newly synthesized β-carboline derivative “B-9-3.” Here, this small molecule showed a promising antitumor activity in vivo along with an enhanced immune response as reflected by a reduction of regulatory T cells and increased CD4+/CD8+ T cells. Further, B-9-3 decreased the number of myofibroblasts not only in the tumor but also in the lung suggesting an anti-metastatic action. The reduction of myofibroblasts was associated with lower expression of epithelial-to-mesenchymal transition markers and a decrease of phosphorylated SMAD2/3 complex indicating the implication of TGF-β signaling pathway in B-9-3’s effect. The blockade of myofibroblasts induction by B-9-3 was also verified in vitro in human fibroblasts treated with TGF-β. To elucidate the mechanism of B-9-3’s action on TGF-β pathway, first, we investigated the molecular interaction between B-9-3 and TGF-β receptors using docking method. Data showed a weak interaction of B-9-3 with the ATP-binding pocket of TGFβRI but a strong one with a ternary complex formed of extracellular domains of TGFβRI, TGFβRII, and TGF-β. In addition, the role of TGFβRI and TGFβRII in B-9-3’s activity was explored in vitro. B-9-3 did not decrease any of the two receptors’ protein level and only reduced phosphorylated SMAD2/3 suggesting that its effect was more probably due to its interaction with the ternary complex rather than decreasing the expression of TGF-β receptors or interfering with their ATP-binding domains. B-9-3 is a small active molecule which acts on the TGF-β signaling pathway and improves the TME to inhibit the proliferation and the metastasis of the tumor with the potential for clinical application.

Dominant Role for Regulatory T Cells in Protecting Females Against Pulmonary Hypertension

RATIONALE

Pulmonary arterial hypertension (PH) is a life-threatening condition associated with immune dysregulation and abnormal regulatory T cell (Treg) activity, but it is currently unknown whether and how abnormal Treg function differentially affects males and females.

OBJECTIVE

To evaluate whether and how Treg deficiency differentially affects male and female rats in experimental PH.

METHODS AND RESULTS

Male and female athymic rnu/rnu rats, lacking Tregs, were treated with the VEGFR2 (vascular endothelial growth factor receptor 2) inhibitor SU5416 or chronic hypoxia and evaluated for PH; some animals underwent Treg immune reconstitution before SU5416 administration. Plasma PGI₂ (prostacyclin) levels were measured. Lung and right ventricles were assessed for the expression of the vasoprotective proteins COX-2 (cyclooxygenase 2), PTGIS (prostacyclin synthase), PDL-1 (programmed death ligand 1), and HO-1 (heme oxygenase 1). Inhibitors of these pathways were administered to athymic rats undergoing Treg immune reconstitution. Finally, human cardiac microvascular endothelial cells cocultured with Tregs were evaluated for COX-2, PDL-1, HO-1, and ER (estrogen receptor) expression, and culture supernatants were assayed for PGI₂ and IL (interleukin)-10. SU5416-treatment and chronic hypoxia produced more severe PH in female than male athymic rats. Females were distinguished by greater pulmonary inflammation, augmented right ventricular fibrosis, lower plasma PGI₂ levels, decreased lung COX-2, PTGIS, HO-1, and PDL-1 expression and reduced right ventricular PDL-1 levels. In both sexes, Treg immune reconstitution protected against PH development and raised levels of plasma PGI₂ and cardiopulmonary COX-2, PTGIS, PDL-1, and HO-1. Inhibiting COX-2, HO-1, and PD-1 (programmed death 1)/PDL-1 pathways abrogated Treg protection. In vitro, human Tregs directly upregulated endothelial COX-2, PDL-1, HO-1, ERs and increased supernatant levels of PGI₂ and IL-10.

CONCLUSIONS

In 2 animal models of PH based on Treg deficiency, females developed more severe PH than males. The data suggest that females are especially reliant on the normal Treg function to counteract the effects of pulmonary vascular injury leading to PH.

Overcoming Barriers of Age to Enhance Efficacy of Cancer Immunotherapy: The Clout of the Extracellular Matrix

There is a growing list of cancer immunotherapeutics approved for use in a population with an increasing number of aged individuals. Cancer immunotherapy (CIT) mediates tumor destruction by activating anti-tumor immune responses that have been silenced through the oncogenic process. However, in an aging individual, immune deregulation is positively correlated with age. In this context, it is vital to examine the age-related changes in the tumor microenvironment (TME) and specifically, those directly affecting critical players to ensure CIT efficacy. Effector T cells, regulatory T cells, myeloid-derived suppressor cells, tumor-associated macrophages, and tumor-associated neutrophils play important roles in promoting or inhibiting the inflammatory response, while cancer-associated fibroblasts are key mediators of the extracellular matrix (ECM). Immune checkpoint inhibitors function optimally in inflamed tumors heavily invaded by CD4 and CD8 T cells. However, immunosenescence curtails the effector T cell response within the TME and causes ECM deregulation, creating a biophysical barrier impeding both effective drug delivery and pro-inflammatory responses. The ability of the chimeric antigen receptor T (CAR-T) cell to artificially induce an adaptive immune response can be modified to degrade essential components of the ECM and alleviate the age-related changes to the TME. This review will focus on the age-related alterations in ECM and immune-stroma interactions within the TME. We will discuss strategies to overcome the barriers of immunosenescence and matrix deregulation to ameliorate the efficacy of CIT in aged subjects.

Vitamin C Fosters the In Vivo Differentiation of Peripheral CD4+ Foxp3- T Cells into CD4+ Foxp3+ Regulatory T Cells but Impairs Their Ability to Prolong Skin Allograft Survival

Regulatory T cells (Tregs) are critical players of immunological tolerance due to their ability to suppress effector T cell function thereby preventing transplant rejection and autoimmune diseases. During allograft transplantation, increases of both Treg expansion and generation, as well as their stable function, are needed to ensure allograft acceptance; thus, efforts have been made to discover new molecules that enhance Treg-mediated tolerance and to uncover their mechanisms. Recently, vitamin C (VitC), known to regulate T cell maturation and dendritic cell-mediated T cell polarization, has gained attention as a relevant epigenetic remodeler able to enhance and stabilize the expression of the Treg master regulator gene Foxp3, positively affecting the generation of induced Tregs (iTregs). In this study, we measured VitC transporter (SVCT2) expression in different immune cell populations, finding Tregs as one of the cell subset with the highest levels of SVCT2 expression. Unexpectedly, we found that VitC treatment reduces the ability of natural Tregs to suppress effector T cell proliferation in vitro, while having an enhancer effect on TGFβ-induced Foxp3⁺ Tregs. On the other hand, VitC increases iTregs generation in vitro and in vivo, however, no allograft tolerance was achieved in animals orally treated with VitC. Lastly, Tregs isolated from the draining lymph nodes of VitC-treated and transplanted mice also showed impaired suppression capacity ex vivo. Our results indicate that VitC promotes the generation and expansion of Tregs, without exhibiting CD4⁺ T cell-mediated allograft tolerance. These observations highlight the relevance of the nutritional status of patients when immune regulation is needed.

Modulatory role of regulatory T cells in a murine model of severe equine asthma

Background

It is accepted that T regulatory cells (Treg) control different types of immune responses. In connection with this role, we have recently described an important increase in CD4+, CD25^high, Foxp3+ lymphocytes in the airway system of horses coursing with an exacerbation of severe equine asthma (EA). To explore the potential role of this population in the resolution of EA inflammation, we used a murine experimental model in which airway neutrophilic inflammation, which is similar to that observed in EA, is induced in mice by continual exposure to Aspergillus fumigatus contaminated hay. This model has the advantage that in mice we may induce a reduction of the Treg population using low doses of cyclophosphamide (Cy).

Results

The results indicated that the percentage of Treg cells increased with allergen exposure, as in horses; and animals partially depleted of Treg cells by treatment with Cy showed increased airway inflammation, demonstrated by an increased percentage of neutrophils and specific immunoglobulins in bronchoalveolar lavage fluid (BALF). Furthermore, a histopathologic study of animals that were pretreated with Cy before antigenic challenge showed higher cellular infiltration in the lung and deeper remodeling changes in the bronchi, including epithelial and goblet cell hyperplasia as well as airway smooth muscle hypertrophy.

Conclusion

In this murine model of EA, the reduced number and function of Treg induced by low doses of Cy, which directly correlates with increased airway inflammation and lung infiltration, indicates that Treg may play a major role in the regulation and resolution of EA.

Metabolic Cooperation and Competition in the Tumor Microenvironment: Implications for Therapy

The tumor microenvironment (TME) is an ensemble of non-tumor cells comprising fibroblasts, cells of the immune system, and endothelial cells, besides various soluble secretory factors from all cellular components (including tumor cells). The TME forms a pro-tumorigenic cocoon around the tumor cells where reprogramming of the metabolism occurs in tumor and non-tumor cells that underlies the nature of interactions as well as competitions ensuring steady supply of nutrients and anapleoretic molecules for the tumor cells that fuels its growth even under hypoxic conditions. This metabolic reprogramming also plays a significant role in suppressing the immune attack on the tumor cells and in resistance to therapies. Thus, the metabolic cooperation and competition among the different TME components besides the inherent alterations in the tumor cells arising out of genetic as well as epigenetic changes supports growth, metastasis, and therapeutic resistance. This review focuses on the metabolic remodeling achieved through an active cooperation and competition among the three principal components of the TME—the tumor cells, the T cells, and the cancer-associated fibroblasts while discussing about the current strategies that target metabolism of TME components. Further, we will also consider the probable therapeutic opportunities targeting the various metabolic pathways as well as the signaling molecules/transcription factors regulating them for the development of novel treatment strategies for cancer.

The use of low-dose metronomic chemotherapy in dogs-insight into a modern cancer field

The era of chemotherapy, which started in the middle of the last century, has been ruled by the routine use of dose-intense protocols, based on the "maximum-tolerated dose" concept. By promoting a balance between patient's quality of life and the goal of rapidly killing as many tumour cells as possible, these protocols still play a prominent role in veterinary oncology. However, with the opening of a new millennium, metronomic chemotherapy (MC) started to be considered a possible alternative to traditional dose-intense chemotherapy. Characterized by a long-term daily administration of lower doses of cytotoxic drugs, this new modality stands out for its unique combination of effects, namely on neovascularization, immune response and tumour dormancy. This article reviews the rationale for treatment with MC, its mechanism of action and the main studies conducted in veterinary medicine, and discusses the key challenges yet to be solved.

Role of Cyclooxygenase-2 Pathway in Creating an Immunosuppressive Microenvironment and in Initiation and Progression of Wilms' Tumor

Wilms' tumors (WT), which accountfor 6% of all childhood cancers, arise from dysregulated differentiation of nephrogenic progenitor cells from embryonic kidneys. Though there is an improvement in the prognosis of WT, still 10% of patients with WT die due to recurrence. Thus more effective treatment approaches are necessary. We previously characterized the inflammatory microenvironment in human WT and observed the robust expression of COX-2. The aim of this study was to extend our studies to analyze the role of COX-2 pathway components in WT progression using a mouse model of WT. Herein, COX-2 pathway components such as COX-2, HIF1-α, p-ERK1/2, and p-STAT3 were upregulated in mouse and human tumor tissues. In our RPPA analysis, COX-2 was up-regulated in M15 cells after Wt1 gene was knocked down. Flow cytometry analysis showed the increased infiltration of immune suppressive inflammatory cells such as pDC's and Treg cells in tumors. The chemotactic chemokines responsible for the infiltration of these cells were also induced in CCR5 and CXCR4 dependent manner respectively. The immunosuppressive cytokines IL-10, TGF-β, and TNF-α were also up-regulated. Furthermore, more pronounced Th2 and Treg induced cytokine response was observed than Th1 response in tumors. Basing on all these evidences it is speculated that COX-2 pathway may be a beneficial target for the treatment of WT. It may be most effective as an adjuvant therapy together with other inhibitors. Thus, our current study provides a good rationale for initiating animal studies to confirm the efficacy of COX-2 inhibitors in decreasing tumor cell growth in vivo.