Immune cells as anti-cancer therapeutic targets and tools

Chronic inflammation is a contributing factor to overall cancer risk as well as cancer promotion and progression; however, pathways regulating onset of cancer-promoting inflammatory responses are still poorly understood. Clinical data suggest that deficient anti-tumor cell-mediated immunity, in combination with enhanced pro-tumor humoral and/or innate immunity (inflammation), are significant factors influencing malignant outcome. Here, we discuss therapeutic implications from clinical data and experimental studies using de novo immune-competent mouse models of cancer development that together are revealing molecular and cellular mechanisms underlying interactions between immune cells and evolving neoplastic cells that regulate cancer outcome. Understanding the functionally significant links between adaptive and innate immunity that regulate cancer development will open new therapeutic opportunities to manipulate aspects of immunobiology and minimize lethal effects of cancer development.     

肝癌小鼠外周血及脾脏T淋巴细胞亚群的变化及其意义

目的:观察小鼠原位肝癌模型外周血以及脾脏T淋巴细胞亚群与正常小鼠之间的差异变化,探讨其差异变化的意义。方法:在正常KM小鼠肝脏种植H22细胞,建立小鼠原位模型。采用流式细胞术,以健康正常小鼠为对照,检测肝癌小鼠外周血以及脾脏T淋巴细胞亚群的变化。结果:与健康正常小鼠相比,肝癌小鼠外周血CD4~+T淋巴细胞、CD4~+/CD8~+比例有显著性降低,CD8~+T淋巴细胞显著性升高;脾脏CD3~+、CD4~+T淋巴细胞有显著性降低。结论:小鼠原位肝癌模型外周血以及脾脏T淋巴细胞亚群发生异常,免疫系统紊乱,可以反映小鼠肝癌的发生、发展。     

前列腺癌患者^89Sr核素治疗后免疫功能的变化

目的：探讨分析前列腺癌患者^89Sr治疗后机体免疫功能的变化及其临床意义。方法：87例前列腺癌患者经^89Srcl2治疗1月,采用流式细胞术检测治疗前后其外周血淋巴细胞亚群,速率散射免疫比浊分析法检测其免疫球蛋白的含量。结果：经^89Sr治疗后,患者CD3、CD19、CD4比例均明显升高,CD8比例明显降低,差异均有统计学意义畔0．05）,而CD16^＋CD56^＋无明显变化;IgG和IgA明显升高,差异均有统计学意义（P〈0．05）,而IgM无明显变化。结论：用^89Srcl2治疗前列腺癌可以有效提高患者的免疫水平,可通过监测机体免疫功能指标的变化^89Sr核素的疗效。     

曲马多、吗啡术后自控镇痛对食管癌患者细胞免疫功能的影响

目的：比较曲马多、吗啡对食管癌术后患者的镇痛疗效以及对机体免疫功能的影响。方法：将本院50 例行食管癌手术患者随 机分成对A 组和B 组,A 组接受硬膜外吗啡镇痛,B 组接受硬膜外曲马多镇痛,常规监测心电图（ECG）、无创血压（BP）、心率 （HR）、血氧饱和度（SPO2）、呼气末二氧化碳分压(PETCO2）。记录两组患者不同时间点视觉模拟疼痛（VAS）评分、不良反应发生 率、外周血T 淋巴细胞亚群(CD3+、CD4+、CD8+)、NK 细胞的变化。结果：两组患者均得到满意的术后镇痛效果,术后1d,A、B两组 患者外周血T淋巴细胞亚群、NK 细胞的水平较术前降低（P<0.05）,且A 组降低幅度明显大于B 组（P<0.05）;术后2d,A 组外周 血T 淋巴细胞亚群、NK 细胞的水平虽有所升高,但仍较术前降低（P<0.05）,B 组CD3+、CD4+、CD8+及NK细胞水平恢复至术前水 平;术后3d,A 组上述指标恢复至麻醉前水平。结论：曲马多在镇痛的同时对机体外周血T 淋巴细胞亚群和NK细胞水平影响较 小,减轻了麻醉对细胞免疫功能的抑制效应。     

Radiation combines with immune checkpoint blockade to enhance T cell priming in a murine model of poorly immunogenic pancreatic cancer

Radiation has been a pillar of cancer therapy for decades. The effects of radiation on the anti-tumour immune response are variable across studies and have not been explicitly defined in poorly immunogenic tumour types. Here, we employed combination checkpoint blockade immunotherapy with stereotactic body radiation therapy and examined the effect on tumour growth and immune infiltrates in subcutaneous and orthotopic mouse models of pancreatic cancer. Although immune checkpoint blockade and radiation were ineffective alone, their combination produced a modest growth delay in both irradiated and non-irradiated tumours that corresponded with significant increases in CD8+ T cells, CD4+ T cells and tumour-specific T cells as identified by IFNγ ELISpot. We conclude that radiation enhances priming of tumour-specific T cells in poorly immunogenic tumours and that the frequency of these T cells can be further increased by combination with immune checkpoint blockade.     

Tumor immune microenvironment: sanctuary of tumor and target for immunotherapy

The tumor immune microenvironment (TIME) is the cellular environment in which tumors exist. This includes: surrounding blood vessels, immune cells, fibroblasts, bone marrow-derived inflammatory cells, lymphocytes, signaling molecules, immune checkpoint proteins and the extracellular matrix (ECM). The TIME plays a critical role in cancer progression and regulation. Tumors can influence the microenvironment by releasing extracellular signals, promoting tumor angiogenesis and inducing peripheral immune tolerance, while the immune cells in the microenvironment can affect the growth and evolution of cancerous cells. The molecules and cells in the TIME influence disease outcome by altering the balance of suppressive versus cytotoxic responses in the vicinity of the tumor. Having a better understanding of the tumor immune microenvironment will pave the way for identifying new targets for immunotherapies that promote cancer elimination.     

Rosiglitazone and Gemcitabine in combination reduces immune suppression and modulates T cell populations in pancreatic cancer

Pancreatic ductal adenocarcinoma is a leading cause of cancer mortality with a dismal 2–5 % 5-year survival rate. Monotherapy with Gemcitabine has limited success, highlighting the need for additional therapies that enhance the efficacy of current treatments. We evaluated the combination of Gemcitabine and Rosiglitazone, an FDA-approved drug for the treatment of type II diabetes, in an immunocompetent transplantable mouse model of pancreatic cancer. Tumor progression, survival, and metastases were evaluated in immunocompetent mice with subcutaneous or orthotopic pancreatic tumors treated with Pioglitazone, Rosiglitazone, Gemcitabine, or combinations of these. We characterized the impact of high-dose Rosiglitazone and Gemcitabine therapy on immune suppressive mediators, including MDSC and T regulatory cells, and on modulation of peripheral and intra-tumoral T cell populations. Combinations of Rosiglitazone and Gemcitabine significantly reduced tumor progression and metastases, enhanced apoptosis, and significantly extended overall survival compared to Gemcitabine alone. Rosiglitazone altered tumor-associated immune suppressive mediators by limiting early MDSC accumulation and intra-tumoral T regulatory cells. Combination therapy with Rosiglitazone and Gemcitabine modulated T cell populations by enhancing circulating CD8⁺ T cells and intra-tumoral CD4⁺ and CD8⁺ T cells while limiting T regulatory cells. The results suggest that Rosiglitazone, in combination with Gemcitabine, decreases immune suppressive mechanisms in immunocompetent animals and provides pre-clinical data in support of combining Rosiglitazone and Gemcitabine as a clinical therapy for pancreatic cancer.     

Focus: Allergic Diseases and Type II Immunity: Intricate Relationship Between Adaptive and Innate Immune System in Allergic Contact Dermatitis

Allergic contact dermatitis (ACD) is a complex immunological allergic disease characterized by the interplay between the innate and adaptive immune system. Initially, the role of the innate immune system was believed to be confined to the initial sensitization phase, while adaptive immune reactions were linked with the advanced elicitation phase. However, recent data predicted a comparatively mixed and interdependent role of both immune systems throughout the disease progression. Therefore, the actual mechanisms of disease progression are more complex and interlinked. The aim of this review is to combine such findings that enhanced our understanding of the pathomechanisms of ACD. Here, we focused on the main cell types from both immune domains, which are involved in ACD, such as CD4⁺ and CD8⁺ T cells, B cells, neutrophils, and innate lymphoid cells (ILCs). Such insights can be useful for devising future therapeutic interventions for ACD.     

CD8+ T cell metabolic changes in breast cancer

Immunometabolism has advanced our understanding of how the cellular environment and nutrient availability regulates immune cell fate. Not only are metabolic pathways closely tied to cell signaling and differentiation, but can induce different subsets of immune cells to adopt unique metabolic programs, influencing disease progression. Dysregulation of immune cell metabolism plays an essential role in the progression of several diseases including breast cancer (BC). Metabolic reprogramming plays a critical role in regulating T cell functions. CD8⁺ T cells are an essential cell type within the tumor microenvironment (TME). To induce antitumor responses, CD8⁺ T cells need to adapt their metabolism to fulfill their energy requirement for effective function. However, different markers and immunologic techniques have made identifying specific CD8⁺ T cells subtypes in BC a challenge to the field. This review discusses the immunometabolic processes of CD8⁺ T cell in the TME in the context of BC and highlights the role of CD8⁺ T cell metabolic changes in tumor progression.     

Activated CD69+ T cells foster immune privilege by regulating IDO expression in tumor-associated macrophages

Substantial evidence indicates that immune activation at stroma can be rerouted in a tumor-promoting direction. CD69 is an immunoregulatory molecule expressed by early-activated leukocytes at sites of chronic inflammation, and CD69(+) T cells have been found to promote human tumor progression. In this study, we showed that, upon encountering autologous CD69(+) T cells, tumor macrophages (MΦs) acquired the ability to produce much greater amounts of IDO protein in cancer nests. The T cells isolated from the hepatocellular carcinoma tissues expressed significantly more CD69 molecules than did those on paired circulating and nontumor-infiltrating T cells; these tumor-derived CD69(+) T cells could induce considerable IDO in monocytes. Interestingly, the tumor-associated monocytes/MΦs isolated from hepatocellular carcinoma tissues or generated by in vitro culture effectively activated circulating T cells to express CD69. IL-12 derived from tumor MΦs was required for early T cell activation and subsequent IDO expression. Moreover, we found that conditioned medium from IDO(+) MΦs effectively suppressed T cell responses in vitro, an effect that could be reversed by adding extrinsic IDO substrate tryptophan or by pretreating MΦs with an IDO inhibitor 1-methyl-DL-tryptophan. These data revealed a fine-tuned collaborative action between different types of immune cells to counteract T cell responses in tumor microenvironment. Such an active induction of immune tolerance should be considered for the rational design of effective immune-based anticancer therapies.     

Immunologic biomarkers as correlates of clinical response to cancer immunotherapy

Over the last few years, several newly developed immune-based cancer therapies have been shown to induce clinical responses in significant numbers of patients. As a result, there is a need to identify immune biomarkers capable of predicting clinical response. If there were laboratory parameters that could define patients with improved disease outcomes after immunomodulation, product development would accelerate, optimization of existing immune-based treatments would be facilitated and patient selection for specific interventions might be optimized. Although there are no validated cancer immunologic biomarkers that are predictive of clinical response currently in widespread use, there is much published literature that has informed investigators as to which markers may be the most promising. Population-based studies of endogenous tumor immune infiltrates and gene expression analyses have identified specific cell populations and phenotypes of immune cells that are most likely to mediate anti-tumor immunity. Further, clinical trials of cancer vaccines and other cancer directed immunotherapy have identified candidate immunologic biomarkers that are statistically associated with beneficial clinical outcomes after immune-based cancer therapies. Biomarkers that measure the magnitude of the Type I immune response generated with immune therapy, epitope spreading, and autoimmunity are readily detected in the peripheral blood and, in clinical trials of cancer immunotherapy, have been associated with response to treatment.     

Crosstalk between cancer‐associated fibroblasts and immune cells in cancer

Multiple studies have shown that cancer‐associated fibroblasts (CAFs) play an important role in tumour progression, including carcinogenesis, invasion, metastasis and the chemoresistance of cancer cells. Immune cells, including macrophages, natural killer cells, dendritic cells and T cells, play a dual role in the tumour microenvironment. Although increasing research has focused on studying interactions between distinct cells in the tumour microenvironment, the complex relationships between CAFs and immune cells remain unclear and need further study. Here, we summarize our current understanding of crosstalk between CAFs and immune cells, which may help clarify their diagnostic and therapeutic value in tumour progression.     

CD73 acts as a prognostic biomarker and promotes progression and immune escape in pancreatic cancer

CD73 is a glycosylphosphatidylinositol (GPI)‐anchored protein that attenuates tumour immunity via cooperating with CD39 to generate immunosuppressive adenosine. Therefore, CD73 blockade has been incorporated into clinical trials for cancers based on preclinical efficacy. However, the biological role and underlying mechanism of CD73 in pancreatic cancer (PC) microenvironment and its prognostic impact have not been comprehensively studied. In this article, we found that the expression of CD73 was up‐regulated in PC tissues and patients with higher CD73 expression had poorer overall survival (OS) and disease‐free survival (DFS) in multiple publicly available databases. Higher CD73 expression was significantly associated with its reduced methylation, and only the hypomethylation of CpG site at cg23172664 was obviously correlated with poorer OS. Then, Metascape analysis and GSEA showed that CD73 may play an important role in PC progression and immune regulations. Notably, CD73 was verified to be negatively correlated with infiltrating levels of CD8⁺ T cells and γδ⁺ T cells in both TCGA and GEO cohorts via the CIBERSORT algorithm. In addition, patients with higher CD73 expression also tended to have higher PD‐L1 expression and tumour mutation load. It seemed that CD73 might be a promising biomarker for the response to the anti‐PD‐1/PD‐L1 treatment in PC. In conclusion, these results reveal that CD73 may function as a promotor in cancer progression and a regulator in immune patterns via CD73‐related pathways. Blockade of CD73 might be a promising therapeutic strategy for PC.     

Increased circulating myeloid-derived suppressor cells correlate with clinical cancer stage,metastatic tumor burden,and doxorubicin–cyclophosphamide chemotherapy

Abnormal accumulation of myeloid-derived suppressor cells (MDSC) is an important mechanism of tumor immune evasion. Cyclophosphamide (CTX) has also been shown in non-tumor bearing animals to cause transient surges in MDSC. Knowledge of MDSC is primarily based on preclinical work, and to date only few published studies have involved cancer patients. The goal of this study was to test the hypothesis that circulating MDSC levels correlate with clinical cancer stage, CTX-based chemotherapy, and metastatic tumor burden. Whole blood was collected from 106 newly diagnosed solid tumor patients (stages I–IV). Percentages of circulating MDSC (Lin^−/Lo, HLA DR−, CD33⁺CD11b⁺) were determined prior to initiation of systemic therapy. In 17 early stage breast cancer patients receiving doxorubicin–cyclophosphamide chemotherapy every 14 days (ddAC) blood was collected on day 1 of each cycle. Circulating MDSC were significantly increased in cancer patients of all stages relative to healthy volunteers. A significant correlation between circulating MDSC and clinical cancer stage was also observed. Moreover, among stage IV patients, those with extensive metastatic tumor burden had the highest percent and absolute number of MDSC. Significant increases in circulating MDSC were observed with ddAC when compared with pretreatment levels. Circulating MDSC levels correlate with clinical cancer stage, ddAC, and metastatic tumor burden. This information must be incorporated into the design of future trials exploring immune-based therapeutic strategies. Pharmacologic modulation of MDSC should also be tested in future clinical trials.     

Impact of CD39 and purinergic signalling on the growth and metastasis of colorectal cancer

Despite improvements in prevention and management of colorectal cancer (CRC), uncontrolled tumor growth with metastatic spread to distant organs remains an important clinical concern. Genetic deletion of CD39, the dominant vascular and immune cell ectonucleotidase, has been shown to delay tumor growth and blunt angiogenesis in mouse models of melanoma, lung and colonic malignancy. Here, we tested the influence of CD39 on CRC tumor progression and metastasis by investigating orthotopic transplanted and metastatic cancer models in wild-type BALB/c, human CD39 transgenic and CD39 deficient mice. We also investigated CD39 and P2 receptor expression patterns in human CRC biopsies. Murine CD39 was expressed by endothelium, stromal and mononuclear cells infiltrating the experimental MC-26 tumors. In the primary CRC model, volumes of tumors in the subserosa of the colon and/or rectum did not differ amongst the treatment groups at day 10, albeit these tumors rarely metastasized to the liver. In the dissemination model, MC-26 cell line-derived hepatic metastases grew significantly faster in CD39 over-expressing transgenics, when compared to CD39 deficient mice. Murine P2Y2 was significantly elevated at both mRNA and protein levels, within the larger liver metastases obtained from CD39 transgenic mice where changes in P2X7 levels were also noted. In clinical samples, lower levels of CD39 mRNA in malignant CRC tissues appeared associated with longer duration of survival and could be linked to less invasive tumors. The modulatory effects of CD39 on tumor dissemination and differential levels of CD39, P2Y2 and P2X7 expression in tumors suggest involvement of purinergic signalling in these processes. Our studies also suggest potential roles for purinergic-based therapies in clinical CRC.     

The clinical value of the changes of peripheral lymphocyte subsets absolute counts in patients with non-small cell lung cancer

IntroductionImmune function strongly influences the outcome of patients with non-small cell lung cancer (NSCLC). It's vital to understand the immune state of patients through detecting the percentage and number of lymphocyte subsets accurately, and helpful to evaluate conditions of prognosis and adjust treatment for patients.MethodsWe conducted a retrospective cohort study in First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China. The absolute counts and percentages of CD3+, CD3 + CD4+, CD3 + CD8+, B and NK cells were determined by single platform technologies. 172 patients received treatment including surgery or chemotherapy after surgery. The factors affecting disease progression were analyzed by Binary Logistic regression. Progression free survival (PFS) calculating survivals were with the method of Kaplan-Meier. The log-rank test and cox's proportional hazard regression (enter method) were used for univariable and multivariable analyses respectively.ResultsRelative to normal controls, patients with NSCLC at different stages showed decreased absolute lymphocyte count obviously, rather than lymphocyte percentages.Different treatments had unlike influence on the homeostasis of lymphocytes and the effects last for a long time. Logistic regression showed CD3 + CD4+ and CD3 + CD8+ could contribute to favorable prognosis. Multivariate analysis of prognostic factors of PFS showed CD3 + CD4+ cell was independent factor for predicting PFS.ConclusionsThe absolute count of CD3+, CD3 + CD4+, CD3 + CD8+, B and NK cells were better indication of the patient's immune state than percentages of each lymphocyte subsets. Immune function was impaired in patients with non-small cell lung. The high level of baseline absolute CD3 + CD4+ cells count contributed to longer progression free survival.Chinese Clinic Trial Registry number: ChiCTR-IOR-17014139; Registry date: 2017/12/25.     

Immune-based mechanisms of cytotoxic chemotherapy: implications for the design of novel and rationale-based combined treatments against cancer

Conventional anticancer chemotherapy has been historically thought to act through direct killing of tumor cells. This concept stems from the fact that cytotoxic drugs interfere with DNA synthesis and replication. Accumulating evidence, however, indicates that the antitumor activities of chemotherapy also rely on several off-target effects, especially directed to the host immune system, that cooperate for successful tumor eradication. Chemotherapeutic agents stimulate both the innate and adaptive arms of the immune system through several modalities: (i) by promoting specific rearrangements on dying tumor cells, which render them visible to the immune system; (ii) by influencing the homeostasis of the hematopoietic compartment through transient lymphodepletion followed by rebound replenishment of immune cell pools; (iii) by subverting tumor-induced immunosuppressive mechanisms and (iv) by exerting direct or indirect stimulatory effects on immune effectors. Among the indirect ways of immune cell stimulation, some cytotoxic drugs have been shown to induce an immunogenic type of cell death in tumor cells, resulting in the emission of specific signals that trigger phagocytosis of cell debris and promote the maturation of dendritic cells, ultimately resulting in the induction of potent antitumor responses. Here, we provide an extensive overview of the multiple immune-based mechanisms exploited by the most commonly employed cytotoxic drugs, with the final aim of identifying prerequisites for optimal combination with immunotherapy strategies for the development of more effective treatments against cancer.     

Initiation of Metastatic Breast Carcinoma by Targeting of the Ductal Epithelium with Adenovirus-Cre: A Novel Transgenic Mouse Model of Breast Cancer

Breast cancer is a heterogeneous disease involving complex cellular interactions between the developing tumor and immune system, eventually resulting in exponential tumor growth and metastasis to distal tissues and the collapse of anti-tumor immunity. Many useful animal models exist to study breast cancer, but none completely recapitulate the disease progression that occurs in humans. In order to gain a better understanding of the cellular interactions that result in the formation of latent metastasis and decreased survival, we have generated an inducible transgenic mouse model of YFP-expressing ductal carcinoma that develops after sexual maturity in immune-competent mice and is driven by consistent, endocrine-independent oncogene expression. Activation of YFP, ablation of p53, and expression of an oncogenic form of K-ras was achieved by the delivery of an adenovirus expressing Cre-recombinase into the mammary duct of sexually mature, virgin female mice. Tumors begin to appear 6 weeks after the initiation of oncogenic events. After tumors become apparent, they progress slowly for approximately two weeks before they begin to grow exponentially. After 7-8 weeks post-adenovirus injection, vasculature is observed connecting the tumor mass to distal lymph nodes, with eventual lymphovascular invasion of YFP+ tumor cells to the distal axillary lymph nodes. Infiltrating leukocyte populations are similar to those found in human breast carcinomas, including the presence of αβ and γδ T cells, macrophages and MDSCs. This unique model will facilitate the study of cellular and immunological mechanisms involved in latent metastasis and dormancy in addition to being useful for designing novel immunotherapeutic interventions to treat invasive breast cancer.     

Regulation of COX2 Expression in Mouse Mammary Tumor Cells Controls Bone Metastasis and PGE2-Induction of Regulatory T Cell Migration

Background

The targeting of the immune system through immunotherapies to prevent tumor tolerance and immune suppression are at the front lines of breast cancer treatment and research. Human and laboratory studies have attributed breast cancer progression and metastasis to secondary organs such as the bone, to a number of factors, including elevated levels of prostaglandin E2 (PGE2) and the enzyme responsible for its production, cyclooxygenase 2 (COX2). Due to the strong connection of COX2 with immune function, we focused on understanding how variance in COX2 expression manipulates the immune profile in a syngeneic, and immune-competent, mouse model of breast cancer. Though there have been correlative findings linking elevated levels of COX2 and Tregs in other cancer models, we sought to elucidate the mechanisms by which these immuno-suppressive cells are recruited to breast tumor and the means by which they promote tumor tolerance.

Methodology/Principal Findings

To elucidate the mechanisms by which exacerbated COX2 expression potentiates metastasis we genetically manipulated non-metastatic mammary tumor cells (TM40D) to over-express COX2 (TM40D-COX2). Over-expression of COX2 in this mouse breast cancer model resulted in an increase in bone metastasis (an observation that was ablated following suppression of COX2 expression) in addition to an exacerbated Treg recruitment in the primary tumor. Interestingly, other immune-suppressive leukocytes, such as myeloid derived suppressor cells, were not altered in the primary tumor or the circulation. Elevated levels of PGE2 by tumor cells can directly recruit CD4+CD25+ cells through interactions with their EP2 and/or EP4 receptors, an effect that was blocked using anti-PGE2 antibody. Furthermore, increased Treg recruitment to the primary tumor contributed to the greater levels of apoptotic CD8+ T cells in the TM40D-COX2 tumors.

Conclusion/Significance

Due to the systemic effects of COX2 inhibitors, we propose targeting specific EP receptors as therapeutic interventions to breast cancer progression.