Differential regulation and function of tumor-infiltrating T cells in different stages of breast cancer patients

A novel CD8+ T cell-related gene signature as a prognostic biomarker in hepatocellular carcinoma

CD8+ T cells have great roles in tumor suppression and elimination of various tumors including hepatocellular carcinoma (HCC). Nonetheless, potential prognostic roles of CD8+ T cell-related genes (CD8Gs) in HCC remains unknown. In our study, 416 CD8Gs were identified in HCC, which were enriched in inflammatory and immune signaling pathways. Using The Cancer Genome Atlas dataset, a 5-CD8Gs risk model (KLRB1, FYN, IL2RG, FCER1G, and DGKZ) was constructed, which was verified in International Cancer Genome Consortium and gene expression omnibus datasets. Furthermore, we found that overall survival was independently correlated with the CD8Gs signature, and it was associated with immune- and cancer-related signaling pathways and immune cells infiltration. Finally, drug sensitivity data indicated that 10 chemotherapeutic drugs held promise as therapeutics for HCC patients with high-risk. In conclusion, multi-databases analysis showed that 5-CD8Gs and their signature could be an indicator to predict candidate drugs for HCC therapy.

Dual Functions of T Lymphocytes in Breast Carcinoma: From Immune Protection to Orchestrating Tumor Progression and Metastasis

Breast cancer (BC) is the most common cancer type in women and the second leading cause of death. Despite recent advances, the mortality rate of BC is still high, highlighting a need to develop new treatment strategies including the modulation of the immune system and immunotherapies. In this regard, understanding the complex function of the involved immune cells and their crosstalk with tumor cells is of great importance. T-cells are recognized as the most important cells in the tumor microenvironment and are divided into several subtypes including helper, cytotoxic, and regulatory T-cells according to their transcription factors, markers, and functions. This article attempts to provide a comprehensive review of the role of T-cell subsets in the prognosis and treatment of patients with BC, and crosstalk between tumor cells and T-cells. The literature overwhelmingly contains controversial findings mainly due to the plasticity of T-cell subsets within the inflammatory conditions and the use of different panels for their phenotyping. However, investigating the role of T-cells in BC immunity depends on a variety of factors including tumor types or subtypes, the stage of the disease, the localization of the cells in the tumor tissue and the presence of different cells or cytokines.

Neoadjuvant chemotherapy modulates exhaustion of T cells in breast cancer patients

Breast cancer is the leading cause of cancer deaths in women worldwide. It has been observed that the incidence of breast cancer increases linearly with age after 45, which suggest a link between cancer, aging, and senescence. A growing body of evidence indicates that the immunosuppressive tumor network in breast cancer patients can lead to T-cell exhaustion and senescence. Cytotoxic chemotherapy is a common treatment for many cancers, and it is hypothesized that its efficacy may be related to immune activation. However, the effects of neoadjuvant chemotherapy on T-cell dysfunction in breast cancer patients are not fully understood. This study aimed to evaluate the impact of neoadjuvant chemotherapy on the expression of exhaustion and senescence markers in T cells in women with breast cancer. Our results showed that T cells from breast cancer patients have a reduced ability to respond to stimulation in-vitro and an increased expression of senescence and exhaustion-associated markers, such as TIM-3, LAG3, and CD57. Furthermore, we found that neoadjuvant chemotherapy has an immunomodulatory effect and reduces the expression of exhaustion markers. Our observations of the immune phenotype of T cells during neoadjuvant chemotherapy treatment highlight its ability to stimulate the immune system against cancer. Therefore, monitoring the response of T cells during chemotherapy may enable early prediction of clinical response.

Confirmation of the Prognostic Value of Foxp3+ Cells in Canine Mammary Tumors

Foxp3+ cell counts were evaluated by immunohistochemistry in 59 canine mammary tumors, 20 adenomas, and 39 carcinomas in three different compartments: intratumoral, within the adjacent stroma, and in the distant stroma. Foxp3+ lymphocyte counts were compared with histotype, grading, presence of lymphatic invasion, immunohistochemical expression of estrogen and progesterone receptors, expression of c-erbB-2, and the overall survival (OS). Our findings confirmed that Foxp3+ cells were significantly higher in canine mammary carcinomas compared to adenomas. A significantly higher number of Foxp3+ cells were detected in grade III carcinomas compared to grade II carcinomas, as well as in tumors with lymphatic invasion and loss of ER-expression. Finally, a high number of Foxp3+ cells was associated with poor prognosis. In conclusion, our findings highlighted the association of Foxp3+ lymphocytes with negative clinicopathological features and shorter overall survival (OS), thus confirming the role of Tregs as a negative prognostic marker in canine mammary carcinomas.

Expression of FOXP3 in Canine Gliomas: Immunohistochemical Study of Tumor-Infiltrating Regulatory Lymphocytes

Dogs develop gliomas with similar histopathological features to human gliomas and share with them the limited success of current therapeutic regimens such as surgery and radiation. The tumor microenvironment in gliomas is influenced by immune cell infiltrates. The present study aims to immunohistochemically characterize the tumor-infiltrating lymphocyte (TIL) population of naturally occurring canine gliomas, focusing on the expression of Forkhead box P3-positive (FOXP3+) regulatory T-cells (Tregs). Forty-three canine gliomas were evaluated immunohistochemically for the presence of CD3+, FOXP3+, and CD20+ TILs. In low-grade gliomas, CD3+ TILs were found exclusively within the tumor tissue. In high-grade gliomas, they were present in significantly higher numbers throughout the tumor and in the brain-tumor junction. CD20+ TILs were rarely found in comparison to CD3+ TILs. FOXP3+ TILs shared a similar distribution with CD3+ TILs. The accumulation of FOXP3+ Tregs within the tumor was more pronounced in astrocytic gliomas than in tumors of oligodendroglial lineage and the difference in expression was significant when comparing low-grade oligodendrogliomas and high-grade astrocytomas. Only high-grade astrocytomas presented FOXP3+ cells with tumoral morphology. In spontaneous canine gliomas, TILs display similar characteristics (density and distribution) as described for human gliomas, supporting the use of the dog as an animal model for translational immunotherapeutic studies.

The Evolving Role of CD8+CD28- Immunosenescent T Cells in Cancer Immunology

Functional, tumor-specific CD8⁺ cytotoxic T lymphocytes drive the adaptive immune response to cancer. Thus, induction of their activity is the ultimate aim of all immunotherapies. Success of anti-tumor immunotherapy is precluded by marked immunosuppression in the tumor microenvironment (TME) leading to CD8⁺ effector T cell dysfunction. Among the many facets of CD8⁺ T cell dysfunction that have been recognized—tolerance, anergy, exhaustion, and senescence—CD8⁺ T cell senescence is incompletely understood. Naïve CD8⁺ T cells require three essential signals for activation, differentiation, and survival through T-cell receptor, costimulatory receptors, and cytokine receptors. Downregulation of costimulatory molecule CD28 is a hallmark of senescent T cells and increased CD8⁺CD28⁻ senescent populations with heterogeneous roles have been observed in multiple solid and hematogenous tumors. T cell senescence can be induced by several factors including aging, telomere damage, tumor-associated stress, and regulatory T (Treg) cells. Tumor-induced T cell senescence is yet another mechanism that enables tumor cell resistance to immunotherapy. In this paper, we provide a comprehensive overview of CD8⁺CD28⁻ senescent T cell population, their origin, their function in immunology and pathologic conditions, including TME and their implication for immunotherapy. Further characterization and investigation into this subset of CD8⁺ T cells could improve the efficacy of future anti-tumor immunotherapy.

Circulating regulatory T cells from breast cancer patients in response to neoadjuvant chemotherapy

Background

Immune escape of tumor cells is a new hallmark of cancer in general, and breast cancer, in particular. Previous studies have demonstrated that the immunological profile in peripheral blood may be a prognostic and/or predictive biomarker in breast cancer. Thus, higher number of regulatory T cells (Tregs) in blood from patients with breast cancer has been reported in relation to normal donors. In the present study, we planned to evaluate the changes in different cell populations in peripheral blood: neutrophils, monocytes and lymphocytes, as well as lymphocyte subpopulations [natural killer (NK), B lymphocytes, T lymphocytes, both CD4⁺ and CD8⁺, and Tregs] from patients with local breast cancer (both Her2⁺ and Her2⁻), before, during and after neoadjuvant chemotherapy.

Methods

We have employed flow cytometry for the cell analysis of fresh samples obtained before and whilst the neoadjuvant treatment was accomplished. We have studied 50 successive patients from the Breast Cancer Unit of the Virgen Macarena University Hospital during 2 years.

Results

Neoadjuvant chemotherapy induced a significant reduction in B cells, especially in Her2⁻ patients, and a reduction in NK cells. CD4⁺ T cells decreased, whereas CD8⁺ cells only decreased in Her2⁻ patients. Tregs were also diminished, especially in Her2⁺ patients, in response to treatment. Thus, higher CD8/Treg ratio was observed in Her2⁺ patients. A higher percentage of Her2⁺ patients (66.6%) achieved complete response than Her2⁻ patients (27.5%). Monocytes and neutrophils were not changed in peripheral blood.

Conclusions

Even though the decrease in B cells and NK cells in response to chemotherapy may be deleterious in the neoadjuvant treatment of breast cancer, the decrease in Tregs and CD4 T cells, but not CD8 T cells, increasing the CD8/Treg ratio, especially in Her2⁺ patients, may reveal a new tool to monitor the immune response in breast cancer treated with chemotherapy in the neoadjuvant setting.

Immunohistochemical Analysis of Foxp3+, CD4+, CD8+ Cell Infiltrates and PD-L1 in Oral Squamous Cell Carcinoma

The immunoexpression of the PD-L1 and the number of immune infiltrating cells have been shown to be a significant prognostic factors in various human cancers. Immunohistochemical method was used to examine the immunoexpression of PD-L1 and number of Foxp3+, CD4+, CD8+ cells in 78 cases of oral squamous cell carcinomas (OSCCs): with better prognosis - OSCCBP (n = 37), and with poorer prognosis - OSCCPP (n = 41), and 18 cases of normal mucosa as a control. The immunoexpression of PD-L1 and the mean number of Foxp3+ cells was significantly increased in OSCCPP group in comparison to OSCCBP and control groups. The mean number of CD4+ cells was significantly increased in OSCCPP group in comparison to OSCCBP and control groups. CD8+ cells were significantly more numerous in OSCCBP group in comparison to OSCCPP and control group. In both OSCCPP and OSCCBP groups there were positive significant correlations between number of Foxp3+ and CD4+ cells. We found positive correlations between the immunoexpression of PD-L1 and numbers of Foxp3+ cells, and negative correlation between the immunoexpression of PD-L1 and numbers of CD8+ cells in both OSCCPP and OSCCBP groups. We found also significant positive correlation between immunoexpression of PD-L1 and the number of CD4+ cells in OSCCPP group. In conclusion, our findings support the hypothesis of involvement of Tregs and PD-L1 in OSCC development and progression.

Chloroquine (CQ) exerts anti-breast cancer through modulating microenvironment and inducing apoptosis

CQ is an anti-malaria drug, which has been used for years. However, there are published articles about its activity in anti-cancers. The aim of this approach was to look at possibility and related mechanisms of anti-breast cancer (mouse breast cancer cell line 4T1) by CQ alone. The studies of anti 4T1 in vitro and in vivo by CQ were performed. The growth of 4T1 in vitro and in vivo, survival of mice post treatment with CQ, changes of immune parameters and microenvironment in mice were evaluated. Our results demonstrate that CQ could markedly inhibit growth of 4T1 in vitro through inducing apoptosis of cells, inhibiting secretion of TGF-β and prolong the mice survival in vivo through boosting immune system by upregulating CD8+ T cell, and through down-regulating tumor associated macrophages (TAM), myeloid derived suppressing cells (MDSC) and Tregs, in microenvironment of mice bearing tumor. This provides a new mode of action for CQ and it is therefore concluded that CQ could be with potential in breast cancer therapy.