Natural killer cells phenotypic characterization as an outcome predictor of HCV-linked HCC after curative treatments

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.

Immune landscape of hepatocellular carcinoma: From dysregulation of the immune responses to the potential immunotherapies

Hepatocellular carcinoma (HCC) presents a considerable global health burden due to its late diagnosis and high morbidity. The liver's specific anatomical and physiological features expose it to various antigens, requiring precise immune regulation. To the best of our knowledge, this is the first time that a comprehensive overview of the interactions between the immune system and gut microbiota in the development of HCC, as well as the relevant therapeutic approaches are discussed. Dysregulation of immune compartments within the liver microenvironment drives HCC pathogenesis, characterized by elevated regulatory cells such as regulatory T cells (Tregs), myeloid-derived suppressor cells, and M2 macrophages as well as suppressive molecules, alongside reduced number of effector cells like T cells, natural killer cells, and M1 macrophages. Dysbiosis of gut microbiota also contributes to HCC by disrupting intestinal barrier integrity and triggering overactivated immune responses. Immunotherapy approaches, particularly immune checkpoint inhibitors, have exhibited promise in HCC management, yet adoptive cell therapy and cancer vaccination research are in the early steps with relatively less favorable outcomes. Further understanding of immune dysregulation, gut microbiota involvement, and therapeutic combination strategies are essential for advancing precision immunotherapy in HCC.

Role of immunotherapies and stem cell therapy in the management of liver cancer: A comprehensive review

Liver cancer (LC) is the sixth most common disease and the third most common cause of cancer-related mortality. The WHO predicts that more than 1 million deaths will occur from LC by 2030. Hepatocellular carcinoma (HCC) is a common form of primary LC. Today, the management of LC involves multiple disciplines, and multimodal therapy is typically selected on an individual basis, considering the intricate interactions between the patient's overall health, the stage of the tumor, and the degree of underlying liver disease. Currently, the treatment of cancers, including LC, has undergone a paradigm shift in the last ten years because of immuno-oncology. To treat HCC, immune therapy approaches have been developed to enhance or cause the body's natural immune response to specifically target tumor cells. In this context, immune checkpoint pathway inhibitors, engineered cytokines, adoptive cell therapy, immune cells modified with chimeric antigen receptors, and therapeutic cancer vaccines have advanced to clinical trials and offered new hope to cancer patients. The outcomes of these treatments are encouraging. Additionally, treatment using stem cells is a new approach for restoring deteriorated tissues because of their strong differentiation potential and capacity to release cytokines that encourage cell division and the formation of blood vessels. Although there is no proof that stem cell therapy works for many types of cancer, preclinical research on stem cells has shown promise in treating HCC. This review provides a recent update regarding the impact of immunotherapy and stem cells in HCC and promising outcomes.

Treatment Options for Hepatocellular Carcinoma Using Immunotherapy: Present and Future

Hepatocellular carcinoma (HCC) is a common cancer, and the body's immune responses greatly affect its progression and the prognosis of patients. Immunological suppression and the maintenance of self-tolerance in the tumor microenvironment are essential responses, and these form part of the theoretical foundations of immunotherapy. In this review, we first discuss the tumor microenvironment of HCC, describe immunosuppression in HCC, and review the major biomarkers used to track HCC progression and response to treatment. We then examine antibody-based therapies, with a focus on immune checkpoint inhibitors (ICIs), monoclonal antibodies that target key proteins in the immune response (programmed cell death protein 1, anti-cytotoxic T-lymphocyte associated protein 4, and programmed death-ligand 1) which have transformed the treatment of HCC and other cancers. ICIs may be used alone or in conjunction with various targeted therapies for patients with advanced HCC who are receiving first-line treatments or subsequent treatments. We also discuss the use of different cellular immunotherapies, including T cell receptor (TCR) T cell therapy and chimeric antigen receptor (CAR) T cell therapy. We then review the use of HCC vaccines, adjuvant immunotherapy, and oncolytic virotherapy, and describe the goals of future research in the development of treatments for HCC.

Key oncogenic signaling pathways affecting tumor-infiltrating lymphocytes infiltration in hepatocellular carcinoma: basic principles and recent advances

The incidence of hepatocellular carcinoma (HCC) ranks first among primary liver cancers, and its mortality rate exhibits a consistent annual increase. The treatment of HCC has witnessed a significant surge in recent years, with the emergence of targeted immune therapy as an adjunct to early surgical resection. Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TIL) has shown promising results in other types of solid tumors. This article aims to provide a comprehensive overview of the intricate interactions between different types of TILs and their impact on HCC, elucidate strategies for targeting neoantigens through TILs, and address the challenges encountered in TIL therapies along with potential solutions. Furthermore, this article specifically examines the impact of oncogenic signaling pathways activation within the HCC tumor microenvironment on the infiltration dynamics of TILs. Additionally, a concise overview is provided regarding TIL preparation techniques and an update on clinical trials investigating TIL-based immunotherapy in solid tumors.

High CD49a+ NK cell infiltrate is associated with poor clinical outcomes in Hepatocellular Carcinoma

NK cells infiltrating Hepatocellular Carcinoma (HCC) may express residency markers such as Integrin Subunit Alpha 1 (CD49a) that have been associated with nurturing functions in the decidua, and characterized by the production of angiogenic factors as well as loss of cytotoxicity. CIBERSORT, a computational analysis method for quantifying cell fractions from bulk tissue gene expression profiles, was used to estimate the infiltrating immune cell composition of the tumor microenvironment from gene expression profiles of a large cohort of 225 HCCs in the public GEO database. Decidual-like CD49a+ NK cells, in addition to another 22 immune cell populations, were characterized and thoroughly investigated so that HCC cell heterogeneity in a large cohort of 225 HCCs from the public GEO database could be studied. An inverse correlation of the expression of CD49a+ NK-cells and CD8+ T-cells suggested a negative association with clinical outcomes. This result was confirmed in a further validation cohort of 100 HCC patients from The Cancer Genome Atlas, Liver Hepatocellular Carcinoma (TCGA-LIHC). Cox regression analysis did not identify CD49a+ cells as a variable independently associated with survival. However, a more abundant infiltrate of this subset was present in patients at a more advanced pathological and clinical HCC stage. In conclusion, we found that NK cells, with a decidual-like gene expression profile, are enriched in HCC, and their abundance increases not only in tumor size but also at advanced stages of the disease suggesting that these cells play a role in tumor growth. For this reason, these NK cells may represent a possible new target for immunotherapeutic approaches in HCC.

Combined analysis of bulk and single-cell RNA sequencing reveals novel natural killer cell-related prognostic biomarkers for predicting immunotherapeutic response in hepatocellular carcinoma

Introduction

Natural killer (NK) cells play an irreplaceable and important role as a subtype of innate immune cells in the contemporary setting of antitumor immunity.

Methods

We chose a total of 1,196 samples for this analysis from the public dataset’s six separate cohorts. To identify 42 NK cell marker genes, we first carried out a thorough study of single-cell RNA sequencing data from the GSE149614 cohort of hepatocellular carcinoma (HCC).

Results

Using the NK cell marker genes in the TCGA cohort, we next created a seven-gene prognostic signature, separating the patients into two categories with distinct survival patterns. This signature’s prognostic prediction ability was well verified across several validation cohorts. Patients with high scores had higher TIDE scores but lower immune cell infiltration percentages. Importantly, low-scoring patients had superior immunotherapy response and prognosis than high-scoring patients in an independent immunotherapy cohort (IMvigor210). Finally, we used CD56 and TUBA1B antibodies for immunohistochemical labeling of HCC tissue sections, and we discovered a lower number of CD56+ cells in the HCC tissue sections with high TUBA1B expression.

Discussion

In summary, our research created a unique prognostic profile based on NK cell marker genes that may accurately predict how well immunotherapy would work for HCC patients.

Tumor microenvironment-mediated immune evasion in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is the third leading cause of tumor-related mortality worldwide. In recent years, the emergency of immune checkpoint inhibitor (ICI) has revolutionized the management of HCC. Especially, the combination of atezolizumab (anti-PD1) and bevacizumab (anti-VEGF) has been approved by the FDA as the first-line treatment for advanced HCC. Despite great breakthrough in systemic therapy, HCC continues to portend a poor prognosis owing to drug resistance and frequent recurrence. The tumor microenvironment (TME) of HCC is a complex and structured mixture characterized by abnormal angiogenesis, chronic inflammation, and dysregulated extracellular matrix (ECM) remodeling, collectively contributing to the immunosuppressive milieu that in turn prompts HCC proliferation, invasion, and metastasis. The tumor microenvironment coexists and interacts with various immune cells to maintain the development of HCC. It is widely accepted that a dysfunctional tumor-immune ecosystem can lead to the failure of immune surveillance. The immunosuppressive TME is an external cause for immune evasion in HCC consisting of 1) immunosuppressive cells; 2) co-inhibitory signals; 3) soluble cytokines and signaling cascades; 4) metabolically hostile tumor microenvironment; 5) the gut microbiota that affects the immune microenvironment. Importantly, the effectiveness of immunotherapy largely depends on the tumor immune microenvironment (TIME). Also, the gut microbiota and metabolism profoundly affect the immune microenvironment. Understanding how TME affects HCC development and progression will contribute to better preventing HCC-specific immune evasion and overcoming resistance to already developed therapies. In this review, we mainly introduce immune evasion of HCC underlying the role of immune microenvironment, describe the dynamic interaction of immune microenvironment with dysfunctional metabolism and the gut microbiome, and propose therapeutic strategies to manipulate the TME in favor of more effective immunotherapy.

Variations in dynamic tumor-associated antigen-specific T cell responses correlate with HCC recurrence after thermal ablation

Background

Ablative therapy is a recommended treatment for hepatocellular carcinoma (HCC) not only for its effective eradication of tumors, but also for its induction of host immunity. However, the high 5-year recurrence rate after ablation underlines the poor understanding of the antitumor immunity response. Here, we investigated the effects of thermal ablation on antitumor immunity.

Methods

We analyzed the dynamics of tumor-associated antigen (TAA)-specific immune responses and changes in peripheral blood mononuclear cell phenotype in patients with HCC before and after tumor ablation. We used the IFN-γ ELISPOT assay and immunophenotyping by flow cytometry to evaluate the effects of ablation on host immunity. The correlation between the T cell response and disease outcome was explored to uncover the efficacy of the immune response in inhibiting HCC recurrence.

Results

Different TAA-specific T cell responses were identified among patients before and after ablation. One week after ablation, there was an improved immune state, with a switch from the dominance of an AFP-specific T cell response to that of a SMNMS-specific T cell response, which was correlated with better survival. Furthermore, an improvement in immune status was accompanied by a lower level of PD1+ and Tim3+ T cells in CD8+ T cells. Although this functional state was not durable, there was a higher degree of AFP-specific T cell responses at 4-weeks post-ablation. Furthermore, T cells presented a more exhausted phenotype at 4-weeks post-ablation than at the 1-week timepoint.

Conclusions

Ablation elicits a transient antitumor immune response in patients with HCC by changing the profile of the T cell response and the expression of immune checkpoint molecules, which correlated with longer recurrence-free survival of patients with HCC.

Emerging immunotherapy for HCC: A guide for hepatologists

HCC is one of the most common cancers worldwide, and the third leading cause of cancer-related death globally. HCC comprises nearly 90% of all cases of primary liver cancer. Approximately half of all patients with HCC receive systemic therapy during their disease course, particularly in the advanced stages of disease. Immuno-oncology has been paradigm shifting for the treatment of human cancers, with strong and durable antitumor activity in a subset of patients across a variety of malignancies including HCC. Immune checkpoint inhibition with atezolizumab and bevacizumab, an antivascular endothelial growth factor neutralizing antibody, has become first-line therapy for patients with advanced HCC. Beyond immune checkpoint inhibition, immunotherapeutic strategies such as oncolytic viroimmunotherapy and adoptive T-cell transfer are currently under investigation. The tumor immune microenvironment of HCC has significant immunosuppressive elements that may affect response to immunotherapy. Major unmet challenges include defining the role of immunotherapy in earlier stages of HCC, evaluating combinatorial strategies that use targeting of the immune microenvironment plus immune checkpoint inhibition, and identifying treatment strategies for patients who do not respond to the currently available immunotherapies. Herein, we review the rationale, mechanistic basis and supporting preclinical evidence, and available clinical evidence for immunotherapies in HCC as well as ongoing clinical trials of immunotherapy.

Targeting Stress Sensor Kinases in Hepatocellular Carcinoma-Infiltrating Human NK Cells as a Novel Immunotherapeutic Strategy for Liver Cancer

Natural killer (NK) cells may become functionally exhausted entering hepatocellular carcinoma (HCC), and this has been associated with tumor progression and poor clinical outcome. Hypoxia, low nutrients, immunosuppressive cells, and soluble mediators characterize the intratumor microenvironment responsible for the metabolic deregulation of infiltrating immune cells such as NK cells. HCC-infiltrating NK cells from patients undergoing liver resection for HCC were sorted, and genome-wide transcriptome profiling was performed. We have identified a marked general upregulation of gene expression profile along with metabolic impairment of glycolysis, OXPHOS, and autophagy as well as functional defects of NK cells. Targeting p38 kinase, a stress-responsive mitogen-activated protein kinase, we could positively modify the metabolic profile of NK cells with functional restoration in terms of TNF-α production and cytotoxicity. We found a metabolic and functional derangement of HCC-infiltrating NK cells that is part of the immune defects associated with tumor progression and recurrence. NK cell exhaustion due to the hostile tumor microenvironment may be restored with p38 inhibitors with a selective mechanism that is specific for tumor-infiltrating-not affecting liver-infiltrating-NK cells. These results may represent the basis for the development of a new immunotherapeutic strategy to integrate and improve the available treatments for HCC.

The Dynamic Role of NK Cells in Liver Cancers: Role in HCC and HBV Associated HCC and Its Therapeutic Implications

Hepatocellular carcinoma (HCC) remains an important complication of chronic liver disease, especially when cirrhosis occurs. Existing treatment strategies include surgery, loco-regional techniques, and chemotherapy. Natural killer cells are distinctive cytotoxic lymphocytes that play a vital role in fighting tumors and infections. As an important constituent of the innate immune system against cancer, phenotypic and functional deviations of NK cells have been demonstrated in HCC patients who also exhibit perturbation of the NK-activating receptor/ligand axis. The rate of recurrence of tumor-infiltrating and circulating NK cells are positively associated with survival benefits in HCC and have prognostic significance, suggesting that NK cell dysfunction is closely related to HCC progression. NK cells are the first-line effector cells of viral hepatitis and play a significant role by directly clearing virus-infected cells or by activating antigen-specific T cells by producing IFN-γ. In addition, chimeric antigen receptor (CAR) engineered NK cells suggest an exclusive opportunity to produce CAR-NKs with several specificities with fewer side effects. In the present review, we comprehensively discuss the innate immune landscape of the liver, particularly NK cells, and the impact of tumor immune microenvironment (TIME) on the function of NK cells and the biological function of HCC. Furthermore, the role of NK cells in HCC and HBV-induced HCC has also been comprehensively elaborated. We also elaborate on available NK cell-based immunotherapeutic approaches in HCC treatment and summarize current advancements in the treatment of HCC. This review will facilitate researchers to understand the importance of the innate immune landscape of NK cells and lead to devising innovative immunotherapeutic strategies for the systematic treatment of HCC.

The Prognostic Value of Natural Killer Cells and Their Receptors/Ligands in Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

Background

Natural killer (NK) cells play major roles in eliminating tumor cells. Preliminary studies have shown that NK cells and their receptors/ligands have prognostic value in malignant tumors. However, the relevance of NK cells and their receptors/ligands level to the prognosis of hepatocellular carcinoma (HCC) remains unclear.

Methods

Several electronic databases were searched from database inception to November 8, 2021. Random effects were introduced to this meta-analysis. The relevance of NK cells and their receptors/ligands level to the prognosis of HCC was evaluated using hazard ratios (HRs) with 95% confidence interval (95%CI).

Results

26 studies were included in the analysis. The pooled results showed that high NK cells levels were associated with better overall survival (HR=0.70, 95%CI 0.57–0.86, P=0.001) and disease-free survival (HR=0.61, 95%CI 0.40-0.93, P=0.022) of HCC patients. In subgroup analysis for overall survival, CD57⁺ NK cells (HR=0.70, 95%CI 0.55-0.89, P=0.004) had better prognostic value over CD56⁺ NK cells (HR=0.69, 95%CI 0.38-1.25, P=0.224), and intratumor NK cells had better prognostic value (HR=0.71, 95%CI 0.55-0.90, P=0.005) over peripheral NK cells (HR=0.66, 95%CI 0.41-1.06, P=0.088). In addition, high level of NK cell inhibitory receptors predicted increased recurrence of HCC, while the prognostic role of NK cell activating receptors remained unclear.

Conclusion

NK cells and their inhibitory receptors have prognostic value for HCC. The prognostic role of NK cell activating receptors is unclear and more high-quality prospective studies are essential to evaluate the prognostic value of NK cells and their receptors/ligands for HCC.

Therapeutic Vaccines against Hepatocellular Carcinoma in the Immune Checkpoint Inhibitor Era: Time for Neoantigens?

Immune checkpoint inhibitors (ICI) have been used as immunotherapy for hepatocellular carcinoma (HCC) with promising but still limited results. Identification of immune elements in the tumor microenvironment of individual HCC patients may help to understand the correlations of responses, as well as to design personalized therapies for non-responder patients. Immune-enhancing strategies, such as vaccination, would complement ICI in those individuals with poorly infiltrated tumors. The prominent role of responses against mutated tumor antigens (neoAgs) in ICI-based therapies suggests that boosting responses against these epitopes may specifically target tumor cells. In this review we summarize clinical vaccination trials carried out in HCC, the available information on potentially immunogenic neoAgs in HCC patients, and the most recent results of neoAg-based vaccines in other tumors. Despite the low/intermediate mutational burden observed in HCC, data obtained from neoAg-based vaccines in other tumors indicate that vaccines directed against these tumor-specific antigens would complement ICI in a subset of HCC patients.

Highly differential count of circulating and tumor infiltrating immune cells in patients with non-HCV/non-HBV hepatocellular carcinoma

Background

Liver transplantation and liver resection are curative options for early hepatocellular carcinoma (HCC). The outcome is in part depended on the immunological response to the malignancy. In this study, we aimed to identify immunological profiles of non-HCV/non-HBV HCC patients.

Methods

Thirty-nine immune cell subsets were measured with multicolor flow cytometry. This immunophenotyping was performed in peripheral blood (PB) and tumor specimens of 10 HCC resection patients and 10 healthy donors. The signatures of the highly differential leukocyte count (hDIF) were analyzed using multidimensional techniques. Functional capability was measured using intracellular IFN-γ staining (Trial Registration DRKS00013567).

Results

The hDIF showed activation (subsets of T-, B-, NK- and dendritic cells) and suppression (subsets of myeloid-derived suppressor cells and T- and B-regulatory cells) of the antitumor response. Principal component analysis of PB and tumor infiltrating leukocytes (TIL) illustrated an antitumor activating gradient. TILs showed functional capability by secreting IFN-γ but did not kill HCC cells.

Conclusions

In conclusion, the measurement of the hDIF shows distinct differences in immune reactions against non-HBV/non-HCV HCC and illustrates an immunosuppressive gradient toward peripheral blood.

Trial Registration

DRKS00013567

Supplementary Information

The online version contains supplementary material available at 10.1007/s00262-021-03061-9.

The effect of the TP53 and RB1 mutations on the survival of hepatocellular carcinoma patients with different racial backgrounds

Background

Racial disparities in the survival of patients with hepatocellular carcinoma (HCC) exist. Gene mutations have a profound effect on carcinogenesis, are easily affected by environment and etiology factors, and may result in survival divergences among patients with different racial backgrounds. This report explores the effects of gene mutations on the survival of American Caucasians and Asian patients.

Methods

The sequencing and clinical data of 336 HCC patients were obtained from The Cancer Genome Atlas (TCGA) database. The sequencing data was subject to gene mutation profiling, and an analysis of immune cell infiltration was conducted. A multivariate analysis was performed to assess the independent effects of gene mutations on patients' overall survival (OS) and disease-free survival (DFS).

Results

Asian HCC patients had a significantly higher level of TP53 mutation frequency than Caucasian HCC patients (Asian vs. Caucasian, 39% vs. 23%; P=0.003). The TP53 mutation was associated with shorter OS [hazard ratio (HR), 2.33; 95% confidence interval (CI), 1.36-3.97; P=0.002] and DFS (HR, 2.2; 95% CI, 1.38-3.51; P<0.001) in Caucasian HCC patients, but had no effect on Asian HCC patients' survival. Compared to Asian HCC patients, Caucasian HCC patients with the TP53 mutation had a decreased proportion of infiltrating M2 macrophages and activating natural killer (NK) cells, and an increased proportion of follicular helper T cells. The RB1 mutation was associated with shorter OS (HR, 3.37; 95% CI, 1.73-6.57; P<0.001) in Asian HCC patients, and shorter DFS (HR, 2.11; 95% CI, 1.15-3.88; P=0.017) in Caucasian HCC patients. Asian HCC patients with the RB1 mutation had a decreased proportion of infiltrating CD8 T cells.

Conclusions

The effects of the TP53 and RB1 mutations on survival differ among Asian and Caucasian HCC patients.

Advances in immunotherapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent disease with a progression that is modulated by the immune system. Systemic therapy is used in the advanced stage and until 2017 consisted only of antiangiogenic tyrosine kinase inhibitors (TKIs). Immunotherapy with checkpoint inhibitors has shown strong anti-tumour activity in a subset of patients and the combination of the anti-PDL1 antibody atezolizumab and the VEGF-neutralizing antibody bevacizumab has or will soon become the standard of care as a first-line therapy for HCC, whereas the anti-PD1 agents nivolumab and pembrolizumab are used after TKIs in several regions. Other immune strategies such as adoptive T-cell transfer, vaccination or virotherapy have not yet demonstrated consistent clinical activity. Major unmet challenges in HCC checkpoint immunotherapy are the discovery and validation of predictive biomarkers, advancing treatment to earlier stages of the disease, applying the treatment to patients with liver dysfunction and the discovery of more effective combinatorial or sequential approaches. Combinations with other systemic or local treatments are perceived as the most promising opportunities in HCC and some are already under evaluation in large-scale clinical trials. This Review provides up-to-date information on the best use of currently available immunotherapies in HCC and the therapeutic strategies under development.

The Putative Role of Natural Killer Cells in Patients with Hepatitis C Virus-Related Hepatocellular Carcinoma

BACKGROUND

Natural Killer (NK) cells have crucial roles in immune responses against malignant transformation including hepatocellular carcinoma (HCC). The NKG2D receptor has a critical role in the NK recognition of target cells.

AIM

We assessed NKG2D receptor expression as a diagnostic biomarker for HCC detection and progression in Egyptian patients with hepatitis C virus (HCV)-related HCC.

METHODS

We classified 81 patients into three groups: chronic hepatitis (21), cirrhotic (30) and HCC (30) patients, with 36 individuals enrolled to the control group. We analyzed NK levels in peripheral blood and NKG2D receptor expression in NK cells using flow cytometry.

RESULTS

We observed a significant decrease in NKG2D (CD314) expression on circulating NK cells and frequency of NK cells expressing NKG2D (CD314) in HCC patients. Also, in patients, larger foci lesions significantly correlated with decreased NK cell numbers. Multiple foci numbers and patients with a Child score C significantly correlated with decreased circulating NK cells expressing NKG2D and decreased NKG2D expression.

CONCLUSION

The percentage of NK cells in peripheral blood and NKG2D receptor expression could function as potential biomarkers for HCC detection and progression.

Adaptive Subsets Limit the Anti-Tumoral NK-Cell Activity in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a global health burden with increasing incidence, poor prognosis and limited therapeutic options. Natural killer (NK) cells exhibit potent anti-tumoral activity and therefore represent potential targets for immunotherapeutic approaches in HCC treatment. However, the anti-tumoral activity of NK cells in HCC associated with different etiologies, and the impact of the heterogeneous NK cell subset, e.g., adaptive and conventional subsets, are not understood in detail. By comparatively analyzing the NK-cell repertoire in 60 HCC patients, 33 liver cirrhosis patients and 36 healthy donors (HD), we show in this study that the NK-cell repertoire is linked to HCC etiology, with increased frequencies of adaptive NK cells in Hepatitis B virus (HBV)-associated HCC. Adaptive NK cells exhibited limited anti-tumoral activity toward liver cancer cells; however, this was not a result of a specific NK-cell impairment in HCC but rather represented an intrinsic feature, since the characteristics of circulating and intra-tumoral adaptive NK cells were conserved between HD, HCC and liver cirrhosis patients. Hence, the expansion of adaptive NK cells with reduced anti-tumoral activity, detectable in HBV-associated HCC, may have implications for tumor surveillance and therapy.

Natural Killer Cells and Regulatory T Cells Cross Talk in Hepatocellular Carcinoma: Exploring Therapeutic Options for the Next Decade

Despite major advances in immunotherapy, hepatocellular carcinoma (HCC) remains a challenging target. Natural Killer (NK) cells are crucial components of the anti-HCC immune response, which can be manipulated for immunotherapeutic benefit as primary targets, modulators of the tumour microenvironment and in synchronising with tumour antigen specific effector CD8 cells for tumour clearance. Regulatory T cells shape the anti-tumour response from effector T cells via multiple suppressive mechanisms. Future research is needed to address the development of novel NK cell-targeted immunotherapy and on restraining Treg frequency and function in HCC. We have now entered a new era of anti-cancer treatment using checkpoint inhibitor (CPI)-based strategies. Combining GMP-NK cell immunotherapy to enhance the frequency of NK cells with CPI targeting both NK and CD8 T cells to release co-inhibitory receptors and enhance the cells anti-tumour immunity of HCC would be an attractive therapeutic option in the treatment of HCC. These therapeutic approaches should now be complemented by the application of genomic, proteomic and metabolomic approaches to understanding the microenvironment of HCC which, together with deep immune profiling of peripheral blood and HCC tissue before and during treatment, will provide the much-needed personalised medicine approach required to improve clinical outcomes for patients with HCC.

Intratumor Regulatory Noncytotoxic NK Cells in Patients with Hepatocellular Carcinoma

Previous studies support the role of natural killer (NK) cells in controlling hepatocellular carcinoma (HCC) progression. However, ambiguity remains about the multiplicity and the role of different NK cell subsets, as a pro-oncogenic function has been suggested. We performed phenotypic and functional characterization of NK cells infiltrating HCC, with the corresponding nontumorous tissue and liver from patients undergoing liver resection for colorectal liver metastasis used as controls. We identified a reduced number of NK cells in tumors with higher frequency of CD56^BRIGHTCD16^- NK cells associated with higher expression of NKG2A, NKp44, and NKp30 and downregulation of NKG2D. Liver-resident (CXCR6⁺) NK cells were reduced in the tumors where T-bet^hiEomes^lo expression was predominant. HCCs showed higher expression of CD49a with particular enrichment in CD49a⁺Eomes⁺ NK cells, a subset typically represented in the decidua and playing a proangiogenic function. Functional analysis showed reduced TNF-α production along with impaired cytotoxic capacity that was inversely related to CXCR6^-, T-bet^hiEomes^lo, and CD49a⁺Eomes⁺ NK cells. In conclusion, we identified a subset of NK cells infiltrating HCC, including non-liver-resident cells that coexpressed CD49a and Eomes and showed reduced cytotoxic potential. This NK cell subset likely plays a regulatory role in proangiogenic function.

Advances in immunotherapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent disease with a progression that is modulated by the immune system. Systemic therapy is used in the advanced stage and until 2017 consisted only of antiangiogenic tyrosine kinase inhibitors (TKIs). Immunotherapy with checkpoint inhibitors has shown strong anti-tumour activity in a subset of patients and the combination of the anti-PDL1 antibody atezolizumab and the VEGF-neutralizing antibody bevacizumab has or will soon become the standard of care as a first-line therapy for HCC, whereas the anti-PD1 agents nivolumab and pembrolizumab are used after TKIs in several regions. Other immune strategies such as adoptive T-cell transfer, vaccination or virotherapy have not yet demonstrated consistent clinical activity. Major unmet challenges in HCC checkpoint immunotherapy are the discovery and validation of predictive biomarkers, advancing treatment to earlier stages of the disease, applying the treatment to patients with liver dysfunction and the discovery of more effective combinatorial or sequential approaches. Combinations with other systemic or local treatments are perceived as the most promising opportunities in HCC and some are already under evaluation in large-scale clinical trials. This Review provides up-to-date information on the best use of currently available immunotherapies in HCC and the therapeutic strategies under development.

Immune-related microRNA signature for predicting prognosis and the immune microenvironment in hepatocellular carcinoma

AIMS

As vital regulators of post-transcription gene expression, microRNAs are involved in the initiation and progression of hepatocellular carcinoma (HCC), including antitumor immune responses. We aimed to identify an immune-related microRNA signature and explore the influence of this signature on the prognosis and immunity of HCC.

MATERIALS AND METHODS

Differentially expressed immune-related microRNAs were identified between high- and low-immunity groups in the TCGA-HCC dataset. Then, Cox regression models were used to construct an immune-related microRNA signature. We assessed the prognostic value and clinical relevance of this signature. Furthermore, we analyzed the effect of the immune-related microRNA signature on immune cells and immune checkpoints.

KEY FINDINGS

We screened 41 differentially expressed immune-related microRNAs, of which 7 microRNAs were used to construct the immune signature. Survival analysis showed that high-risk patients had a shorter survival. The immune-related microRNA signature was an independent prognostic marker and was associated with the clinical stage. To understand the functional mechanism of the seven-microRNA signature, we predicted target genes of microRNAs. Enrichment analysis indicated that these target genes participated in immune responses. Moreover, we found that the microRNA signature was related to tumor-infiltrating immune cells. In high-risk patients, there was a higher expression of inhibitory immune checkpoints. On the contrary, the expression of stimulatory immune checkpoints was lower in high-risk patients.

SIGNIFICANCE

We successfully identified an immune-related microRNA signature that was strongly correlated with the prognosis and immune microenvironment of HCC. The immune-related microRNAs signature might have important implications for improving the clinical outcomes of HCC patients.

Energy metabolism and cell motility defect in NK-cells from patients with hepatocellular carcinoma

Functional rescue of NK-cells in solid tumors represents a central aim for new immunotherapeutic strategies. We have conducted a genomic, phenotypic and functional analysis of circulating NK-cells from patients with HCV-related liver cirrhosis and hepatocellular carcinoma. NK-cells were sorted from patients with HCC or liver cirrhosis and from healthy donors. Comparative mRNA gene expression profiling by whole-human-genome microarrays of sorted NK-cells was followed by phenotypic and functional characterization. To further identify possible mediators of NK-cell dysfunction, an in vitro model using media conditioned with patients' and controls' plasma was set up. Metabolic and cell motility defects were identified at the genomic level. Dysregulated gene expression profile has been translated into reduced cytokine production and degranulation despite a prevalent phenotype of terminally differentiated NK-cells. NKG2D-downregulation, high SMAD2 phosphorylation and other phenotypic and molecular alterations suggested TGF-β as possible mediator of this dysfunction. Blocking TGF-β could partially restore functional defects of NK-cells from healthy donors, exposed to TGF-β rich HCC patients' plasma, suggesting that TGF-β among other molecules may represent a suitable target for immunotherapeutic intervention aimed at NK-cell functional restoration. By an unbiased approach, we have identified energy metabolism and cell motility defects of circulating NK-cells as main mechanisms responsible for functional NK-cell impairment in patients with hepatocellular carcinoma. This opens the way to test different approaches to restore NK-cell response in these patients.

Sorafenib may enhance antitumour efficacy in hepatocellular carcinoma patients by modulating the proportions and functions of natural killer cells

Dysfunction of natural killer (NK) cells is associated with poor prognosis in hepatocellular carcinoma (HCC). We explored the phenotypic and functional characteristics of peripheral blood NK cells in HCC patients following sorafenib treatment.Peripheral blood samples were collected from 60 HCC patients in a single centre (2015~2017) and 45 healthy donors. The percentage and cytoplasmic granule production of NK cells were analysed. Subset proportions were evaluated for their associations with the modified Response Evaluation Criteria in Solid Tumors (mRECIST), time to progression, and median overall survival (OS).Compared with baseline, the percentages of total and CD56^dimCD16⁺ NK cells increased after two months of treatment, while the percentage of CD56^brightCD16^- NK cells decreased, leading to a dramatically reduced ratio of CD56^bright and CD56^dim NK cells (ratio^bri/dim). Patients with low ratio^bri/dim exhibited better mRECIST responses and longer median OS than those with high ratio^bri/dim. The expression levels of granzyme B and perforin in total NK cells and in both subsets of cells were increased after treatment.This study showed that sorafenib could affect the proportions and functions of peripheral CD56^brightCD16^- and CD56^dimCD16⁺ NK cells, which was associated with the outcomes including OS of HCC patients.

Hepatitis C

Hepatitis C is a global health problem, and an estimated 71·1 million individuals are chronically infected with hepatitis C virus (HCV). The global incidence of HCV was 23·7 cases per 100 000 population (95% uncertainty interval 21·3-28·7) in 2015, with an estimated 1·75 million new HCV infections diagnosed in 2015. Globally, the most common infections are with HCV genotypes 1 (44% of cases), 3 (25% of cases), and 4 (15% of cases). HCV transmission is most commonly associated with direct percutaneous exposure to blood, via blood transfusions, health-care-related injections, and injecting drug use. Key high-risk populations include people who inject drugs, men who have sex with men, and prisoners. Approximately 10-20% of individuals who are chronically infected with HCV develop complications, such as cirrhosis, liver failure, and hepatocellular carcinoma over a period of 20-30 years. Direct-acting antiviral therapy is now curative, but it is estimated that only 20% of individuals with hepatitis C know their diagnosis, and only 15% of those with known hepatitis C have been treated. Increased diagnosis and linkage to care through universal access to affordable point-of-care diagnostics and pangenotypic direct-acting antiviral therapy is essential to achieve the WHO 2030 elimination targets.

Immune landscape of hepatocellular carcinoma microenvironment: Implications for prognosis and therapeutic applications

The development of immunotherapy for solid tumours has boosted interest in the contexture of tumour immune microenvironment (TIME). Several lines of evidence indicate that the interplay between tumour cells and TIME components is a key factor for the evolution of hepatocellular carcinoma (HCC) and for the likelihood of response to immunotherapeutics. The availability of high-resolution methods will be instrumental for a better definition of the complexity and diversity of TIME with the aim of predicting disease outcome, treatment response and possibly new therapeutic targets. Here, we review current knowledge about the immunological mechanisms involved in shaping the clinical course of HCC. Effector cells, regulatory cells and soluble mediators are discussed for their role defining TIME and as targets for immune modulation, together with possible immune signatures for optimization of immunotherapeutic strategies.

Natural killer cells involved in tumour immune escape of hepatocellular carcinomar

Natural killer cells are the first line of host immune surveillance and play major roles in the defence against infection and tumours. Hepatic NK cells exhibit unique phenotypic and functional characteristics compared to circulating and spleen NK cells, such as higher levels of cytolytic activity and cytotoxicity mediators against tumour cells. However, the activities of NK cells may be reversed during tumour progression. Recent studies demonstrated that hepatic NK cells were exhausted in hepatocellular carcinoma (HCC) and exhibited impaired cytolytic activity and decreased production of effector cytokines. The present review discusses current knowledge on the role of exhausted NK cells in promoting HCC development and the mechanisms contributing to tumour immune escape, including an imbalance of activating and inhibitory receptors on NK cells, abnormal receptor-ligand interaction, and cross-talk with immune cells and other stromal cells in the tumour environment. We provide a fundamental basis for further study of innate immunity in tumour progression and serve the purpose of exploring new HCC treatment strategies.

Deficient Natural Killer Cell NKp30-Mediated Function and Altered NCR3 Splice Variants in Hepatocellular Carcinoma

The activating natural cytotoxicity receptor NKp30 is critical for natural killer (NK) cell function and tumor immune surveillance. The natural cytotoxicity receptor-3 (NCR3) gene is transcribed into several splice variants whose physiological relevance is still incompletely understood. In this study, we investigated the role of NKp30 and its major ligand B7 homolog 6 (B7-H6) in patients with hepatocellular carcinoma (HCC). Peripheral blood NK cell phenotype was skewed toward a defective/exhausted immune profile with decreased frequencies of cells expressing NKp30 and natural killer group 2, member D and an increased proportion of cells expressing T-cell immunoglobulin and mucin-domain containing-3. Moreover, NKp30-positive NK cells had a reduced expression of NCR3 immunostimulatory splice variants and an increased expression of the inhibitory variant in patients with advanced tumor, resulting in deficient NKp30-mediated functionality. Tumor-infiltrating lymphocytes showed a prevalent inhibitory NKp30 isoform profile, consistent with decreased NKp30-mediated function. Of note, there were significant differences in the cytokine milieu between the neoplastic and the surrounding non-neoplastic tissue, which may have further influenced NKp30 function. Exposure of NK cells to B7-H6-expressing HCC cells significantly down-modulated NKp30, that was prevented by small interfering RNA-mediated knockdown, suggesting a role for this ligand in inhibiting NKp30-mediated responses. Interestingly, B7-H6 expression was reduced in HCC tissue and simultaneously augmented as a soluble form in HCC patients, particularly those with advanced staging or larger nodule size. Conclusion: These findings provide evidence in support of a role of NKp30 and its major ligand in HCC development and evolution.

Rationale and design of the Hepatocellular carcinoma Early Detection Strategy study: A multi-center longitudinal initiative of the National Cancer Institute's Early Detection Research Network

BACKGROUND

Hepatocellular carcinoma (HCC) is a common malignancy with a steadily rising incidence and associated morbidity and mortality. Cirrhosis of the liver is presently the leading risk factor for developing HCC. Abdominal imaging, with or without alpha-fetoprotein (AFP) testing, every 6 months is the current surveillance strategy for patients at risk. The available biomarkers for detecting this cancer at an early stage have inadequate sensitivity and specificity.

METHODS

The Hepatocellular carcinoma Early Detection Strategy (HEDS) study, a multi-center initiative of the National Cancer Institutes' (NCI) Early Detection Research Network (EDRN), launched an effort to establish what has become the nation's largest comprehensive biorepository and database on patients at high risk of developing HCC. The cohort has been developed in seven clinical centers across the USA. Subjects are enrolled for a five-year period involving data and specimen collection every six months in accordance with standard surveillance for HCC. Extensive clinical data are collected and specimens are stored at a central repository.

RESULTS

The database and biorepository contain longitudinally collected clinical data and serum and plasma samples from 1482 participants with cirrhosis and without evidence of HCC at baseline. Fifty-six percent are male, 85% Caucasian, 30% have a history of chronic HCV and 71% have compensated cirrhosis.

CONCLUSIONS

The HEDS cohort provides opportunities for the continued study of the incidence and course of HCC in a comprehensively followed population of patients at high risk for this malignancy. Further, the EDRN biorepository provides a distinct opportunity for the development of novel biomarkers. Trial registry URL: https://edrn.nci.nih.gov/protocols/316-hepatocellular-carcinoma-early-detection-strategy.

The circulating pool of functionally competent NK and CD8+ cells predicts the outcome of anti-PD1 treatment in advanced NSCLC

INTRODUCTION

A prospective investigation of the circulating immune profile in NSCLC patients receiving nivolumab was performed to identify potentially predictive parameters.

METHODS

Flow Cytometry of peripheral blood (PB) CD3+, CD8+, CD4+, NK, Treg and MDSCs was prospectively performed in 31 consecutive advanced NSCLC patients at baseline (T0) and after 2 (T1) and 4 (T2) cycles of bi-weekly nivolumab. Functional molecules (PD-1, CD3ζ, Granzyme B, Perforin), cell proliferation (Ki67) and NK receptors (NKG2 A, NKG2D, NKp30) were also explored. The immunohistochemical evaluation of PD-L1 and TILs was restricted to available tumor biopsies. Tissue and circulating parameters were correlated to clinico-pathological features and treatment outcomes.

RESULTS

KRAS mutations, active smoking, COPD and steroid treatment conditioned a different distribution of circulating phenotypes. At baseline, clinical benefit (CB, n = 19) group displayed higher number of phenotypically active NK and PD-1+CD8+ cells (p < 0.01) compared to non-responders (NR, n = 12). Prolonged survival outcomes (p < 0.01) were recorded in cases with high baseline circulating NK and PD-1+CD8+ cells. At tissue level, low PD-1 expression in CD8 + TILs was a positive prognostic feature (p < 0.001). Strikingly, high circulating NK and PD-1+CD8+ cells combined with low PD-1/CD8+ ratio in TILs characterized a privileged context able to provide a significantly prolonged (p < 0.01) progression-free survival (PFS). During PD-1 blockade, NKs progressively raised in CB while declined in NR (p < 0.05) and this phenomenon was counterbalanced by parallel changes in Treg.

CONCLUSION

The functional pool of circulating NKs associated with a divergent PD-1 expression in blood and tissue CD8+ lymphocytes portrays an immune profile predictive of anti-PD1 treatment efficacy.

Natural Killer Cell Dysfunction in Hepatocellular Carcinoma: Pathogenesis and Clinical Implications

Hepatocellular carcinoma (HCC) is currently the third leading cause of malignancy-related mortalities worldwide. Natural killer (NK) cells are involved in the critical role of first line immunological defense against cancer development. Defects in NK cell functions are recognized as important mechanisms for immune evasion of tumor cells. NK cell function appears to be attenuated in HCC, and many previous reports suggested that NK cells play a critical role in controlling HCC, suggesting that boosting the activity of dysfunctional NK cells can enhance tumor cell killing. However, the detailed mechanisms of NK cell dysfunction in tumor microenvironment of HCC remain largely unknown. A better understanding of the mechanisms of NK cell dysfunction in HCC will help in the NK cell-mediated eradication of cancer cells and prolong patient survival. In this review, we describe the various mechanisms underlying human NK cell dysfunction in HCC. Further, we summarize current advances in the approaches to enhance endogenous NK cell function and in adoptive NK cell therapies, to cure this difficult-to-treat cancer.

Newly diagnosed hepatocellular carcinoma in patients with advanced hepatitis C treated with DAAs: A prospective population study

BACKGROUND & AIMS

Direct-acting antiviral agents (DAAs) are safe and effective in patients with hepatitis C. Conflicting data were reported on the risk of hepatocellular carcinoma (HCC) during/after therapy with DAAs. The aim of this study was to evaluate the incidence of newly diagnosed HCC and associated risk factors in patients with advanced hepatitis C treated with DAAs.

METHODS

The study is based on the NAVIGATORE platform, a prospectively recording database of all patients with hepatitis C receiving DAAs in the Veneto region of Italy. The inclusion criteria were: fibrosis stage ≥F3. The exclusion criteria were: Child-Turcotte-Pugh (CTP)-C, liver transplantation before DAAs, history or presence of HCC, follow-up <4 weeks after starting DAAs. A total of 3,917 out of 4,234 consecutive patients were included, with a mean follow-up of 536.2 ± 197.6 days.

RESULTS

Overall, HCC was diagnosed in 55 patients. During the first year, HCC incidence was 0.46% (95% CI 0.12-1.17) in F3, 1.49% (1.03-2.08) in CTP-A and 3.61% (1.86-6.31) in CTP-B cirrhotics; in the second year, HCC incidences were 0%, 0.2%, and 0.69%, respectively. By multivariate analysis, HCC was significantly associated with an aspartate aminotransferase to platelet ratio ≥2.5 (hazard ratio [HR] 2.03; 95% CI 1.14-3.61; p = 0.016) and hepatitis B virus infection (HR 3.99; 1.24-12.91; p = 0.021). Failure to achieve a sustained virological response was strongly associated with development of HCC (HR 9.09; 5.2-16.1; p = 0.0001). A total of 29% of patients with HCC had an aggressive tumor, often seen in the early phase of treatment.

CONCLUSIONS

These data, obtained in a large, prospective, population-based study, indicate that in patients with advanced hepatitis C receiving DAAs, the risk of "de novo" hepatocarcinoma during the first year is not higher, and might be lower, than that of untreated patients. The risk further declines thereafter. Early hepatocarcinoma appearance may reflect pre-existing, microscopic, undetectable tumors.

LAY SUMMARY

Hepatocellular carcinoma is one of the complications of hepatitis C related cirrhosis. Treating patients with advanced hepatitis C with the new interferon-free direct-acting antiviral agents has been associated with improvement in liver function and survival, while more conflicting data have been reported regarding the risk of hepatocellular carcinoma. We report the results of a prospective population study on the incidence of newly diagnosed hepatocellular carcinoma in patients with advanced hepatitis C treated with direct-acting antiviral agents, clearly indicating that the residual hepatocellular carcinoma risk is reduced and declines progressively with time after a sustained virological response. Development of a liver tumor during/after therapy was associated with known risk factors and with virological failure.

Next generation immune-checkpoints for cancer therapy

The discovery and clinical application of immune-checkpoint inhibitors has dramatically improved the treatments, outcomes and therapeutic concepts in multiple tumor settings. This breakthrough was mainly based on monoclonal antibodies blocking the inhibitory molecule CTLA-4 and or the PD-1/PD-L1 axis, with the aim of counteracting major tumor immune evasion mechanisms. Even acknowledging these important successes, not all the patients benefit from these treatments. Translational and clinical research efforts are ongoing to explore the potentialities of a new generation of immune-modulatory molecules to extend current clinical applications and contrast the unsolved issues of resistance and disease relapse that still affects a considerable rate of patients. New immune-checkpoints, with either stimulatory or inhibitory functions are emerging with key roles in regulating T cell response but also affecting other crucial effectors belonging to the innate immune response (e.g., natural killer). Their therapeutic exploitation, either alone or in strategical combinations, is providing important preclinical results, holding promises currently explored in initial clinical trials. The first results point toward favorable safety profiles with selective hints of activity in challenging settings. Important issues regarding the dose, schedule and rational combinations remain open and data from the clinical studies are needed. Here we provide an overview of the main emerging stimulatory or inhibitory immune-checkpoints exploitable in cancer treatment, briefly reporting their biological function, preclinical activity and preliminary clinical data.

Hepatocellular carcinoma: Prospects for natural killer cell immunotherapy

Liver disease is a growing cause of death in the United Kingdom and the incidence of hepatocellular carcinoma (HCC) is rising (http://www.cancerresearchuk.org/). The combination of an immunosuppressive environment within the liver and suboptimal host anti-tumour immune responses may account for the poor survival outcome of HCC. Understanding how tumours evade immune recognition coupled with new insights into the unique immunological environment within the liver will be critical to developing liver-specific immunotherapies.

Hepatitis C Virus and Hepatocellular Carcinoma: Pathogenetic Mechanisms and Impact of Direct-Acting Antivirals

INTRODUCTION

Globally, between 64 and 103 million people are chronically infected with Hepatitis C virus (HCV), with more than 4.6 million people in the United States and is associated with more than 15.000 deaths annually. Chronic infection can result in cirrhosis and hepatocellular carcinoma.

EXPLANATION

Epidemiological studies have indicated that persistent infection with hepatitis C virus (HCV) is a major risk for the development of hepatocellular carcinoma (HCC), mainly through chronic inflammation, cell deaths, and proliferation. Despite the new direct-acting antiviral drugs (DAA's) being able to clear the HCV, HCC recurrence rate in these patients is still observed.

CONCLUSION

In this review we highlighted some aspects that could be involved in the onset of HCV-induced HCC such as immune system, viral factors and host genetics factors.Moreover, we focused on some of the last reports about the effects of DAA's on the HCV clearance and their potential implications in HCC recurrence.

Emerging targets in cancer immunotherapy

The first generation of immune checkpoint inhibitors (anti-CTLA-4 and anti-PD-1/PD-L1) targeted natural immune homeostasis pathways, co-opted by cancers, to drive anti-tumor immune responses. These agents led to unprecedented results in patients with previously incurable metastatic disease and may become first-line therapies for some advanced cancers. However, these agents are efficacious in only a minority of patients. Newer strategies are becoming available that target additional immunomodulatory mechanisms to activate patients' own anti-tumor immune responses. Herein, we present a succinct summary of emerging immune targets with reported pre-clinical efficacy that have progressed to active investigation in clinical trials. These emerging targets include co-inhibitory and co-stimulatory markers of the innate and adaptive immune system. In this review, we discuss: 1) T lymphocyte markers: Lymphocyte Activation Gene 3 [LAG-3], T-cell Immunoglobulin- and Mucin-domain-containing molecule 3 [TIM-3], V-domain containing Ig Suppressor of T cell Activation [VISTA], T cell ImmunoGlobulin and ITIM domain [TIGIT], B7-H3, Inducible T-cell Co-stimulator [ICOS/ICOS-L], CD27/CD70, and Glucocorticoid-Induced TNF Receptor [GITR]; 2) macrophage markers: CD47/Signal-Regulatory Protein alpha [SIRPα] and Indoleamine-2,3-Dioxygenase [IDO]; and 3) natural killer cell markers: CD94/NKG2A and the Killer Immunoglobulin-like receptor [KIR] family. Finally, we briefly highlight combination strategies and potential biomarkers of response and resistance to these cancer immunotherapies.

Immunological Predictors of Nonresponse to Directly Acting Antiviral Therapy in Patients With Chronic Hepatitis C and Decompensated Cirrhosis

BACKGROUND

Sustained virological response rates (SVRs) to directly acting antiviral (DAA) therapy for hepatitis C virus (HCV) are lower in decompensated cirrhosis. Markers of innate immunity predict nonresponse to interferon-based HCV treatment; however, whether they are associated with the response to DAAs in patients with decompensation is not known.

METHODS

Information on demographics, adherence, viral kinetics, and resistance were gathered prospectively from a cohort with decompensated cirrhosis treated with 12 weeks of DAAs. C-X-C motif chemokine-10 (CXCL-10) level and T-cell and natural killer (NK) cell phenotype were analyzed pretreatment and at 4 and 12 weeks of treatment.

RESULTS

Of 32 patients, 24 of 32 (75%) achieved SVR (responders). Eight of 32 (25%) experienced relapse after the end of treatment (nonresponders). There were no differences in demographics or adherence between groups. Nonresponders had higher CXCL-10; 320 pg/mL (179461) vs 109 pg/mL (88170) in responders (P < .001) and differential CXCL-10 dynamics. Nonresponders had lower NK cell frequency, higher expression of activation receptor NKp30, and lower frequency of the NK subset CD56-CD16+.

CONCLUSIONS

Nonresponders to DAAs displayed a different NK phenotype and CXCL-10 profile to responders. Nonresponders did not have poorer adherence or baseline virological resistance, and this shows that immunological parameters are associated with treatment response to interferon-free treatment for HCV in individuals with decompensated cirrhosis.