Application of tissue-specific NK and NKT cell activity for tumor immunotherapy

NK cell-based immunotherapy in hepatocellular carcinoma: An attractive therapeutic option for the next decade

Hepatocellular carcinoma (HCC), a major subtype of liver cancer, poses significant therapeutic challenges due to its late diagnosis and rapid progression. The evolving landscape of immunotherapy offers a beacon of hope, with natural killer (NK) cells emerging as pivotal players in combating HCC. NK cells are unique cytotoxic lymphocytes that are essential in the fight against infections and malignancies. Phenotypic and functional NK cell abnormalities have been shown in HCC patients, indicating their significance as a component of the innate immune system against cancer. This review elucidates the critical role of NK cells in combating HCC, focusing on their interaction with the tumor microenvironment, the development of NK cell-based therapies, and the innovative strategies to enhance their efficacy in the immunosuppressive milieu of HCC. The review delves into the various therapeutic strategies, including autologous and allogeneic NK cell therapies, genetic engineering to improve NK cell resilience and targeting, and the integration of NK cells with other immunotherapeutic approaches like checkpoint inhibitors and oncolytic virotherapy. By highlighting recent advancements and the ongoing challenges in the field, this review sets the stage for future research directions that could unlock the full potential of NK cell-based immunotherapy for HCC, offering a beacon of hope for patients battling this formidable cancer.

New insights into iNKT cells and their roles in liver diseases

Natural killer T cells (NKTs) are an important part of the immune system. Since their discovery in the 1990s, researchers have gained deeper insights into the physiology and functions of these cells in many liver diseases. NKT cells are divided into two subsets, type I and type II. Type I NKT cells are also named iNKT cells as they express a semi-invariant T cell-receptor (TCR) α chain. As part of the innate immune system, hepatic iNKT cells interact with hepatocytes, macrophages (Kupffer cells), T cells, and dendritic cells through direct cell-to-cell contact and cytokine secretion, bridging the innate and adaptive immune systems. A better understanding of hepatic iNKT cells is necessary for finding new methods of treating liver disease including autoimmune liver diseases, alcoholic liver diseases (ALDs), non-alcoholic fatty liver diseases (NAFLDs), and liver tumors. Here we summarize how iNKT cells are activated, how they interact with other cells, and how they function in the presence of liver disease.

Cross Talk Between Natural Killer T and Dendritic Cells and Its Impact on T Cell Responses in Infections

Both innate and adaptive immunity is vital for host defense against infections. Dendritic cells (DCs) are critical for initiating and modulating adaptive immunity, especially for T-cell responses. Natural killer T (NKT) cells are a small population of innate-like T cells distributed in multiple organs. Many studies have suggested that the cross-talk between these two immune cells is critical for immunobiology and host defense mechanisms. Not only can DCs influence the activation/function of NKT cells, but NKT cells can feedback on DCs also, thus modulating the phenotype and function of DCs and DC subsets. This functional feedback of NKT cells on DCs, especially the preferential promoting effect on CD8α+ and CD103+ DC subsets in lymphoid and non-lymphoid tissues, significantly impacts the systemic and local adaptive CD4 and CD8 T cell responses in infections. This review focuses on the two-way interaction between NKT cells and DCs, emphasizing the importance of NKT cell feedback on DCs in bridging innate and adaptive immune responses for host defense purposes.

Patients with BRAF-Mutant Advanced/Metastatic Melanoma: Original Research on the Treatment Reality in Germany and Austria in the Era of Choice

INTRODUCTION

Cutaneous melanoma is one of the most aggressive forms of skin neoplasms and represents a major cause of neoplastic or cancer death in Europe. Without adequate therapy, the 5-year survival rate is 15% when the disease metastasizes to distant organs. The objective of our study was to evaluate the status quo of the current treatment standards in stage IV melanoma and rationale for therapy decisions in Germany and Austria between January 2016 and September 2018.

METHODS

In this retrospective, anonymized registry, data of male and female patients with unresectable advanced/metastatic BRAF-positive cutaneous melanoma treated in the first, second, and third line with registered substances were analyzed using descriptive statistics.

RESULTS

Ninety-nine patients (50.5% male) received a total of 172 treatment lines. The first (99 patients), second (56 patients), and third (17 patients) treatment lines were documented. Within the 80.8% of patients with stage IV melanoma, targeted therapy (TT) was more frequently administered as a first-line treatment than immunotherapy (IO) with checkpoint inhibitors (59.6% TT vs. 40.4% IO). Across all lines, patients received TT in 54.7% and IO in 43.0% of the cases. As targeted agents, dabrafenib plus trametinib was predominantly prescribed (72.3%), whereas the monotherapy with anti-programmed cell death protein 1 and anti-cytotoxic T lymphocyte-associated protein 4 antibodies or their combination was prescribed similarly often (50.0% vs. 47.3%). Most commonly, the treatment type was switched from TT to IO or vice versa upon disease progression. The most frequent rationales for prescribing either TT or IO were remission pressure (72.9%) or physician's preference (45.0%), respectively. Disease progression was a more frequent cause of treatment discontinuation than undesired events.

CONCLUSION

Patients in Germany and Austria with unresectable advanced or metastatic BRAF-mutant melanoma predominantly receive guideline-recommended treatments. TT was more frequently administered than IO while the rationale for prescribing a specific treatment type differed between the two.

Recent Advances: The Imbalance of Immune Cells and Cytokines in the Pathogenesis of Hepatocellular Carcinoma

Recent advancement in the immunological understanding of genesis of hepatocellular carcinoma (HCC) has implicated a decline in anti-tumour immunity on the background of chronic inflammatory state of liver parenchyma. The development of HCC involves a network of immunological activity in the tumour microenvironment involving continuous interaction between tumour and stromal cells. The reduction in anti-tumour immunity is secondary to changes in various immune cells and cytokines, and the tumour microenvironment plays a critical role in modulating the process of liver fibrosis, hepatocarcinogenesis, epithelial-mesenchymal transition (EMT), tumor invasion and metastasis. Thus, it is considered as one of primary factor behind the despicable tumour behavior and observed poor survival; along with increased risk of recurrence following treatment in HCC. The primary intent of the present review is to facilitate the understanding of the complex network of immunological interactions of various immune cells, cytokines and tumour cells associated with the development and progression of HCC.

Depression promotes hepatocellular carcinoma progression through a glucocorticoid-mediated upregulation of PD-1 expression in tumor-infiltrating NK cells

There is a growing belief that depression was positively associated with the progression of liver cancer. However, the driving molecular events behind the depression in liver cancer are poorly understood and need to be elucidated. Since hyperactivity of the hypothalamic-pituitary-adrenal axis during depression leads to the excessive release of glucocorticoids (GCs), which suppress the activity of natural killer (NK) cells, we hypothesized that high levels of GCs during depression may inhibit function of tumor-infiltrating NK cells during the progress of the liver cancer. Using chronic unpredictable mild stress-induced depressed mice model, we showed that the progression of liver cancer was significantly accelerated in the depressed mice. The high levels of GCs were observed in both depressed mice and depressed patients with liver cancer. Importantly, the expression of programmed death (PD)-1 on NK cells was specifically increased in the tumor microenvironment rather than that in blood or spleen. Coculture studies demonstrated that the expression of PD-1 was significantly increased and cytotoxicity of NK92 cells was remarkably decreased by the dexamethasone treatment through PD-L1-dependent pathway. To the best of our knowledge, we first found that PD-1/PD-L1-mediated exhaustion of infiltrated NK cells promoted hepatocellular carcinoma progression under depression and provided a novel strategy for GC-mediated antidepressant therapy in patients with liver cancer.

Tumor-Infiltrating Leukocyte Composition and Prognostic Power in Hepatitis B- and Hepatitis C-Related Hepatocellular Carcinomas

Background: Tumor-infiltrating leukocytes (TILs) are immune cells surrounding tumor cells, and several studies have shown that TILs are potential survival predictors in different cancers. However, few studies have dissected the differences between hepatitis B- and hepatitis C-related hepatocellular carcinoma (HBV−HCC and HCV−HCC). Therefore, we aimed to determine whether the abundance and composition of TILs are potential predictors for survival outcomes in HCC and which TILs are the most significant predictors. Methods: Two bioinformatics algorithms, ESTIMATE and CIBERSORT, were utilized to analyze the gene expression profiles from 6 datasets, from which the abundance of corresponding TILs was inferred. The ESTIMATE algorithm examined the overall abundance of TILs, whereas the CIBERSORT algorithm reported the relative abundance of 22 different TILs. Both HBV−HCC and HCV−HCC were analyzed. Results: The results indicated that the total abundance of TILs was higher in non-tumor tissue regardless of the HCC type. Alternatively, the specific TILs associated with overall survival (OS) and recurrence-free survival (RFS) varied between subtypes. For example, in HBV−HCC, plasma cells (hazard ratio [HR] = 1.05; 95% CI 1.00–1.10; p = 0.034) and activated dendritic cells (HR = 1.08; 95% CI 1.01–1.17; p = 0.03) were significantly associated with OS, whereas in HCV−HCC, monocytes (HR = 1.21) were significantly associated with OS. Furthermore, for RFS, CD8+ T cells (HR = 0.98) and M0 macrophages (HR = 1.02) were potential biomarkers in HBV−HCC, whereas neutrophils (HR = 1.01) were an independent predictor in HCV−HCC. Lastly, in both HBV−HCC and HCV−HCC, CD8+ T cells (HR = 0.97) and activated dendritic cells (HR = 1.09) had a significant association with OS, while γ delta T cells (HR = 1.04), monocytes (HR = 1.05), M0 macrophages (HR = 1.04), M1 macrophages (HR = 1.02), and activated dendritic cells (HR = 1.15) were highly associated with RFS. Conclusions: These findings demonstrated that TILs are potential survival predictors in HCC and different kinds of TILs are observed according to the virus type. Therefore, further investigations are warranted to elucidate the role of TILs in HCC, which may improve immunotherapy outcomes.

Flip-flops of natural killer cells in autoimmune diseases versus cancers: Immunologic axis

Natural killer (NK) cells play an essential role in the immune response to infections, inflammations, and malignancies. Recent studies suggest that NK cell surface receptors and cytokines are the key points of the disease development and protection. We hypothesized that the interactions between NK cell receptors and targeted cells construct an eventual niche, and this niche has an eventual profile in various autoimmune diseases and cancers. The NK cells preactivated with cytokines, such as interleukin-2 (IL-2), IL-12, IL-15, and IL-18 can have higher cytotoxicity; however, the toxic side effect of IL-2 should be considered. The vicissitudes of NK cell profile and its receptors obey the environmental communications and cell interactions. Our vision around the NK cells as an immune axis remained dual, and we still cannot judge the immune responses based on the NK cell flip-flop. A design of eventual niche to monitor the NK cell and targeted cell interaction is needed to strengthen our ability in diagnosis and treatment approaches based on the NK cells. Here, we have reviewed the shifts in the NK cells and their surface receptors in autoimmune diseases, solid tumors, and leukemia, and also discussed the effective chemokines that affect NK cell activation and proliferation. The main aim of this review is to present a broader vision of the NK cell changes in autoimmune disease and cancers.

Elevated preoperative aspartate aminotransferase to lymphocyte ratio index as an independent prognostic factor for patients with hepatocellular carcinoma after hepatic resection

Few studies have elucidated the relationship between preoperative aspartate aminotransferase (AST) to lymphocyte ratio and high incidence of hepatocellular carcinoma (HCC). In search of a simple non-invasive prognostic marker, we investigated the prognostic significance of AST to lymphocyte ratio index (ALRI) in HCC. We reviewed retrospectively clinical parameters of 371 HCC patients who were treated with hepatectomy. Receiver operating characteristic (ROC) curve analysis was performed to determine the cut-off value of preoperative ALRI. The predictive value of preoperative ALRI in HCC was evaluated by univariate and multivariate analyses using Cox proportional hazards regression modeling, and the survival probability of HCC patients was acquired by the Kaplan-Meier plots. In addition, stratified analysis was used to investigate the impact of preoperative ALRI on survival in different HCC subgroups. The results showed that preoperative ALRI was closely correlated with age (p = 0.007), median size (p = 0.004), clinical tumor-node-metastasis (TNM) stage (p < 0.001), and portal vein tumor thrombosis (PVTT) (p < 0.001). Survival analysis indicated that HCC patients with preoperative ALRI > 25.2 have a poorer disease-free survival (DFS) and overall survival (OS) after tumor resection. Multivariate analysis further identified preoperative ALRI > 25.2 (p = 0.002), III-IV of TNM stage (p = 0.011), PVTT (p = 0.035), size of tumor > 5 cm (p < 0.001) as independent risk factors of DFS; and preoperative ALRI > 25.2 (p = 0.001), III-IV of TNM stage (p = 0.005), PVTT (p = 0.012), size of tumor > 5 cm (p < 0.001), recurrence (p < 0.001) as independent prognostic factors for OS in HCC patients. Additionally, preoperative ALRI also showed different prognostic value in various subgroups of HCC. Elevated preoperative ALRI as a noninvasive, simple, and easily assessable parameter is an independent effective predictor of prognosis for patients with HCC.

Effect of cytokine-induced killer cells on immune function in patients with lung cancer

Cytokine-induced killer (CIK) cells have been used as adoptive immunotherapy in cancer. The present study evaluated the effect of CIK cells on immune function in patients with lung cancer. Patients were divided into three groups, according to the treatment received prior to CIK cell treatment: CIK group (no prior treatment), Che-Sur group (prior chemotherapy and surgery) and Che-Rad group (prior chemotherapy and radiotherapy). Following treatment, the average percentage of cluster of differentiation (CD)3⁺CD4⁺, CD3⁺, natural killer (NK) and NKT cells in peripheral blood was significantly higher than that prior to CIK treatment in the Che-Sur and CIK groups, and the levels of interferon-γ in serum were significantly higher than those prior to CIK treatment in the Che-Sur and CIK groups. On the contrary, the levels of interleukin-10 had decreased in these groups following CIK treatment. Subsequently, patients were divided into three groups according to the percentage of CD3⁺CD56⁺ CIK cells that were administered to the patients. The number of NK and NKT cells increased with increasing number of CD3⁺CD56⁺ cells. The patients in the CIK and Che-Sur groups were the most benefited ones following CIK treatment, contrarily to those in the Che-Rad group, since the increase in the number of CD3⁺CD56⁺ CIK cells in the aforementioned patients enhanced the number of NK cells, which exhibit antitumor activity.

Immunology of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is primarily a malignancy of the liver, advancing from a damaged, cirrhotic liver to HCC. Globally, HCC is the sixth most prevalent cancer and the third-most prevalent reason for neoplastic disease-related deaths. A diverse array of infiltrating immunocytes regulates the development and progression of HCC, as is the case in many other cancers. An understanding of the various immune components during HCC becomes necessary so that novel therapeutic strategies can be designed to combat the disease. A dysregulated immune system (including changes in the number and/or function of immune cells, cytokine levels, and the expression of inhibitory receptors or their ligands) plays a key role in the development of HCC. Alterations in either the innate or adaptive arm of the immune system and cross-talk between them make the immune system tolerant to tumors, leading to disease progression. In this review, we have discussed the status and roles of various immune effector cells (e.g., dendritic cells, natural killer cells, macrophages, and T cells), their cytokine profile, and the chemokine-receptor axis in promoting or impeding HCC.

Pivotal roles of ILCs in hepatic diseases

Innate lymphoid cells (ILCs) are involved in the development of mucosal-associated lymphoid tissues and serve as a rapid and early source of the effector cytokines that are typically associated with the T helper cell subsets in response to pathogen-induced changes in the microenvironment. Recent research has implicated ILCs as potential contributing factors to the spectrum of inflammation-related hepatic diseases, particularly hepatitis, fibrosis and carcinoma. In this review, we summarize the current knowledge on the roles of ILCs in these hepatic pathogeneses, providing insights into the underlying cellular and signaling mechanisms to help guide the future research to elucidate the ILCs' characters under normal and diseased conditions and provide interventional targets with therapeutic potential.

Cell transfer therapy for cancer: past, present, and future

Cell transfer therapy for cancer has made a rapid progress recently and the immunotherapy has been recognized as the fourth anticancer modality after operation, chemotherapy, and radiotherapy. Lymphocytes used for cell transfer therapy include dendritic cells, natural killer (NK) cells, and T lymphocytes such as tumor-infiltrating lymphocytes (TILs) and cytotoxic T lymphocytes (CTLs). In vitro activated or engineered immune cells can traffic to cancer tissues to elicit persistent antitumor immune response which is very important especially after immunosuppressive treatments such as chemotherapy. In this review, we overviewed recent advances in the exploration of dendritic cells, NK cells, and T cells for the treatment of human cancer cells.

Role of lymphocytes in liver cancer

Hepatocellular carcinoma (HCC) typically occurs in patients with chronic inflammatory liver diseases, such as viral hepatitis or (non-)alcoholic steatohepatitis. Inflammation appears indeed as a crucial factor in hepatocarcinogenesis. Nevertheless, sophisticated animal models and studies of human samples revealed that the HCC also elicits antitumor immune responses. Patrolling and infiltrating lymphocytes (e.g., NKT and T cells, respectively) can exert decisive functions in the transition from chronic hepatic inflammation to cancer as well as in antitumor immune responses. An improved understanding of the cellular and molecular mechanisms whereby inflammation promotes or restricts hepatocarcinogenesis will open new avenues for therapeutic approaches to liver cancer.

Fine tuning a well-oiled machine: Influence of NK1.1 and NKG2D on NKT cell development and function

Natural killer T cells (NKT) represent a group of CD1d-restricted T-lineage cells that provide a functional interface between innate and adaptive immune responses in infectious disease, cancer, allergy and autoimmunity. There have been remarkable advances in understanding the molecular events that underpin NKT development in the thymus and in the complex array of functions in the periphery. Most functional studies have focused on activation of T cell antigen receptors expressed by NKT cells and their responses to CD1d presentation of glycolipid and related antigens. Receiving less attention has been several molecules that are hallmarks of Natural Killer (NK) cells, but nonetheless expressed by NKT cells. These include several activating and inhibitory receptors that may fine-tune NKT development and survival, as well as activation via antigen receptors. Herein, we review the possible roles of the NK1.1 and NKG2D receptors in regulating development and function of NKT cells in health and disease. We suggest that pharmacological alteration of NKT activity should consider the potential complexities commensurate with NK1.1 and NKG2D expression.

Selenium nanoparticle-enriched Lactobacillus brevis causes more efficient immune responses in vivo and reduces the liver metastasis in metastatic form of mouse breast cancer

BACKGROUND AND THE PURPOSE OF THE STUDY

Selenium enriched Lactobacillus has been reported as an immunostimulatory agent which can be used to increase the life span of cancer bearing animals. Lactic acid bacteria can reduce selenium ions to elemental selenium nanoparticles (SeNPs) and deposit them in intracellular spaces. In this strategy two known immunostimulators, lactic acid bacteria (LAB) and SeNPs, are concomitantly administered for enhancing of immune responses in cancer bearing mice.

METHODS

Forty five female inbred BALB/c mice were divided into three groups of tests and control, each containing 15 mice. Test mice were orally administered with SeNP-enriched Lactobacillus brevis or Lactobacillus brevis alone for 3 weeks before tumor induction. After that the administration was followed in three cycles of seven days on/three days off. Control group received phosphate buffer saline (PBS) at same condition. During the study the tumor growth was monitored using caliper method. At the end of study the spleen cell culture was carried out for both NK cytotoxicity assay and cytokines measurement. Delayed type hypersensitivity (DTH) responses were also assayed after 72h of tumor antigen recall. Serum lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) levels were measured, the livers of mice were removed and prepared for histopathological analysis.

RESULTS

High level of IFN-γ and IL-17 besides the significant raised in NK cytotoxicity and DTH responses were observed in SeNP-enriched L. brevis administered mice and the extended life span and decrease in the tumor metastasis to liver were also recorded in this group compared to the control mice or L.brevis alone administered mice.

CONCLUSION

Our results suggested that the better prognosis could be achieved by oral administration of SeNP-enriched L. brevis in highly metastatic breast cancer mice model.

NK cell-based immunotherapy for malignant diseases

Natural killer (NK) cells play critical roles in host immunity against cancer. In response, cancers develop mechanisms to escape NK cell attack or induce defective NK cells. Current NK cell-based cancer immunotherapy aims to overcome NK cell paralysis using several approaches. One approach uses expanded allogeneic NK cells, which are not inhibited by self histocompatibility antigens like autologous NK cells, for adoptive cellular immunotherapy. Another adoptive transfer approach uses stable allogeneic NK cell lines, which is more practical for quality control and large-scale production. A third approach is genetic modification of fresh NK cells or NK cell lines to highly express cytokines, Fc receptors and/or chimeric tumor-antigen receptors. Therapeutic NK cells can be derived from various sources, including peripheral or cord blood cells, stem cells or even induced pluripotent stem cells (iPSCs), and a variety of stimulators can be used for large-scale production in laboratories or good manufacturing practice (GMP) facilities, including soluble growth factors, immobilized molecules or antibodies, and other cellular activators. A list of NK cell therapies to treat several types of cancer in clinical trials is reviewed here. Several different approaches to NK-based immunotherapy, such as tissue-specific NK cells, killer receptor-oriented NK cells and chemically treated NK cells, are discussed. A few new techniques or strategies to monitor NK cell therapy by non-invasive imaging, predetermine the efficiency of NK cell therapy by in vivo experiments and evaluate NK cell therapy approaches in clinical trials are also introduced.

Natural killer cells in liver disease

Natural killer (NK) cells are enriched in lymphocytes within the liver and have unique phenotypic features and functional properties, including tumor necrosis factor-related apoptosis-inducing ligand-dependent cytotoxicity and specific cytokine profiles. As a key component of innate immunity in the liver, NK cells perform critical roles in host defense against pathogens and tumors through their natural cytotoxicity and cytokine production, and they also act as regulatory cells by engaging in reciprocal interactions with other types of liver cells through cell-to-cell contact and the production of cytokines. Accumulating evidence from the last decade suggests that NK cells play an important role in controlling viral hepatitis, liver fibrosis, and liver tumorigenesis, but also contribute to the pathogenesis of liver injury and inflammation. The characterization of intrahepatic NK cell functions has not only helped us to better understand the pathogenesis of liver disease, but has also revealed new therapeutic targets for managing this disease.

The antitumor effect of the toll-like receptor 3 ligand polyinosinic-cytidylic acid as an adjuvant

Although polyinosinic-polycytidylic acid (poly(I:C)) has been applied in tumor immunity as a Toll-like receptor 3 (TLR3) ligand, the interaction between poly(I:C) and TLR3 is still unclear, as are the mechanisms underlying the antitumor effect of poly(I:C). Our aim was to investigate the interaction between poly(I:C) and TLR3, as well as the mechanisms underlying the antitumor effect of poly(I:C). NK92 cells were maintained in medium (untreated group), or medium containing E7(44-62) (E7 group) or E7(44-62)+poly(I:C) (poly(I:C)/E7 group), and we measured the expression of TLR3 mRNA, p-p65, and IκB-α protein. The cells were first incubated in medium alone or medium containing TLR3 monoclonal antibody, and then in medium containing poly(I:C)/E7. Finally, we measured the level of interferon-beta (INF-β) in the supernatant and determined the tumor cell-killing effect of the NK92 cells. At 1 h, the expression of TLR3 mRNA in the poly(I:C)/E7 group was markedly higher than that in the untreated and E7 groups (P < 0.05). When compared with the poly(I:C)/E7 group, the expression of IκB-α was dramatically increased in the E7 and untreated groups, and the expression of p-p65 was dramatically decreased in the E7 and untreated groups (all P < 0.05). At 24 h, INF-β content and tumor cell-killing activity in the poly(I:C)/E7 group were markedly higher than those in the untreated group (P < 0.001, <0.05, respectively). Treatment with TLR3 monoclonal antibody significantly inhibited poly(I:C)/E7-induced INF-β secretion and tumor cell-killing activity in NK92 cells (P < 0.001, <0.05, respectively). The interaction between poly(I:C) and TLR3 plays an important role in the antitumor immunity of NK92 cells. In addition, the interaction between poly(I:C) and TLR3 increases INF-β expression, which may be attributed to the activation of NFκB.

Novel molecular, cytotoxical, and immunological study on promising and selective anticancer activity of mung bean sprouts

BACKGROUND

The anticancer and immunomodulatory activity of mung bean sprouts (MBS) and the underlying mechanisms against human cervical and hepatocarcinoma cancer cells were explored.

METHODS

MBS cytotoxicity and MBS-induced anticancer cytokines, TNF-α and IFN-β from cancer cells, and immunological cytokines, IL-4, IFN-γ, and IL-10 from peripheral mononuclear cells (PMNC) were assessed by MTS and ELISA assays. Apoptotic cells were investigated by flow cytometry. The expression level of apoptotic genes (Bax, BCL-2, Capsases 7-9) and cell cycle regulatory genes (cyclin D, E, and A) and tumor suppressor proteins (p27, p21, and p53) was assessed by real-time qPCR in the cancer cells treated with extract IC50.

RESULTS

The cytotoxicity on normal human cells was significantly different from HeLa and HepG2 cells, 163.97 ± 5.73, 13.3 ± 0.89, and 14.04 ± 1.5 mg/ml, respectively. The selectivity index (SI) was 12.44 ± 0.83 for HeLa and 11.94 ± 1.2 for HepG2 cells. Increased levels of TNF-α and IFN-β were observed in the treated HeLa and HepG2 culture supernatants when compared with untreated cells. MBS extract was shown to be an immunopolarizing agent by inducing IFNγ and inhibiting IL-4 production by PBMC; this leads to triggering of CMI and cellular cytotoxicity. The extract induced apoptosis, in a dose and time dependent manner, in treated HeLa and HepG2, but not in untreated, cells (P < 0.05). The treatment significantly induced cell cycle arrest in G0/G1 in HeLa cells. The percentage of cells in G0/G1 phase of the treated HeLa cells increased from 62.87 ± 2.1%, in untreated cells, to 80.48 ± 2.97%. Interestingly, MBS IC50 induced the expression of apoptosis and tumor suppressor related genes in both HeLa and HepG2 cells. MBS extract succeeded in inducing cdk-inhibitors, p21, p53, and p27 in HeLa cells while it induced only p53 in HepG2 cells (P < 0.05). This is a clue for the cell type- specific interaction of the studied extract. These proteins inhibit the cyclin-cdk complexes apart from the presence of some other components that might stimulate some cyclins such as cyclin E, A, and D.

CONCLUSION

MBS extract was shown to be a potent anticancer agent granting new prospects of anticancer therapy using natural products.

Infiltrating CD57+ inflammatory cells in head and neck squamous cell carcinoma: clinicopathological analysis and prognostic significance

This study investigated the immunodetection of CD57+ inflammatory cells in patients with head and neck squamous cell carcinoma (HNSCC) and its association with clinicopathological parameters and overall survival. Data collected from the morphological analysis and immunohistochemical reaction testing of archived HNSCC specimens (n=70) were statistically analyzed by bivariate and multivariate statistical testing at a significance level of P<0.05. The results indicate that CD57+ inflammatory cells predominate within the peritumoral stroma of HNSCC lesions and the existence of two significant relationships: between high CD57+ cell density and the development of a tumor of a large size [odds ratio (OR)=5.610, 95% confidence interval (CI)=1.516-20.763) and between high CD57+ cell density and the development of locoregional metastatic disease (OR=3.401, 95% CI=1.162-9.951). A significant difference in the rate of survival was detected only in HNSCC patients that presented large size tumors (OR=4.747, 95% CI=1.281-17.594). Together, these results suggest that although high CD57+ inflammatory cell density is associated with HNSCC lesions of greater clinical severity, the variable of cell density is not an independent predictor of HNSCC patient survival. Our findings also suggest that the relatively aggressive infiltration of CD57+ inflammatory cells in the peritumoral stroma of head and neck carcinomas may contribute to an ineffective locoregional antitumoral response.

Immunoregulation of hepatitis B virus infection--rationale and clinical application

Hepatitis B virus (HBV) is susceptible to the cellular immune responses, especially to the signal of interferon (IFN)-gamma. The action of IFN-gamma is pleiotropic, and causes downregulation of HBV in protein, RNA, and possibly DNA levels. Therefore, therapeutic vaccination to induce cellular immune responses to HBV is a promising approach for controlling chronic HBV infection. A number of clinical trials with this approach have been conducted to date, however, they have not been as successful as initially expected. T-cell exhaustion induced by the excessive HBV antigens caused by persistent infection is thought to be one of the main causes of poor responses to therapeutic vaccination. In this review, the mechanisms behind immunoregulation of HBV replication and immunodysfunction during chronic HBV infection are summarized, and novel approaches to improve the efficacy of therapeutic vaccination, from basic research to clinical trials, are introduced.

Consequences of TCDD treatment on intra-hepatic lymphocytes during liver regeneration

Increasing evidence demonstrates a physiological role for the aryl hydrocarbon receptor (AhR) in regulating hepatocyte cell cycle progression. Previous studies have used a murine model of liver regeneration to show that exposure to the potent exogenous AhR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), suppresses hepatocyte proliferation in vivo. Based on recent reports that natural killer (NK) cells negatively regulate liver regeneration, coupled with the well-established immunomodulatory effects of TCDD, it was hypothesized that alterations in lymphocyte activation contribute to the suppression of liver regeneration in TCDD-treated mice. To test this, mice were treated with TCDD (20 μg/kg) 1 day prior to 70% partial hepatectomy (PH), in which two-thirds of the liver was surgically resected. Lymphocytes were collected from the remnant liver and analyzed by flow cytometry. Whereas exposure to TCDD did not alter the number of NK cells or CD3(+) T-cells recovered from the regenerating liver, it reduced the percentage and number of intra-hepatic NKT cells 42 h after PH. With regard to lymphocyte activation, TCDD treatment transiently increased CD69 expression on NK and NKT cells 12 h after PH, but had no effect on intracellular levels of IFNγ in NK, NKT, or CD3(+) T-cells. To determine the relevance of NK cells to the suppression of liver regeneration by TCDD, mice were treated with anti-Asialo GM-1 (ASGM-1) antibody to deplete NK cells prior to TCDD treatment and PH, and hepatocyte proliferation was measured using bromodeoxyuridine incorporation. Exposure to TCDD was found to inhibit hepatocyte proliferation in the regenerating liver of NK cell-depleted mice and control mice to the same extent. Hence, it is unlikely that enhanced numbers or increased activation of NK cells contribute to the suppression of liver regeneration in TCDD-treated mice.

Genomic modeling of tumor onset and progression in a mouse model of aggressive human liver cancer

A comprehensive understanding of molecular mechanisms driving cancer onset and progression should provide a basis for improving early diagnosis, biomarker discovery and treatment options. A key value of genetically engineered mice for modeling human cancer is the possibility to analyze the entire process of tumor development. Here, we applied functional genomics approach to study step-by-step development of hepatocellular carcinoma (HCC) in the c-Myc/Tgfα transgenic mouse model of aggressive human liver cancer. We report that coexpression of c-Myc and Tgfα induces progressive and cumulative transcriptional alterations in the course of liver oncogenesis. Functional analysis of deregulated genes at the early stage of HCC disease supports a model of active hepatocyte proliferation on the background of chronic oxidative stress generated by a general metabolic disorder. In addition, early and persistent deregulation of numerous immune-related genes suggested that disruption of immune microenvironment may contribute to oncogenic process in this model of accelerated liver carcinogenesis. In particularly, by flow cytometry analysis, we found loss of the major histocompatibility complex class I expression in dysplastic hepatocytes followed by upregulation of numerous activating ligands for natural killer (NK) cells concomitant with a drastic decrease in hepatic NK cell frequency. In conclusion, our study provides a comprehensive characterization of sequential molecular changes during a stepwise progression of preneoplastic lesions toward HCC and highlights a critical role of metabolic disorders and innate immunity at the early stages of liver cancer.

IFN-γ production by lung NK cells is critical for the natural resistance to pulmonary metastasis of B16 melanoma in mice

NK cells are effector lymphocytes playing a critical role in the natural resistance against tumors. However, the precise mechanisms underlying NK cell-mediated natural resistance against tumor metastasis are still unrevealed. B16 cells, mouse melanoma cells, were resistant to freshly isolated NK cell-mediated killing; nevertheless, NK cells were critical for natural resistance against experimental lung metastasis of B16 cells. We found that lung metastasis was increased significantly in IFN-γ(-/-) mice but not pfp(-/-), IFN-αR(-/-), or IL-12/IL-18(-/-) mice. Interestingly, freshly isolated lung NK cells, but not spleen or liver NK cells, displayed augmented IFN-γ production after B16 inoculation. Adoptive transfer of pfp(-/-) NK cells, but not IFN-γ(-/-) NK cells, significantly decreased B16 lung metastasis in IFN-γ(-/-) and pfp/IFN-γ(-/-)mice. Lung metastases of IFN-γRDN B16 was also increased in NK cell-depleted or IFN-γ(-/-) mice, suggesting that the IFN-γ response of host cells was required in the NK cell and IFN-γ-mediated antimetastatic effect. Our results demonstrate that IFN-γ production from lung resident NK cells is a key response in the natural resistance to the experimental lung metastasis of NK cell-resistant tumor cells.

Critical role of interleukin-17/interleukin-17 receptor axis in mediating Con A-induced hepatitis

Concanavalin A (Con A)-induced hepatitis is thought to be a T-cell-mediated disease with active destruction of liver cells. Interleukin (IL)-17 is a cytokine produced principally by CD4(+) T cells. However, whether IL-17/IL-17 receptor (IL-17/IL-17R)-mediated responses are involved in T-cell-mediated Con A-induced liver injury remains unclear. In this study, we found that IL-17 expression was highly elevated in liver tissues during Con A-induced hepatitis. The increased levels of IL-17 were paralleled with the severity of liver injury reflected by Alanine aminotransaminase and histological assay as well as the secretion of tumor necrosis factor (TNF)-α and IL-6. Blockage of IL-17 significantly ameliorated Con A-induced hepatitis, while overexpression of IL-17 systemically resulted in massive hepatocyte necrosis in mice. Furthermore, overexpression of an IL-17R immunoglobulin G1 fusion protein significantly attenuated liver inflammation after acute Con A treatment. High expression of IL-17R on Kupffer cells was also observed along with the production of cytokines including TNF-α and IL-6. Inhibition of Kupffer cells by gadolinium chloride completely prevented Con A-induced liver injury and cytokine release. Finally, IL-17-expressing CD4(+) T and natural killer T cells were greatly increased in Con A-injected mice compared with that in controls. Overall, our results indicate that IL-17R signaling is critically involved in the pathogenesis in Con A-induced hepatitis, and blockade of IL-17/IL-17R signaling pathway may represent a novel therapeutic intervention in human autoimmune-related hepatitis.

Immunotherapy for lung cancers

Lung cancer is the leading cause of cancer-related deaths worldwide. Although treatment methods in surgery, irradiation, and chemotherapy have improved, prognosis remains unsatisfactory and developing new therapeutic strategies is still an urgent demand. Immunotherapy is a novel therapeutic approach wherein activated immune cells can specifically kill tumor cells by recognition of tumor-associated antigens without damage to normal cells. Several lung cancer vaccines have demonstrated prolonged survival time in phase II and phase III trials, and several clinical trials are under investigation. However, many clinical trials involving cancer vaccination with defined tumor antigens work in only a small number of patients. Cancer immunotherapy is not completely effective in eradicating tumor cells because tumor cells escape from host immune scrutiny. Understanding of the mechanism of immune evasion regulated by tumor cells is required for the development of more effective immunotherapeutic approaches against lung cancer. This paper discusses the identification of tumor antigens in lung cancer, tumor immune escape mechanisms, and clinical vaccine trials in lung cancer.

TCR-dependent and -independent activation underlie liver-specific regulation of NKT cells

The fate of invariant NKT (iNKT) cells following activation remains controversial and unclear. We systemically examined how iNKT cells are regulated following TCR-dependent and -independent activation with α-galactosylceramide (αGC) or IL-18 plus IL-12, respectively. Our studies reveal activation by αGC or IL-18 plus IL-12 induced transient depletion of iNKT cells exclusively in the liver that was independent of caspase 3-mediated apoptosis. The loss of iNKT cells was followed by repopulation and expansion of phenotypically distinct cells via different mechanisms. Liver iNKT cell expansion following αGC, but not IL-18 plus IL-12, treatment required an intact spleen and IFN-γ. Additionally, IL-18 plus IL-12 induced a more prolonged expansion of liver iNKT cells compared with αGC. iNKT cells that repopulate the liver following αGC had higher levels of suppressive receptors PD-1 and Lag3, whereas those that repopulate the liver following IL-18 plus IL-12 had increased levels of TCR and ICOS. In contrast to acute treatment that caused a transient loss of iNKT cells, chronic αGC or IL-18 plus IL-12 treatment caused long-term systemic loss requiring an intact thymus for repopulation of the liver. This report reveals a previously undefined role for the liver in the depletion of activated iNKT cells. Additionally, TCR-dependent and -independent activation differentially regulate iNKT cell distribution and phenotype. These results provide new insights for understanding how iNKT cells are systemically regulated following activation.

Human obesity reduces the number of hepatic leptin receptor (ob-R) expressing NK cells

OBJECTIVE

In the industrialized world, obesity is an increasing socioeconomic health problem. Obese subjects have a higher risk of developing several types of cancer. NK cells are an integral component of the innate immune system, able to destruct tumor cells. The adipokine leptin plays a crucial role in the development of obesity and its related diseases. Peripheral leptin signaling is modulated by the liver.

METHODS

The aim of this study was to evaluate the number of hepatic NK cells (CD56+) and the number of leptin-receptor positive (Ob-R+) cells in the livers of five normal-weight and five obese humans. Livers were removed during autopsy and accurately defined sections were stained immunohistochemically and CD56+, Ob-R+, and double-positive cells were quantified.

RESULTS

Results revealed a dramatic reduction of NK cells and Ob-R-expressing NK cells in the livers of obese individuals.

CONCLUSIONS

The present study demonstrates, for the first time, body-weight-dependent numbers of hepatic NK cells. This supports the hypothesis of obesity-associated alterations of immune cell numbers in different human organs.

IL-15R alpha-IgG1-Fc enhances IL-2 and IL-15 anti-tumor action through NK and CD8+ T cells proliferation and activation

Natural killer (NK) cells-based immunotherapy is one of the most promising treatments for incurable malignant tumors. NK cells in combination with monoclonal antibodies to surface antigens of the tumor cell have been proved to be effective in a number of clinical trials. A limiting step in the development of successful cellular immunotherapy lies in developing an efficient and economic method to expand appropriate amount of NK cells and CD8(+) T cells. In this study, we constructed a humanized IL-15Ralpha-IgG1-Fc, which mimicked IL-15 trans-presentation. The feasibility of expanding populations of the human NK and CD8(+) T cells by IL-15Ralpha-IgG1-Fc complexes was tested. We then measured the cytotoxicity of expanded NK and CD8(+) T cells against tumor cell lines and primary tumor cells. When tested ex vivo, IL-2/IL-15Ralpha-IgG1-Fc complexes significantly enhanced NK and CD8(+) T cells expansion, isolated or non-isolated from PBMCs. The effect of IL-15Ralpha-IgG1-Fc was dependent on the presence of IL-2 or IL-15. IL-15Ralpha-IgG1-Fc complexes increased NK, CD8(+) T and NKT cells ratio in PBMC and BMMC after 14 days incubation. High level of granzyme B expression was observed in the supernatant of the complexes-treated NK cells. Expanded NK and CD8(+) T cell populations had cytotoxic function against the PC3, LNCaP, K562 and chronic lymphocytic leukemia (CLL) patient primary B cell lymphoma. We concluded that IL-2/IL-15Ralpha-IgG1-Fc significantly enhanced NK, CD8(+) T and NKT cells expansion, which possess strong anti-tumor activity. These data support clinical testing IL-2/IL-15Ralpha-IgG1-Fc expanded NK cells in patients with prostate cancer and CLL.

Advances in cellular therapy for the treatment of thyroid cancer

Up to now, there are no curative therapies available for the subset of metastasized undifferentiated/anaplastic thyroid carcinomas. This review describes the possible use of immunocompetent cells which may help to restore the antitumor immune recognition for treating an existing tumor or preventing its recurrence. The most prominent experimental strategy is the use of dendritic cells (DCs) which are highly potent in presenting tumor antigens. Activated DCs subsequently migrate to draining lymph nodes where they present antigens to naïve lymphocytes and induce cytotoxic T cells (CTL). Alternatively to DC therapy, adoptive cell transfer may be performed by either using natural killer cells or ex vivo maturated CTLs. Within this review article we will focus on recent advances in the understanding of anti-tumor immune responses, for example, in thyroid carcinomas including the advances which have been made for the identification of potential tumor antigens in thyroid malignancies.