Regulatory T cells increase in breast cancer and in stage IV breast cancer

The modulatory role of dendritic cell-T cell cross-talk in breast cancer: Challenges and prospects

Antigen recognition and presentation are highlighted as the first steps in developing specialized antigen responses. Dendritic cells (DCs) are outstanding professional antigen-presenting cells (APCs) responsible for priming cellular immunity in pathological states, including cancer. However, the diminished or repressed function of DCs is thought to be a substantial mechanism through which tumors escape from the immune system. In this regard, DCs obtained from breast cancer (BC) patients represent a notably weakened potency to encourage specific T-cell responses. Additionally, impaired DC-T-cell cross-talk in BC facilitates the immune evade of cancer cells and is connected with tumor advancement, immune tolerance, and adverse prognosis for patients. In this review we aim to highlight the available knowledge on DC-T-cell interactions in BC aggressiveness and show its therapeutic potential in BC treatment.

Immunostimulatory Properties of Chemotherapy in Breast Cancer: From Immunogenic Modulation Mechanisms to Clinical Practice

Breast cancer (BC) is the most common malignancy among females. Chemotherapy drugs remain the cornerstone of treatment of BC and undergo significant shifts over the past 100 years. The advent of immunotherapy presents promising opportunities and constitutes a significant complementary to existing therapeutic strategies for BC. Chemotherapy as a cytotoxic treatment that targets proliferation malignant cells has recently been shown as an effective immune-stimulus in multiple ways. Chemotherapeutic drugs can cause the release of damage-associated molecular patterns (DAMPs) from dying tumor cells, which result in long-lasting antitumor immunity by the key process of immunogenic cell death (ICD). Furthermore, Off-target effects of chemotherapy on immune cell subsets mainly involve activation of immune effector cells including natural killer (NK) cells, dendritic cells (DCs), and cytotoxic T cells, and depletion of immunosuppressive cells including Treg cells, M2 macrophages and myeloid-derived suppressor cells (MDSCs). Current mini-review summarized recent large clinical trials regarding the combination of chemotherapy and immunotherapy in BC and addressed the molecular mechanisms of immunostimulatory properties of chemotherapy in BC. The purpose of our work was to explore the immune-stimulating effects of chemotherapy at the molecular level based on the evidence from clinical trials, which might be a rationale for combinations of chemotherapy and immunotherapy in BC.

A Mathematical Model of Breast Tumor Progression Based on Immune Infiltration

Breast cancer is the most prominent type of cancer among women. Understanding the microenvironment of breast cancer and the interactions between cells and cytokines will lead to better treatment approaches for patients. In this study, we developed a data-driven mathematical model to investigate the dynamics of key cells and cytokines involved in breast cancer development. We used gene expression profiles of tumors to estimate the relative abundance of each immune cell and group patients based on their immune patterns. Dynamical results show the complex interplay between cells and molecules, and sensitivity analysis emphasizes the direct effects of macrophages and adipocytes on cancer cell growth. In addition, we observed the dual effect of IFN-γ on cancer proliferation, either through direct inhibition of cancer cells or by increasing the cytotoxicity of CD8+ T-cells.

Hampering Stromal Cells in the Tumor Microenvironment as a Therapeutic Strategy to Destem Cancer Stem Cells

Cancer stem cells (CSCs) within the tumor bulk play crucial roles in tumor initiation, recurrence and therapeutic resistance. In addition to intrinsic regulation, a growing body of evidence suggests that the phenotypes of CSCs are also regulated extrinsically by stromal cells in the tumor microenvironment (TME). Here, we discuss the current knowledge of the interplay between stromal cells and cancer cells with a special focus on how stromal cells drive the stemness of cancer cells and immune evasive mechanisms of CSCs. Knowledge gained from the interaction between CSCs and stromal cells will provide a mechanistic basis for the development of novel therapeutic strategies for the treatment of cancers.

Tumor-infiltrating regulatory T cells, CD8/Treg ratio, and cancer stem cells are correlated with lymph node metastasis in patients with early breast cancer

BACKGROUND

Tumor-infiltrating lymphocytes are an important component of the tumor microenvironment (TME) in breast cancer. They have been linked with tumor pathogenesis in advanced stages. However, little is known about their contribution in early phases. In this study, we analyzed the infiltration of leukocytes and cancer stem cells (CSC) in tumors from patients with early breast cancer.

METHODS

Samples of blood and tumor tissue from 30 patients with breast cancer were collected, and the number of dendritic cells (DC), T cells, and CSC were analyzed by flow cytometry.

RESULTS

Tumor-infiltrating CD4 and CD8 T cells expressed higher levels of cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) compared with peripheral T cells. Regulatory T cells (Treg) were enriched in tumors and overexpressed glucocorticoid-induced TNFR-related protein and CTLA-4. Tumor Treg had a positive correlation with the amount of myeloid DC (mDC) and disease progression. The CD8/Treg ratio was associated with lymph node metastasis and tumor stages. The main subset of DC in early breast tumors was mDC, while plasmacytoid DC were almost absent. CSC were present in most tumors with higher frequencies in patients with lymph node metastasis. CSC were also associated with the amount of tumor-infiltrating Treg.

CONCLUSION

Early breast cancer has an inflammatory milieu characterized by mDC, Treg, and CSC infiltration. The frequencies of Treg, CSC and CD8/Treg ratio were associated with disease progression. The composition of leukocytes and the presence of CSC in early breast tumors should be considered for the development of new therapeutic approaches.

Nutritional, immunological and antioxidant defense status of outpatients diagnosed with colorectal cancer - a case-control study of the little-studied population

This cross-sectional study was conducted to investigate nutritional and immunological status of colorectal cancer (CRC) patients in a little-studied population from developing country, Pakistan. Data on 81 CRC patients and 37 healthy controls (HCs) were collected on nutritional status, nutrient intake, percent body fat (%BF), selected immunological parameters, phytochemical index (PI), healthy eating index (HEI), and prognostic nutrition index (PNI). Blood samples were used for immunological and antiradical defense potential (expressed as 50% hemolysis time; HT₅₀). Results show 40/81 (49.4%) patients reported weight loss in past 3-6 mo, Significant differences were found in HEI values between patients vs. HCs, and between patients in low vs. high PNI groups (P, for all trends <0.05). Patients in the higher PNI group were heavier, had higher % BF, higher energy intake, and higher PI score as compared to patients in the low PNI group (P < 0.05). Low PNI was positively associated with non-significantly lower CD4:CD8 ratios, higher B-cells and NK cells (P, for all trends >0.05), but with significantly higher hs-CRP levels, and lower HT₅₀ values (P, for all trends <0.001). In conclusion, CRC patients in a little-studied population have compromised nutritional and immunological health with lower HEI and PNI scores.

IL-8 analogue CXCL8 (3-72) K11R/G31P, modulates LPS-induced inflammation via AKT1-NF-kβ and ERK1/2-AP-1 pathways in THP-1 monocytes

IL-8 is elevated during inflammation, and it initiates cascade of down-stream reactions. Its antagonist, CXCL8 (3-72) K11R/G31P (G31P), represses inflammatory reactions via competitive binding to CXC chemokine family, preferentially G protein-couple receptors (GPCRs) CXCR1/2. This study reports the effect of G31P on the transcription profile of lipopolysaccharide (LPS) induced inflammation in THP-1 monocytes ex-vivo. LPS (1 µg/ml) induced elevation of IL-8 was significantly reduced by G31P (20 µg/ml and 30 µg/ml), with relatively increased inhibition of CXCR2 than CXCR1. Transcription of IL-1β, IL-6, and TNF-α were significantly inhibited, while IL-10 remained relatively unchanged. G31P treatment also had repressing effect on the inflammatory associated enzymes COX-2, MMP-2, and MMP-9. Significant restriction of c-Fos, and NF-kβ mRNA expression was observed, while that of c-Jun was marginally elevated. Conversely, SP-1 mRNA expression was seen to increase appreciably by G31P treatment. While the translation of pAKT, pERK1/2, and p65- NF-kβ were down-regulated by the G31P following THP-1 cells stimulation with LPS, reactive oxygen species (ROS) expression was on the positive trajectory. Collectively, the IL-8 analogue, G31P, modulates the inflammatory profile of LPS induced inflammation in THP-1 monocytes via AKT1-NF-kβ and ERK1/2-AP-1 pathways.

A novel potential effective strategy for enhancing the antitumor immune response in breast cancer patients using a viable cancer cell-dendritic cell-based vaccine

Dendritic cells (DCs) have been used in a number of clinical trials for cancer immunotherapy; however, they have achieved limited success in solid tumors. Consequently the aim of the present study was to identify a novel potential immunotherapeutic target for breast cancer patients through in vitro optimization of a viable DC-based vaccine. Immature DCs were primed by viable MCF-7 breast cancer cells and the activity and maturation of DCs were assessed through measuring CD83, CD86 and major histocompatibility complex (MHC)-II expression, in addition to different T cell subpopulations, namely CD4+ T cells, CD8+ T cells, and CD4+CD25+ forkhead box protein 3 (Foxp3)+ regulatory T cells (Tregs), by flow cytometric analysis. Foxp3 level was also measured by enzyme-linked immunosorbent assay (ELISA) in addition to reverse-transcription quantitative polymerase chain reaction. The levels of interleukin-12 (IL-12) and interferon-γ (IFN-γ) were determined by ELISA. Finally, the cytotoxicity of cytotoxic T lymphocytes (CTLs) was evaluated through measuring lactate dehydrogenase (LDH) release by ELISA. The results demonstrated that CD83+, CD86+ and MHC-II+ DCs were significantly elevated (P<0.001) following priming with breast cancer cells. In addition, there was increased activation of CD4+ and CD8+ T-cells, with a significant decrease of CD4+CD25+Foxp3+ Tregs (P<0.001). Furthermore, a significant downregulation of FOXP3 gene expression (P<0.001) was identified, and a significant decrease in the level of its protein following activation (P<0.001) was demonstrated by ELISA. Additionally, significant increases in the secretion of IL-12 and IFN-γ (P=0.001) were observed. LDH release was significantly increased (P<0.001), indicating a marked cytotoxicity of CTLs against cancer cells. Therefore viable breast cancer cell-DC-based vaccines could expose an innovative avenue for a novel breast cancer immunotherapy.

A panel containing PD-1, IL-2Rα, IL-10, and CA15-3 as a biomarker to discriminate breast cancer from benign breast disease

Introduction

Programmed cell death protein 1 (PD-1), an immune checkpoint molecule, has recently been recognized as a predictive and prognostic biomarker in several malignant tumors, but its diagnostic value remains largely unknown. We aimed to investigate the differential diagnostic efficiency of PD-1 and other immune molecules and propose a panel of immune molecules combined with cancer antigen 15-3 (CA15-3) to distinguish breast cancer (BC) from benign breast disease (BBD).

Patients and methods

Ninety-one eligible BC patients and 31 BBD patients were enrolled. Pretreatment peripheral blood was collected and tested for mRNA expression of PD-1, cytotoxic T lymphocyte antigen 4, forkhead box P3, transforming growth factor beta, interleukin-10 (IL-10), IL-2 receptor alpha (IL-2Rα), and cluster of differentiation 28 by quantitative reverse transcription PCR.

Results

The diagnostic areas under curve (AUCs) of PD-1, IL-2Rα, and IL-10 for BC-BBD discrimination were 0.764, 0.758, and 0.743, respectively. The diagnostic efficiencies of these three parameters in distinguishing early-stage or advanced BC from BBD were consistent with a role in BC-BBD discrimination. A panel of PD-1 + IL-10 + IL-2Rα + CA15-3 showed the highest AUC (0.862), with a sensitivity of 0.933 and a specificity of 0.724, for BC-BBD discrimination. In addition, for early-stage BC discrimination, this panel also had the highest AUC (0.811), with a sensitivity of 0.933 and a specificity of 0.614, while for advanced BC discrimination, a panel of PD-1 + IL-10 + CA15-3 exhibited the highest AUC (0.896), with a sensitivity of 0.933 and a specificity of 0.783.

Conclusion

These data indicate that the panel containing PD-1, IL-2Rα, IL-10, and CA15-3 can effectively discriminate BC from BBD with a high efficiency. After further confirmation, it could be used to complement conventional imaging modalities, especially in discriminating early-stage BC from BBD.

Role of regulatory T cells and CD8+ T lymphocytes in the dissemination of circulating tumor cells in primary invasive breast cancer

Circulating tumor cells (CTCs) dissemination is involved in tumor metastasis and is an independent prognostic factor in patients with primary and metastatic breast cancer. Regulatory T cells (Tregs) and cluster of differentiation (CD)8⁺ T lymphocytes are the main types of immune cells in the tumor microenvironment and exert opposite roles on the progression and outcome of breast cancer. The aim of the present study was to evaluate the associations between CTCs and intratumoral/peritumoral Tregs and CD8⁺ T lymphocytes in breast cancer. Peripheral CTCs were detected by a multi-marker quantitative polymerase chain reaction platform in 167 patients with invasive breast cancer. Intratumoral/peritumoral Tregs and CD8⁺ T lymphocytes were assessed by immunohistochemistry in 167 patients with invasive breast cancer to establish an association between these cell types and detection of peripheral CTCs. CTCs were detected in 55% of the patients with breast cancer. The prevalence of CTCs was positively associated with the number of intratumoral (P=0.002) and peritumoral Tregs (P=0.045), and the primary tumor size (P=0.012). This result was verified by analyzing intratumoral Tregs (P=0.044) and primary tumor size (P=0.044) with multivariate analysis, which indicated that the CTC-positive rate increased with an increasing number of intratumoral Tregs and a larger tumor size In the multivariate analysis, other variables including menopause, tumor-node-metastasis stage and peritumoral Tregs were not associated with the prevalence of CTCs. The prevalence of CTCs was inversely and weakly associated with the number of peritumoral CD8⁺ T lymphocytes using the univariate analysis, however this result was not statistically significant (P=0.470). In conclusion, regulatory T cells and CD8⁺ T lymphocytes may be involved, at least in part, in the CTCs dissemination of breast cancer, whereby Tregs appear to exert the dominant effect. Furthermore, the role of Tregs in the progression of breast cancer may be mediated by suppressing the dissemination of CTCs, which is primarily determined by intratumoral Tregs.

CAR T cell therapy for breast cancer: harnessing the tumor milieu to drive T cell activation

BACKGROUND

The adoptive transfer of T cells redirected to tumor via chimeric antigen receptors (CARs) has produced clinical benefits for the treatment of hematologic diseases. To extend this approach to breast cancer, we generated CAR T cells directed against mucin1 (MUC1), an aberrantly glycosylated neoantigen that is overexpressed by malignant cells and whose expression has been correlated with poor prognosis. Furthermore, to protect our tumor-targeted cells from the elevated levels of immune-inhibitory cytokines present in the tumor milieu, we co-expressed an inverted cytokine receptor linking the IL4 receptor exodomain with the IL7 receptor endodomain (4/7ICR) in order to transform the suppressive IL4 signal into one that would enhance the anti-tumor effects of our CAR T cells at the tumor site.

METHODS

First (1G - CD3ζ) and second generation (2G - 41BB.CD3ζ) MUC1-specific CARs were constructed using the HMFG2 scFv. Following retroviral transduction transgenic expression of the CAR±ICR was assessed by flow cytometry. In vitro CAR/ICR T cell function was measured by assessing cell proliferation and short- and long-term cytotoxic activity using MUC1+ MDA MB 468 cells as targets. In vivo anti-tumor activity was assessed using IL4-producing MDA MB 468 tumor-bearing mice using calipers to assess tumor volume and bioluminescence imaging to track T cells.

RESULTS

In the IL4-rich tumor milieu, 1G CAR.MUC1 T cells failed to expand or kill MUC1+ tumors and while co-expression of the 4/7ICR promoted T cell expansion, in the absence of co-stimulatory signals the outgrowing cells exhibited an exhausted phenotype characterized by PD-1 and TIM3 upregulation and failed to control tumor growth. However, by co-expressing 2G CAR.MUC1 (signal 1 - activation + signal 2 - co-stimulation) and 4/7ICR (signal 3 - cytokine), transgenic T cells selectively expanded at the tumor site and produced potent and durable tumor control in vitro and in vivo.

CONCLUSIONS

Our findings demonstrate the feasibility of targeting breast cancer using transgenic T cells equipped to thrive in the suppressive tumor milieu and highlight the importance of providing transgenic T cells with signals that recapitulate physiologic TCR signaling - [activation (signal 1), co-stimulation (signal 2) and cytokine support (signal 3)] - to promote in vivo persistence and memory formation.

Tumor inherent interferons: Impact on immune reactivity and immunotherapy

Immunotherapy has revolutionized cancer treatment, with sustained responses to immune checkpoint inhibitors reported in a number of malignancies. Such therapeutics are now being trialed in aggressive or advanced cancers that are heavily reliant on untargeted therapies, such as triple negative breast cancer. However, responses have been underwhelming to date and are very difficult to predict, leading to an inability to accurately weigh up the benefit-to-risk ratio for their implementation. The tumor immune microenvironment has been closely linked to immunotherapeutic response, with superior responses observed in patients with T cell-inflamed or 'hot' tumors. One class of cytokines, the type I interferons, are a major dictator of tumor immune infiltration and activation. Tumor cell inherent interferon signaling dramatically influences the immune microenvironment and the expression of immune checkpoint proteins, hence regulators and targets of this pathway are candidate biomarkers of immunotherapeutic response. In support of a link between IFN signaling and immunotherapeutic response, the combination of type I interferon inducers with checkpoint immunotherapy has recently been demonstrated critical for a sustained anti-tumor response in aggressive breast cancer models. Here we review evidence that links type I interferons with a hot tumor immune microenvironment, response to checkpoint inhibitors and reduced risk of metastasis that supports their use as biomarkers and therapeutics in oncology.

Predictive value of peripheral regulatory T cells in non-small cell lung cancer patients undergoing radiotherapy

Background

Studies increasingly focus on the impact of radiotherapy on immunity; however, the role of peripheral cellular immunity prior to radiotherapy in cancer patients remains largely unknown. In this study, we investigated the predictive roles of lymphocyte subsets on tumor progression in non-small cell lung cancer (NSCLC) patients undergoing radiotherapy, and their expression in NSCLC patients at first relapse.

Methods

We enrolled 70 NSCLC patients and 14 age- and sex-matched healthy donors and tested the lymphocyte subsets in their peripheral blood by flow cytometry. Among them, 40 newly diagnosed patients received radiotherapy and were enrolled to investigate the predictive value of lymphocyte subsets on tumor progression after radiotherapy by uni- and multivariate analyses; 30 patients at first relapse were included to evaluate the differences of lymphocyte subsets between them and first diagnosed patients and healthy volunteers.

Results

Increased proportions of regulatory T cells, CD8+ T cells, and CD8+CD28- T cells and decreased CD4+ T cells and CD4/CD8 ratios were observed in NSCLC patients at first relapse compared to newly diagnosed patients. In the 40 first diagnosed patients undergoing radiotherapy, uni- and multivariate analyses showed that increased level of regulatory T cells correlated with poor progression-free survival (hazard ratio = 2.55 and 3.76, P = 0.022 and 0.010, respectively).

Conclusions

Peripheral regulatory T cells were increased and independently predict tumor progression in NSCLC patients undergoing radiotherapy, suggesting the promising combination of radiotherapy and immunotherapy.

Low BMI is correlated with increased TGF-β and IL-10 mRNA levels in the peripheral blood of breast cancer patients

Transforming growth factor-β (TGF-β), interleukin-10 (IL-10), and forkhead box P3 (Foxp3) have important roles in breast cancer development. Previous studies confirmed a correlation between these immune molecules and tumor characteristics, but their association with nutritional status in breast cancer is largely unknown. We aimed to investigate the association between body mass index (BMI), hemoglobin, total protein, albumin, globulin (GLB), albumin/GLB ratio (AGR), pre-albumin, prognostic nutritional index, and TGF-β, IL-10, and Foxp3 mRNA expression in patients with breast cancer. Quantitative real-time PCR was used to detect the mRNA expression of TGF-β, IL-10, and Foxp3 in the peripheral blood of 107 patients with breast cancer and 21 healthy controls. We found that TGF-β mRNA levels were 2.6-fold, 3.2-fold, and 2.3-fold higher in patients with low BMI (<23), low AGR, and high GLB, respectively, than in their counterparts (P < 0.05). In addition, IL-10 mRNA expression levels in patients with normal BMI (<23) were 2.8-fold and 3.5-fold higher than in those who were overweight (23≤ BMI <25) and obese (BMI ≥ 25), respectively (P < 0.05). In addition, TGF-β, IL-10, and Foxp3 mRNA levels were significantly higher in patients with breast cancer than in healthy controls (P < 0.05). In summary, our results suggest that nutritional status, especially BMI, may strongly affect systematic immune function in patients with breast cancer. © 2018 IUBMB Life, 70(3):237-245, 2018.

The effects of EPA and DHA enriched fish oil on nutritional and immunological markers of treatment naïve breast cancer patients: a randomized double-blind controlled trial

BACKGROUND

We evaluated the effects of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids enriched fish oil (FO) on nutritional and immunological parameters of treatment naïve breast cancer patients.

METHODS

In a randomized double blind controlled trial, the FO group (FG) patients were supplemented with 2 g/ day of FO concentrate containing 1.8 g of n-3 fatty acids during 30 days. The placebo group (PG) received 2 g/ day of mineral oil. At baseline and after the intervention, plasma levels of n-3 fatty acids, dietary intake, weight, body composition, biochemical and immunological markers were assessed.

RESULTS

At the end of the intervention period, no between group differences were observed regarding anthropometric parameters. There was a significant increase in the plasma phospholipid EPA (p = 0.004), DHA (p = 0.007) of the FG patients. In FG patients the percentages of peripheral blood CD4+ T lymphocytes and serum high sensitivity C-reactive protein (hsCRP) levels were maintained while in PG patients there was a significant increase in hsCRP (p = 0.024). We also observed a significant reduction in the percentage of CD4+ T lymphocytes in the peripheral blood (p = 0.042) of PG patients. No changes in serum proinflammatory cytokine and prostaglandin E2 levels were observed.

CONCLUSIONS

Supplementation of newly diagnosed breast cancer patients with EPA and DHA led to a significant change in the composition of plasma fatty acids, maintained the level of CD4+ T cells and serum levels of hsCRP, suggestive of a beneficial effect on the immune system and less active inflammatory response.

TRIAL REGISTRATION

Brazilian Clinical Trials Registry (REBEC): RBR-2b2hqh. Registered 29 April 2013, retrospectively registered.

The prognostic value of peripheral CD4+CD25+ T lymphocytes among early stage and triple negative breast cancer patients receiving dendritic cells-cytokine induced killer cells infusion

Objective

This study aimed to assess the prognostic value of CD4⁺CD25⁺ T lymphocyte in peripheral blood among breast cancer patients treated with adoptive T lymphocytes immunotherapy.

Methods

217 patients participated in the follow-up study. CD4⁺CD25⁺ proportion was measured by flow cytometry in peripheral T cells. The median survival was estimated by Kaplan-Meier curve, Log-rank test and Cox hazard proportion regression model, between groups of CD4⁺CD25⁺ proportion more than 5% and less than or equal to 5% in peripheral T cells.

Results

Peripheral CD4⁺CD25⁺ T lymphocytes had not a relationship with progression-free survival. It was featured that above 5% peripheral CD4⁺CD25⁺ proportion of T cells was related with the median overall survival by a shorten of 51 months (p < 0.05) with the HR 1.65 (95%CI 1.04, 2.62). Above 5% CD4⁺CD25⁺proportion of T cells produced the HR to be 1.76 (95%CI 1.07, 2.87) In stage 0-II patients, and 3.59 (95%CI 1.05, 12.29) in triple negative breast cancer patients.

Conclusion

Cellular immunity restoration recovered by adoptive T cell infusions which resulted in less proportion of peripheral CD4⁺CD25⁺T lymphocytes could be a potential prognostic indicator among early stage and triple negative patients.

Peripheral blood leukocyte populations and urinary neopterin during chemotherapy in patients with breast cancer

The aim of the present study was to investigate serial changes in urinary neopterin and the populations of peripheral blood lymphocytes in breast cancer patients treated with primary chemotherapy. Thirty patients with breast cancer, including 20 patients undergoing primary chemotherapy treated with the combination of doxorubicin and cyclophosphamide with sequential administration of paclitaxel-based therapy (cohort A), and 10 patients presenting for first-line therapy of metastatic disease and treated with the combination of bevacizumab, taxane and carboplatin (cohort M) were studied. Healthy female blood donors served as control group. Significant differences were observed in baseline relative and absolute counts of peripheral blood lymphocyte subpopulations between both patient cohorts and controls. Significant changes of peripheral blood lymphocyte subpopulations were also observed during the course of chemotherapy. However, no significant changes of urinary neopterin concentrations and no correlation between urinary neopterin and peripheral blood lymphocyte counts were observed. In conclusion, present data demonstrate the presence of significant differences in peripheral blood leukocyte phenotype in breast cancer patients even before the start of primary chemotherapy. Significant changes were observed during the course of chemotherapy.

CD4+CD25+ regulatory T cells in tumor immunity

Regulatory T cells (Tregs) are essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases. Depletion of Tregs results in the onset of a variety of autoimmune diseases. Tregs are defined based on expression of CD4, CD25, and the transcription factor, FoxP3. It is now clear that three inhibitory cytokines, IL-10, IL-35 and TGF-β, are key mediators of Tregs function. Tregs have been shown to be important contributors to the development of immune tolerance toward tumors and play a critical role in the induction of tolerance to tumor associated antigens and suppression of anti-tumor immunity. Increasing researches support the existence of elevated numbers of regulatory T cells in cancer patients. Poor prognosis and decreased survival rates are closely correlated with higher Treg cell frequencies. Depletion of Tregs or blockade of their immune inhibitory role can enhance anti-tumor effects. Recent evidence suggests that Tregs may be responsible for the failure of host anti-tumor immunity by suppressing cytotoxic T-cells. In this review, we discuss cellular and molecular mechanisms in the differentiation and function of Tregs in tumor immunity.

Frequency of CD4+CD25+Foxp3+ cells in peripheral blood in relation to urinary bladder cancer malignancy indicators before and after surgical removal

Tumor cells communicate with stromal cells, including cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs), to form microenvironment inhibiting immune responses. Regulatory T cells (Tregs, CD4+CD25+FoxP3+) stimulate immune tolerance and facilitate tumor progression. We analyzed the changes in Treg frequencies assessed using flow cytometry in the peripheral blood of patients with urothelial bladder cancer before and after tumor-removal. Changes in Treg frequency were investigated in relation to clinicopathomorphological indicators of tumor malignancy and expression of RCAS1 on CAFs and TAMs. Higher Treg frequencies were observed in early phase of tumor growth (pTa-pT2), in larger tumors, with more aggressive type of invasion, and with expression of RCAS1. The later phase of tumor development, accompanied by a nonclassic differentiations and pT3-pT4 advancement, had lower number of tumor infiltrating lymphocytes (TILs) and lower Treg frequency. Furthermore, in pT2-pT4 tumors, a decreased post-surgery Treg frequency was associated with poorer prognosis: patients with the lowest frequency of Tregs died first. These findings strongly suggest that the Treg frequencies at later phase of tumor growth, associated with a low anti-tumor response, represent a new and important prognostic indicator in urinary bladder cancer.

Antitumour actions of interferons: implications for cancer therapy

The interferons (IFNs) are a family of cytokines that protect against disease by direct effects on target cells and by activating immune responses. The production and actions of IFNs are finely tuned to achieve maximal protection and avoid the potential toxicity associated with excessive responses. IFNs are back in the spotlight owing to mounting evidence that is reshaping how we can exploit this pathway therapeutically. As IFNs can be produced by, and act on, both tumour cells and immune cells, understanding this reciprocal interaction will enable the development of improved single-agent or combination therapies that exploit IFN pathways and new 'omics'-based biomarkers to indicate responsive patients.

Bone specific immunity and its impact on metastasis

Bone is one of the most common sites of metastasis in solid malignancy. Contributing to this osteotropism are the dynamic interactions between tumor cells and the numerous cell types resident in the normal bone, particularly osteoclasts and osteoblasts, which create a tumor supporting microenvironment. However, disseminated cells are detected in the bone marrow long before evidence of metastatic outgrowth, and it is likely that prolonged survival is also reliant on immunoescape. Compared with other peripheral organs such as the lung and spleen, the bone marrow constitutes a unique immune cell compartment that likely provides an immune privileged niche for disseminated tumor cells. This includes the large proportions of immunosuppressive cells, including myeloid derived suppressor cells and regulatory T cells, that blunt the activity of cytotoxic lymphocytes involved in tumor immunosurveillance. This review highlights key aspects of the osteoimmune landscape and emerging mechanisms by which tumor cells create or co-opt an immunosuppressed niche to support their outgrowth in bone. Future studies in this field are likely to shed light on the differences in immunoregulation between the bone and other sites including the primary tumor, and the potential for immunotherapeutics in treating disseminated disease in the bone. However, more immunocompetent models, that recapitulate tumor heterogeneity and bone metastasis need to be developed to accelerate this field.

C/EBPβ expression is an independent predictor of overall survival in breast cancer patients by MHCII/CD4-dependent mechanism of metastasis formation

CCAAT-enhancer binding protein β (C/EBPβ) is a transcription factor that has a critical role in mammary gland development and breast cancer progression. Loss of C/EBPβ increases metastatic dissemination of mouse mammary tumor cells. However, the mechanism by which C/EBPβ expression affects metastasis formation remains unknown. This study aims at determining the relationship between C/EBPβ and survival of breast cancer patients, and elucidating C/EBPβ's link with metastasis formation. C/EBPβ expression was evaluated in 137 cases of human breast cancer, and the correlation with overall survival was estimated by Kaplan–Meier analysis. Additionally, the mouse 4T1 tumor model was used for in vivo studies. Decreased C/EBPβ expression was found to be associated with shorter overall survival of breast cancer patients. In the murine 4T1 model, loss of C/EBPβ affects tumor growth, morphology and promotes metastatic spread to the lungs. Immunohistochemical analyses showed that C/EBPβ inhibition leads to increased major histocompatibility complex II (MHCII) expression, followed by the accumulation of CD45-, CD3- and CD4-positive (CD4+) lymphocytes in the tumors. Inflammation involvement in C/EBPβ-mediated metastasis formation was confirmed by DNA microarray and by experiments on CD4+ cell-deprived nude mice. Additionally, anti-CD3 and anti-CD4 treatments of C/EBPβ-silenced tumor-bearing mice resulted in reverting the C/EBPβ effect on tumor growth and metastasis. Altogether, C/EBPβ is a predictor of overall survival in breast cancer patients, and affects tumor growth, morphology and lung metastasis formation in murine 4T1 model. The mechanism of metastasis formation involves immunologic response depending on C/EBPβ-mediated activation of MHCII and accumulation of CD4+ lymphocytes in the tumor.

Levels of lymphocyte subsets in peripheral blood prior treatment are associated with aggressive breast cancer phenotypes or subtypes

The aim of this study was to assess associations between ER, Ki67, Her-2 phenotypes, molecular subtypes of breast cancer and circulating levels of lymphocyte subsets (CD4+, CD8+, NK, CD19+, CD20+) and the ratio of CD4+ to CD8+ prior to treatment. Cells from peripheral blood were counted by flow cytometry, ER, Her-2, and Ki67 expressions were detected by pathological examination, and Her-2 was also detected by FISH. We conducted a case-case comparison of 494 women with newly diagnosed breast cancer to evaluate association between levels of lymphocyte subsets in peripheral blood and breast cancer phenotypes [ER- vs. ER+; Ki67 ≥ 14 % vs. Ki67 < 14 %; Her-2+ vs. Her-2-; triple-negative breast cancer (TNBC) vs. luminal A]. Women with the highest levels of CD3+ (OR 0.45, 95 % CI 0.22-0.94), CD4+ (OR 0.22, 95 % CI 0.08-0.59), and the ratio of CD4+/CD8+ (OR 0.17, 95 % CI 0.06-0.47) were least likely to have TNBCs compared with luminal A cancers. The highest tertile of CD8+ (OR 3.67, 95 % CI 1.06-12.72) and NK (OR 2.64, 95 % CI 1.12-6.24) was significantly associated with TNBC compared with luminal A cancer. ER-, Ki67 ≥ 14 %, Her-2+ were associated with low levels of CD4+ and CD4+/CD8+ compared with ER+, Ki67 < 14 %, Her-2-. Women in the highest level of CD8+ had more likelihood to have ER- and Her-2+ compared with ER+ and Her-2-. High levels of NK cells were associated with increased risk of ER- compared with ER+ cancers. Highest levels of CD19+ and CD20+ were associated with low risk of ER-, compared with ER+ cancers. These findings show that immune function differs among different breast cancer phenotypes or subtypes and is associated with ER-, Her-2+, Ki67 ≥ 14 %, and TNBC which are likely to be aggressive phenotypes.

Loss of Dab2 expression in breast cancer cells impairs their ability to deplete TGF-β and induce Tregs development via TGF-β

Dab2 is a multifunctional adapter protein which is frequently under-expressed in a variety of cancers. It is implicated in many critical functions, including several signaling pathways, cell arrangement, differentiation of stem cells, and receptor endocytosis. Transforming growth factor-β (TGF-β) is a secreted multifunctional protein that controls several developmental processes and pathogenesis of many diseases. It has been documented that Dab2 played an important role in TGF-β receptors endocytosis. Here, we present evidence that re-expression of Dab2 in SK-BR-3 cell partially restored its ability to deplete TGF-β in surrounding medium by normalizing the trafficking of TGF-β receptors. We also demonstrate that the difference in TGF-β depletions produced by Dab2 expression was sufficient to impact on the conversion of naive CD4+ T cells to regulatory T cells (Tregs), and thus inhibited the proliferation of T cells. This work revealed a critical result that breast cancer cell was deficient in Dab2 expression and related receptor endocytosis-mediated TGF-β depletion, which may contribute to the accumulation of TGF-β in tumor microenvironment and the induction of immune tolerance.

CD4+CD25(high), CD8+CD28- cells and thyroid autoantibodies in breast cancer patients

Aim of the study

To investigate the percentage of CD4+CD25^high cells (including Treg cells) and CD8+CD28– cells in breast cancer patients with and without high levels of autoimmune thyroid antibodies.

Material and methods

Thirty-five women with breast cancer (9 of them having high thyroid antibodies) and fourteen healthy subjects were enrolled in this study. Flow cytometry was used to count CD4+CD25^high cells and CD8+CD28– suppressive cells (CD8 cell subtypes).

Results

In the patient group, the percentage of CD28– cells in CD8+ lymphocytes were higher [67.50% (55.1180.33) vs. 51.56% (42.5766.38); p = 0.021] and the percentage of CD28+CD45RO– cells (memory cells) in CD8+ lymphocytes were lower than in the control group. CD4+CD25^high cell percentage in CD4+ lymphocytes was elevated in the patient group [6.44% (4.528.74) vs. 2.97% (1.724.34); p < 0.001]. When the cytometric parameters were compared between patients (with high vs. normal thyroid antibodies), the distribution of CD8+ cell subgroups was also similar. CD4+CD25^high cells among CD4+ lymphocytes were decreased in patients with high levels of thyroid antibodies [5.19% (3.426.17) vs. 6.99% (4.829.95); p = 0.043].

Conclusions

CD4+CD25^high cells may play a role in autoimmunity of breast cancer patients, and may be a predictive marker. Advanced studies which evaluate the possible links between regulatory cells and autoimmunity should be established in cancer patients.

Regulating the regulators in cancer-immunosuppression in multiple myeloma (MM)

An effective immune response requires a prompt but measured action against the pathological insult, to prevent over-zealous inflammatory-mediated tissue destruction. In cancer, defective or incompetent immune responses may paradoxically result in disease progression despite an immune attempt at elimination. Tumour-induced immunosuppression may not only result from soluble factors and altered antigenicity, but also from cellular-mediated tumour-induced immune evasion. Multiple myeloma (MM) is associated with both cellular and humoral immune deficiencies and increased T(Reg) cells. In vitro modelling has indicated that the tumour cells directly induce functional T(Reg) cells. In light of this recent evidence, it now seems that the most promising and synergistic approaches for cancer immunotherapy would involve specific anti-tumour immunity and simultaneous reduction of tumour-induced immune-regulation. This review sets out the basic understanding of the human immune response, its dysregulation in cancer and proposes how this knowledge may influence future treatment strategies to maximise the anti-tumour immune response.

Tumor-released survivin induces a type-2 t cell response and decreases cytotoxic T cell function, in vitro

Clinical studies of T cell profiles from cancer patients have shown a skewing toward a type-2 T cell response with decreased cytotoxic T cell function. However, the primary cause of this shift remains unknown. Here we show that tumor-released Survivin, an inhibitor of apoptosis (IAP) protein and tumor-specific antigen, is taken up by T cells and alters their response. The addition of Survivin to T cell cultures resulted in decreased T cell proliferation and reduced cytotoxic CD8(+) T cell function. Additionally, type 1 cell numbers and IFN-γ and IL-2 production were significantly reduced, while IL-4 release and type 2 T cell numbers increased. In contrast, the function and numbers of Th17 and T regulatory cells were not affected. These studies show that tumor-released Survivin modulates T cells resulting in a phenotype similar to that observed in cancer patients with a polarity shift from a type 1 to a type 2 response.