Autologous Tumor Cell Lysate-Loaded Dendritic Cell Vaccine Inhibited Tumor Progression in an Orthotopic Murine Model for Hepatocellular Carcinoma

Immunosuppressive tumor microenvironment in the progression, metastasis, and therapy of hepatocellular carcinoma: from bench to bedside

Hepatocellular carcinoma (HCC) is a highly heterogeneous malignancy with high incidence, recurrence, and metastasis rates. The emergence of immunotherapy has improved the treatment of advanced HCC, but problems such as drug resistance and immune-related adverse events still exist in clinical practice. The immunosuppressive tumor microenvironment (TME) of HCC restricts the efficacy of immunotherapy and is essential for HCC progression and metastasis. Therefore, it is necessary to elucidate the mechanisms behind immunosuppressive TME to develop and apply immunotherapy. This review systematically summarizes the pathogenesis of HCC, the formation of the highly heterogeneous TME, and the mechanisms by which the immunosuppressive TME accelerates HCC progression and metastasis. We also review the status of HCC immunotherapy and further discuss the existing challenges and potential therapeutic strategies targeting immunosuppressive TME. We hope to inspire optimizing and innovating immunotherapeutic strategies by comprehensively understanding the structure and function of immunosuppressive TME in HCC.

Immunotherapy for hepatocellular carcinoma: A promising therapeutic option for advanced disease

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide, and its incidence continues to increase. Despite improvements in both medical and surgical therapies, HCC remains associated with poor outcomes due to its high rates of recurrence and mortality. Approximately 50% of patients require systemic therapies that traditionally consist of tyrosine kinase inhibitors. Recently, however, immune checkpoint inhibitors have revolutionized HCC management, providing new therapeutic options. Despite these major advances, the different factors involved in poor clinical responses and molecular pathways leading to resistance following use of these therapies remain unclear. Alternative strategies, such as adoptive T cell transfer, vaccination, and virotherapy, are currently under evaluation. Combinations of immunotherapies with other systemic or local treatments are also being investigated and may be the most promising opportunities for HCC treatment. The aim of this review is to provide updated information on currently available immunotherapies for HCC as well as future perspectives.

Cellular based treatment modalities for unresectable hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and is unfortunately associated with an overall poor prognosis and high mortality. Early and intermediate stages of HCC allow for treatment with surgical resection, ablation and even liver transplantation, however disease progression warrants conventional systemic therapy. For years treatment options were limited to molecular-targeting medications, of which sorafenib remains the standard of care. The recent development and success of immune checkpoint inhibitors has proven to be a breakthrough in the treatment of HCC, but there is an urgent need for the development of further novel therapeutic treatments that prolong overall survival and minimize recurrence. Current investigation is focused on adoptive cell therapy including chimeric antigen receptor-T cells (CAR-T cells), T cell receptor (TCR) engineered T cells, dendritic cells, natural killer cells, and tumor infiltrating lymphocyte cells, which have shown remarkable success in the treatment of hematological and solid tumor malignancies. In this review we briefly introduce readers to the currently approved systemic treatment options and present clinical and experimental evidence of HCC immunotherapeutic treatments that will hopefully one day allow for revolutionary change in the treatment modalities used for unresectable HCC. We also provide an up-to-date compilation of ongoing clinical trials investigating CAR-T cells, TCR engineered T cells, cancer vaccines and oncolytic viruses, while discussing strategies that can help overcome commonly faced challenges when utilizing cellular based treatments.

Cell Therapy for Liver Disease: From Promise to Reality

Over the last decade, there has been a considerable progress in the development of cell therapy products for the treatment of liver diseases. The quest to generate well-defined homogenous cell populations with defined mechanism(s) of action has enabled the progression from use of autologous bone marrow stem cells comprising of heterogeneous cell populations to allogeneic cell types such as monocyte-derived macrophages, regulatory T cells, mesenchymal stromal cells, macrophages, etc. There is growing evidence regarding the multiple molecular mechanisms pivotal to various therapeutic effects and hence, careful selection of cell therapy product for the desired putative effects is crucial. In this review, we have presented an overview of the cell therapies that have been developed thus far, with preclinical and clinical evidence for their use in liver disease. Limitations associated with these therapies have also been discussed. Despite the advances made, there remain multiple challenges to overcome before cell therapies can be considered as viable treatment options, and these include larger scale clinical trials, scalable production of cells according to good manufacturing practice standards, pathways for delivery of cell therapy within hospital environments, and costs associated with the production.

Immunotherapy for Hepatocellular Carcinoma: A 2021 Update

Hepatocellular carcinoma (HCC) is one of one of the most frequent liver cancers and the fourth leading cause of cancer-related mortality worldwide. Current treatment options such as surgery, neoadjuvant chemoradiotherapy, liver transplantation, and radiofrequency ablation will benefit only a very small percentage of patients. Immunotherapy is a novel treatment approach representing an effective and promising option against several types of cancer. The aim of our study is to present the currently ongoing clinical trials and to evaluate the efficacy of immunotherapy in HCC. In this paper, we demonstrate that combination of different immunotherapies or immunotherapy with other modalities results in better overall survival (OS) and progression-free survival (PFS) compared to single immunotherapy agent. Another objective of this paper is to demonstrate and highlight the importance of tumor microenvironment as a predictive and prognostic marker and its clinical implications in immunotherapy response.

Dendritic cell-based vaccine targeting aspartate-β-hydroxylas represents a promising therapeutic strategy for HCC

Background: Dendritic cells (DCs)-mediated immunotherapy has been considered as a promising antitumor method. Aspartate-β-hydroxylase (AAH) is a potential immunotherapeutic target for hepatocellular carcinoma (HCC). Materials & methods: C57BL/6 mice were immunized by AAH-DCs vaccine constructed ex vivo. Killing tumor cells effect of active T cells induced by AAH-DCs vaccine on HCC cells were measured in vitro and vivo. The underlying mechanism was preliminarily investigated. Results: T cells response when activated by AAH-DCs vaccine showed a significant inhibition effect on HCC cells in vitro and in tumor-bearing mice models when compared with controls. Additionally, compared with the control group, increased expressions of Caspase8, Caspase 3 and Bax, and declined expression of Bcl-2 were observed in AAH-DCs vaccine group. Conclusion: AAH-DCs vaccine could stimulate T cell responses against HCC, which was possibly achieved via pro-apoptosis mechanism.

Liver DCs in health and disease

Hepatic dendritic cells represent a unique and multifaceted subset of antigen-presenting leukocytes that orchestrate specified immune responses in the liver. They are constantly exposed to antigens and signals derived not only from the hepatic microenvironment and the systemic circulation but also from the portal vein draining the gut and conveying food antigens as well as microbial compounds. Modulated by these various factors they shape intrahepatic immune responses during acute and chronic liver diseases, hepatocellular carcinoma and allograft tolerance as well as systemic responses to gut-derived components. Hence, hepatic DC are central targets to decipher and fine-tune innate and adaptive hepatic immune responses as well as tolerance. This review focuses on the origin of hepatic DC, the different DC subsets present in the liver and their functionality during different acute and chronic liver diseases in mice and men and will discuss potential DC directed therapeutic interventions in liver disease.

Honokiol-enhanced cytotoxic T lymphocyte activity against cholangiocarcinoma cells mediated by dendritic cells pulsed with damage-associated molecular patterns

BACKGROUND

Cholangiocarcinoma or biliary tract cancer has a high mortality rate resulting from late presentation and ineffective treatment strategy. Since immunotherapy by dendritic cells (DC) may be beneficial for cholangiocarcinoma treatment but their efficacy against cholangiocarcinoma was low. We suggest how such anti-tumor activity can be increased using cell lysates derived from an honokiol-treated cholangiocarcinoma cell line (KKU-213L5).

AIM

To increase antitumour activity of DCs pulsed with cell lysates derived from honokiol-treated cholangiocarcinoma cell line (KKU-213L5).

METHODS

The effect of honokiol, a phenolic compound isolated from Magnolia officinalis, on choangiocarcinoma cells was investigated in terms of the cytotoxicity and the expression of damage-associated molecular patterns (DAMPs). DCs were loaded with tumour cell lysates derived from honokiol-treated cholangiocarcinoma cells their efficacy including induction of T lymphocyte proliferation, proinflammatory cytokine production and cytotoxicity effect on target cholangiocarcinoma cells were evaluated.

RESULTS

Honokiol can effectively activate cholangiocarcinoma apoptosis and increase the release of damage-associated molecular patterns. DCs loaded with cell lysates derived from honokiol-treated tumour cells enhanced priming and stimulated T lymphocyte proliferation and type I cytokine production. T lymphocytes stimulated with DCs pulsed with cell lysates of honokiol-treated tumour cells significantly increased specific killing of human cholangiocarcinoma cells compared to those associated with DCs pulsed with cell lysates of untreated cholangiocarcinoma cells.

CONCLUSION

The present findings suggested that honokiol was able to enhance the immunogenicity of cholangiocarcinoma cells associated with increased effectiveness of DC-based vaccine formulation. Treatment of tumour cells with honokiol offers a promising approach as an ex vivo DC-based anticancer vaccine.

Antigen-loaded dendritic cells triggers a specific cytotoxic T lymphocytes immune response against hepatocellular carcinoma: in vitro study

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the common malignancies, characterized by poor response to conventional therapeutic options. Immunotherapy with dendritic cells (DCs)-vaccines is one of the most successful strategies used for the treatment of HCC. However, the methods applied in the preparation of antigen-loaded DCs are important factors for optimization of DCs vaccines.

PURPOSE

The present study was conducted to investigate the effect of HCC-whole tumor cell lysate prepared using rapid repetitive freeze-thaw cycles on the immunogenicity of DCs and evaluate the ability of whole tumor cell lysate-pulsed DCs vaccine to induce a specific cytotoxic T lymphocytes (CTLs) response against HepG2 cell line.

METHODS

Immature DCs generated from peripheral blood monocytes were randomized into two groups: control DCs and whole tumor cell lysate-pulsed DCs. Phenotypic analysis of the DCs' cell maturation marker CD83 and co-stimulatory molecule CD86 was performed. HCC-specific cytotoxic activity of CD8⁺ CTLs was measured in vitro.

RESULTS

Loading of DCs with necrotic whole cell lysate resulted in non-significant changes in DCs' expression of CD83, but a significant increase in expression of CD86. In addition, CD8⁺ CTLs stimulated with whole tumor cell lysate-pulsed DCs showed a high cytotoxic activity that specifically attack HepG2 cells.

CONCLUSION

Our findings indicated that pulsation of DCs with whole tumor cell lysate prepared by repetitive freeze-thaw cycles could efficiently enhance the ability of DCs to induce proliferation and clonal expansion of CD8⁺ CTLs. Data herein, also indicated that whole tumor cell lysate-pulsed DCs triggers a specific CD8⁺ CTLs against HCC tumor cells.

Immunotherapeutic strategies for treatment of hepatocellular carcinoma with antigen-loaded dendritic cells: in vivo study

Hepatocellular carcinoma (HCC) is one of the major health problems in the world. DCs-based vaccines are a promising immunotherapeutic strategy that aims at the optimal for induction of a specific antitumor immune response and destruction of tumor cells. The present study was conducted to investigate the immunogenic characters of whole tumor lysate-pulsed DCs vaccine and its ability to induce a specific antitumor immune response in HCC mice model. We also evaluate the effectiveness of prophylactic and therapeutic immunization strategies against HCC in mice models. Mice-derived DCs were in vitro loaded with whole tumor lysate prepared from liver tissue of HCC mice and evaluated for expression of surface maturation markers CD83 and CD86. In vivo immunization of mice with whole tumor lysate-pulsed DCs was performed in two strategies; prophylactic (pre-exposure to HCC) and therapeutic (post-exposure to HCC). Effectiveness of both protocols was investigated in terms of histopathological examination of liver sections and measurement of serum levels of immune cytokines interferon-γ (IFN-γ) and interleukin-2 (IL-2). Loading of DCs with whole tumor cell lysate exhibited a significant increase in expression of CD83 and CD86. In vivo administration of prophylactic doses of whole tumor lysate-pulsed DCs in mice before induction of HCC evokes a strong antitumor immune response presented by absence of malignant cells in liver sections and the significant increase in IFN-γ and IL-2. Data herein indicated that prophylactic vaccination with whole tumor lysate-pulsed DCs exhibited an effective antitumor immune response against HCC more than therapeutic protocol.

Effect of dendritic cell-based immunotherapy on hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND AIMS

Dendritic cell (DC)-based immunotherapy has recently been reported frequently in the treatment of hepatocellular carcinoma (HCC); however, its efficacy remains controversial. In this study, we aimed to evaluate the clinical efficacy of DC-based immunotherapy on HCC by conducting a systematic review and meta-analysis.

METHODS

PubMed, Cochrane Library, Embase and Web of Science were searched to identify clinical trials on DC-based immunotherapy for HCC published up to January 31, 2018. The articles were selected according to pre-established inclusion criteria and methodologic quality, and publication bias were evaluated.

RESULTS

A total of 1276 cases from 19 clinical trials were included. Compared with traditional treatment, further DC-based therapy enhanced the CD4⁺ T/CD8⁺ T ratio (standardized mean difference: 0.68, 95% confidence interval [CI] 0.46-0.89, P < 0.001); increased the 1-year, 18-month and 5-year progression-free survival (PFS) rate and the 1-year, 18-month and 2-year overall survival (OS) rate (relative risk > 1, P < 0.05), prolonged the median PFS time (median survival ratio [MSR]: 1.98, 95% CI: 1.60-2.46, P < 0.001) and median OS time (MSR: 1.72, 95% CI: 1.51-1.96, P < 0.001). Adverse reactions were mild.

CONCLUSIONS

DC-based therapy not only enhanced anti-tumor immunity, improved the survival rate and prolonged the survival time of HCC patients, but it was also safe. These findings will provide encouraging information for further development of DC-based immunotherapy as an adjuvant treatment for HCC. However, the results must be interpreted with caution because of the small study numbers, publication bias and the various of study designs, pre-treatment and therapeutic processes of DCs.