Hyper-IL-15 suppresses metastatic and autochthonous liver cancer by promoting tumour-specific CD8+ T cell responses

IL2 Targeted to CD8+ T Cells Promotes Robust Effector T-cell Responses and Potent Antitumor Immunity

IL2 signals pleiotropically on diverse cell types, some of which contribute to therapeutic activity against tumors, whereas others drive undesired activity, such as immunosuppression or toxicity. We explored the theory that targeting of IL2 to CD8+ T cells, which are key antitumor effectors, could enhance its therapeutic index. To this aim, we developed AB248, a CD8 cis-targeted IL2 that demonstrates over 500-fold preference for CD8+ T cells over natural killer and regulatory T cells (Tregs), which may contribute to toxicity and immunosuppression, respectively. AB248 recapitulated IL2's effects on CD8+ T cells in vitro and induced selective expansion of CD8+T cells in primates. In mice, an AB248 surrogate demonstrated superior antitumor activity and enhanced tolerability as compared with an untargeted IL2Rβγ agonist. Efficacy was associated with the expansion and phenotypic enhancement of tumor-infiltrating CD8+ T cells, including the emergence of a "better effector" population. These data support the potential utility of AB248 in clinical settings. Significance: The full potential of IL2 therapy remains to be unlocked. We demonstrate that toxicity can be decoupled from antitumor activity in preclinical models by limiting IL2 signaling to CD8+ T cells, supporting the development of CD8+ T cell-selective IL2 for the treatment of cancer. See related article by Kaptein et al. p. 1226.

Exploiting the immune system in hepatic tumor targeting: Unleashing the potential of drugs, natural products, and nanoparticles

Hepatic tumors present a formidable challenge in cancer therapeutics, necessitating the exploration of novel treatment strategies. In recent years, targeting the immune system has attracted interest to augment existing therapeutic efficacy. The immune system in hepatic tumors includes numerous cells with diverse actions. CD8+ T lymphocytes, T helper 1 (Th1) CD4+ T lymphocytes, alternative M1 macrophages, and natural killer (NK) cells provide the antitumor immunity. However, Foxp3+ regulatory CD4+ T cells (Tregs), M2-like tumor-associated macrophages (TAMs), and myeloid-derived suppressor cells (MDSCs) are the key immune inhibitor cells. Tumor stroma can also affect these interactions. Targeting these cells and their secreted molecules is intriguing for eliminating malignant cells. The current review provides a synopsis of the immune system components involved in hepatic tumor expansion and highlights the molecular and cellular pathways that can be targeted for therapeutic intervention. It also overviews the diverse range of drugs, natural products, immunotherapy drugs, and nanoparticles that have been investigated to manipulate immune responses and bolster antitumor immunity. The review also addresses the potential advantages and challenges associated with these approaches.

IL-37 dampens immunosuppressive functions of MDSCs via metabolic reprogramming in the tumor microenvironment

Interleukin-37 (IL-37) has been shown to inhibit tumor growth in various cancer types. However, the immune regulatory function of IL-37 in the tumor microenvironment is unclear. Here, we established a human leukocyte antigen-I (HLA-I)-matched humanized patient-derived xenograft hepatocellular carcinoma (HCC) model and three murine orthotopic HCC models to study the function of IL-37 in the tumor microenvironment. We found that IL-37 inhibited HCC growth and promoted T cell activation. Further study revealed that IL-37 impaired the immunosuppressive capacity of myeloid-derived suppressor cells (MDSCs). Pretreatment of MDSCs with IL-37 before adoptive transfer attenuated their tumor-promoting function in HCC tumor-bearing mice. Moreover, IL-37 promoted both glycolysis and oxidative phosphorylation in MDSCs, resulting in the upregulation of ATP release, which impaired the immunosuppressive capacity of MDSCs. Collectively, we demonstrated that IL-37 inhibited tumor development through dampening MDSCs' immunosuppressive capacity in the tumor microenvironment via metabolic reprogramming, making it a promising target for future cancer immunotherapy.

Serum immune biomarker levels combined with hepatitis B virus infection status predict early recurrence of early-stage hepatocellular carcinoma with microvascular invasion after liver resection

INTRODUCTION

The tumor immune response plays a vital role in cancer recurrence in patients with malignancies. We aim to clarify the risk factors for early recurrence and investigate the efficacy of blood-based biomarkers to predict the risk of early recurrence in early-stage hepatocellular carcinoma (HCC) patients with microvascular invasion (MVI) after hepatectomy.

MATERIALS AND METHODS

A total of 101 cases of HCC with MVI who underwent liver resection were enrolled. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors of early recurrence. We calculated the area under the receiver operating characteristic curve to evaluate the performance of the four biomarkers identified as risk factors for early recurrence.

RESULTS

Multiple logistic regression analysis indicated that complement (C)4, cluster of differentiation (CD)4+, immunoglobulin A (IgA), and hepatitis B virus (HBV) DNA of greater than 500 IU/mL were correlated with early recurrence of HCC. The area under the curve was greater for the combination model than for the HBV DNA, CD4+, IgA, or C4 models alone.

CONCLUSION

Preoperative serum CD4+, C4, IgA, and HBV DNA levels were linked with early recurrence of early-stage HCC with MVI and the combination model was of considerable predictive value for the prognosis of HCC with MVI.

T-Lymphocyte Gene-Regulated CCL5 and Its Association with Extrahepatic Metastasis in Hepatocellular Carcinoma

BACKGROUND

Extrahepatic metastasis in hepatocellular carcinoma (HCC) greatly limits the prognostic survival of HCC patients. Levels of preoperative peripheral lymphocyte subsets and cytokines in the serum for predicting extrahepatic spread of hepatocellular carcinoma are still not common in clinical practice. The aim of this study is to investigate the value and mechanisms of peripheral lymphocyte subsets and cytokines in predicting extrahepatic spread of HCC.

METHODS

We used a retrospective design to analyze data pertaining to a total of 380 patients with HCC who were examined for peripheral T-lymphocyte subsets before receiving microwave ablation. We performed Cox regression analysis to screen out independent risk factors and used pathology specimens from the patients and public databases of liver cancer to investigate the correlation between cytokines and intra-tumor immune cells.

RESULTS

The CD4low group had better metastasis-free 1-year, 3-year, and 5-year survival rates compared to the CD4high group (80% vs 69%, 67% vs 51%, and 57% vs 39%, respectively; HR 1.7 (1.2, 2.3), P = 0.0019). Similarly, the CD8high group had better metastasis-free 1-year, 3-year, and 5-year survival rates compared to the CD8low group (65% vs 78%, 46% vs 64%, and 34% vs 54%, respectively; HR 0.6 (0.4, 0.8), P < 0.001). Patients with the CD4high/CD8low phenotype had significantly worse metastasis-free survival times compared to other patients (HR 2.0 (1.5, 2.8), P < 0.001). Additionally, T lymphocyte-specific genes (CD4, CD8) were correlated with CCL5 expression, which was also positively correlated with the level of intra-tumoral infiltrating CD8 T cells and the prognosis of HCC patients.

CONCLUSION

Both CD4+ and CD8+ T lymphocyte subsets were independent risk factors for extrahepatic metastasis in HCC. Serum CCL5 levels could indicate the infiltration level of intra-tumoral CD8+ T cells and the risk of extrahepatic metastasis in HCC patients, aiding in patient risk stratification for metastasis.

Multiple TMA-aided CRISPR/Cas13a platform for highly sensitive detection of IL-15 to predict immunotherapeutic response in nasopharyngeal carcinoma

BACKGROUND

Immune checkpoint inhibitors (ICIs)-based treatments have been recommended as the first line for refractory recurrent and/or metastatic nasopharyngeal carcinoma (NPC) patients, yet responses vary, and predictive biomarkers are urgently needed. We selected serum interleukin-15 (sIL-15) out of four interleukins as a candidate biomarker, while most patients' sIL-15 levels were too low to be detected by conventional methods, so it was necessary to construct a highly sensitive method to detect sIL-15 in order to select NPC patients who would benefit most or least from ICIs.

METHODS

Combining a primer exchange reaction (PER), transcription-mediated amplification (TMA), and a immuno-PER-TMA-CRISPR/Cas13a system, we developed a novel multiple signal amplification platform with a detection limit of 32 fg/mL, making it 153-fold more sensitive than ELISA.

RESULTS

This platform demonstrated high specificity, repeatability, and versatility. When applied to two independent cohorts of 130 NPC sera, the predictive value of sIL-15 was accurate in both cohorts (area under the curve: training, 0.882; validation, 0.898). Additionally, lower sIL-15 levels were correlated with poorer progression-free survival (training, HR: 0.080, p<0.0001; validation, HR: 0.053, p<0.0001).

CONCLUSION

This work proposes a simple and sensitive approach for sIL-15 detection to provide insights for personalized immunotherapy of NPC patients.

Liver metastasis from colorectal cancer: pathogenetic development, immune landscape of the tumour microenvironment and therapeutic approaches

Colorectal cancer liver metastasis (CRLM) is one of the leading causes of death among patients with colorectal cancer (CRC). Although immunotherapy has demonstrated encouraging outcomes in CRC, its benefits are minimal in CRLM. The complex immune landscape of the hepatic tumour microenvironment is essential for the development of a premetastatic niche and for the colonisation and metastasis of CRC cells; thus, an in-depth understanding of these mechanisms can provide effective immunotherapeutic targets for CRLM. This review summarises recent studies on the immune landscape of the tumour microenvironment of CRLM and highlights therapeutic prospects for targeting the suppressive immune microenvironment of CRLM.

Hydrodynamic Delivery: Characteristics, Applications, and Technological Advances

The principle of hydrodynamic delivery was initially used to develop a method for the delivery of plasmids into mouse hepatocytes through tail vein injection and has been expanded for use in the delivery of various biologically active materials to cells in various organs in a variety of animal species through systemic or local injection, resulting in significant advances in new applications and technological development. The development of regional hydrodynamic delivery directly supports successful gene delivery in large animals, including humans. This review summarizes the fundamentals of hydrodynamic delivery and the progress that has been made in its application. Recent progress in this field offers tantalizing prospects for the development of a new generation of technologies for broader application of hydrodynamic delivery.

Analysis of Immune and Inflammatory Microenvironment Characteristics of Noncancer End-Stage Liver Disease

Chronic liver injury eventually progresses to cirrhosis and end-stage liver disease (ESLD), which are the leading causes of death in patients with liver disease worldwide. ESLD has a variety of etiologies and a complex pathogenesis. This study analyzed the characteristics of ESLD by studying the immune microenvironment and inflammatory microenvironment of ESLD caused by 4 noncancer diseases, including HBV-ALF, ALF, AILD, and AH. We collected transcriptome data from noncancer ESLD patients, collected liver tissue samples and blood samples from ESLD liver transplant patients, and analyzed the immune and inflammatory microenvironments in the liver and blood. The results showed that with the exception of HBV-induced ESLD, there were no significant differences in immune microenvironment scores among patients with ESLD caused by other noncancer diseases. Moreover, there were no significant differences in the inflammatory microenvironment in the liver and blood of patients with ESLD caused by the 4 noncancer diseases. Furthermore, we found that the cytokine, IL-15, could predict the prognosis of ESLD patients.

Type I and II interferon signaling in colorectal cancer liver metastasis

Metastatic colorectal cancer is one of the leading causes of cancer-related deaths worldwide. Traditional chemotherapy extended the lifespan of cancer patients by only a few months, but targeted therapies and immunotherapy prolonged survival and led to long-term remissions in some cases. Type I and II interferons have direct pro-apoptotic and anti-proliferative effects on cancer cells and stimulate anti-cancer immunity. As a result, interferon production by cells in the tumor microenvironment is in the spotlight of immunotherapies as it affects the responses of anti-cancer immune cells. However, promoting effects of interferons on colorectal cancer metastasis have also been reported. Here we summarize our knowledge about pro- and anti-metastatic effects of type I and II interferons in colorectal cancer liver metastasis and discuss possible therapeutic implications.

Change of tumor-infiltrating lymphocyte of associating liver partition and portal vein ligation for staged hepatectomy for hepatocellular carcinoma

BACKGROUND

The role of tumor-infiltrating lymphocytes (TILs) in the growth and progression of hepatocellular carcinoma (HCC) has attracted widespread attention.

AIM

To evaluate the feasibility of associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) for massive HCC by exploring the role of TIL in the tumor microenvironment.

METHODS

Fifteen massive HCC patients who underwent ALPPS treatment and 46 who underwent hemi-hepatectomy were selected for this study. Propensity score matching was utilized to match patients in ALPPS and hemi-hepatectomy groups (1:1). Quantitative analysis of TILs in tumor and adjacent tissues between the two groups was performed by immunofluorescence staining and further analyses with oncological characteristics. In the meantime, trends of TILs in peripheral blood were compared between the two groups during the perioperative period.

RESULTS

Continuous measurement of tumor volume and necrosis volume showed that the proportion of tumor necrosis volume on the seventh day after stage-I ALPPS was significantly higher than the pre-operative value (P = 0.024). In the preoperative period of stage-I ALPPS, the proportion of tumor necrosis volume in the high CD8⁺ T cell infiltration group was significantly higher than that in the low group (P = 0.048).

CONCLUSION

TIL infiltration level maintained a dynamic balance during the preoperative period of ALPPS. Compared with right hemi-hepatectomy, the ALPPS procedure does not cause severe immunosuppression with the decrease in TIL infiltration and pathological changes in immune components of peripheral blood. Our results suggested that ALPPS is safe and feasible for treating massive HCC from the perspective of immunology. In addition, high CD8⁺ T cell infiltration is associated with increasing tumor necrosis in the perioperative period of ALPPS.

iNKT: A new avenue for CAR-based cancer immunotherapy

Chimeric antigen receptor (CAR) T cell is a T lymphocyte-based immunotherapy, which achieves great successes in treating blood malignancies and provides new hope to cue advanced cancer patients. Invariant natural killer T (iNKT) cells are a kind of special T lymphocytes characterized by expressing invariant TCR of Vα24Vβ11 to recognize CD1d-presented glycolipid antigens, which bridge innate and adaptive immune responses. iNKT cells themselves show strong anti-tumor effect in tumor models via CD1d-mediated killing of CD1d-positive tumor cells and immunosuppressive TAMs and MDSCs, and are closely related to the prognosis of cancer patients. iNKT cells are not restricted to polymorphic human leukocyte antigen (HLA) and can prevent Graft versus Host Disease (GvHD), which makes it to be an ideal CAR vector for allogeneic therapy. Although CAR-iNKT was developed and verified by several different teams and attracts more and more attentions, many obstacles are still needed to be resolved before obtaining CAR-iNKT therapeutics. In this review, we summarized the current status of clinical application of iNKT cells and the latest achievements of CAR-iNKT cells, which provides new insight in CAR-iNKT development and usages.

Targeting Immune Cells in the Tumor Microenvironment of HCC: New Opportunities and Challenges

Immune associated cells in the microenvironment have a significant impact on the development and progression of hepatocellular carcinoma (HCC) and have received more and more attention. Different types of immune-associated cells play different roles, including promoting/inhibiting HCC and several different types that are controversial. It is well known that immune escape of HCC has become a difficult problem in tumor therapy. Therefore, in recent years, a large number of studies have focused on the immune microenvironment of HCC, explored many mechanisms worth identifying tumor immunosuppression, and developed a variety of immunotherapy methods as targets, laying the foundation for the final victory in the fight against HCC. This paper reviews recent studies on the immune microenvironment of HCC that are more reliable and important, and provides a more comprehensive view of the investigation of the immune microenvironment of HCC and the development of more immunotherapeutic approaches based on the relevant summaries of different immune cells.

Development and Validation of a Gene Mutation-Associated Nomogram for Hepatocellular Carcinoma Patients From Four Countries

Background: Genomic alteration is the basis of occurrence and development of carcinoma. Specific gene mutation may be associated with the prognosis of hepatocellular carcinoma (HCC) patients without distant or lymphatic metastases. Hence, we developed a nomogram based on prognostic gene mutations that could predict the overall survival of HCC patients at early stage and provide reference for immunotherapy.

Methods: HCC cohorts were obtained from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases. The total patient was randomly assigned to training and validation sets. Univariate and multivariate cox analysis were used to select significant variables for construction of nomogram. The support vector machine (SVM) and principal component analysis (PCA) were used to assess the distinguished effect of significant genes. Besides, the nomogram model was evaluated by concordance index, time-dependent receiver operating characteristics (ROC) curve, calibration curve and decision curve analysis (DCA). Gene Set Enrichment Analysis (GSEA), CIBERSORT, Tumor Immune Dysfunction and Exclusion (TIDE) and Immunophenoscore (IPS) were utilized to explore the potential mechanism of immune-related process and immunotherapy.

Results: A total of 695 HCC patients were selected in the process including 495 training patients and 200 validation patients. Nomogram was constructed based on T stage, age, country, mutation status of DOCK2, EYS, MACF1 and TP53. The assessment showed the nomogram has good discrimination and high consistence between predicted and actual data. Furthermore, we found T cell exclusion was the potential mechanism of malignant progression in high-risk group. Meanwhile, low-risk group might be sensitive to immunotherapy and benefit from CTLA-4 blocker treatment.

Conclusion: Our research established a nomogram based on mutant genes and clinical parameters, and revealed the underlying association between these risk factors and immune-related process.

Anti-PD-1/PD-L1 Based Combination Immunotherapy to Boost Antigen-Specific CD8+ T Cell Response in Hepatocellular Carcinoma

Simple Summary

The cytotoxic T cell response against hepatocellular carcinoma antigens is exhausted and fails in its task of deleting tumoral cells. These cells are featured by the expression of negative immune checkpoints that can be modulated to restore T cell function. The blockade of the PD-1/PD-L1 pathway has shown promising results in rescuing hepatocellular carcinoma-specific CD8 T cells but only a reduced group of cases is sensitive to this treatment and the effect is usually temporary. Therefore, new anti-PD-1 based combinatory strategies are underway to increase the response by adding the effect of blocking neo-angiogenesis and other negative immune checkpoints, boosting positive immune checkpoints, blocking suppressive cytokines, or inducing the expression of tumoral neoantigens. The restoration of T cell responses with these anti-PD-1 based combinatory therapies will change the outcome of advanced hepatocellular carcinoma.

Abstract

Thirty to fifty percent of hepatocellular carcinomas (HCC) display an immune class genetic signature. In this type of tumor, HCC-specific CD8 T cells carry out a key role in HCC control. Those potential reactive HCC-specific CD8 T cells recognize either HCC immunogenic neoantigens or aberrantly expressed host’s antigens, but they become progressively exhausted or deleted. These cells express the negative immunoregulatory checkpoint programmed cell death protein 1 (PD-1) which impairs T cell receptor signaling by blocking the CD28 positive co-stimulatory signal. The pool of CD8 cells sensitive to anti-PD-1/PD-L1 treatment is the PD-1dim memory-like precursor pool that gives rise to the effector subset involved in HCC control. Due to the epigenetic imprints that are transmitted to the next generation, the effect of PD-1 blockade is transient, and repeated treatments lead to tumor resistance. During long-lasting disease, besides the TCR signaling impairment, T cells develop other failures that should be also set-up to increase T cell reactivity. Therefore, several PD-1 blockade-based combinatory therapies are currently under investigation such as adding antiangiogenics, anti-TGFβ1, blockade of other negative immune checkpoints, or increasing HCC antigen presentation. The effect of these combinations on CD8⁺ T cells is discussed in this review.

Non-viral vector mediated CKb11 with folic acid modification regulates macrophage polarization and DC maturation to elicit immune response against cancer

The immunosuppressive tumor microenvironment (TME) of cancer strongly hinders the anti-tumor immune responses, thereby resulting in disappointing responses to immunotherapy. Chemoattractive and promotive traits of chemokines exerted on leukocytes have garnered interest in improving the efficiency of immunotherapy by increasing the infiltration of immune cells in the TME. In this study, a folic acid (FA) -modified gene delivery system based on the self-assembly of DOTAP, MPEG-PCL-MPEG, and FA-PEG-PCL-PEG-FA, namely F-PPPD, was developed to deliver plasmids encoding the immunostimulating chemokine CKb11. The delivery of plasmid CKb11 (pCKb11) by F-PPPD nanoparticles resulted in the high secretion of CKb11 from tumor cells, which successfully activated T cells, suppressed the M2 polarization of macrophages, promoted the maturation of dendritic cells (DCs), facilitated the infiltration of natural killer (NK) cells and inhibited the infiltration of immunosuppressive cells in tumor tissues. Administration of F-PPPD/pCKb11 also significantly suppressed the cancer progression. Our study demonstrated a nanotechnology-enabled delivery of pCKb11, that remodeled the immunosuppressive TME, for cancer treatment.

•

Immunosuppressive tumor microenvironment hinders the intratumoral immune responses.

•

Immunogene therapy is one of new therapies, which brings dawn to the cancer patients.

•

Non-viral vectors have shown great potential in immunogene therapy.

•

FA modified non-viral vector carrying CKb11 activates the immunity against cancer.

"Complimenting the Complement": Mechanistic Insights and Opportunities for Therapeutics in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and a leading cause of death in the US and worldwide. HCC remains a global health problem and is highly aggressive with unfavorable prognosis. Even with surgical interventions and newer medical treatment regimens, patients with HCC have poor survival rates. These limited therapeutic strategies and mechanistic understandings of HCC immunopathogenesis urgently warrant non-palliative treatment measures. Irrespective of the multitude etiologies, the liver microenvironment in HCC is intricately associated with chronic necroinflammation, progressive fibrosis, and cirrhosis as precedent events along with dysregulated innate and adaptive immune responses. Central to these immunological networks is the complement cascade (CC), a fundamental defense system inherent to the liver which tightly regulates humoral and cellular responses to noxious stimuli. Importantly, the liver is the primary source for biosynthesis of >80% of complement components and expresses a variety of complement receptors. Recent studies implicate the complement system in liver inflammation, abnormal regenerative responses, fibrosis, carcinogenesis, and development of HCC. Although complement activation differentially promotes immunosuppressive, stimulant, and angiogenic microenvironments conducive to HCC development, it remains under-investigated. Here, we review derangement of specific complement proteins in HCC in the context of altered complement regulatory factors, immune-activating components, and their implications in disease pathogenesis. We also summarize how complement molecules regulate cancer stem cells (CSCs), interact with complement-coagulation cascades, and provide therapeutic opportunities for targeted intervention in HCC.

IL-7 During Antigenic Stimulation Using Allogeneic Dendritic Cells Promotes Expansion of CD45RA-CD62L+CD4+ Invariant NKT Cells With Th-2 Biased Cytokine Production Profile

Invariant natural killer T (iNKT) cells are innate-like T lymphocytes cells that recognize glycolipid antigens associated with CD1d, non-classical antigen presenting proteins. They can drive either pro-inflammatory (Th-1) or anti-inflammatory (Th-2) immune microenvironment through the production of both Th-1 and Th-2 type cytokines upon activation, thus play a vital role in cancer, infection, and autoimmune diseases. Adoptive cell therapy using ex vivo expanded iNKT cells is a promising approach to enhance anti-tumor immunity or immunosuppression. However, overcoming phenotypic and functional heterogeneity and promoting in vivo persistency of iNKT cells remains to be a challenge. Here, we compared various methods for ex vivo expansion of human iNKT cells and assessed the quality of expansion, phenotype, and cytokine production profile of expanded iNKT cells. While a direct stimulation of iNKT cells in peripheral blood mononuclear cells with agonist glycolipid led to the expansion of iNKT cells in varying degrees, stimulation of enriched iNKT cells by irradiated autologous peripheral blood mononuclear cells or allogeneic dendritic cells resulted in consistent expansion of highly pure iNKT cells. Interestingly, the mode of antigenic stimulation influenced the dominant subtype of expanded iNKT cells. Further, we evaluated whether additional IL-7 or IL-15 during antigenic stimulation with allogeneic dendritic cells can improve the phenotypic heterogeneity and modify cytokine production profile of iNKT cells expanded from 18 consecutive donors. The presence of IL-7 or IL-15 during antigenic stimulation did not affect the fold of expansion or purity of expanded iNKT cells. However, IL-7, but not IL-15, led to a better expansion of CD4⁺ iNKT cells, enhanced Th-2 type cytokine production of CD4⁺ iNKT cells, and maintained the expansion of central memory (CD45RA^-CD62L⁺) CD4⁺ iNKT cells. Our results suggest the addition of IL-7 during antigenic stimulation with allogeneic dendritic cells can promote the expansion of CD62L⁺Th-2⁺CD4⁺ human iNKT cells that can be used as novel immunotherapeutic to control excessive inflammation to treat various autoimmune diseases.

Atypical immunometabolism and metabolic reprogramming in liver cancer: Deciphering the role of gut microbiome

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related mortality worldwide. Much recent research has delved into understanding the underlying molecular mechanisms of HCC pathogenesis, which has revealed to be heterogenous and complex. Two major hallmarks of HCC include: (i) a hijacked immunometabolism and (ii) a reprogramming in metabolic processes. We posit that the gut microbiota is a third component in an entanglement triangle contributing to HCC progression. Besides metagenomic studies highlighting the diagnostic potential in the gut microbiota profile, recent research is pinpointing the gut microbiota as an instigator, not just a mere bystander, in HCC. In this chapter, we discuss mechanistic insights on atypical immunometabolism and metabolic reprogramming in HCC, including the examination of tumor-associated macrophages and neutrophils, tumor-infiltrating lymphocytes (e.g., T-cell exhaustion, regulatory T-cells, natural killer T-cells), the Warburg effect, rewiring of the tricarboxylic acid cycle, and glutamine addiction. We further discuss the potential involvement of the gut microbiota in these characteristics of hepatocarcinogenesis. An immediate highlight is that microbiota metabolites (e.g., short chain fatty acids, secondary bile acids) can impair anti-tumor responses, which aggravates HCC. Lastly, we describe the rising 'new era' of immunotherapies (e.g., immune checkpoint inhibitors, adoptive T-cell transfer) and discuss for the potential incorporation of gut microbiota targeted therapeutics (e.g., probiotics, fecal microbiota transplantation) to alleviate HCC. Altogether, this chapter invigorates for continuous research to decipher the role of gut microbiome in HCC from its influence on immunometabolism and metabolic reprogramming.

Regulation of aging and cancer by enhanced environmental activation of a hypothalamic-sympathoneural-adipocyte axis

Social and environmental factors impact cancer and energy balance profoundly. Years ago, our lab established the existence of a novel brain-fat interaction we termed the "hypothalamic-sympathoneural-adipocyte (HSA) axis", through which complex environmental stimuli provided by an enriched environment regulate body composition, energy balance, and development of cancer. We have spent a significant portion of the past decade to further characterize the broad health benefits of an enriched environment (for example, leanness, enhanced immune function, and cancer resistance), and to identify mediators in the brain and periphery along the HSA axis. This review summarizes our recent work regarding the interface between endocrinology, immunology, cancer biology, aging, and neuroscience. We will discuss the interplay between these systemic phenomena and how the HSA axis can be targeted for regulation of cancer and aging.

Antioxidant Capacity-Related Preventive Effects of Shoumei (Slightly Fermented Camellia sinensis) Polyphenols against Hepatic Injury

Shoumei is a kind of white tea (slightly fermented Camellia sinensis) that is rich in polyphenols. In this study, polyphenols were extracted from Shoumei. High-performance liquid chromatography (HPLC) showed that the polyphenols included mainly gallic acid, catechin, hyperoside, and sulfuretin. In an in vitro experiment, H₂O₂ was used to induce oxidative damage in human normal hepatic L-02 cells. In an animal experiment, CCl₄ was used to induce liver injury. The in vitro results showed that Shoumei polyphenols inhibited oxidative damage in normal hepatic L-02 cells, and the in vivo results showed that the polyphenols effectively reduced liver index values in mice with liver injury. The polyphenols also decreased aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), triglyceride (TG), total cholesterol (TC), blood urea nitrogen (BUN), nitric oxide (NO), malondialdehyde (MDA), interleukin 6 (IL-6), interleukin 12 (IL-12), tumour necrosis factor alpha (TNF-α), and interferon gamma (IFN-γ) levels and increased albumin (ALB), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) levels in the serum of mice with liver injury. Furthermore, pathological observation showed that the Shoumei polyphenols reduced CCl₄-induced hepatocyte damage. qRT-PCR and Western blotting showed that the polyphenols upregulated the mRNA and protein expression of neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), manganese- (Mn-) SOD, copper/zinc- (Cu/Zn-) SOD, CAT, and inhibitor of nuclear factor kappa B (NF-κB) alpha (IκB-α) and downregulated the expression of inducible nitric oxide synthase (iNOS) and NF-κB p65. The Shoumei polyphenols had a preventive effect against CCl₄-induced mouse liver injury equivalent to that of silymarin. The four polyphenols identified as the key substances responsible for this effect mediated the effect through their antioxidant capacity. These results suggest that Shoumei polyphenols are high-quality natural products with liver-protective effects.

Preventive effect of lemon seed flavonoids on carbon tetrachloride-induced liver injury in mice

The aim of this study was to determine the preventive effect of lemon seed flavonoids (LSF) on carbon tetrachloride-induced liver injury in mice. Liver injury was induced by injection with 2 mL kg-1 of carbon tetrachloride after administration of LSF by gavage. Liver index, serological parameters, and expression intensities of related mRNA and protein in the liver tissue were observed. The results indicated that LSF reduced liver weight and liver index, downregulated serum levels of AST, ALT, ALP, TG, TC, BUN, NO, and MDA, and upregulated levels of ALB, SOD, CAT, and GSH-Px in the mice with liver injury. It also downregulated serum cytokines, such as IL-6, IL-12, TNF-α, and IFN-γ in these mice. qPCR and western blot confirmed that LSF upregulated mRNA and protein expression of Mn-SOD, Cu/Zn-SOD, CAT, GSH-Px, and IκB-α, and downregulated expression of NF-κB-p65, iNOS, COX-2, TNF-α, IL-1β, and IL-6 in the liver tissue of mice with liver injury. The preventive effect on carbon tetrachloride-induced liver injury was attributed to (-)-epigallocatechin, caffeic acid, (-)-epicatechin, vitexin, quercetin, and hesperidin, which were active substances that were detected in LSF by HPLC. Moreover, the effect of LSF is similar to that of silymarin, but the synergistic effect of the five active substances working in concert acted to produce a more robust liver-protecting effect.

Systematic review of the roles of interleukins in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a primary liver cancer with high morbidity and mortality that is often accompanied by immune system disorders and local lymphocyte infiltration. Tumor-infiltrating lymphocytes, cancer cells, stromal cells, and the numerous cytokines they produce, such as chemokines, interferons, tumor necrosis factors, and interleukins, collectively constitute the tumor microenvironment. As a main type of immune effector, interleukin plays opposing roles in regulating tumor cell progression, adhesion, and migration according to its different subtypes. Many reports have concentrated on the roles that interleukins play in HCC, but understanding them systematically remains challenging. This study reviewed the current data to comprehensively summarize the relationships between HCC progression and human interleukin gene families.

S-15 in combination of Akt inhibitor promotes the expansion of CD45RA-CCR7+ tumor infiltrating lymphocytes with high cytotoxic potential and downregulating PD-1+Tim-3+ cells as well as regulatory T cells

Background

Autologous tumor-infiltrating lymphocytes (Tils) immunotherapy is a promising treatment in patients with advanced hepatocellular cancer. Although Tils treatment has shown great promise, their persistence and the efficacy after adoptive-transfer are insufficient and remain a challenge. Studies have demonstrated that IL-15 and Akt inhibitor can regulate T cell differentiation and memory. Here, we constructed S-15 (Super human IL-15), a fusion protein consisting of human IL-15, the sushi domain of the IL-15 receptor α chain and human IgG-Fc. Herein we compared the effects of S-15 with IL-2 or in combination with Akti on the expansion and activation of Tils.

Methods

Hepatocellular cancer tissues were obtained from 6 patients, Tils were expanded using IL-2, IL-2/S-15, IL-2/Akti or in combination IL-2/S-15/Akti. At day 10, anti-CD3 antibody was added to the culture media and expanded to day 25. The composition, exhaustion and T-cell differentiation markers (CD45RA/CCR7) were analyzed by flow cytometry.

Results

We found that IL-2/S-15/Akti expanded Tils and showed the highest percentage of central memory CD45RA^-CCR7⁺ phenotype prior to anti-CD3 antibody activation and after anti-CD3 antibody activation. T cells cultured with IL-2/S-15/Akti exhibited a mixture of CD4⁺, CD8⁺, and CD3⁺CD4^-CD8^- T cells; S-15 in combination with Akt inhibitor downregulated the expression of PD-1⁺Tim-3⁺ on Tils and decreased the Tregs in Tils. Additionally, the Tils expanded in the presence of the Akt inhibitor and S-15 showed enhanced antitumor activity as indicated by the increase in IFN-γ producing tumor infiltrating CD8⁺ T cells and without comprising the Tils expansion.

Conclusion

Our study elucidates that IL-2/S-15/Akti expanded Tils and represent a viable source for the cellular therapy for patients with hepatocellular cancer.

Isolation and Identification of Lactobacillus plantarum HFY05 from Natural Fermented Yak Yogurt and Its Effect on Alcoholic Liver Injury in Mice

Yak yogurt is a type of naturally fermented dairy product prepared by herdsmen in the Qinghai-Tibet Plateau, which is rich in microorganisms. In this study, a strain of Lactobacillus plantarum was isolated and identified from yak yogurt in Hongyuan, Sichuan Province and named Lactobacillus plantarum HFY05 (LP-HFY05). LP-HFY05 was compared with a common commercial strain of Lactobacillus delbrueckii subsp. bulgaricus (LDSB). LP-HFY05 showed better anti-artificial gastric acid and bile salt effects than LDSB in in vitro experiments, indicating its potential as a probiotic. In animal experiments, long-term alcohol gavage induced alcoholic liver injury. LP-HFY05 effectively reduced the liver index of mice with liver injury, downregulated the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, triglyceride, total cholesterol, blood urea nitrogen, nitric oxide, and MDA and upregulated the levels of albumin, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase in the serum of liver-injured mice. LP-HFY05 also reduced the levels of interleukin (IL)-6, IL-12, tumor necrosis factor-alpha, and interferon-gamma in the serum of liver-injured mice. The pathological observations showed that LP-HFY05 reduced the damage to liver cells caused by alcohol. Quantitative polymerase chain reaction and Western blot assays further showed that LP-HFY05 upregulated neuronal nitric oxide synthase, endothelial nitric oxide synthase, manganese-SOD, cuprozinc-SOD, CAT, and inhibitor of κB-α mRNA and protein expression and downregulated the expression of nuclear factor-κB-p65 and inducible nitric oxide synthase in the livers of liver-injured mice. A fecal analysis revealed that LP-HFY05 regulated the microbial content in the intestinal tract of mice with liver injury, increased the content of beneficial bacteria, including Bacteroides, Bifidobacterium, and Lactobacillus and reduced the content of harmful bacteria, including Firmicutes, Actinobacteria, Proteobacteria, and Enterobacteriaceae, thus, regulating intestinal microorganisms to protect against liver injury. The effect of LP-HFY05 on liver-injured mice was better than that of LDSB, and the effect was similar to that of silymarin. LP-HFY05 is a high-quality microbial strain with a liver protective effect on experimental mice with alcoholic liver injury.

White Peony (Fermented Camellia sinensis) Polyphenols Help Prevent Alcoholic Liver Injury via Antioxidation

White peony is a type of white tea (Camellia sinensis) rich in polyphenols. In this study, polyphenols were extracted from white peony. In vitro experiments showed that white peony polyphenols (WPPs) possess strong free radical scavenging capabilities toward 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Long-term alcohol gavage was used to induce alcoholic liver injury in mice, and relevant indices of liver injury were examined. WPPs effectively reduced the liver indices of mice with liver injury. The serum levels of aspartate aminotransferase (ATS), alanine aminotransferase (ALT), alkaline phosphatase (ALP), triglycerides (TG), total cholesterol (TC), blood urea nitrogen (BUN), nitric oxide (NO), and malondialdehyde (MDA) were downregulated, while those of albumin (ALB), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) were upregulated. WPPs also reduced the serum levels of interluekin-6 (IL-6), interluekin-12 (IL-12), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ) in mice with liver injury. Pathology results showed that WPPs reduced alcohol-induced liver cell damage. Quantitative polymerase chain reaction (qPCR) and western blot results revealed that WPPs upregulated the mRNA and protein expressions of neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), manganese superoxide dismutase (Mn-SOD), cupro–zinc superoxide dismutase (Cu/Zn-SOD), and CAT and downregulated iNOS expression in the liver of mice with liver injury. WPPs protected against alcoholic liver injury, and this effect was equivalent to that of silymarin. High-performance liquid chromatography revealed that WPPs mainly contained the polyphenols gallic acid, catechinic acid, and hyperoside, which are critical for exerting preventive effects against alcoholic liver injury. Thus, WPPs are high-quality natural products with liver protective effects.

Lenvatinib promotes antitumor immunity by enhancing the tumor infiltration and activation of NK cells

Based on previous reports, the efficacy of lenvatinib against cancer is mainly attributed to its antiangiogenic activity and its ability to suppress tumor proliferation, which are mediated by targeting receptor tyrosine kinases (RTKs). However, the effects of lenvatinib on tumor immune modulation have rarely been explored. Here, we show that lenvatinib effectively inhibited murine melanoma and renal cancer, and this inhibition was associated with enhanced tumor infiltration by natural killer (NK) cells. Critically, lenvatinib-induced tumor growth inhibition was attenuated by antibody-mediated NK cell depletion or the blockade of NK cell chemotaxis with an anti-CXCR3 blocking antibody. In addition, the expression of natural cytotoxicity receptors (NCRs) by tumor-infiltrating NK cells and the expression of cytotoxic cytokines in the tumor tissue were also augmented by lenvatinib. These data thus suggest that lenvatinib may be used not only as a direct cytotoxic drug against tumor angiogenesis and proliferation but also as a potent adjunct for enhancing the efficacy of immune-based cancer therapies by enhancing the tumor infiltration and activation of NK cells.

SUMO-Specific Protease 1 Is Critical for Myeloid-Derived Suppressor Cell Development and Function

Myeloid-derived suppressor cells (MDSC) can suppress immunity and promote tumorigenesis, and their abundance is associated with poor prognosis. In this study, we show that SUMO1/sentrin-specific peptidase 1 (SENP1) regulates the development and function of MDSC. SENP1 deficiency in myeloid cells promoted MDSC expansion in bone marrow, spleen, and other organs. Senp1^-/- MDSC showed stronger immunosuppressive activity than Senp1^+/+ MDSC; we observed no defects in the differentiation of myeloid precursor cell in Senp1^-/- mice. Mechanistically, SENP1-mediated regulation of MDSC was dependent on STAT3 signaling. We identified CD45 as a specific STAT3 phosphatase in MDSC. CD45 was SUMOylated in MDSC and SENP1 could deconjugate SUMOylated CD45. In Senp1^-/- MDSC, CD45 was highly SUMOylated, which reduced its phosphatase activity toward STAT3, leading to STAT3-mediated MDSC development and function. These results reveal a suppressive function of SENP1 in modulating MDSC expansion and function via CD45-STAT3 signaling axis. SIGNIFICANCE: These findings show that increased SUMOylation of CD45 via loss of SENP1 suppresses CD45-mediated dephosphorylation of STAT3, which promotes MDSC development and function, leading to tumorigenesis.

Adipocytes: A Novel Target for IL-15/IL-15Rα Cancer Gene Therapy

IL-15 is a proinflammatory cytokine that plays an essential role in the development and activation of natural killer (NK) cells. Adipose tissue acts as an endocrine organ that secretes cytokines and is an important reservoir for lymphocytes. We hypothesized that activation of the IL-15 signaling in adipose tissue will activate and expand the NK cell population and control tumor growth. We recently developed an adipocyte-targeting recombinant adeno-associated viral (rAAV) vector with minimal off-target transgene expression in the liver. Here, we used this rAAV system to deliver an IL-15/IL-15Rα complex to the abdominal fat by intraperitoneal (i.p.) injection. Adipose IL-15/IL-15Rα complex gene transfer led to the expansion of NK cells in the adipose tissue and spleen in normal mice without notable side effects. The i.p. injection of rAAV-IL-15/IL-15Rα complex significantly suppressed the growth of Lewis lung carcinoma implanted subcutaneously and exerted a significant survival advantage in a B16-F10 melanoma metastasis model. The antitumor effects were associated with the expansion of the NK cells in the blood, spleen, abdominal fat, and tumor, as well as the enhancement of NK cell maturity. Our proof-of-concept preclinical studies demonstrate the safety and efficacy of the adipocyte-specific IL-15/IL-15Rα complex vector as a novel cancer immune gene therapy.

Immunobiology of the IL-15/IL-15Rα complex as an antitumor and antiviral agent

Interleukin (IL)-15 is essential for natural killer (NK), NKT and memory (m) CD8⁺ T cell development and function, and is currently under investigation as an immunotherapeutic agent for the treatment of cancer. Recently, the creation of IL-15 superagonist by complexing IL-15 and its high affinity receptor alpha (IL-15 Rα) in solution, inspired by the natural trans-presentation of IL-15, advances the potential of IL-15-based tumor immunotherapy. IL-15 superagonist shows promising advantages over monomeric IL-15 such as sustaining high circulating concentrations due to prolonged half-life and more potently stimulating NK and CD8⁺ T effector lymphocytes. So far, there are three different forms of recombinant IL-15 superagonist fusion protein based on configurational modifications. Gene therapy using engineered cells co-expressing IL-15/IL-15 Rα complex for cancer treatment is also emerging. All forms have demonstrated efficacy in causing tumor regression in animal studies, which provides strong rationale for advancing IL-15 superagonist through clinical trials. To date, there are fourteen phase I/II IL-15 superagonist trials in cancer patients and one phase I trial in HIV patients. Information generated by ongoing trials regarding the toxicity and efficacy of IL-15 superagonist is awaited. Finally, we elaborate on immunotoxicity caused by IL-15 superagonist in preclinical studies and discuss important safety considerations.

MicroRNA-491 regulates the proliferation and apoptosis of CD8(+) T cells

T lymphocyte-mediated immune responses are critical for antitumour immunity; however, T cell function is impaired in the tumour environment. MicroRNAs are involved in regulation of the immune system. While little is known about the function of intrinsic microRNAs in CD8⁺ T cells in the tumour microenvironment. Here, we found that miR-491 was upregulated in CD8⁺ T cells from mice with colorectal cancer. Retroviral overexpression of miR-491 in CD8⁺ and CD4⁺ T cells inhibited cell proliferation and promoted cell apoptosis and decreased the production of interferon-γ in CD8⁺ T cells. We found that miR-491 directly targeted cyclin-dependent kinase 4, the transcription factor T cell factor 1 and the anti-apoptotic protein B-cell lymphoma 2-like 1 in CD8⁺ T cells. Furthermore, tumour-derived TGF-β induced miR-491 expression in CD8⁺ T cells. Taken together, our results suggest that miR-491 can act as a negative regulator of T lymphocytes, especially CD8⁺ T cells, in the tumour environment; thus, this study provides a novel insight on dysfunctional CD8⁺ T cells during tumourigenesis and cancer progression. In conclusion, miR-491 may be a new target for antitumour immunotherapy.

Stimulation of Natural Killer Cell-Mediated Tumor Immunity by an IL15/TGFβ-Neutralizing Fusion Protein

The clinical efficacy of immune cytokines used for cancer therapy is hampered by elements of the immunosuppressive tumor microenvironment such as TGFβ. Here we demonstrate that FIST15, a recombinant chimeric protein composed of the T-cell-stimulatory cytokine IL15, the sushi domain of IL15Rα and a TGFβ ligand trap, can overcome immunosuppressive TGFβ to effectively stimulate the proliferation and activation of natural killer (NK) and CD8⁺ T cells with potent antitumor properties. FIST15-treated NK and CD8⁺ T cells produced more IFNγ and TNFα compared with treatment with IL15 and a commercially available TGFβ receptor-Fc fusion protein (sTβRII) in the presence of TGFβ. Murine B16 melanoma cells, which overproduce TGFβ, were lysed by FIST15-treated NK cells in vitro at doses approximately 10-fold lower than NK cells treated with IL15 and sTβRII. Melanoma cells transduced to express FIST15 failed to establish tumors in vivo in immunocompetent murine hosts and could only form tumors in beige mice lacking NK cells. Mice injected with the same cells were also protected from subsequent challenge by unmodified B16 melanoma cells. Finally, mice with pre-established B16 melanoma tumors responded to FIST15 treatment more strongly compared with tumors treated with control cytokines. Taken together, our results offer a preclinical proof of concept for the use of FIST15 as a new class of biological therapeutics that can coordinately neutralize the effects of immunosuppressive TGFβ in the tumor microenvironment while empowering tumor immunity. Cancer Res; 76(19); 5683-95. ©2016 AACR.

IL-15/sIL-15Rα gene transfer suppresses Lewis lung cancer growth in the lungs, liver and kidneys

Nearly 40% of people with lung cancer have tumor growth in other organs at the time of diagnosis. Current treatment strategies for patients with late-stage lung cancer are primarily palliative and only showed modest efficacy. The current study takes advantage of the hydrodynamic gene delivery technique to evaluate the antitumor activity of interleukin (IL)-15/sIL-15Rα on lung tumors growing in the lungs, liver and kidneys. We demonstrate that hydrodynamic tail vein injection of 2 μg of AG209 DP muIL-15sRα+IL-15 plasmid resulted in serum IL-15/sIL-15Rα reaching a peak level of ~10 μg ml(-1) 1 day after the injection and gradually declined to ~5 ng ml(-1) within 3 days. Quantitative PCR analysis revealed that overexpression of IL-15/sIL-15Rα induced the activation of natural killer and T cells, evidenced by increased mRNA levels of marker genes including granzyme B, perforin, Ifn-γ, T-bet and Cd8 in the lungs, liver and kidneys. Importantly, transfer of the Il-15/sIl-15Rα gene alone, or in combination with gemcitabine chemotherapy, significantly inhibited the tumor growth in these three organs and prolonged median survival time of treated mice by 1.7- and 3.3-fold, respectively. The therapeutic benefits are principally blockade and elimination of tumor growth in the liver and kidneys. Taken together, these results suggest that IL-15/sIL-15Rα-based gene therapy could be an effective approach to treat late-stage lung cancer with metastases in other organs.

IL-15 Superagonist-Mediated Immunotoxicity: Role of NK Cells and IFN-γ

IL-15 is currently undergoing clinical trials to assess its efficacy for treatment of advanced cancers. The combination of IL-15 with soluble IL-15Rα generates a complex termed IL-15 superagonist (IL-15 SA) that possesses greater biological activity than IL-15 alone. IL-15 SA is considered an attractive antitumor and antiviral agent because of its ability to selectively expand NK and memory CD8(+) T (mCD8(+) T) lymphocytes. However, the adverse consequences of IL-15 SA treatment have not been defined. In this study, the effect of IL-15 SA on physiologic and immunologic functions of mice was evaluated. IL-15 SA caused dose- and time-dependent hypothermia, weight loss, liver injury, and mortality. NK (especially the proinflammatory NK subset), NKT, and mCD8(+) T cells were preferentially expanded in spleen and liver upon IL-15 SA treatment. IL-15 SA caused NK cell activation as indicated by increased CD69 expression and IFN-γ, perforin, and granzyme B production, whereas NKT and mCD8(+) T cells showed minimal, if any, activation. Cell depletion and adoptive transfer studies showed that the systemic toxicity of IL-15 SA was mediated by hyperproliferation of activated NK cells. Production of the proinflammatory cytokine IFN-γ, but not TNF-α or perforin, was essential to IL-15 SA-induced immunotoxicity. The toxicity and immunological alterations shown in this study are comparable to those reported in recent clinical trials of IL-15 in patients with refractory cancers and advance current knowledge by providing mechanistic insights into IL-15 SA-mediated immunotoxicity.

Immunotherapy of metastatic and autochthonous liver cancer with IL-15/IL-15Rα fusion protein

Liver cancer has a poor prognosis. Our recent study demonstrates that hyper-IL-15, composed of IL-15 and the sushi domain of IL-15 receptor α chain, provides an effective therapy against well-established metastatic and autochthonous liver cancers in mouse models by triggering activation and expansion of hepatic CD8⁺ T cells.

Current concepts of immune based treatments for patients with HCC: from basic science to novel treatment approaches

The recent approval of two immune checkpoint inhibitors for the treatment of malignant melanoma has sparked great interest by physicians and basic scientists searching for novel therapeutics for GI cancer. Chronic inflammation is recognised as a major risk factor for the development of hepatocellular carcinoma (HCC) and makes this type of cancer a potentially ideal target for an immune based treatment approach. Further evidence for a critical role of immune responses in patients with HCC is derived from the fact that immune signatures and profiles predict patients' outcome as well as the fact that tumour-induced spontaneous antitumour immunity can be detected. In addition ablative therapies can lead to changes in the number, phenotype and function of different immune cell subsets, which correlate with patients' survival. Various HCC-specific mouse models have been developed, which improve our understanding of hepatocarcinogenesis and tumour-immune cell interactions, and lead to the development of novel immune based treatment approaches, which are currently being evaluated in preclinical and in early clinical settings. Immune checkpoint blockade along with adoptive immune cell therapy and vaccine approaches are currently being evaluated either alone or in combination with other treatments. Here, we provide an overview for the rationale of immunotherapy in HCC, summarise ongoing studies and provide a perspective for immune based approaches in patients with HCC.