Prevalence of regulatory T cells is increased in peripheral blood and tumor microenvironment of patients with pancreas or breast adenocarcinoma

Postoperative Adjuvant Therapy for Resectable Pancreatic Cancer With Gemcitabine and Adoptive Immunotherapy

OBJECTIVES

We previously described adoptive immunotherapy (AIT) with cytotoxic T lymphocytes (CTLs) stimulated by the mucin 1 (MUC1)-expressing human pancreatic cancer cell line YPK-1 (MUC1-CTLs) and demonstrated that MUC1-CTLs might prevent liver metastasis. In the present study, we combined gemcitabine (GEM) and AIT for the treatment of pancreatic cancer.

METHODS

A total of 43 patients who underwent radical pancreatectomy received treatment with MUC1-CTLs and GEM. After surgery, MUC1-CTLs were induced and administered intravenously 3 times, and GEM administered according to the standard regimen for 6 months. The patients whose relative dose intensity of GEM was 50% or more and who received 2 or more MUC1-CTL treatments were used as the adequate treatment group (n = 21).

RESULTS

In the adequate treatment group, disease-free survival was 15.8 months, and overall survival was 24.7 months. Liver metastasis was found only in 7 patients (33%), and local recurrence occurred in 4 patients (19%). The independent prognostic factor of long-term disease-free survival on multivariate analysis was the average number of CTLs administered (P = 0.0133).

CONCLUSIONS

The combination therapy with AIT and GEM prevented liver metastasis and local recurrence. Moreover, the disease free-survival was improved in patients who received sufficient CTLs.

The role and significance of VEGFR2+ regulatory T cells in tumor immunity

Tumor development is closely related to angiogenesis, and VEGFR2 plays an important role in tumor angiogenesis. It is broadly expressed in the blood vessels, especially in the microvessels of tumor tissues. Furthermore, VEGFR2 is detected on the surface of the cell membrane in various immune cells, such as dendritic cells, macrophages, and regulatory T cells (Tregs). Tregs, which are one of the key negative regulatory factors in tumor immune microenvironments, show high-level expression of VEGFR2 which participates in the regulation of immunosuppressive function. VEGFR2+ Tregs play a potent suppressive role in the formation of immunosuppressive microenvironments. A large number of reports have proven the synergistic effects between targeted therapy for VEGFR2 and immunotherapy. The depression of VEGFR2 activity on T cells can significantly reduce the infiltration of Tregs into the tumor tissue. Targeted therapy for VEGFR2+ Tregs also provides a new choice for the clinical treatment of malignant solid tumors. In this paper, the role and significance of VEGFR2+ Tregs in tumor immunity in recent years are reviewed.

Human lung tumor FOXP3+ Tregs upregulate four "Treg-locking" transcription factors

Experimental data indicate that FOXP3+ Tregs can markedly curtail host antitumor immune responses, but the properties of human intratumoral Tregs are still largely unknown, in part due to significant methodologic problems. We studied the phenotypic, functional, epigenetic, and transcriptional features of Tregs in 92 patients with non-small-cell lung cancer, comparing the features of Tregs within tumors versus corresponding blood, lung, and lymph node samples. Intratumoral Treg numbers and suppressive function were significantly increased compared with all other sites but did not display a distinctive phenotype by flow cytometry. However, by undertaking simultaneous evaluation of mRNA and protein expression at the single-cell level, we demonstrated that tumor Tregs have a phenotype characterized by upregulated expression of FOXP3 mRNA and protein as well as significantly increased expression of EOS, IRF4, SATB1, and GATA1 transcription factor mRNAs. Expression of these "Treg-locking" transcription factors was positively correlated with levels of FOXP3 mRNA, with highest correlations for EOS and SATB1. EOS had an additional, FOXP3 mRNA-independent, positive correlation with FOXP3 protein in tumor Tregs. Our study identifies distinctive features of intratumoral Tregs and suggests that targeting Treg-locking transcription factors, especially EOS, may be of clinical importance for antitumor Treg-based therapy.

Interleukin-35 on B cell and T cell induction and regulation

Interleukin (IL)-35 is a relatively newly discovered member of IL-12 cytokine family that is unique in that it is a dimer formed by two subunits. The review documents the structure, secretion and signal transduction of IL-35, the regulation effect of IL-35 on B cells and T cells as well as the adoptive transfer of IL-35+ regulatory B cells (Breg), therapeutic prospects of recombinant IL-35 (rIL-35) and IL-35 regulation role in various diseases. B-cell regulation expands the regulatory range of IL-35 and alters the view that IL-10 is the chief immune mechanism for Breg cells which secrete IL-35. IL-35 induces Breg cells, which then can induce Treg cells. IL-35 also plays an immunomodulatory role in the human body.

Therapeutic blockade of Foxp3 in experimental breast cancer models

PURPOSE

Regulatory T cells (Tregs) impair the clinical benefit of cancer immunotherapy. To optimize the antitumor efficacy of therapeutic dendritic cell (DC) vaccines, we aimed to inhibit Foxp3, a transcription factor required for Treg function.

METHODS

Mice bearing established syngeneic LM3 and 4T1 breast tumors were treated with antitumor DC vaccines and a synthetic peptide (P60) that has been shown to inhibit Foxp3.

RESULTS

Treatment with P60 improved the therapeutic efficacy of DC vaccines in these experimental models. In addition, monotherapy with P60 inhibited tumor growth in immunocompetent as well as in immuno-compromised animals bearing established tumors. We found expression of Foxp3 in human and murine breast tumor cells. P60 inhibited IL-10 secretion in breast cancer cells that expressed Foxp3.

CONCLUSIONS

Our results suggest that Foxp3 blockade improves the therapeutic efficacy of DC vaccines by inhibition of Tregs and through a direct antitumor effect. This strategy could prove useful to neutralize the immunosuppressive microenvironment and to boost antitumor immunity in breast cancer.

Bacterial Toxins for Cancer Therapy

Several pathogenic bacteria secrete toxins to inhibit the immune system of the infected organism. Frequently, they catalyze a covalent modification of specific proteins. Thereby, they block production and/or secretion of antibodies or cytokines. Moreover, they disable migration of macrophages and disturb the barrier function of epithelia. In most cases, these toxins are extremely effective enzymes with high specificity towards their cellular substrates, which are often central signaling molecules. Moreover, they encompass the capacity to enter mammalian cells and to modify their substrates in the cytosol. A few molecules, at least of some toxins, are sufficient to change the cellular morphology and function of a cell or even kill a cell. Since many of those toxins are well studied concerning molecular mechanisms, cellular receptors, uptake routes, and structures, they are now widely used to analyze or to influence specific signaling pathways of mammalian cells. Here, we review the development of immunotoxins and targeted toxins for the treatment of a disease that is still hard to treat: cancer.

Metabolic Regulation of Tregs in Cancer: Opportunities for Immunotherapy

The promising outcomes observed in cancer immunotherapy are evidence that the immune system provides a powerful arsenal for the restriction of tumor outgrowth; however, the immunosuppressive tumor microenvironment (TME) is known to impair antitumor immunity and impede the efficacy of cancer immunotherapies. Regulatory T cells (Tregs), which prevent overt immune responses and autoimmunity, accumulate aberrantly in some types of tumor to suppress antitumor immunity and support the establishment of an immunosuppressive microenvironment. Ablation of Tregs has been shown to not only unleash antitumor immunity and interrupt formation of an immunosuppressive TME, but also lead to severe autoimmune disorders. Therefore, it is essential to develop approaches to specifically target intratumoral Tregs. Herein, we summarize the immunomodulatory functions of Tregs in the TME and discuss how metabolic regulation of Tregs can facilitate intratumoral Treg accumulation.

Interleukin-35 as a predictor of prostate cancer in patients undergoing initial prostate biopsy

Background

Interleukin (IL)-35 is a novel inhibitory cytokine and has recently been implicated in tumor immunity. However, the role of IL-35 in prostate cancer (PCa) has not been elucidated.

Objective

To evaluate the role of plasma IL-35 in the diagnosis and prognosis of PCa in Chinese patients undergoing initial prostate biopsy.

Materials and methods

Using ELISA, plasma IL-35 levels were measured in 180 patients, who underwent a prostate biopsy. The clinical correlation of IL-35 with clinicopathological parameters was also evaluated. Univariate and multivariate logistic regression and receiver operating characteristic (ROC) curve analysis were performed to establish the role of IL-35 as a clinical biomarker.

Results

Seventy-five (41.6%) of patients were histopathologically confirmed to have PCa. Plasma IL-35 levels were significantly higher in PCa patients (134.48±78.48 pg/mL) compared to non-PCa patients (67.22±24.08 pg/mL). ROC analysis showed that IL-35 was an independent predictor of PCa. Furthermore, IL-35 was found to be a significantly independent predictor of PCa in a group of patients with prostate-specific antigen levels between 4 and 10 ng/mL; was also able to predict advanced PCa from localized PCa and bone metastasis positive PCa from negative PCa.

Conclusion

Our data suggest for the first time that plasma IL-35 levels are correlated with PCa and is the independent predictor of PCa progression and metastasis. Thus, IL-35 could be utilized as a potential biomarker for diagnosis and prognosis of PCa, could also aid in decision making and predict the stage of the disease.

Characterization of tumor-associated T-lymphocyte subsets and immune checkpoint molecules in head and neck squamous cell carcinoma

The composition of tumor-infiltrating lymphocytes (TIL) reflects biology and immunogenicity of cancer. Here, we characterize T-cell subsets and expression of immune checkpoint molecules in head and neck squamous cell carcinoma (HNSCC). We analyzed TIL subsets in primary tumors (n = 34), blood (peripheral blood mononuclear cells (PBMC); n = 34) and non-cancerous mucosa (n = 7) of 34 treatment-naïve HNSCC patients and PBMC of 15 healthy controls. Flow cytometry analyses revealed a highly variable T-cell infiltration mainly of an effector memory phenotype (CD45RA-/CCR7-). Naïve T cells (CD45RA+/CCR7+) were decreased in the microenvironment compared to PBMC of patients, while regulatory T cells (CD4+/CD25+/CD127low and CD4+/CD39+) were elevated. Furthermore, we performed digital image analyses of entire cross sections of HNSCC to define the 'Immunoscore' (CD3+ and CD8+ cell infiltration in tumor core and invasive margin) and quantified MHC class I expression on tumor cells by immunohistochemistry. Immune checkpoint molecules cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1) were increased in TILs compared to peripheral T cells in flow-cytometric analysis. Human papillomavirus (HPV) positive tumors showed higher numbers of TILs, but a similar composition of T-cell subsets and checkpoint molecule expression compared to HPV negative tumors. Taken together, the tumor microenvironment of HNSCC is characterized by a strong infiltration of regulatory T cells and high checkpoint molecule expression on T-cell subsets. In view of increasingly used immunotherapies, a detailed knowledge of TILs and checkpoint molecule expression on TILs is of high translational relevance.

Phase II Trial of Adjuvant Immunotherapy with Autologous Tumor-derived Gp96 Vaccination in Patients with Gastric Cancer

Background/Aims: Autologous, tumor-derived, heat shock protein gp96 peptide complexes have antitumor potential. We conducted the first Phase II trial to evaluate the safety and efficacy of gp96 vaccination in adjuvant settings for patients with gastric cancer.

Methods: We enrolled 73 consecutive patients from October 2012 to December 2015. Thirty-eight patients received gp96 vaccination plus chemotherapy and 35 received chemotherapy alone. The primary endpoints were disease-free survival (DFS) and toxicity. The secondary endpoints were overall survival (OS) and tumor-specific immune responses.

Results: There were comparable baseline characteristics between the two groups. Tumor-specific immune responses increased significantly after gp96 vaccination. gp96 vaccination plus chemotherapy was well tolerated and there were no gp96-related serious adverse events. Patients who received gp96 vaccination had improved DFS compared with those who did not [p = 0.045; hazard ratio (HR): 0.47; 95% confidence interval (CI): 0.23-0.96]. The 2-year OS rates were 81.9% and 67.9% for the gp96 vaccination and chemotherapy alone group, respectively (p = 0.123; HR: 0.42; 95% CI: 0.15-1.24).

Conclusion: gp96 vaccination elicits tumor-specific immune responses and can be safely used in adjuvant settings combined with chemotherapy. Patients with less-aggressive diseases might benefit from gp96 therapy.

Combination radiotherapy and cantharidin inhibits lung cancer growth through altering tumor infiltrating lymphocytes

This study aimed to detect the effect of combination radiotherapy and cantharidin on lung cancer growth. We found that combination therapy with radiotherapy and cantharidin was more effective in inhibiting the tumor growth than radiotherapy or cantharidin alone. It decreased the percentage of CD4+ Tregs and enhanced the percentage of CD8+ T cells, CD4+ Teff cells when comparing to that of single treatment. Combination therapy promoted a great increase in double producing CD8+ T cells and CD4+ Teff cells in tumor infiltrating lymphocytes. Overexpression of CTLA4 reversed the inhibitory action of combination treatment on cancer growth. Our data suggest that combining radiotherapy and cantharidin may have synergistic effects in driving tumor rejection by increasing T-cell infiltration, proliferation and cytokine production.

The long noncoding RNA lnc-EGFR stimulates T-regulatory cells differentiation thus promoting hepatocellular carcinoma immune evasion

Long noncoding RNAs play a pivotal role in T-helper cell development but little is known about their roles in Treg differentiation and functions during the progression of hepatocellular carcinoma (HCC). Here, we show that lnc-epidermal growth factor receptor (EGFR) upregulation in Tregs correlates positively with the tumour size and expression of EGFR/Foxp3, but negatively with IFN-γ expression in patients and xenografted mouse models. Lnc-EGFR stimulates Treg differentiation, suppresses CTL activity and promotes HCC growth in an EGFR-dependent manner. Mechanistically, lnc-EGFR specifically binds to EGFR and blocks its interaction with and ubiquitination by c-CBL, stabilizing it and augmenting activation of itself and its downstream AP-1/NF-AT1 axis, which in turn elicits EGFR expression. Lnc-EGFR links an immunosuppressive state to cancer by promoting Treg cell differentiation, thus offering a potential therapeutic target for HCC.

The role of long noncoding RNAs in regulating T-cell differentiation within the tumour microenvironment is unclear. Here the authors identify a lncRNA that, through direct interactions with EGFR, promotes T-regulatory cell differentiation within the microenvironment of hepatocellular carcinoma, thus promoting tumour growth via immune suppression.

Natural Killer Cells Response to IL-2 Stimulation Is Distinct between Ascites with the Presence or Absence of Malignant Cells in Ovarian Cancer Patients

Peritoneal ascites are a distinguishable feature of patients with advanced epithelial ovarian cancer (EOC). The presence of different lymphocyte subsets has been reported in EOC-associated ascites, which also can or not contain malignant cells. The goal of this study was to analyze the functional characteristics of natural killer (NK) cells from EOC-associated ascites in terms of their expression of activating receptors and ascites’ contents of lymphocyte subtypes, cytokine profile and presence of EOC cells. NK cell function was evaluated by the expression of the degranulation marker CD107a in resting and interleukin (IL)-2 stimulated NK cells from ascites and blood. Degranulation of NK cells from EOC cell-free ascites was significantly (p < 0.05) higher than all the other groups, either in their resting state or after IL-2 stimulation, suggesting a previous local stimulation. In contrast, treatment with IL-2 had no effect on NK cells from ascites with EOC cells. The amount of regulatory T cells was significantly higher in ascites with EOC cells compared to EOC cell-free ascites. Ascites with EOC cells also had higher levels of tumor necrosis factor (TNF)-α, suggesting inflammation related to the malignancy. In conclusion, the functional performance of NK cells was distinct between EOC cell-free ascites and ascites with EOC cells. The impairment of NK cell response to IL-2 in ascites with EOC cells was consistent with an immunosuppressive tumor microenvironment.

Tackling immunomonitoring in gastrointestinal cancer

PURPOSE OF REVIEW

The growing awareness that the immune system is a key player in the antitumoral response and the excellent clinical results achieved in some settings with anti-programmed cell death 1 (PD1)/programmed death ligand 1 (PDL1) and anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4) drugs has led to the rise of immunotherapy as a supplement or an alternative to conventional cancer treatment. The high costs associated with these therapies, their significant toxicity and the need to understand and circumvent immune escape mechanisms raise the urgent need for immunological assessment of therapy response. The study of the immunological parameters before, during and after treatment is referred to as immunomonitoring. This review discusses the current knowledge of immunomonitoring markers in gastrointestinal cancers.

RECENT FINDINGS

The last decade has seen a collaborative effort to standardize the assays performed in clinical trials to assess response to immunotherapy. Since then, multiple studies have been conducted on blood samples, biopsies and surgical specimens to determine their immunological profiles leading to the identification of several immunological markers possessing a predictive value of response to treatment.

SUMMARY

Future research will focus on detangling the predictive value of immune markers in different therapeutic models, and also to develop new noninvasive means to monitor the immune response of patients. VIDEO ABSTRACT: http://links.lww.com/COON/A20.

Preferential accumulation of regulatory T cells with highly immunosuppressive characteristics in breast tumor microenvironment

Immunosuppressive cells such as regulatory T cells (Tregs) have an ambiguous role in breast cancer prognosis, with studies reporting both positive and negative correlations between Treg infiltration and prognosis. This discrepancy could be due to the different immunosuppressive molecules present in these cells. In the present study, we phenotypically characterize different Treg subsets infiltrating the tumor microenvironment (TME), compared to adjacent normal tissue and peripheral blood of primary breast cancer (PBC) patients. We report that the majority of tumor-infiltrating CD4+ and CD8+ T cells have terminally exhaustive phenotype as assessed by CD39 and PD-1 expressions. We also show that Tregs are accumulated in breast TME compared to normal tissue. Further characterization of Tregs showed that these are mainly FoxP3+Helios+ and express high levels of CTLA-4 and PD-1. This preferential accumulation of FoxP3+Helios+ Treg subset with co-expression of different immune inhibitory molecules might have a negative effect on breast cancer prognosis. Taken together, our results suggest that breast tumor cells might utilize Tregs, and different suppressive pathways involving CD39, PD-1 and CTLA-4 molecules in creating an immune-subversive environment for them to survive, and a dual blockade of these immunosuppressive molecules might be considered as an effective method in breast cancer treatment.

Blockage of FOXP3 transcription factor dimerization and FOXP3/AML1 interaction inhibits T regulatory cell activity: sequence optimization of a peptide inhibitor

Although T regulatory cells (Treg) are essential for the prevention of autoimmune diseases, their immunoregulatory function restrains the induction of immune responses against cancer. Thus, development of inhibitors of FOXP3, a key transcription factor for the immunosuppressive activity of Treg, might give new therapeutic opportunities. In a previous work we identified a peptide (named P60) able to enter into the cells, bind to FOXP3, and impair Treg activity in vitro and in vivo. Here we show that P60 binds to the intermediate region of FOXP3 and inhibits its homodimerization as well as its interaction with the transcription factor AML1. Alanine-scanning of P60 revealed the relevance of each position on FOXP3 binding, homodimerization, association with AML1 and inhibition of Treg activity. Introduction of alanine at positions 2, 5 and 11 improved the activity of the original P60, whereas alanine mutations at positions 1, 7, 8, 9, 10 and 12 were detrimental. Multiple mutation experiments allowed us to identify peptides with higher FOXP3 binding affinity and stronger biological activity than the original P60. Head to tail macrocyclization of peptide P60-D2A-S5A improved Treg inhibition and enhanced anti-tumor activity of anti-PD1 antibodies in a model of hepatocellular carcinoma. Introduction of a D-aminoacid at position 2 augmented significantly microsomal stability while maintained FOXP3 binding capacity and Treg inhibition in vitro. In vivo, when combined with the cytotoxic T-cell epitope AH1, it induced protection against CT26 tumor implantation. This study provides important structure–function relationships essential for further drug design to inhibit Treg cells in cancer.

Emerging therapies for breast cancer

HER2 and CDK4/6 are undoubted two most important biological targets for breast cancer. Anti-HER2 treatments enhance objective response and progression-free survival/disease-free survival as well as overall survival. Three CDK4/6 inhibitors consistently improve objective response and progression-free survival; however, overall survival data are waited. Optimization of chemotherapy and endocrine strategies remains an unmet need. Check point inhibitor-based immunotherapy combined with chemotherapy is a promising field, especially for triple-negative breast cancer.

Oncolytic viral therapy for pancreatic cancer

Outcomes of pancreatic adenocarcinoma (PDA) remain dismal despite extensive clinical investigation. Combination chemotherapy provides modest improvements in survival above best supportive care, and immunotherapy has thus far not proven effective. Nevertheless, growing insight into antitumor immunity and the tumor microenvironment has inspired the discovery of novel agents targeting PDA. Oncolytic viruses represent an emerging class of immunotherapeutic agents that have undergone extensive preclinical investigation and warrant further investigation in well-designed clinical trials.

Regulatory T cells as suppressors of anti-tumor immunity: Role of metabolism

Novel concepts in immunometabolism support the hypothesis that glucose consumption is also used to modulate anti-tumor immune responses, favoring growth and expansion of specific cellular subsets defined in the past as suppressor T cells and currently reborn as regulatory T (Treg) cells. During the 1920s, Otto Warburg and colleagues observed that tumors consumed high amounts of glucose compared to normal tissues, even in the presence of oxygen and completely functioning mitochondria. However, the role of the Warburg Effect is still not completely understood, particularly in the context of an ongoing anti-tumor immune response. Current experimental evidence suggests that tumor-derived metabolic restrictions can drive T cell hyporesponsiveness and immune tolerance. For example, several glycolytic enzymes, deregulated in cancer, contribute to tumor progression independently from their canonical metabolic activity. Indeed, they can control apoptosis, gene expression and activation of specific intracellular pathways, thus suggesting a direct link between metabolic switches and pro-tumorigenic transcriptional programs. Focus of this review is to define the specific metabolic pathways controlling Treg cell immunobiology in the context of anti-tumor immunity and tumor progression.

Knockdown of HVEM, a Lymphocyte Regulator Gene, in Ovarian Cancer Cells Increases Sensitivity to Activated T Cells

Ovarian cancer is highly malignant with a gradually increasing incidence and a high mortality rate. Immunosuppression is induced in ovarian cancer, although the mechanism detail is not clear. It has been indicated that HVEM (herpesvirus entry mediator) B- and T-lymphocyte attenuator (BTLA) negatively regulates the immune responses of T lymphocytes. Here, HVEM mRNA was found to be elevated in ovarian cancer tissue samples and primary ovarian cancer cells in comparison with benign tissue samples. We then knocked down HVEM expression in an ovarian cancer cell line, OVCAR3, by lentivirus-based small hairpin RNA (shRNA). Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis showed that HVEM-shRNA had no effect on the proliferation, early apoptosis, or cell cycle distribution of OVCAR3. We then isolated activated T cells and performed coculture experiments in Transwell. Remarkably, HVEM-silenced ovarian cancer cells (primary ovarian cancer cells and OVCAR3) increased the number of T cells and the secretion of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), while activated T cells promoted the apoptosis of HVEM-silenced ovarian cancer cells. The current study partially explains the immune escape mechanism of ovarian cancer cells and provides a possible target for immunotherapy.

Targeting CD38 Suppresses Induction and Function of T Regulatory Cells to Mitigate Immunosuppression in Multiple Myeloma

Purpose: We study CD38 levels in immunosuppressive CD4⁺CD25^highFoxp3⁺ regulatory T cells (Treg) and further define immunomodulating effects of a therapeutic CD38 mAb isatuximab/SAR650984 in multiple myeloma.Experimental Design: We evaluated percentages of CD38-expressing subsets in Tregs from normal donors and multiple myeloma patients. Peripheral blood mononuclear cells (PBMC) were then treated with isatuximab with or without lenalidomide or pomalidomide to identify their impact on the percentage and immunosuppressive activity of Tregs on CD4⁺CD25^- T cells (Tcons). We investigated the mechanism of increased Tregs in multiple myeloma patients in ex vivo cocultures of multiple myeloma cells with PBMCs or Tcons.Results: CD38 expression is higher on Tregs than Tcons from multiple myeloma patients versus normal donors. CD38 levels and the percentages of CD38^high Tregs are increased by lenalidomide and pomalidomide. Isatuximab preferentially decreases Treg and increases Tcon frequencies, which is enhanced by pomalidomide/lenalidomide. Isatuximab reduces Foxp3 and IL10 in Tregs and restores proliferation and function of Tcons. It augments multiple myeloma cell lysis by CD8⁺ T and natural killer cells. Coculture of multiple myeloma cells with Tcons significantly induces Tregs (iTregs), which express even higher CD38, CD25, and FoxP3 than natural Tregs. This is associated with elevated circulating CD38⁺ Tregs in multiple myeloma patients versus normal donors. Conversely, isatuximab decreases multiple myeloma cell- and bone marrow stromal cell-induced iTreg by inhibiting both cell-cell contact and TGFβ/IL10. Finally, CD38 levels correlate with differential inhibition by isatuximab of Tregs from multiple myeloma versus normal donors.Conclusions: Targeting CD38 by isatuximab can preferentially block immunosuppressive Tregs and thereby restore immune effector function against multiple myeloma. Clin Cancer Res; 23(15); 4290-300. ©2017 AACR.

High tumor-infiltrating FoxP3+ T cells predict poor survival in estrogen receptor-positive breast cancer: A meta-analysis

AIMS

Tumor-infiltrating FoxP3⁺ T cells and FoxP3⁺ tumor cells have been reported in breast cancer (BC), which impaired immunity and promoted tumors progression. However, their prognostic value for survival in patients with breast BC remains controversial.

METHODS

A meta-analysis was performed. Original data included the hazard ratios (HR) of overall survival (OS), relapse-free survival and odds ratio (OR) in BC patients. We pooled HR/OR with 95% confidence intervals (CI) to estimate the hazard.

RESULTS

The overall survival of high tumor-infiltrating FoxP3⁺ T cells patients was lower than low tumor-infiltrating FoxP3⁺ T cells patients with estrogen receptor (ER)-positive (HR 0.86, 95% CI 0.77-0.96; P = 0.009) but not ER-negative (HR 1.09, 95% CI 0.82-1.45; P = 0.569) BC. And FoxP3⁺ tumor cells were not associated with the overall survival and recurrences of BC patients (P > 0.05). In addition, a significant association was revealed between high tumor-infiltrating FoxP3⁺ T cells and grade (I + II/III: OR 0.31, 95% CI 0.17-0.56; P < 0.001), ER status (present: OR 2.39, 95% CI 1.51-3.76; P < 0.001), HER2 status (present: OR 0.53, 95% CI 0.36-0.78; P = 0.001), PR status (present: OR 1.88, 95% CI 1.31-2.71; P < 0.001). And a significant association was revealed between positive FoxP3⁺ tumor cells and Nodal status (present: OR 0.48, 95% CI 0.23-0.97; P = 0.04), grade (I + II/III: OR 0.44, 95% CI 0.22-0.85; P = 0.01), PR status (present: OR 2.37, 95% CI 1.54-3.36; P < 0.001).

CONCLUSIONS

High tumor-infiltrating FoxP3⁺ T cells were associated with a poorer prognosis for ER-positive BC, but not for ER-negative BC.

The Mechanisms and Effects of Physical Activity on Breast Cancer

Breast cancer is the most common cancer in women. An extensive part of this health problem can be prevented by an active lifestyle. Physical activity can reduce the risk of breast cancer, reduce the rate of recurrence, and increase the survival rate of patients with breast cancer. The aim of this review was to summarize our current knowledge regarding the effects of physical activity on breast cancer risk, recurrence, and survival. Furthermore, we investigated 5 possible underlying mechanisms through which physical activity has an influence on breast cancer (ie, a reduction of sex hormones, metabolic hormones, adipokines and oxidative stress, and an improvement of the immune function). In this review, we give a complete overview of this subject.

CD8, FoxP3, and CD45RO+ Lymphocytic Infiltrates in Type I and Type II Endometrial Cancers in African American and European American Females

African American (AA) females with endometrial carcinoma have a significantly worse prognosis with regard to disease-free survival and overall survival than their European American (EA) counterparts and this finding is true across all stages and grades. The presence of tumor-infiltrating lymphocytes (TILs) has been demonstrated to be of prognostic significance in a variety of malignancies, including endometrial cancers. This study aims to determine whether clinically significant differences in levels of CD8+ cytotoxic T lymphocytes, FoxP3+ regulatory T lymphocytes, and CD45RO+ memory T lymphocytes exist between races and to document the clinical impact of TILs. One hundred ten patients with endometrial adenocarcinoma, treated with hysterectomy from 2003 to 2011 were studied. Patients were selected to provide equal representation across type and grade for both EAs and AAs. Immunohistochemical stains were used to highlight CD8-positive, FoxP3-positive, and CD45RO-positive TILs at the endometrial-myometrial interface on slides from paraffin-embedded tissue. Patients with "high" or "low" levels of TILs were compared with respect to the race, tumor type, and survival. High levels of CD45RO+ TILs were associated with improved overall survival in EA women (hazard ratio, 0.32; 95% confidence interval, 0.11-0.92; P=0.034). Comparatively, AA women with high levels of CD45RO+ TILs received no survival benefit (hazard ratio, 0.96; 95% confidence interval, 0.35-2.64; P=0.94). High levels of CD8-positive or FoxP3-positive TILs, alone, had no impact on survival. EA patients with TILs containing high levels of CD45RO cells but low levels of CD8+ cells lost the survival benefit; however, limited numbers preclude significant conclusions from this observation. Neither tumor type nor race were predictive of the levels of TILs of any type. Further study with a larger sample size is required to determine the impact of TIL subtype combinations on survival.

The Evolution of Triple-Negative Breast Cancer: From Biology to Novel Therapeutics

Triple-negative breast cancer (TNBC) is clinically defined as lacking expression of the estrogen receptor (ER), progesterone receptor (ER), and HER2. Historically, TNBC has been characterized by an aggressive natural history and worse disease-specific outcomes compared with other breast cancer subtypes. The advent of next-generation sequencing (NGS) has allowed for the dissection of TNBC into molecular subtypes (i.e., basal-like, claudin-low). Within TNBC, several subtypes have emerged as "immune-activated," consistently illustrating better disease outcome. In addition, NGS has revealed a host of molecular features characteristic of TNBC, including high rates of TP53 mutations, PI3K and MEK pathway activation, and genetic similarities to serous ovarian cancers, including inactivation of the BRCA pathway. Identified genetic vulnerabilities of TNBC have led to promising therapeutic approaches, including DNA-damaging agents (i.e., platinum salts and PARP inhibitors), as well as immunotherapy. Platinum salts are routinely incorporated into the treatment of metastatic TNBC; however, best outcomes are observed among those with deficiencies in the BRCA pathway. Although the incorporation of platinum in the neoadjuvant care of patients with TNBC yields higher pathologic complete response (pCR) rates, the impact on longer-term outcome is less clear. The presence of immune infiltrate in TNBC has shown both a predictive and prognostic role. Checkpoint inhibitors, including PD-1 and PD-L1 inhibitors, are under investigation in the setting of metastatic TNBC and have shown responses in initial clinical trials. Finally, matching emerging therapeutic strategies to optimal subtype of TNBC is of utmost importance as we design future research strategies to improve patient outcome.

The Role of Tumor Microenvironment in Cancer Immunotherapy

The field of tumor immunology and immunotherapy has undergone a renaissance in the past decade do in large part to a better understanding of the tumor immune microenvironment. After suffering countless successes and setbacks in the twentieth century, immunotherapy has now come to the forefront of cancer research and is recognized as an important tool in the anti-tumor armamentarium. The goal of therapy is to aid the immune system in recognition and destruction of tumor cells by enhancing its ability to react to tumor antigens. This traditionally has been accomplished by induction of adaptive immunity through vaccination or through passive delivery of immunologic effectors as in the case of adoptive cell transfer. The recent discovery of immune "checkpoints" whose purpose is to suppress immune activity and prevent auto-immunity has created a new angle by which reactivity to tumors can be enhanced. Blockers of these checkpoints have yielded impressive clinical results and have recently been approved for use in a wide variety of malignancies. With data showing increasing rates of not only treatment response, but complete remissions, immunotherapy is poised to become an increasingly utilized therapy in the treatment of cancer.

Immunotherapy in pancreatic cancer treatment: a new frontier

Pancreatic cancer is a highly aggressive and lethal cancer characterized by high invasiveness, local and extensive dissemination at time of diagnosis and resistance to treatment. Few therapies have shown efficacy in the past and even standard of care therapies yield only modest improvements in the mortality of patients with advanced or metastatic disease. Efforts have been undertaken to study the pancreatic tumor microenvironment and have established its complex and immunosuppressive nature which could explain the high resistance to chemotherapy. Novel therapies targeting the tumor microenvironment with an aim to decrease this resistance, improve immune tolerance and increase the efficacy of the current treatment have shown some promising preliminary results in preclinical and clinical trials. We review the current advances in the field of immunotherapy and their effectiveness as a potential treatment strategy in the pancreatic cancer.

CD4+ regulatory T cells in gastric cancer mucosa are proliferating and express high levels of IL-10 but little TGF-β

BACKGROUND

An increase of regulatory T cells, defined as CD25^high- and/or FOXP3⁺-expressing CD4⁺ T cells, within tumors has been reported in several studies. Tregs promote tumor growth by modulating the antitumor immune response, mainly through inhibition of T-cell-mediated tumor cell killing: this has been suggested to be dependent on IL-10 and/or TGF-β. In stomach cancer, the mechanisms behind the accumulation of Tregs in tumor tissue has not been fully elucidated, and neither has Treg gene expression in situ.

MATERIALS AND METHODS

Stomach tissue from gastric cancer patients undergoing gastric resection was analyzed using flow cytometry and cell sorting, followed by RT-PCR.

RESULTS

We observed that stomach CD4⁺ FOXP3⁺ T cells proliferated to a higher degree than CD4⁺ FOXP3^- T cells, which may contribute to Treg accumulation in the mucosa. By analyzing DNA methylation, we demonstrated that both proliferating and nonproliferating FOXP3⁺ T cells exhibited complete demethylation of the FOXP3 gene, indicating a stable FOXP3 expression in both cell populations. Furthermore, analysis of T-cell populations isolated directly from the tumor and tumor-free mucosa demonstrated that CD4⁺ CD25^high T cells have a higher IL-10/IFN-γ gene expression ratio but express lower levels of TGF-β than CD4⁺ CD25^low/- T cells.

CONCLUSION

We demonstrate strong proliferation among regulatory CD4⁺ FOXP3⁺ CD25^high T cells in the gastric cancer mucosa. These local Treg express a suppressive cytokine profile characterized by high IL-10 and low TGF-β and IFN-γ production.

Adaptive immunity programmes in breast cancer

The role of the immune system in shaping cancer development and patient prognosis has recently become an area of intense focus in industry and academia. Harnessing the adaptive arm of the immune system for tumour eradication has shown great promise in a variety of tumour types. Differences between tissues, however, necessitate a greater understanding of the adaptive immunity programmes that are active within each tumour type. In breast cancer, adaptive immune programmes play diverse roles depending on the cellular infiltration found in each tumour. Cytotoxic T lymphocytes and T helper type 1 cells can induce tumour eradication, whereas regulatory T cells and T helper type 2 cells are known to be involved in tumour-promoting immunosuppressive responses. Complicating these matters, heterogeneous expression of hormone receptors and growth factors in different tumours leads to disparate, patient-specific adaptive immune responses. Despite this non-conformity in adaptive immune behaviours, encouraging basic and clinical results have been observed that suggest a role for immunotherapeutic approaches in breast cancer. Here, we review the literature pertaining to the adaptive immune response in breast cancer, summarize the primary findings relating to the breast tumour's biology, and discuss potential clinical immunotherapies.

Dendritic cell-based immunotherapy

Immunotherapy using dendritic cell (DC)-based vaccination is an approved approach for harnessing the potential of a patient's own immune system to eliminate tumor cells in metastatic hormone-refractory cancer. Overall, although many DC vaccines have been tested in the clinic and proven to be immunogenic, and in some cases associated with clinical outcome, there remains no consensus on how to manufacture DC vaccines. In this review we will discuss what has been learned thus far about human DC biology from clinical studies, and how current approaches to apply DC vaccines in the clinic could be improved to enhance anti-tumor immunity.

Regulatory T cells in cancer immunotherapy

FOXP3-expressing regulatory T (Treg) cells, which suppress aberrant immune response against self-antigens, also suppress anti-tumor immune response. Infiltration of a large number of Treg cells into tumor tissues is often associated with poor prognosis. There is accumulating evidence that the removal of Treg cells is able to evoke and enhance anti-tumor immune response. However, systemic depletion of Treg cells may concurrently elicit deleterious autoimmunity. One strategy for evoking effective tumor immunity without autoimmunity is to specifically target terminally differentiated effector Treg cells rather than all FOXP3⁺ T cells, because effector Treg cells are the predominant cell type in tumor tissues. Various cell surface molecules, including chemokine receptors such as CCR4, that are specifically expressed by effector Treg cells can be the candidates for depleting effector Treg cells by specific cell-depleting monoclonal antibodies. In addition, other immunological characteristics of effector Treg cells, such as their high expression of CTLA-4, active proliferation, and apoptosis-prone tendency, can be exploited to control specifically their functions. For example, anti-CTLA-4 antibody may kill effector Treg cells or attenuate their suppressive activity. It is hoped that combination of Treg-cell targeting (e.g., by reducing Treg cells or attenuating their suppressive activity in tumor tissues) with the activation of tumor-specific effector T cells (e.g., by cancer vaccine or immune checkpoint blockade) will make the current cancer immunotherapy more effective.

Prognostic value of circulating regulatory T cell subsets in untreated non-small cell lung cancer patients

The role of the different circulating regulatory T-cells (Treg) subsets, as well as their correlation with clinical outcome of non-small cell lung cancer (NSCLC) patients is poorly understood. Peripheral blood from 156 stage III/IV chemotherapy-naive NSCLC patients and 31 healthy donors (HD) was analyzed with flow cytometry for the presence and functionality of CD4⁺ Treg subsets (naive, effector and terminal effector). Their frequencies were correlated with the clinical outcome. All CD4⁺ Treg subsets exhibited highly suppressive activity by TGF-β and IL-10 production. The percentages of naive Treg were found elevated in NSCLC patients compared to HD and were associated with poor clinical outcome, whereas the percentage of terminal effector Treg was lower compared to HD and higher levels were correlated with improved clinical response. At baseline, normal levels of naive and effector Treg were associated with longer overall survival (OS) compared to high levels, while the high frequency of the terminal effector Treg was correlated with longer Progression-Free Survival and OS. It is demonstrated, for first time, that particular CD4⁺ Treg subtypes are elevated in NSCLC patients and their levels are associated to the clinical outcome. The blocking of their migration to the tumor site may be an effective therapeutic strategy.

PD-1 and PD-L1 Immune Checkpoint Blockade to Treat Breast Cancer

Immune checkpoint inhibition represents a major recent breakthrough in the treatment of malignant diseases including breast cancer. Blocking the programmed death receptor-1 (PD-1) and its ligand, PD-L1, has shown impressive antitumor activity and may lead to durable long-term disease control, especially in the triple-negative subtypes of breast cancer (TNBC). Although immune checkpoint blockade is generally well tolerated, specific immune-related adverse events (irAEs) may occur. This review summarizes the clinical efficacy, perspectives, and future challenges of using PD-1/PD-L1-directed antibodies in the treatment of breast cancer.

Breast Cancer Immunology and Immunotherapy: Current Status and Future Perspectives

Cancer immunology has gained renewed interest in the past few years due to emerging findings on mechanisms involved in tumoral immune evasion. Indisputably, immune edition is currently considered a critical hallmark of cancer. Basic research has revealed new targets which can be modulated in the clinical setting with new compounds and strategies. As recent evidence confirms, breast cancer (BC) is a complex and heterogeneous disease in which host immune responses play a substantial role. T-infiltrating lymphocytes measurement is suggested as a powerful new tool necessary to predict early BC evolution, especially in HER2-positive and triple negative subtypes. However, T-infiltrating lymphocytes, genomic platforms, and many other biomarkers in tissue and peripheral blood (e.g., regulatory T cells and myeloid-derived suppressor cells) are not the only factors being evaluated regarding their potential role as prognostic and/or predictive factors. Many ongoing clinical trials are exploring the activity of immune checkpoint modulators in BC treatment, both in the advanced and neoadjuvant setting. Although this field is expanding with exciting new discoveries and promising clinical results-and creating great expectations-there remain many uncertainties yet to be addressed satisfactorily before this long awaited therapeutic promise can come to fruition.

Prognostic impact of the tumor-infiltrating regulatory T-cell (Foxp3+)/activated cytotoxic T lymphocyte (granzyme B+) ratio on resected left-sided pancreatic cancer

Among the subsets of tumor-infiltrating lymphocytes (TILs), activated cytotoxic T lymphocytes (granzyme B+) have an antitumor effect, while regulatory T lymphocytes [forkhead box P3 (Foxp3)+] suppress the antitumor immune response. The aim of the present study was to investigate the possible associations between TIL subsets and survival outcomes in patients with left-sided pancreatic ductal adenocarcinoma (PDAC). From January 2000 to December 2008, 30 patients who underwent curative distal pancreatectomy without neoadjuvant chemoradiotherapy due to left-sided PDAC were enrolled in the present study. TIL subsets were enumerated by immunohistochemical staining for cluster of differentiation (CD)3, CD4, CD8, Foxp3 and granzyme B in the intra-tumoral areas of tissue blocks. Patients were divided into two groups according to the median value of the absolute counts and relative ratios of TIL subsets. In the univariate analysis, age, gender, tumor size, nodal stage, tumor differentiation and lymphovascular/perineural invasion were not significantly associated with survival outcome. However, low levels of preoperative cancer antigen (CA) 19-9 were associated with a longer overall survival (OS), although the association was not significant (37 vs. 18 months; P=0.061). A high level of granzyme B+ was associated with enhanced disease-free survival (DFS) (25 vs. 10 months; P=0.023), and a low Foxp3+/granzyme B+ ratio was associated with a favorable prognosis in terms of DFS (25 vs. 8 months; P=0.008) and OS (47 vs. 17 months; P=0.003). In the multivariate analysis, the ratio of Foxp3+/granzyme B+ was an independent prognostic factor for determining DFS [Exp(B), 3.060; 95% confidence interval (CI), 1.259-47.436; P=0.014] and OS [Exp(B), 3.580; 95% CI, 1.460-8.780; P=0.005]. Among the clinicopathological factors, low levels of CA 19-9 were significantly associated with a low Foxp3+/granzyme B+ ratio (P=0.016). The results of the present study suggested that a low Foxp3+/granzyme B+ ratio may be useful for predicting a good prognosis in surgically resected left-sided PDAC.

Elevated regulatory T cells, surface and intracellular CTLA-4 expression and interleukin-17 in the lung cancer microenvironment in humans

Regulatory T cells (Tregs) play an important role in the suppression of the immune response in lung cancer. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) expressed on T lymphocytes is capable of downregulating cytotoxic T cells and is constitutively expressed on Tregs. Little is known about the population of Tregs with two forms of CTLA-4: surface (s) and intracellular (in) in the lung cancer environment. Th17 cells defined by production of IL-17 have pleiotropic functions in anticancer immune response. Our aim was to detect the elements of immune response regulation in lung cancer in three compartments: by analysis of bronchoalveolar lavage fluid (BALF) from the lung affected by cancer (clBALF), healthy symmetrical lung (hlBALF) and peripheral blood (PB) from the same patient. A total of 54 samples were collected. Tregs, (s)CTLA-4, (in)CTLA-4 were detected by flow cytometry with antibodies against CD4, CD25, Foxp3, CD127, CTLA-4, and concentration of IL-17 was estimated by ELISA. We observed a significantly higher proportion of Tregs in clBALF than in hlBALF or PB (8.5 vs. 5.0 vs. 5.1%, respectively, p < 0.05). The median proportion of (in)CTLA-4+ Tregs was higher in clBALF than in hlBALF or PB (89.0, 81.5, 56.0%, p < 0.05). IL-17 concentration was the highest in clBALF-6.6 pg/ml. We observed a significant correlation between the proportion of Tregs and (in)CTLA-4+ Tregs with IL-17A concentration in clBALF. We confirmed significant differences in the proportion of regulatory elements between cancerous lung and healthy lung and PB and the usefulness of BALF analysis in evaluation of immune response regulation in local lung cancer environment.

Hypoxia-induced CCL28 promotes recruitment of regulatory T cells and tumor growth in liver cancer

Tumor cells craft microenvironment to overcome growth disadvantages and adjust to escape the immunosurveillance during tumorigenesis and metastasis. The evolving adaption to the changing microenvironment is exemplified by the development of strategies to deal with hypoxia resulted from fast proliferation of the tumor cells. In this study, we found that hypoxia hepatocellular carcinoma (HCC) cells recruited Regulatory T cells (Tregs) and expressed more Chemokine (C-C motif) ligand 28 (CCL28). Deletion of CCL28 inhibited Treg recruitment. Furthermore, overexpression of CCL28 promoted tumor growth and Treg infiltration in vivo. Enhanced angiogenesis and VEGF expression was also observed. Moreover, inhibition of HIF1α reversed hypoxia-induced CCL28 upregulation. Taken together, our results demonstrate that HCC recruits Tregs to promote angiogenesis under hypoxic condition by upregulating CCL28 expression. These findings establish a link between Tregs and hypoxia in HCC growth and may provide a new potential therapeutic target for treating HCC.

CXCL10/CXCR3 signaling mobilized-regulatory T cells promote liver tumor recurrence after transplantation

BACKGROUND & AIMS

Liver graft injury and tumor recurrence are the major challenges of liver transplantation for the patients with hepatocellular carcinoma (HCC). Here, we aimed to explore the role and mechanism of liver graft injury mobilizing regulatory T cells (Tregs), which lead to late phase tumor recurrence after liver transplantation.

METHODS

The correlation among tumor recurrence, liver graft injury and Tregs mobilization were studied in 257 liver transplant recipients with HCC and orthotopic rat liver transplantation models. The direct roles of CXCL10/CXCR3 signaling on Tregs mobilization and tumor recurrence were investigated in CXCL10-/- and CXCR3-/- mice models with hepatic IR injury.

RESULTS

Clinically, patients received the graft with graft weight ratio (GWR) <60% had higher HCC recurrence after liver transplantation than the recipients with GWR ⩾60% graft. More circulating Tregs and higher intragraft TLR4/CXCL10/CXCR3 levels were detected in recipients with GWR <60% graft. These results were further validated in rat transplantation model. Foxp3+ cells and expressions of TLR4, CXCL10, TGFβ, CTLA-4 and CD274 were increased in rat liver tumor tissues from small-for-size graft group. In mouse model, the mobilization and recruitment of Tregs were decreased in TLR4-/-, CXCL10-/- and CXCR3-/- mice compared to wild-type mice. Moreover, less CXCR3+ Tregs were recruited into liver in CXCL10-/- mice after hepatic IR injury. The knockout of CXCL10 and depletion of Tregs inhibited tumor recurrence after hepatic IR injury.

CONCLUSION

CXCL10/CXCR3 signaling upregulated at liver graft injury directly induced the mobilization and intragraft recruitment of Tregs, which further promoted HCC recurrence after transplantation.

LAY SUMMARY

There were positive correlation among tumor recurrence, circulating Tregs and liver graft injury after human transplantation for HCC patients. The knockout of CXCL10 decreased hepatic recruitment of CXCR3+ Tregs and late phase tumor recurrence after hepatic IR injury.

Assessment of variation in immunosuppressive pathway genes reveals TGFBR2 to be associated with risk of clear cell ovarian cancer

BACKGROUND

Regulatory T (Treg) cells, a subset of CD4+ T lymphocytes, are mediators of immunosuppression in cancer, and, thus, variants in genes encoding Treg cell immune molecules could be associated with ovarian cancer.

METHODS

In a population of 15,596 epithelial ovarian cancer (EOC) cases and 23,236 controls, we measured genetic associations of 1,351 SNPs in Treg cell pathway genes with odds of ovarian cancer and tested pathway and gene-level associations, overall and by histotype, for the 25 genes, using the admixture likelihood (AML) method. The most significant single SNP associations were tested for correlation with expression levels in 44 ovarian cancer patients.

RESULTS

The most significant global associations for all genes in the pathway were seen in endometrioid ( p = 0.082) and clear cell ( p = 0.083), with the most significant gene level association seen with TGFBR2 ( p = 0.001) and clear cell EOC. Gene associations with histotypes at p < 0.05 included: IL12 ( p = 0.005 and p = 0.008, serous and high-grade serous, respectively), IL8RA ( p = 0.035, endometrioid and mucinous), LGALS1 ( p = 0.03, mucinous), STAT5B ( p = 0.022, clear cell), TGFBR1 ( p = 0.021 endometrioid) and TGFBR2 ( p = 0.017 and p = 0.025, endometrioid and mucinous, respectively).

CONCLUSIONS

Common inherited gene variation in Treg cell pathways shows some evidence of germline genetic contribution to odds of EOC that varies by histologic subtype and may be associated with mRNA expression of immune-complex receptor in EOC patients.

Regulatory T cells, especially ICOS+ FOXP3+ regulatory T cells, are increased in the hepatocellular carcinoma microenvironment and predict reduced survival

Hepatocellular carcinoma (HCC) is a common malignant tumour, especially in Asia. Its prognosis is poor, and there are limited methods for predicting patient survival. This study was carried out to analyse the prognostic value of tumour-infiltrating lymphocytes (TILs), especially regulatory T cells (Tregs), in HCC patients. TILs were analysed in 57 randomly selected HCC patients. The prognostic effects of groups with high and low numbers were evaluated by the Kaplan-Meier and Cox model analyses. Although higher densities of CD3+, CD4+, and CD8+ cytotoxic lymphocytes (CTLs) as well as CD56+ NK cells and CD68+ macrophages were observed in peritumoural tissue, increased numbers of forkhead/winged helix transcription factor P3+ (FOXP3+) Tregs were found in intratumoural tissue. Additionally, regarding ICOS+ FOXP3+ Tregs, an increased prevalence in carcinoma was not only associated with the absolute number but also with the percentage of FOXP3+ cells. Higher Treg levels in tumour tissues indicated a worse prognosis, and the FOXP3+ Tregs/CD4+ T cells ratio was an independent prognostic factor for OS. Therefore, FOXP3+ Tregs, especially ICOS+ FOXP3+ Tregs, contribute to the immunosuppressive HCC microenvironment. High tumour-infiltrating Tregs are thought to be an unfavourable prognostic indicator of HCC.

Restoring Lost Anti-HER-2 Th1 Immunity in Breast Cancer: A Crucial Role for Th1 Cytokines in Therapy and Prevention

The ErbB/B2 (HER-2/neu) oncogene family plays a critical role in the development and metastatic spread of several tumor types including breast, ovarian and gastric cancer. In breast cancer, HER-2/neu is expressed in early disease development in a large percentage of DCIS lesions and its expression is associated with an increased risk of invasion and recurrence. Targeting HER-2 with antibodies such as trastuzumab or pertuzumab has improved survival, but patients with more extensive disease may develop resistance to therapy. Interestingly, response to HER-2 targeted therapies correlates with presence of immune response genes in the breast. Th1 cell production of the cytokines interferon gamma (IFNγ) and TNFα can enhance MHC class I expression, PD-L1 expression, augment apoptosis and tumor senescence, and enhances growth inhibition of many anti-breast cancer agents, including anti-estrogens and HER-2 targeted therapies. Recently, we have identified that a loss of anti-HER-2 CD4 Th1 in peripheral blood occurs during breast tumorigenesis and is dramatically diminished, even in Stage I breast cancers. The loss of anti-HER-2 Th1 response is specific and not readily reversed by standard therapies. In fact, this loss of anti-HER-2 Th1 response in peripheral blood correlates with lack of complete response to neoadjuvant therapy and diminished disease-free survival. This defect can be restored with HER-2 vaccinations in both DCIS and IBC. Correcting the anti-HER-2 Th1 response may have significant impact in improving response to HER-2 targeted therapies. Development of immune monitoring systems for anti-HER-2 Th1 to identify patients at risk for recurrence could be critical to improving outcomes, since the anti-HER-2 Th1 response can be restored by vaccination. Correction of the cellular immune response against HER-2 may prevent recurrence in high-risk patients with DCIS and IBC at risk of developing new or recurrent breast cancer.

Crucial Contributions by T Lymphocytes (Effector, Regulatory, and Checkpoint Inhibitor) and Cytokines (TH1, TH2, and TH17) to a Pathological Complete Response Induced by Neoadjuvant Chemotherapy in Women with Breast Cancer

The tumour microenvironment consists of malignant cells, stroma, and immune cells. Prominent tumour-infiltrating lymphocytes (TILs) in breast cancer are associated with a good prognosis and are predictors of a pathological complete response (pCR) with neoadjuvant chemotherapy (NAC). The contribution of different T effector/regulatory cells and cytokines to tumour cell death with NAC requires further characterisation and was investigated in this study. Breast tumours from 33 women with large and locally advanced breast cancers undergoing NAC were immunohistochemically (intratumoural, stromal) assessed for T cell subsets and cytokine expression using labelled antibodies, employing established semiquantitative methods. Prominent levels of TILs and CD4⁺, CD8⁺, and CTLA-4⁺ (stromal) T cells and CD8⁺ : FOXP3⁺ ratios were associated with a significant pCR; no association was seen with FOXP3⁺, CTLA-4⁺ (intratumoural), and PD-1⁺ T cells. NAC significantly reduced CD4⁺, FOXP3⁺, CTLA-4⁺ (stromal) (concurrently blood FOXP3⁺, CTLA-4⁺ Tregs), and PD-1⁺ T cells; no reduction was seen with CD8⁺ and CTLA-4⁺ (intratumoural) T cells. High post-NAC tumour levels of FOXP3⁺ T cells, IL-10, and IL-17 were associated with a failed pCR. Our study has characterised further the contribution of T effector/regulatory cells and cytokines to tumour cell death with NAC.

Context- and Tissue-Specific Regulation of Immunity and Tolerance by Regulatory T Cells

The immune system has evolved to defend the organism against an almost infinite number of pathogens in a locally confined and antigen-specific manner while at the same time preserving tolerance to harmless antigens and self. Regulatory T (Treg) cells essentially contribute to an immunoregulatory network preventing excessive immune responses and immunopathology. There is emerging evidence that Treg cells not only operate in secondary lymphoid tissue but also regulate immune responses directly at the site of inflammation. Hence, the classification of Treg cells might need to be further extended by Treg cell subsets that are functionally and phenotypically polarized by their residency. In this review, we discuss recent findings on these tissue-resident Treg cell subsets and how these cells may operate in a tissue- and context-dependent manner.

Worse outcome in breast cancer with higher tumor-infiltrating FOXP3+ Tregs : a systematic review and meta-analysis

BACKGROUND

Forkhead box P3(FOXP3) is known as the optimum maker for regulatory T cells(Tregs), which are conventionally thought to induce immune tolerance to disturb the antitumor immunity. However, the research on the prognostic significance of tumor-infiltrating FOXP3+ Tregs in breast cancer is still limited and the results are controversial.

METHODS

We searched for studies in PubMed, EMBASE and Web of Science prior to January 2015. The correlation between FOXP3+ tumor-infiltrating lymphocytes(TILs) and breast cancer prognosis was analyzed. The meta-analysis was performed using STATA 11.0. Pooled hazard ratios (HRs) with 95 % confidence intervals (CIs) were used to estimate the degree of the association between FOXP3+ TILs and prognosis of breast cancers, while relative ratios (RRs) were used to evaluate the relationship between FOXP3+ TILs and clinicopathological features of breast cancers.

RESULT

A total of 15 studies comprising 8666 breast cancer patients met the inclusion criteria. Our results showed that higher FOXP3+ TILs level was significantly associated with poor prognosis in terms of overall survival (OS) (pooled HR:1.60, 95 % CI:1.06-2.42; P < 0.05). We found that breast cancer with higher FOXP3+ TILs level was positively correlated with c-erbB-2 positive status (pooled RR:1.52, 95 % CI:1.32-1.75; P < 0.05), lymph node positive status(pooled RR:1.17, 95 % CI:1.04-1.32; P < 0.05) while there was a negative association with ER positive status(pooled RR:0.65, 95 % CI:0.56-0.76; P < 0.05) and PR positive status(pooled RR:0.66, 95 % CI:0.51-0.87; P < 0.05).

CONCLUSION

The present results of meta-analysis showed that higher FOXP3+ TILs level in patients with breast cancer led to poor overall survival (OS) and was significantly associated with c-erbB-2 status, lymph node status, ER status and PR status. FOXP3+ TILs level is a promising prognostic factor in breast cancer.

Pancreatic adenocarcinoma up-regulated factor (PAUF) enhances the accumulation and functional activity of myeloid-derived suppressor cells (MDSCs) in pancreatic cancer

Pancreatic cancer is characterized by an immunosuppressive tumor microenvironment (TME) with a profound immune infiltrate populated by a significant number of myeloid-derived suppressor cells (MDSCs). MDSCs have been increasingly recognized for their role in immune evasion and cancer progression as well as their potential as a target for immunotherapy. However, not much is known about the mechanisms regulating their behavior and function in the pancreatic TME. Here we report that pancreatic adenocarcinoma up-regulated factor (PAUF), a soluble protein involved in pancreatic tumorigenesis and metastasis, plays a role as an enhancer of tumor-infiltrating MDSC and its functional activity. We show that PAUF enhanced the accumulation of MDSCs in the spleen and tumor tissues of PAUF-overexpressing tumor cell-injected mice. In addition, PAUF was found to enhance the immunosuppressive function of MDSCs via the TLR4-mediated signaling pathway, which was demonstrated by PAUF-induced increased levels of arginase, nitric oxide (NO), and reactive oxygen species (ROS). The role of PAUF in modulating the functional properties of MDSCs was further demonstrated by the use of a PAUF-neutralizing antibody that caused a decreased number of tumor-infiltrating MDSCs and reduced MDSC immunosuppressive activity. The observations made in mice were confirmed in human pancreatic cancer patient-derived MDSCs, supporting the clinical relevance of our findings. Collectively, we conclude that the PAUF is a powerful and multifunctional promoter of tumor growth through increase and functional activation of MDSCs, suggesting therapeutic potential for targeting PAUF in pancreatic cancers.

Immunologic and Metabolic Features of Pancreatic Ductal Adenocarcinoma Define Prognostic Subtypes of Disease

PURPOSE

Pancreatic ductal adenocarcinoma (PDA) is associated with an immunosuppressive microenvironment that supports the growth of the malignancy as well as immune system evasion. Here we examine markers of immunosuppression in PDA within the context of the glycolytic tumor microenvironment, their interrelationship with tumor biology and association with overall survival.

EXPERIMENTAL DESIGN

We utilized tissue microarrays consisting of 223 PDA patients annotated for clinical stage, tumor size, lymph node involvement, and survival. Expression of CD163, FoxP3, PD-L1, and MCT4 was assessed by IHC and statistical associations were evaluated by univariate and multivariate analysis. Multimarker subtypes were defined by random forest analysis. Mechanistic interactions were evaluated using PDA cell lines and models for myeloid differentiation.

RESULTS

PDA exhibits discrete expression of CD163, FoxP3, and PD-L1 with modest individual significance. However, combined low expression of these markers was associated with improved prognosis (P = 0.02). PDA tumor cells altered macrophage phenotype and function, which supported enhanced invasiveness in cell-based models. Lactate efflux mediated by MCT4 was associated with, and required for, the selective conversion of myeloid cells. Correspondingly, MCT4 expression correlated with immune markers in PDA cases, and increased the significance of prognostic subtypes (P = 0.002).

CONCLUSIONS

There exists a complex interplay between PDA tumor cells and the host immune system wherein immunosuppression is associated with negative outcome. MCT4 expression, representative of the glycolytic state of PDA, contributes to the phenotypic conversion of myeloid cells. Thus, metabolic status of PDA tumors is an important determinant of the immunosuppressive environment. Clin Cancer Res; 22(14); 3606-17. ©2016 AACR.

Monitoring and functional characterization of the lymphocytic compartment in pancreatic ductal adenocarcinoma patients

BACKGROUND/OBJECTIVES

Pancreatic ductal adenocarcinoma (PDAC) still has a poor prognosis and current treatments including immunotherapy often fail. This might be due to the pronounced immunosuppressive milieu impairing infiltration and function of immune effector cells. This study aimed at a comprehensive analysis of immune cells in PDAC patients by determining absolute and relative peripheral blood cell numbers of immune cell subsets along with their functional capacity.

METHODS

Whole blood cells or isolated peripheral blood mononuclear cells were characterized by flow cytometry. PDAC tissues were analyzed by immunohistochemistry. Anti-tumor activity of immune effector cells was determined by RTCA system.

RESULTS

Our data demonstrate that relative CD4⁺ memory- and regulatory T cell numbers were enhanced, whereas determination of absolute cell numbers revealed generally lower immune cell numbers in PDAC patients compared to healthy controls. γδ T cells accumulated at higher numbers compared to αβ T cells in the malignant ductal epithelium of PDAC tissues indicating that γδ T cells infiltrate into the tumor. Cytotoxicity against tumor cells of even small numbers of T- and NK cells could be induced by a bispecific antibody targeting CD3⁺ T cells to human epidermal growth factor receptor (HER)2 expressing PDAC cells or Trastuzumab. Importantly, a critical number of γδ T cells was required for significant tumor cell killing by a bispecific antibody engaging the γδ T cell receptor on γδ T cells and HER2 on tumor cells.

CONCLUSION

Monitoring immune cells along with the determination of their functional capacity provides a comprehensive assessment as a prerequisite for a personalized immunotherapeutic PDAC treatment.