Malignant and non-malignant lung tissue areas are differentially populated by natural killer cells and regulatory T cells in non-small cell lung cancer

UCA1 Inhibits NKG2D-mediated Cytotoxicity of NK Cells to Breast Cancer

BACKGROUND

Natural killer cells play important roles in tumor immune surveillance, and cancer cells must resist this surveillance in order to progress and metastasise.

INTRODUCTION

The study aimed to explore the mechanism of how breast cancer cells become resistant to the cytotoxicity of NK cells.

METHODS

We established NK-resistant breast cancer cells by exposing MDA-MB-231 cells and MCF-7 cells to NK92 cells. Profiles of lncRNA were compared between the NK-resistant and parental cell lines. Primary NK cells were isolated by MACS, and the NK attacking effect was tested by non-radioactive cytotoxicity. The change in lncRNAs was analyzed by Gene-chip. The interaction between lncRNA and miRNA was displayed by Luciferase assay. The regulation of the gene was verified by QRT-PCR and WB. The clinical indicators were detected by ISH, IH, and ELISA, respectively.

RESULTS

UCA1 was found to be significantly up-regulated in both NK-resistant cell lines, and we confirmed such up-regulation on its own to be sufficient to render parental cell lines resistant to NK92 cells. We found that UCA1 up-regulated ULBP2 via the transcription factor CREB1, while it up-regulated ADAM17 by "sponging" the miR-26b-5p. ADAM17 facilitated the shedding of soluble ULBP2 from the surface of breast cancer cells, rendering them resistant to killing by NK cells. UCA1, ADAM17, and ULBP2 were found to be expressed at higher levels in bone metastases of breast cancer than in primary tumors.

CONCLUSION

Our data strongly suggest that UCA1 up-regulates ULBP2 expression and shedding, rendering breast cancer cells resistant to killing by NK cells.

Harnessing Natural Killer Cells for Lung Cancer Therapy

Lung cancer is the leading cause of cancer-related death worldwide. Although natural killer (NK) cells are garnering interest as a potential anticancer therapy because they selectively recognize and eliminate cancer cells, their use in treating solid tumors, including lung cancer, has been limited due to impediments to their efficacy, such as their limited ability to reach tumor tissues, the reduced antitumor activity of tumor-infiltrating NK cells, and the suppressive tumor microenvironment (TME). This comprehensive review provides an in-depth analysis of the cross-talk between the lung cancer TME and NK cells. We highlight the various mechanisms used by the TME to modulate NK-cell phenotypes and limit infiltration, explore the role of the TME in limiting the antitumor activity of NK cells, and discuss the current challenges and obstacles that hinder the success of NK-cell-based immunotherapy for lung cancer. Potential opportunities and promising strategies to address these challenges have been implemented or are being developed to optimize NK-cell-based immunotherapy for lung cancer. Through critical evaluation of existing literature and emerging trends, this review provides a comprehensive outlook on the future of NK-cell-based immunotherapy for treating lung cancer.

Targeting redox regulation and autophagy systems in cancer stem cells

Cancer is a dysregulated cellular level pathological condition that results in tumor formation followed by metastasis. In the heterogeneous tumor architecture, cancer stem cells (CSCs) are essential to push forward the progression of tumors due to their strong pro-tumor properties such as stemness, self-renewal, plasticity, metastasis, and being poorly responsive to radiotherapy and chemotherapeutic agents. Cancer stem cells have the ability to withstand various stress pressures by modulating transcriptional and translational mechanisms, and adaptable metabolic changes. Owing to CSCs heterogeneity and plasticity, these cells display varied metabolic and redox profiles across different types of cancers. It has been established that there is a disparity in the levels of Reactive Oxygen Species (ROS) generated in CSCs vs Non-CSC and these differential levels are detected across different tumors. CSCs have unique metabolic demands and are known to change plasticity during metastasis by passing through the interchangeable epithelial and mesenchymal-like phenotypes. During the metastatic process, tumor cells undergo epithelial to mesenchymal transition (EMT) thus attaining invasive properties while leaving the primary tumor site, similarly during the course of circulation and extravasation at a distant organ, these cells regain their epithelial characteristics through Mesenchymal to Epithelial Transition (MET) to initiate micrometastasis. It has been evidenced that levels of Reactive Oxygen Species (ROS) and associated metabolic activities vary between the epithelial and mesenchymal states of CSCs. Similarly, the levels of oxidative and metabolic states were observed to get altered in CSCs post-drug treatments. As oxidative and metabolic changes guide the onset of autophagy in cells, its role in self-renewal, quiescence, proliferation and response to drug treatment is well established. This review will highlight the molecular mechanisms useful for expanding therapeutic strategies based on modulating redox regulation and autophagy activation to targets. Specifically, we will account for the mounting data that focus on the role of ROS generated by different metabolic pathways and autophagy regulation in eradicating stem-like cells hereafter referred to as cancer stem cells (CSCs).

The Function of NK Cells in Tumor Metastasis and NK Cell-Based Immunotherapy

Metastatic tumors cause the most deaths in cancer patients. Treating metastasis remains the primary goal of current cancer research. Although the immune system prevents and kills the tumor cells, the function of the immune system in metastatic cancer has been unappreciated for decades because tumors are able to develop complex signaling pathways to suppress immune responses, leading them to escape detection and elimination. Studies showed NK cell-based therapies have many advantages and promise for fighting metastatic cancers. We here review the function of the immune system in tumor progression, specifically focusing on the ability of NK cells in antimetastasis, how metastatic tumors escape the NK cell attack, as well as the recent development of effective antimetastatic immunotherapies.

Identification of a prognostic index system and tumor immune infiltration characterization for lung adenocarcinoma based on mRNA molecular of pyroptosis

Background and purpose

Pyroptosis is a form of programmed cell death, which plays an important role in tumorigenesis, progression, and regulation of the tumor microenvironment. It can affect lung adenocarcinoma (LUAD) progression. This study aimed to construct a pyroptosis-related mRNA prognostic index (PRMPI) for LUAD and clarify the tumor microenvironment infiltration characterization of LUAD.

Materials and methods

We performed a univariate Cox regression analysis for pyroptosis-related mRNAs in the TCGA cohort. Then, we used LASSO Cox regression to establish a PRMPI. The quantitative real time polymerase chain reaction (qRT-PCR) was used to quantify the relative expression of pyroptosis-related mRNAs. The CPTAC cohort was used to confirm the stability and wide applicability of the PRMPI. The single-sample gene set enrichment analysis (ssGSEA) was performed to assess the tumor microenvironment infiltration characterization.

Results

A total of 36 pyroptosis-related mRNAs were identified. The PRMPI was established based on five pyroptosis-related mRNAs. The expression patterns of these mRNAs were verified in LUAD samples from our medical center by qRT-PCR. High-PRMPI patients had worse overall survival than low-PRMPI patients. The result was validated in the CPTAC cohort. The comprehensive analysis indicated that the high-PRMPI patients exhibited lower immune activity, more aggressive immunophenotype, lower expression of immune checkpoint molecule, higher TP53 mutation rate, and higher tumor stemness than low-PRMPI patients. Low-PRMPI patients may be more sensitive to immunotherapy, while high-PRMPI patients may benefit more from chemotherapy and targeted therapy.

Conclusions

The PRMPI may be a promising biomarker to predict the prognosis, tumor microenvironment infiltration characterization, and the response to adjuvant therapy in LUAD.

Underlying mechanisms of evasion from NK cells as rational for improvement of NK cell-based immunotherapies

Natural killer (NK) cells belong to the family of innate immune cells with the capacity to recognize and kill tumor cells. Different phenotypes and functional properties of NK cells have been described in tumor patients, which could be shaped by the tumor microenvironment. The discovery of HLA class I-specific inhibitory receptors controlling NK cell activity paved the way to the fundamental concept of modulating immune responses that are regulated by an array of inhibitory receptors, and emphasized the importance to explore the potential of NK cells in cancer therapy. Although a whole range of NK cell-based approaches are currently being developed, there are still major challenges that need to be overcome for improved efficacy of these therapies. These include escape of tumor cells from NK cell recognition due to their expression of inhibitory molecules, immune suppressive signals of NK cells, reduced NK cell infiltration of tumors, an immune suppressive micromilieu and limited in vivo persistence of NK cells. Therefore, this review provides an overview about the NK cell biology, alterations of NK cell activities, changes in tumor cells and the tumor microenvironment contributing to immune escape or immune surveillance by NK cells and their underlying molecular mechanisms as well as the current status and novel aspects of NK cell-based therapeutic strategies including their genetic engineering and their combination with conventional treatment options to overcome tumor-mediated evasion strategies and improve therapy efficacy.

Recruited and Tissue-Resident Natural Killer Cells in the Lung During Infection and Cancer

Natural killer (NK) cells are an important component of the innate immune system, and have a key role in host defense against infection and in tumor surveillance. Tumors and viruses employ remarkably similar strategies to avoid recognition and killing by NK cells and so much can be learnt by comparing NK cells in these disparate diseases. The lung is a unique tissue environment and immune cells in this organ, including NK cells, exist in a hypofunctional state to prevent activation against innocuous stimuli. Upon infection, rapid NK cell infiltration into the lung occurs, the amplitude of which is determined by the extent of inflammation and damage. Activated NK cells kill infected cells and produce pro-inflammatory cytokines and chemokines to recruit cells of the adaptive immune system. More recent evidence has shown that NK cells also play an additional role in resolution of inflammation. In lung cancer however, NK cell recruitment is impaired and those that are present have reduced functionality. The majority of lung NK cells are circulatory, however recently a small population of tissue-resident lung NK cells has been described. The specific role of this subset is yet to be determined, but they show similarity to resident memory T cell subsets. Whether resident or recruited, NK cells are important in the control of pulmonary infections, but equally, can drive excessive inflammation if not regulated. In this review we discuss how NK cells are recruited, controlled and retained in the specific environment of the lung in health and disease. Understanding these mechanisms in the context of infection may provide opportunities to promote NK cell recruitment and function in the lung tumor setting.

Neutrophil and Natural Killer Cell Interactions in Cancers: Dangerous Liaisons Instructing Immunosuppression and Angiogenesis

The tumor immune microenvironment (TIME) has largely been reported to cooperate on tumor onset and progression, as a consequence of the phenotype/functional plasticity and adaptation capabilities of tumor-infiltrating and tumor-associated immune cells. Immune cells within the tumor micro (tissue-local) and macro (peripheral blood) environment closely interact by cell-to-cell contact and/or via soluble factors, also generating a tumor-permissive soil. These dangerous liaisons have been investigated for pillars of tumor immunology, such as tumor associated macrophages and T cell subsets. Here, we reviewed and discussed the contribution of selected innate immunity effector cells, namely neutrophils and natural killer cells, as "soloists" or by their "dangerous liaisons", in favoring tumor progression by dissecting the cellular and molecular mechanisms involved.

The Biological Role and Therapeutic Potential of NK Cells in Hematological and Solid Tumors

NK cells are an attractive target for cancer immunotherapy due to their potent antitumor activity. The main advantage of using NK cells as cytotoxic effectors over T cells is a reduced risk of graft versus host disease. At present, several variants of NK-cell-based therapies are undergoing clinical trials and show considerable effectiveness for hematological tumors. In these types of cancers, the immune cells themselves often undergo malignant transformation, which determines the features of the disease. In contrast, the current use of NK cells as therapeutic agents for the treatment of solid tumors is much less promising. Most studies are at the stage of preclinical investigation, but few progress to clinical trials. Low efficiency of NK cell migration and functional activity in the tumor environment are currently considered the major barriers to NK cell anti-tumor therapies. Various therapeutic combinations, genetic engineering methods, alternative sources for obtaining NK cells, and other techniques are aiming at the development of promising NK cell anticancer therapies, regardless of tumorigenesis. In this review, we compare the role of NK cells in the pathogenesis of hematological and solid tumors and discuss current prospects of NK-cell-based therapy for hematological and solid tumors.

The Impact of NK Cell-Based Therapeutics for the Treatment of Lung Cancer for Biologics: Targets and Therapy

Lung cancer has a dismal prognosis and novel targeted therapies leave still room for major improvements and better outcomes. Immunotherapy targeting immune checkpoint (IC) proteins, either as single agents or in combination with chemotherapy, is active but responders constitute only approximately 10-15% of non-small cell lung cancer (NSCLC) patients. Other effector immune cells such as CAR-T cells or NK cells may help to overcome the limitations of the IC inhibitor therapies for lung cancer. NK cells can kill tumor cells without previous priming and are present in the circulatory system and lymphoid organs. Tissue-residing NK cells differ from peripheral effector cells and, in case of the lung, comprise CD56bright CD16-negative populations showing high cytokine release but low cytotoxicity in contrast to the circulating CD56dim CD16-positive NK cells exhibiting high cytotoxic efficacy. This local attenuation of NK cell killing potency seems due to a specific stage of NK differentiation, immunosuppressive factors as well as presence of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (TREGs). Improved NK cell-based immunotherapies involve IL-2-stimulated effector cells, NK cells expanded with the help of cytokines, permanent NK cell lines, induced pluripotent stem cell-derived NK cells and NK cells armed with chimeric antigen receptors. Compared to CAR T cell therapy, NK cells administration is devoid of graft-versus-host disease (GvHD) and cytokine-release syndrome. Although NK cells are clearly active against lung cancer cells, the low-cytotoxicity differentiation state in lung tumors, the presence of immunosuppressive leucocyte populations, limited infiltration and adverse conditions of the microenvironment need to be overcome. This goal may be achieved in the future using large numbers of activated and armed NK cells as provided by novel methods in NK cell isolation, expansion and stimulation of cytotoxic activity, including combinations with monoclonal antibodies in antibody-dependent cytotoxicity (ADCC). This review discusses the basic characteristics of NK cells and the potential of NK cell preparations in cancer therapy.

NK cells sense tumors, course of disease and treatments: Consequences for NK-based therapies

The recent findings on NK activation indicate that these cells are important antitumor effectors. NK cells participate in the graft-vs.-leukemia effect to control the relapse in leukemic patients transplanted with allogeneic hematopoietic stem cells. In various tumors, correlation between NK cell infiltrates and prognosis were reported. However, tumor-infiltrating NK cells are yet poorly characterized. We here summarize our results and the recent studies of the literature on tumor-infiltrating NK cells, and discuss the impact of these novel insights into NK cell responses against tumors for the design of NK cell-based therapies.

NK Cells in the Tumor Microenvironment

Natural killer cells are powerful effectors of innate immunity that constitute a first line of defense against cancer. NK cells express an array of germline-encoded receptors which allow them to eliminate transformed cells and spare normal, healthy cells. Owing to their ability to kill circulating tumor cells, NK cells play a major role in the protection against cancer metastases. There is also convincing evidence that NK cells protect against some hematological cancers such as acute myeloid leukemia. However, the importance of NK cells for the control of established solid tumors is rather uncertain. Several mechanisms impede NK cell-mediated elimination of solid tumors, starting with the incapacity of NK cells to infiltrate the core of the tumor. In addition, immune escape mechanisms are at play in both solid and hematological cancers. These include the immunoediting of tumor cells and aberrant chronic inflammation that renders NK cells ineffective. In this chapter, I review the phenotypic characteristics of NK cells within the tumor microenvironment. Furthermore, I describe the mechanisms by which NK cells contribute to antitumor immunity. Finally, I review the different immune-evasion factors that impair NK cell activity against cancer.

NOX2-Derived Reactive Oxygen Species in Cancer

The formation of reactive oxygen species (ROS) by the myeloid cell NADPH oxidase NOX2 is critical for the destruction of engulfed microorganisms. However, recent studies imply that ROS, formed by NOX2⁺ myeloid cells in the malignant microenvironment, exert multiple actions of relevance to the growth and spread of neoplastic cells. By generating ROS, tumor-infiltrating myeloid cells and NOX2⁺ leukemic myeloid cells may thus (i) compromise the function and viability of adjacent cytotoxic lymphocytes, including natural killer (NK) cells and T cells, (ii) oxidize DNA to trigger cancer-promoting somatic mutations, and (iii) affect the redox balance in cancer cells to control their proliferation and survival. Here, we discuss the impact of NOX2-derived ROS for tumorigenesis, tumor progression, regulation of antitumor immunity, and metastasis. We propose that NOX2 may be a targetable immune checkpoint in cancer.

β3-Adrenoceptors as Putative Regulator of Immune Tolerance in Cancer and Pregnancy

Understanding the mechanisms of immune tolerance is currently one of the most important challenges of scientific research. Pregnancy affects the immune system balance, leading the host to tolerate embryo alloantigens. Previous reports demonstrated that β-adrenergic receptor (β-AR) signaling promotes immune tolerance by modulation of NK and Treg, mainly through the activation of β2-ARs, but recently we have demonstrated that also β3-ARs induce an immune-tolerant phenotype in mice bearing melanoma. In this report, we demonstrate that β3-ARs support host immune tolerance in the maternal microenvironment by modulating the same immune cells populations as recently demonstrated in cancer. Considering that β3-ARs are modulated by oxygen levels, we hypothesize that hypoxia, through the upregulation of β3-AR, promotes the biological shift toward a tolerant immunophenotype and that this is the same trick that embryo and cancer use to create an aura of immune-tolerance in a competent immune environment. This study confirms the analogies between fetal development and tumor progression and suggests that the expression of β3-ARs represents one of the strategies to induce fetal and tumor immune tolerance.

Effect of interleukins (IL-2, IL-15, IL-18) on receptors activation and cytotoxic activity of natural killer cells in breast cancer cell

INTRODUCTION

Breast cancer is one of the leading cause of cancer deaths in women. Metastasis in BC is caused by immunosurveillance deficiency, such NK cell maturation, low NK activity and decreasing cytotoxicity. This study was performed to improve activating receptors and cytotoxicity of NK cells using interleukins (ILs).

METHODS

Human recombinant IL-2, -15, and -18 were used to induce NK cells. We measured the activating and inhibiting receptors, proliferation activity of NK cells, and the cytotoxicity of NK cells on BC cells (MCF7). The effects of ILs were tested on the NK cell receptors CD314, CD158a and CD107a with flowcytometry, proliferation at various incubation times with 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and concentrations of TNF-α and IFN-γ by NK cells with ELISA.

RESULTS

ILs increased NK cell receptor levels (CD314, CD158a, and CD107a) at 24 hours of incubation. ILs increased NK cell viability, which increased with longer incubation. Moreover, ILs-induced NK cells inhibited proliferation in MCF7 cells, as well as increased TNF-α, IFN-γ, PRF1 and GzmB secretion.

CONCLUSION

IL-2, IL-15, and IL-18 improved activating receptors and proliferation of NK cells. IL-induced NK cells increased TNF-α, IFN-γ, PRF1 and GzmB secretion and cytotoxic activity on BC cells. High NK cell numbers increased BC cell growth inhibition.

Natural killer cells: a review of biology, therapeutic potential and challenges in treatment of solid tumors

Natural killer (NK) cells lead immune surveillance against cancer and early elimination of small tumors. Owing to their ability to engage tumor targets without the need of specific antigen, the therapeutic potential of NK cells has been extensively explored in hematological malignancies. In solid tumors, however, their role in the clinical arena remains poorly exploited despite a broad accumulation of preclinical data. In this article, we review our current knowledge of NK cells’ biology, and highlight the challenges facing NK cell antitumor strategies in solid tumors. We further summarize the abundant preclinical attempts at overcoming these challenges, present past and ongoing clinical trial data and finally discuss the potential impact of novel insights on the development of NK cell-based therapies.

Role of cytokines in combinatorial immunotherapeutics of non-small cell lung cancer through systems perspective

Lung cancer is the leading cause of deaths related to cancer and accounts for more than a million deaths per year. Various new strategies have been developed and adapted for treatment; still the survival for 5 years is just 16% in patients with non‐small cell lung cancer (NSCLC). Most of these strategies to combat NSCLC whether it is a drug molecule or immunotherapy/vaccine candidate require a big cost and time. Integration of computational modeling with systems biology has opened new avenues for understanding complex cancer biology. Resolving the complex interactions of various pathways and their crosstalk leading to oncogenic changes could identify new therapeutic targets with lesser cost and time. Herein, this review provides an overview of various aspects of NSCLC along with available strategies for its cure concluding with our insight into how systems approach could serve as a therapeutic intervention dissecting the immunologic parameters and cross talk between various pathways involved.

Branched mannans from the mushroom Cantharellus cibarius enhance the anticancer activity of natural killer cells against human cancers of lung and colon

Cantharellus cibarius branched mannans increase natural killer cells NK92 viability and proliferation and enhance their cytotoxicity against lung and colon cancer cells A549 and LS180, at the same time they do not affect lung and colon epithelial cells NL20 and CCD841 CoN.

Mechanisms and Functions of Chemerin in Cancer: Potential Roles in Therapeutic Intervention

Chemerin [RARRES2 [retinoic acid receptor responder 2], TIG2 [tazarotene induced gene 2 (TIG2)]] is a multifunctional cytokine initially described in skin cultures upon exposure to the synthetic retinoid tazarotene. Its secreted pro-form, prochemerin, is widely expressed, found systemically, and is readily converted into active chemerin by various proteases. Subsequent studies elucidated major roles of chemerin as both a leukocyte chemoattractant as well as an adipokine. Chemerin's main chemotactic receptor, the G-protein coupled receptor CMKLR1, is expressed on macrophages, dendritic, and NK cells. With respect to its role in immunology, chemerin mediates trafficking of these cells to sites of inflammation along its concentration gradient, and likely helps coordinate early responses, as it has been shown to have antimicrobial and angiogenic properties, as well. Recently, there has been mounting evidence that chemerin is an important factor in various cancers. As with its role in immune responses-where it can act as both a pro- and anti-inflammatory mediator-the potential functions or correlations chemerin has in or with cancer appears to be context dependent. Most studies, however, suggest a downregulation or loss of chemerin/RARRES2 in malignancies compared to the normal tissue counterparts. Here, we perform a comprehensive review of the literature to date and summarize relevant findings in order to better define the roles of chemerin in the setting of the tumor microenvironment and tumor immune responses, with an ultimate focus on the potential for therapeutic intervention.

Uncovering the underlying physical mechanism for cancer-immunity of MHC class I diversity

The cancer cells are heterogeneous populated, which can be classified as MHC class I positive and MHC I class negative. They influence the immune system differently. In this work, we build a core cancer-immune circuit of MHC class I diversity including MHC class I positive cancer type, MHC I class I negative cancer type and 4 immune cell types to uncover the underlying mechanism of the cancer immunity based on the underlying landscape topography. We quantify four steady state attractors, normal state, two low cancer states and a high cancer state. The landscape topography changes upon changes in cancer self-activation and the related killing rate of the killer cells are illustrated. It demonstrates that the competition between the two cancer cell types. We simulate the tumorigenesis and development of cancer according to its biological process and classify these into 7 stages. This landscape framework provides a quantitative way to understand characteristics of these two cancer cell types under immune microenvironment and the underlying physical mechanisms of cancer cell evolution along cancer development.

Role of natural killer cells in lung cancer

PURPOSE

One of the key immune cells involved in the pathogenesis of lung cancer is natural killer (NK) cells and these cells are novel targets for therapeutic applications in lung cancer. The purpose of this review is to summarize the current literature on lung cancer pathogenesis with a focus on the interaction between NK cells and smoking, how these factors are related to the pathogenesis of lung cancer and how NK cell-based immunotherapy effect lung cancer survival.

METHODS

The relevant literature from PubMed and Medline databases is reviewed in this article.

RESULTS

The cytolytic potential of NK cells are reduced in lung cancer and increasing evidence suggests that improving NK cell functioning may induce tumor regression. Recent clinical trials on NK cell-based novel therapies such as cytokines including interleukin (IL)-15, IL-12 and IL-2, NK-92 cell lines and allogenic NK cell immunotherapy showed promising results with less adverse effects on the lung cancer survival.

CONCLUSIONS

The NK cell targeting strategy has not yet been approved for lung cancer treatment. More clinical studies focusing on the role of NK cells in lung cancer pathogenesis are warranted to develop novel NK cell-based therapeutic approaches for the treatment of lung cancer.

New strategies in immunotherapy for lung cancer: beyond PD-1/PD-L1

Immunotherapy has significantly altered the treatment landscape for many cancers, including non-small cell lung cancer (NSCLC). Currently approved immuno-oncology agents for lung cancer are aimed at the reversal of immune checkpoints, programmed death protein-1 (PD-1) and programmed death ligand-1 (PD-L1). Although responses to checkpoint inhibitors are encouraging, and in some cases durable, these successes are not universal among all treated patients. In order to optimize our treatment approach utilizing immunotherapy, we must better understand the interaction between cancer and the immune system and evasion mechanisms. In this review, we will provide an overview of the immune system and cancer, and review novel therapies that promote tumor antigen release for immune system detection, activate the effector T-cell response, and reverse inhibitory antitumor signals.

Restoration of Natural Killer Cell Antimetastatic Activity by IL12 and Checkpoint Blockade

Immune checkpoint therapies target tumor antigen-specific T cells, but less is known about their effects on natural killer (NK) cells, which help control metastasis. In studying the development of lung metastases, we found that NK cells lose their cytotoxic capacity and acquire a molecular signature defined by the expression of coinhibitory receptors. In an effort to overcome this suppressive mechanism, we evaluated NK cell responses to the immunostimulatory cytokine IL12. Exposure to IL12 rescued the cytotoxicity of NK cells but also led to the emergence of an immature NK cell population that expressed high levels of the coinhibitory molecules PD-1, Lag-3, and TIGIT, thereby limiting NK cell-mediated control of pulmonary metastases. Notably, checkpoint blockade therapy synergized with IL12 to fully enable tumor control by NK cells, demonstrating that checkpoint blockers are not only applicable to enhance T cell-mediated immunotherapy, but also to restore the tumor-suppressive capacity of NK cells. Cancer Res; 77(24); 7059-71. ©2017 AACR.

Recombinant Antibodies to Arm Cytotoxic Lymphocytes in Cancer Immunotherapy

Immunotherapy has the potential to support and expand the body's own armamentarium of immune effector functions, which have been circumvented during malignant transformation and establishment of cancer and is presently considered to be the most promising treatment option for cancer patients. Recombinant antibody technologies have led to a multitude of novel antibody formats, which are in clinical development and hold great promise for future therapies. Among these formats, bispecific antibodies are extremely versatile due to their high efficacy to recruit and activate anti-tumoral immune effector cells, their excellent safety profile, and the opportunity for use in combination with cellular therapies. This review article summarizes the latest developments in cancer immunotherapy using immuno-engagers for recruiting T cells and NK cells to the tumor site. In addition to antibody formats, malignant cell targets, and immune cell targets, opportunities for combination therapies, including check point inhibitors, cytokines and adoptive transfer of immune cells, will be summarized and discussed.

Mast cell phenotype, TNFα expression and degranulation status in non-small cell lung cancer

Mast cell infiltration of tumour islets represents a survival advantage in non-small cell lung cancer (NSCLC). The phenotype and activation status of these mast cells is unknown. We investigated the mast cell phenotype in terms of protease content (tryptase-only [MC_T], tryptase + chymase [MC_TC]) and tumour necrosis factor-alpha (TNFα) expression, and extent of degranulation, in NSCLC tumour stroma and islets. Surgically resected tumours from 24 patients with extended survival (ES; mean survival 86.5 months) were compared with 25 patients with poor survival (PS; mean survival 8.0 months) by immunohistochemistry. Both MC_T and MC_TC in tumour islets were higher in ES (20.0 and 5.6 cells/mm² respectively) compared to PS patients (0.0 cells/mm²) (p < 0.0001). Both phenotypes expressed TNFα in the islets and stroma. In ES 44% of MC_T and 37% of MC_TC expressed TNFα in the tumour islets. MC_T in the ES stroma were more degranulated than in those with PS (median degranulation index = 2.24 versus 1.73 respectively) (p = 0.0022), and ES islet mast cells (2.24 compared to 1.71, p < 0.0001). Since both MC_T and MC_TC infiltrating tumour islets in ES NSCLC patients express TNFα, the cytotoxic activity of this cytokine may confer improved survival in these patients. Manipulating mast cell microlocalisation and functional responses in NSCLC may offer a novel approach to the treatment of this disease.

Lung Cancer Subtypes Generate Unique Immune Responses

Lung cancer, the leading cause of cancer-related deaths worldwide, is a heterogeneous disease comprising multiple histologic subtypes that harbor disparate mutational profiles. Immune-based therapies have shown initial promise in the treatment of lung cancer patients but are limited by low overall response rates. We sought to determine whether the host immune response to lung cancer is dictated, at least in part, by histologic and genetic differences, because such correlations would have important clinical ramifications. Using mouse models of lung cancer, we show that small cell lung cancer (SCLC) and lung adenocarcinoma (ADCA) exhibit unique immune cell composition of the tumor microenvironment. The total leukocyte content was markedly reduced in SCLC compared with lung ADCA, which was validated in human lung cancer specimens. We further identified key differences in immune cell content using three models of lung ADCA driven by mutations in Kras, p53, and Egfr Although Egfr-mutant cancers displayed robust myeloid cell recruitment, they failed to mount a CD8⁺ immune response. In contrast, Kras-mutant tumors displayed significant expansion of multiple immune cell types, including CD8⁺ cells, regulatory T cells, IL-17A-producing lymphocytes, and myeloid cells. A human tissue microarray annotated for KRAS and EGFR mutations validated the finding of reduced CD8⁺ content in human lung ADCA. Taken together, these findings establish a strong foundational knowledge of the immune cell contexture of lung ADCA and SCLC and suggest that molecular and histological traits shape the host immune response to cancer.

Natural killer cell-based adoptive immunotherapy eradicates and drives differentiation of chemoresistant bladder cancer stem-like cells

BACKGROUND

High-grade non-muscle invasive bladder cancer (NMIBC) has a high risk of recurrence and progression to muscle-invasive forms, which seems to be largely related to the presence of tumorigenic stem-like cell populations that are refractory to conventional therapies. Here, we evaluated the therapeutic potential of Natural Killer (NK) cell-based adoptive immunotherapy against chemoresistant bladder cancer stem-like cells (CSCs) in a pre-clinical relevant model, using NK cells from healthy donors and NMIBC patients.

METHODS

Cytokine-activated NK cells from healthy donors and from high-grade NMIBC patients were phenotypically characterized and assayed in vitro against stem-like and bulk differentiated bladder cancer cells. Stem-like cells were isolated from two bladder cancer cell lines using the sphere-forming assay. The in vivo therapeutic efficacy was evaluated in mice bearing a CSC-induced orthotopic bladder cancer. Animals were treated by intravesical instillation of interleukin-activated NK cells. Tumor response was evaluated longitudinally by non-invasive bioluminescence imaging.

RESULTS

NK cells from healthy donors upon activation with IL-2 and IL-15 kills indiscriminately both stem-like and differentiated tumor cells via stress ligand recognition. In addition to cell killing, NK cells shifted CSCs towards a more differentiated phenotype, rendering them more susceptible to cisplatin, highlighting the benefits of a possible combined therapy. On the contrary, NK cells from NMIBC patients displayed a low density on NK cytotoxicity receptors, adhesion molecules and a more immature phenotype, losing their ability to kill and drive differentiation of CSCs. The local administration, via the transurethral route, of activated NK cells from healthy donors provides an efficient tumor infiltration and a subsequent robust tumoricidal activity against bladder cancer with high selective cytolytic activity against CSCs, leading to a dramatic reduction in tumor burden from 80 % to complete remission.

CONCLUSION

Although pre-clinical, our results strongly suggest that an immunotherapeutic strategy using allogeneic activated NK cells from healthy donors is effective and should be exploited as a complementary therapeutic strategy in high-risk NMIBC patients to prevent tumor recurrence and progression.

CD16 is indispensable for antibody-dependent cellular cytotoxicity by human monocytes

Antibody-dependent cellular cytotoxicity (ADCC) is exerted by immune cells expressing surface Fcγ receptors (FcγRs) against cells coated with antibody, such as virus-infected or transformed cells. CD16, the FcγRIIIA, is essential for ADCC by NK cells, and is also expressed by a subset of human blood monocytes. We found that human CD16− expressing monocytes have a broad spectrum of ADCC capacities and can kill cancer cell lines, primary leukemic cells and hepatitis B virus-infected cells in the presence of specific antibodies. Engagement of CD16 on monocytes by antibody bound to target cells activated β2-integrins and induced TNFα secretion. In turn, this induced TNFR expression on the target cells, making them susceptible to TNFα-mediated cell death. Treatment with TLR agonists, DAMPs or cytokines, such as IFNγ, further enhanced ADCC. Monocytes lacking CD16 did not exert ADCC but acquired this property after CD16 expression was induced by either cytokine stimulation or transient transfection. Notably, CD16+ monocytes from patients with leukemia also exerted potent ADCC. Hence, CD16+ monocytes are important effectors of ADCC, suggesting further developments of this property in the context of cellular therapies for cancer and infectious diseases.

Mathematical model of tumor-immune surveillance

We present a novel mathematical model involving various immune cell populations and tumor cell populations. The model describes how tumor cells evolve and survive the brief encounter with the immune system mediated by natural killer (NK) cells and the activated CD8(+) cytotoxic T lymphocytes (CTLs). The model is composed of ordinary differential equations describing the interactions between these important immune lymphocytes and various tumor cell populations. Based on up-to-date knowledge of immune evasion and rational considerations, the model is designed to illustrate how tumors evade both arms of host immunity (i.e. innate and adaptive immunity). The model predicts that (a) an influx of an external source of NK cells might play a crucial role in enhancing NK-cell immune surveillance; (b) the host immune system alone is not fully effective against progression of tumor cells; (c) the development of immunoresistance by tumor cells is inevitable in tumor immune surveillance. Our model also supports the importance of infiltrating NK cells in tumor immune surveillance, which can be enhanced by NK cell-based immunotherapeutic approaches.

NK Cells, Tumor Cell Transition, and Tumor Progression in Solid Malignancies: New Hints for NK-Based Immunotherapy?

Several evidences suggest that NK cells can patrol the body and eliminate tumors in their initial phases but may hardly control established solid tumors. Multiple factors, including the transition of tumor cells towards a proinvasive/prometastatic phenotype, the immunosuppressive effect of the tumor microenvironment, and the tumor structure complexity, may account for limited NK cell efficacy. Several putative mechanisms of NK cell suppression have been defined in these last years; conversely, the cross talk between NK cells and tumor cells undergoing different transitional phases remains poorly explored. Nevertheless, recent in vitro studies and immunohistochemical analyses on tumor biopsies suggest that NK cells could not only kill tumor cells but also influence their evolution. Indeed, NK cells may induce tumor cells to change the expression of HLA-I, PD-L1, or NKG2D-L and modulate their susceptibility to the immune response. Moreover, NK cells may be preferentially located in the borders of tumor masses, where, indeed, tumor cells can undergo Epithelial-to-Mesenchymal Transition (EMT) acquiring prometastatic phenotype. Finally, the recently highlighted role of HMGB1 both in EMT and in amplifying the recruitment of NK cells provides further hints on a possible effect of NK cells on tumor progression and fosters new studies on this issue.

Postoperative Regulatory T-Cells and Natural Killer Cells in Stage I Nonsmall Cell Lung Cancer Underwent Video-assisted Thoracoscopic Lobectomy or Thoracotomy

BACKGROUND

Regulatory T-cells (Treg) play key roles in suppressing cell-mediated immunity in cancer patients. Little is known about perioperative Treg fluctuations in nonsmall cell lung cancer (NSCLC). Video-assisted thoracoscopic (VATS) lobectomy, as a minimal invasive procedure for treating NSCLC, may have relatively less impact on the patient's immune system. This study aimed to observe perioperative dynamics of circulating Treg and natural killer (NK) cell levels in NSCLC patients who underwent major lobectomy by VATS or thoracotomy.

METHODS

Totally, 98 consecutive patients with stage I NSCLC were recruited and assigned into VATS or thoracotomy groups. Peripheral blood samples were taken on 1-day prior to operation, postoperative days (PODs) 1, 3, 7, 30, and 90. Circulating Treg and NK cell counts were assayed by flow cytometry, defined as CD4 + CD25 + CD127 low cells in CD4 + lymphocytes and CD56 + 16 + CD3- cells within CD45 + leukocytes respectively. With SPSS software version 21.0 (SPSS Inc., USA), differences between VATS and thoracotomy groups were determined by one-way analysis of variance (ANOVA), and differences between preoperative baseline and PODs in each group were evaluated by one-way ANOVA Dunnett t-test.

RESULTS

In both groups, postoperative Treg percentages were lower than preoperative status. No statistical difference was found between VATS and thoracotomy groups on PODs 1, 3, 7, and 30. On POD 90, Treg percentage in VATS group was significantly lower than in thoracotomy group (5.26 ± 2.75 vs. 6.99 ± 3.60, P = 0.012). However, a higher level of NK was found on all PODs except on POD 90 in VATS group, comparing to thoracotomy group.

CONCLUSIONS

Lower Treg level on POD 90 and higher NK levels on PODs 1, 3, 7, 30 in VATS group might imply better preserved cell-mediated immune function in NSCLC patients, than those in thoracotomy group.

Pathogen-Associated Molecular Patterns Induced Crosstalk between Dendritic Cells, T Helper Cells, and Natural Killer Helper Cells Can Improve Dendritic Cell Vaccination

A coordinated cellular interplay is of crucial importance in both host defense against pathogens and malignantly transformed cells. The various interactions of Dendritic Cells (DC), Natural Killer (NK) cells, and T helper (Th) cells can be influenced by a variety of pathogen-associated molecular patterns (PAMPs) and will lead to enhanced CD8⁺ effector T cell responses. Specific Pattern Recognition Receptor (PRR) triggering during maturation enables DC to enhance Th1 as well as NK helper cell responses. This effect is correlated with the amount of IL-12p70 released by DC. Activated NK cells are able to amplify the proinflammatory cytokine profile of DC via the release of IFN-γ. The knowledge on how PAMP recognition can modulate the DC is of importance for the design and definition of appropriate therapeutic cancer vaccines. In this review we will discuss the potential role of specific PAMP-matured DC in optimizing therapeutic DC-based vaccines, as some of these DC are efficiently activating Th1, NK cells, and cytotoxic T cells. Moreover, to optimize these vaccines, also the inhibitory effects of tumor-derived suppressive factors, for example, on the NK-DC crosstalk, should be taken into account. Finally, the suppressive role of the tumor microenvironment in vaccination efficacy and some proposals to overcome this by using combination therapies will be described.

Genetic polymorphisms and expression of HLA-G and its receptors, KIR2DL4 and LILRB1, in non-small cell lung cancer

Human leukocyte antigen-G (HLA-G) is a nonclassical HLA class I molecule absent from most normal tissues but detected in many malignant tumors. It is recognized by cells of the immune system using LILRB1, KIR2DL4 and LILRB2 receptors. We attempted to find out whether some polymorphisms of HLA-G, LILRB1 and KIR2DL4 genes are associated with susceptibility to nonsmall cell lung cancer (NSCLC). Four polymorphisms in HLA-G, i.e. -964A>G (rs1632947), -725C>G>T (rs1233334), -716T>G (rs2249863) in the promoter, and a 14 base pair insertion/deletion (14 bp indel) in the 3'-untranslated region (3'UTR), and five in LILRB1 - 5651G>A (rs41308748) in intron 14, 5717C>T L622L (rs1061684), 5724G>A E625K (rs16985478), 5774 C>A P641P (rs41548213) in exon 15, and 5806C>T (rs8101240) in 3'UTR - as well as 9620 9A/10A (rs11410751) polymorphism in exon 7 of KIR2DL4 were typed using different laboratory techniques. Only one single nucleotide polymorphism (SNP) in HLA-G (-964A>G) and one in LILRB1 (5724G>A) were found to influence the risk of NSCLC. In addition, 5724G>A was associated with protection from tumor cell infiltration of regional lymph nodes. Most importantly, we detected HLA-G and LILRB1 expression in tumor specimens, but no correlation with genetic polymorphisms was observed. HLA-G and LILRB1 protein expression levels in tumor tissue were significantly correlated with tumor stage.

[Research progress of nutrition support for patients with lung cancer during chemotherapy]

原发性肺癌是最常见的恶性肿瘤之一，目前其发病率、死亡率均居第一位，在我国仍呈现上升趋势。肺癌患者常常伴有营养不良和消瘦，化疗时细胞毒药物的不良反应可能导致患者营养状况进一步恶化而降低抗肿瘤治疗疗效和患者的生活质量。随着癌症姑息治疗的发展以及患者对生存质量的更高要求，营养支持治疗将成为在化疗过程中维持患者良好的营养状态以及增强自身免疫力的重要辅助治疗手段，在提高肺癌患者化疗耐受性和改善预后等方面发挥积极作用。现就肺癌患者在化疗期间联合应用营养支持治疗的研究进展做一综述。

Generation of MHC class I diversity in primary tumors and selection of the malignant phenotype

Intratumor heterogeneity among cancer cells is promoted by reversible or irreversible genetic alterations and by different microenvironmental factors. There is considerable experimental evidence of the presence of a variety of malignant cell clones with a wide diversity of major histocompatibility class I (MHC-I) expression during early stages of tumor development. This variety of MHC-I phenotypes may define the evolution of a particular tumor. Loss of MHC-I molecules frequently results in immune escape of MHC-negative or -deficient tumor cells from the host T cell-mediated immune response. We review here the results obtained by our group and other researchers in animal models and humans, showing how MHC-I intratumor heterogeneity may affect local oncogenicity and metastatic progression. In particular, we summarize the data obtained in an experimental mouse cancer model of a methylcholanthrene-induced fibrosarcoma (GR9), in which isolated clones with different MHC-I expression patterns demonstrated distinct local tumor growth rates and metastatic capacities. The observed "explosion of diversity" of MHC-I phenotypes in primary tumor clones and the molecular mechanism ("hard"/irreversible or "soft"/reversible) responsible for a given MHC-I alteration might determine not only the metastatic capacity of the cells but also their response to immunotherapy. We also illustrate the generation of further MHC heterogeneity during metastatic colonization and discuss different strategies to favor tumor rejection by counteracting MHC-I loss. Finally, we highlight the role of MHC-I genes in tumor dormancy and cell cycle control.

Cellular and molecular immunology of lung cancer: therapeutic implications

Although the incidence of lung cancer is declining, the prognosis remains poor. This is likely due to lack of early detection and only recent developments in selective cancer therapies. Key immune cells involved in the pathogenesis of lung cancer include CD4(+) T lymphocytes, macrophages, dendritic cells and NK cells. The growing understanding of these cells indicates a highly complex and intertwined network of their involvement in each stage of lung cancer. Immune cell types and numbers affect prognosis and could offer an opportunity for clinical therapeutic applications. However, an incomplete understanding of immune cell involvement and the underlying processes in lung cancer still remain. Deeper investigation focusing on the role of the immune cells will further the understanding of lung carcinogenesis and develop novel therapeutic approaches for the treatment and management of patients with more specialized and selective lung cancer.

Higher susceptibility of NOD/LtSz-scid Il2rg (-/-) NSG mice to xenotransplanted lung cancer cell lines

Purpose

No lung cancer xenograft model using non-obese diabetic (NOD)-scid Il2rg^−/− mice has been reported. The purpose of this study is to select a suitable mouse strain as a xenogenic host for testing tumorigenicity of lung cancer.

Materials and methods

We directly compared the susceptibility of four immunodeficient mouse strains, c-nu, C.B-17 scid, NOD-scid, and NOD/LtSz-scid Il2rg^−/− (NSG) mice, for tumor formation from xenotransplanted lung cancer cell lines. Various numbers (10¹–10⁵ cells/head) of two lung cancer cell lines, A549 and EBC1, were subcutaneously inoculated and tumor sizes were measured every week up to 12 weeks.

Results

When 10⁴ EBC1 cells were inoculated, no tumor formation was observed in BALB/c-nu or C.B-17 scid mice. Tumors developed in two of the five NOD-scid mice (40%) and in all the five NSG mice (100%). When 10³ EBC1 cells were injected, no tumors developed in any strain other than NSG mice, while tumorigenesis was achieved in all the five NSG mice (100%, P=0.0079) within 9 weeks. NSG mice similarly showed higher susceptibility to xenotransplantation of A549 cells. Tumor formation was observed only in NSG mice after inoculation of 10³ or fewer A549 cells (40% vs 0% in 15 NSG mice compared with others, respectively, P=0.0169). We confirmed that the engrafted tumors originated from inoculated human lung cancer cells by immunohistochemical staining with human cytokeratin and vimentin.

Conclusion

NSG mice may be the most suitable strain for testing tumorigenicity of lung cancer, especially if only a few cells are available.

NK cell phenotypic modulation in lung cancer environment

Background

Nature killer (NK) cells play an important role in anti-tumor immunotherapy. But it indicated that tumor cells impacted possibly on NK cell normal functions through some molecules mechanisms in tumor microenvironment.

Materials and methods

Our study analyzed the change about NK cells surface markers (NK cells receptors) through immunofluorescence, flow cytometry and real-time PCR, the killed function from mouse spleen NK cell and human high/low lung cancer cell line by co-culture. Furthermore we certificated the above result on the lung cancer model of SCID mouse.

Results

We showed that the infiltration of NK cells in tumor periphery was related with lung cancer patients' prognosis. And the number of NK cell infiltrating in lung cancer tissue is closely related to the pathological types, size of the primary cancer, smoking history and prognosis of the patients with lung cancer. The expression of NK cells inhibitor receptors increased remarkably in tumor micro-environment, in opposite, the expression of NK cells activated receptors decrease magnificently.

Conclusions

The survival time of lung cancer patient was positively related to NK cell infiltration degree in lung cancer. Thus, the down-regulation of NKG2D, Ly49I and the up-regulation of NKG2A may indicate immune tolerance mechanism and facilitate metastasis in tumor environment. Our research will offer more theory for clinical strategy about tumor immunotherapy.

TGFβ in T cell biology and tumor immunity: Angel or devil?

The evolutionally conserved transforming growth factor β (TGFβ) affects multiple cell types in the immune system by either stimulating or inhibiting their differentiation and function. Studies using transgenic mice with ablation of TGFβ or its receptor have revealed the biological significance of TGFβ signaling in the control of T cells. However, it is now clear that TGFβ is more than an immunosuppressive cytokine. Disruption of TGFβ signaling pathway also leads to impaired generation of certain T cell populations. Therefore, in the normal physiological state, TGFβ actively maintains T cell homeostasis and regulates T cell function. However, in the tumor microenvironment, TGFβ creates an immunosuppressive milieu that inhibits antitumor immunity. Here, we review recent advances in our understanding of the roles of TGFβ in the regulation of T cells and tumor immunity.

Effect of administration of BMDC vaccine sensitized by heat shocked hepal-6 cell proteins on intratumoral CD25+Foxp3+ Tregs in mouse hepatocellular carcinoma

AIM: To determine whether the bone marrow derived dendritic cell (BMDC) vaccine sensitized by heat shocked hepal-6 cell proteins affects the infiltration of intratumoral CD25⁺Foxp3⁺ Tregs in a mouse hepatocellular carcinoma (HCC) model.

METHODS: In the presence of GM-CSF and IL-4, BMDCs were induced in vitro. BMDCs were sensitized by heat shocked hepal-6 cell proteins to generate a vaccine for HCC. The expression of CD11c, CCR7, CD80 and CD86 on these sensitized BMDCs were analyzed by FACS. The anti-tumor effect of this vaccine was evaluated using a mouse HCC model established by subcutaneous injection of Hepal-6 cells. Eight days later, the tumor-bearing mice were divided into four groups, which underwent intratumoral injection of BMDCs sensitized by heat shocked hepal-6 cell proteins, serum-free culture medium, BMDCs without sensitization and BMDCs sensitized by unheated hepal-6 cell proteins (once every 7 d, 2 times altogether), respectively. Nine days after final administration, the mice were sacrificed and the tumor samples were taken for immunofluorescence staining for CD8⁺ cells and intratumoral CD25⁺Foxp3⁺ Tregs.

RESULTS: Light microscopy and scanning electron microscopy showed that BMDCs propagated in the presence of GM-CSF and IL-4 displayed the typical morphological characteristics of dendritic cells. Immunocytochemical staining showed that they expressed the dendritic cell marks including CD11c, CCR7, CD80 and CD86. Compared with the controls (BMDCs without sensitization or sensitized by unheated hepal-6 cells proteins), the BMDCs sensitized by heat shocked hepal-6 cells proteins showed increased expression of CD11c (67.2 ± 4.49 vs 52.4 ± 5.20, 58.4 ± 4.43), CCR7 (65.4 ± 5.34 vs 45.9 ± 5.04, 57.0 ± 3.46), CD80 (62.9 ± 4.69 vs 46.9 ± 4.75, 54.4 ± 3.47) and CD86 (73.3 ± 3.58 vs 60.1 ± 2.98, 63.7 ± 3.10) (P < 0.01 for all). Compared with the controls, the mice administrated with the BMDC vaccine sensitized by heat shocked Hepal-6 cell proteins showed increased CD8⁺ T cells (55.0 ± 4.11 vs 38.2 ± 3.34, 44.6 ± 4.29, 45.6 ± 4.92, P < 0.01 for all) and decreased intratumoral CD25⁺Foxp3⁺ Tregs (0.37 ± 0.028 vs 1.31 ± 0.020, 0.77 ± 0.057, 0.57 ± 0.062, P < 0.05 for all).

CONCLUSION: Heat shocked hepal-6 cell protein sensitization can upregulate the expression of CD11c, CCR7, CD80 and CD86 on BMDCs in vitro. Administration with this BMDC vaccine can increase CD8⁺ T cells and decrease intratumoral CD25⁺Foxp3⁺ Tregs in HCC mice.

Cancer-Induced Alterations of NK-Mediated Target Recognition: Current and Investigational Pharmacological Strategies Aiming at Restoring NK-Mediated Anti-Tumor Activity

Despite evidence of cancer immune-surveillance, which plays a key role in tumor rejection, cancer cells can escape immune recognition through different mechanisms. Thus, evasion to Natural killer (NK) cell-mediated anti-tumor activity is commonly described and is mediated by various mechanisms, mainly cancer cell-induced down-regulation of NK-activating receptors (NCRs, NKG2D, DNAM-1, and CD16) as well as up-regulation of inhibitory receptors (killer-cell immunoglobulin-like receptors, KIRs, NKG2A). Alterations of NK cells lead to an impaired recognition of tumor cells as well as a decreased ability to interact with immune cells. Alternatively, cancer cells downregulate expression of ligands for NK cell-activating receptors and up-regulate expression of the ligands for inhibitory receptors. A better knowledge of the extent and the mechanisms of these defects will allow developing pharmacological strategies to restore NK cell ability to recognize and lyse tumor cells. Combining conventional chemotherapy and immune modulation is a promising approach likely to improve clinical outcome in diverse neoplastic malignancies. Here, we overview experimental approaches as well as strategies already available in the clinics that restore NK cell functionality. Yet successful cancer therapies based on the manipulation of NK cell already have shown efficacy in the context of hematologic malignancies. Additionally, the ability of cytotoxic agents to increase susceptibility of tumors to NK cell lysis has been studied and may require improvement to maximize this effect. More recently, new strategies were developed to specifically restore NK cell phenotype or to stimulate NK cell functions. Overall, pharmacological immune modulation trends to be integrated in therapeutic strategies and should improve anti-tumor effects of conventional cancer therapy.

Asymmetrical Fc engineering greatly enhances antibody-dependent cellular cytotoxicity (ADCC) effector function and stability of the modified antibodies

Antibody-dependent cellular cytotoxicity (ADCC) is mediated through the engagement of the Fc segment of antibodies with Fcγ receptors (FcγRs) on immune cells upon binding of tumor or viral antigen. The co-crystal structure of FcγRIII in complex with Fc revealed that Fc binds to FcγRIII asymmetrically with two Fc chains contacting separate regions of the FcγRIII by utilizing different residues. To fully explore this asymmetrical nature of the Fc-FcγR interaction, we screened more than 9,000 individual clones in Fc heterodimer format in which different mutations were introduced at the same position of two Fc chains using a high throughput competition AlphaLISA® assay. To this end, we have identified a panel of novel Fc variants with significant binding improvement to FcγRIIIA (both Phe-158 and Val-158 allotypes), increased ADCC activity in vitro, and strong tumor growth inhibition in mice xenograft human tumor models. Compared with previously identified Fc variants in conventional IgG format, Fc heterodimers with asymmetrical mutations can achieve similar or superior potency in ADCC-mediated tumor cell killing and demonstrate improved stability in the CH2 domain. Fc heterodimers also allow more selectivity toward activating FcγRIIA than inhibitory FcγRIIB. Afucosylation of Fc variants further increases the affinity of Fc to FcγRIIIA, leading to much higher ADCC activity. The discovery of these Fc variants will potentially open up new opportunities of building the next generation of therapeutic antibodies with enhanced ADCC effector function for the treatment of cancers and infectious diseases.

Regulatory T cells, interleukin (IL)-6, IL-8, vascular endothelial growth factor (VEGF), CXCL10, CXCL11, epidermal growth factor (EGF) and hepatocyte growth factor (HGF) as surrogate markers of host immunity in patients with renal cell carcinoma

OBJECTIVE

To identify a phenotype that could be informative and prognostic in patients with renal cell carcinoma (RCC) peripheral blood was evaluated for TH1, TH2, regulatory T cells (Tregs), natural killer (NK) and NKT cells and for cytokines/chemokines.

PATIENTS AND METHODS

Peripheral blood from 77 patients with RCC and 40 healthy controls was evaluated by flow cytometry using monoclonal antibodies against CD4, CD25, FoxP3, CD45RA, CD45RO, CD152, CD184, CD279, CD3, CD16, CD56, CD161, CD158a, CD4, CD26, CD30, CD183 and CD184. A concomitant evaluation of 38 molecules was conducted in patients' serum using a multiplex biometric ELISA-based immunoassay.

RESULTS

The number of NK cells CD3⁻/CD16⁺, CD3⁻/CD16⁺/CD161⁺ (NK) and CD3⁻/CD16⁺/CD161⁺/CD158a⁺ (NK- Kir 2+) was greater in the patients with RCC (P < 0.05); and the number of Treg cells CD4⁺/CD25(high+)/FOXP3⁺ and the subset CD4⁺/CD25(high+)/FOXP3⁺/CD45RA⁺ (naïve) and CD45R0⁺(memory) cells, were greater in the patients with RCC (P < 0.001). An increase in the following was observed in the serum of patients with RCC compared with healthy controls: interleukin (IL)-4, IL-6, IL-8, IL-10, G-CSF, CXCL10, CXCL11, hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF). According to Ingenuity Pathway Analysis (IPA), CXCL10, IL-6, IL-8, epidermal growth factor (EGF), HGF and VEGF were associated with a network that controls cellular movement, tissue development and cellular growth. Kaplan-Meier analysis for disease-free survival showed that high numbers of CD4⁺/CD25(high+)/FOXP3⁺/CD45RA⁺ (Treg naïve) and low numbers of CD3⁻/CD16⁺/CD161⁺/CD158a⁺ (NK-Kir+) cells predict short disease-free survival in patients with RCC.

CONCLUSION

Concomitant evaluation of Treg (CD4⁺/CD25(high+)/FOXP3⁺ and CD4⁺/CD25(high+)/FOXP3⁺/CD45RA⁺) and of six soluble factors (IL-6, IL-8 ,VEGF, CXCL10, CXCL11, EGF, HGF) might be a surrogate marker of host immunity in patients with RCC.

Adenocarcinoma contains more immune tolerance regulatory t-cell lymphocytes (versus squamous carcinoma) in non-small-cell lung cancer

BACKGROUND

Regulatory T lymphocytes (Tregs) are known to have host-immune dampening effects in many tumors and to be associated with increased tumor recurrence. Pharmacologic therapies have been developed to target these cells and hence strengthen the host's immune system. The FoxP3 gene is a marker of Tregs and can be visualized with immunohistochemistry (IHC). We investigated the presence and pattern of Tregs in non-small-cell lung tumors to determine possible therapeutic targets in lung cancer.

METHODS

We selected archival samples of primary lung carcinoma and benign inflamed lung from 32 surgical resections. We created a tissue array containing duplicate cores from the N1 and N2 nodal stations from 16 of the cases along with paired benign lung and tumor. We used whole-slide analysis for the other 16 cases. We used FoxP3 IHC to visualize Tregs in all lymphoid tissue present and to assess the quantity and pattern within the tissues.

RESULTS

All lymphoid tissue contains Tregs, but adenocarcinoma had significantly higher levels than both inflammatory lung controls and squamous carcinomas (p ≤ 0.008). Benign N1 lymph nodes (from patients with lung cancer) showed higher numbers of Tregs for adenocarcinoma versus squamous carcinoma.

CONCLUSIONS

These findings reveal that Tregs are present in all lung tissues examined, but with significant enrichment in adenocarcinoma. This may lead to a more permissive microenvironment for adenocarcinoma and may explain aggressive patterns of tumor spread for this histology. Lung cancer patients with adenocarcinoma histology may benefit most from Treg-targeted therapy.

Killer cell immunoglobulin-like receptor gene associations with autoimmune and allergic diseases, recurrent spontaneous abortion, and neoplasms

Killer cell immunoglobulin-like receptors (KIRs) are a family of cell surface inhibitory or activating receptors expressed on natural killer cells and some subpopulations of T lymphocytes. KIR genes are clustered in the 19q13.4 region and are characterized by both allelic (high numbers of variants) and haplotypic (different numbers of genes for inhibitory and activating receptors on individual chromosomes) polymorphism. This contributes to diverse susceptibility to diseases and other clinical situations. Associations of KIR genes, as well as of genes for their ligands, with selected diseases such as psoriasis vulgaris and atopic dermatitis, rheumatoid arthritis, recurrent spontaneous abortion, and non-small cell lung cancer are discussed in the context of NK and T cell functions.

Shaping of NK cell responses by the tumor microenvironment

Natural killer (NK) cells belong to the innate immune system and are potent cytolytic and cytokine-producing effector cells in response to tumor targets. NK cell based anti-tumor immunotherapy was so far mainly successful in patients with different types of leukemia. For instance, acute myeloid leukemia (AML) patients displayed a prolonged survival if transplanted with haploidentical stem cells giving rise to NK cells with a mismatch in inhibitory killer immunoglobulin receptors (KIRs) and recipients' HLA class I. Although promising results have been achieved with hematological tumors, solid tumors are in most cases poorly controlled by NK cells. Therapeutic protocols that aimed at improving NK cell responses in patients with solid malignancies succeeded in increasing NK cell numbers and functional responses of NK cells isolated from the patients' peripheral blood. However, in the majority of cases tumor progression and overall survival of patients were not significantly improved. There is increasing evidence that tumor-associated NK cells become gradually impaired during tumor progression compared to NK cells from peripheral blood and healthy tissues. Future protocols of NK cell based immunotherapy should integrate three important aspects to improve NK cell anti-tumor activity: facilitating NK cell migration to the tumor site, enhancing their infiltration into the tumor tissue and ensuring subsequent efficient activation in the tumor. This review summarizes the current knowledge of tumor-infiltrating NK cells and the influence of the tumor microenvironment on their phenotype and function.

Tumor-induced CD8+ T-cell dysfunction in lung cancer patients

Lung cancer is the leading cause of cancer deaths worldwide and one of the most common types of cancers. The limited success of chemotherapy and radiotherapy regimes have highlighted the need to develop new therapies like antitumor immunotherapy. CD8+ T-cells represent a major arm of the cell-mediated anti-tumor response and a promising target for developing T-cell-based immunotherapies against lung cancer. Lung tumors, however, have been considered to possess poor immunogenicity; even so, lung tumor-specific CD8+ T-cell clones can be established that possess cytotoxicity against autologous tumor cells. This paper will focus on the alterations induced in CD8+ T-cells by lung cancer. Although memory CD8+ T-cells infiltrate lung tumors, in both tumor-infiltrating lymphocytes (TILs) and malignant pleural effusions, these cells are dysfunctional and the effector subset is reduced. We propose that chronic presence of lung tumors induces dysfunctions in CD8+ T-cells and sensitizes them to activation-induced cell death, which may be associated with the poor clinical responses observed in immunotherapeutic trials. Getting a deeper knowledge of the evasion mechanisms lung cancer induce in CD8+ T-cells should lead to further understanding of lung cancer biology, overcome tumor evasion mechanisms, and design improved immunotherapeutic treatments for lung cancer.

NK cells: key to success of DC-based cancer vaccines?

The cytotoxic and regulatory antitumor functions of natural killer (NK) cells have become attractive targets for immunotherapy. Manipulation of specific NK cell functions and their reciprocal interactions with dendritic cells (DCs) might hold therapeutic promise. In this review, we focus on the engagement of NK cells in DC-based cancer vaccination strategies, providing a comprehensive overview of current in vivo experimental and clinical DC vaccination studies encompassing the monitoring of NK cells. From these studies, it is clear that NK cells play a key regulatory role in the generation of DC-induced antitumor immunity, favoring the concept that targeting both innate and adaptive immune mechanisms may synergistically promote clinical outcome. However, to date, DC vaccination trials are only infrequently accompanied by NK cell monitoring. Here, we discuss different strategies to improve DC vaccine preparations via exploitation of NK cells and provide a summary of relevant NK cell parameters for immune monitoring. We underscore that the design of DC-based cancer vaccines should include the evaluation of their NK cell stimulating potency both in the preclinical phase and in clinical trials.