Alpha-fetoprotein specific CD4 and CD8 T cell responses in patients with hepatocellular carcinoma

ZNF765 is a prognostic biomarker of hepatocellular carcinoma associated with cell cycle, immune infiltration, m6A modification, and drug susceptibility

Hepatocellular carcinoma (HCC) is an ongoing challenge worldwide. Zinc finger protein 765 (ZNF765) is an important zinc finger protein that is related to the permeability of the blood-tumor barrier. However, the role of ZNF765 in HCC is unclear. This study evaluated the expression of ZNF765 in hepatocellular carcinoma and the impact of its expression on patient prognosis based on The Cancer Genome Atlas (TCGA). Immunohistochemical assays (IHC) were used to examine protein expression. Besides, a colony formation assay was used to examine cell viability. We also explored the relationship between ZNF765 and chemokines in the HCCLM3 cells by qRT-PCR. Moreover, we examined the effect of ZNF765 on cell resistance by measurement of the maximum half-inhibitory concentration. Our research revealed that ZNF765 expression in HCC samples was higher than that in normal samples, whose upregulation was not conducive to the prognosis. The results of GO, KEGG, and GSEA showed that ZNF765 was associated with the cell cycle and immune infiltration. Furthermore, we confirmed that the expression of ZNF765 had a strong connection with the infiltration level of various immune cells, such as B cells, CD4+ T cells, macrophages, and neutrophils. In addition, we found that ZNF765 was associated with m6A modification, which may affect the progression of HCC. Finally, drug sensitivity testing found that patients with HCC were sensitive to 20 drugs when they expressed high levels of ZNF765. In conclusion, ZNF765 may be a prognostic biomarker related to cell cycle, immune infiltration, m6A modification, and drug sensitivity for hepatocellular carcinoma.

The Profile and Role of Tumor-infiltrating Lymphocytes in Hepatocellular Carcinoma: An Immunohistochemical Study

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. Tumor-infiltrating lymphocytes (TILs) are a class of cells that form the tumor microenvironment and thus have an effect on carcinogenesis. The aim of this study was to investigate the immunohistochemical expression of CD8, CD4, cytotoxic T lymphocyte-associated protein-4 (CTLA-4), and granzyme B in HCC and their correlation with clinicopathologic parameters and prognosis. This study was carried out on 112 cases of HCC. High percentage of CD8+ TILs was associated with large tumors and adjacent noncirrhotic liver. High percentage of CD4+ TILs and high CD4 to CD8 ratio were associated with nonviral etiology, low alpha fetoprotein, and direct acting antiviral treatment. High percentage of CTLA-4-positive TILs tended to be associated with high-grade HCC, while a high percentage of CTLA-4 in tumor cells was associated with multiple lesions and low tumor grade. High percentage of granzyme B+ TILs was associated with low grade, early stage, and absence of tumor recurrence. High CD4 percentage and high CD4/CD8 ratio affected patients' overall survival. There is a dynamic interaction between the different subsets of lymphocytes in the environment of HCC manifested by coparallel expression of CD4 and CD8 augmenting the expression of CTLA-4, and only CD8 augments the expression of granzyme B. This opens the gate for the beneficial role of immunotherapy in the management of HCC, reducing recurrence and improving survival.

Deciphering and Reversing Immunosuppressive Cells in the Treatment of Hepatocellular Carcinoma

Use of immune checkpoint inhibitors (ICIs) in hepatocellular carcinoma (HCC) has been partially successful. However, most HCC patients do not respond to immunotherapy. HCC has been shown to induce several immune suppressor mechanisms in patients. These suppressor mechanisms include involvement of myeloid-derived suppressor cells, regulatory T-cells, functionally impaired dendritic cells (DCs), neutrophils, monocytes, and tumor associated macrophages. The accumulation of immunosuppressive cells may lead to an immunosuppressive tumor microenvironment as well as the dense fibrotic stroma which may contribute to immune tolerance. Our laboratory has been investigating different cellular mechanisms of immune suppression in HCC patients. In vitro as well as in vivo studies have demonstrated that abrogation of the suppressor cells enhances or unmasks tumor-specific antitumor immune responses. Two or three effective systemic therapies including ICIs and/or molecular targeted therapies and the addition of innovative combination therapies targeting immune suppressor cells may lead to increased immune recognition with a greater tumor response. We reviewed the literature for the latest research on immune suppressor cells in HCC, and here we provide a comprehensive summary of the recent studies in this field.

Molecular mechanisms of circular RNAs, transforming growth factor-β, and long noncoding RNAs in hepatocellular carcinoma

At the heart of hepatocellular carcinoma (HCC) lies disruption of signaling pathways at the level of molecules, genes, and cells. Non‐coding RNAs (ncRNAs) have been implicated in the disease progression of HCC. For instance, dysregulated expression of circular RNAs (circRNAs) has been observed in patients with HCC. As such, these RNAs are potential therapeutic targets and diagnostic markers for HCC. Long non‐coding RNAs (lncRNAs), a type of ncRNA, have also been recognized to participate in the initiation and progression of HCC. Transforming growth factor‐beta (TGF‐β) is another element which is now recognized to play crucial roles in HCC. It has been implicated in many biological processes such as survival, immune surveillance, and cell proliferation. In HCC, TGF‐β promotes disease progression by two mechanisms: an intrinsic signaling pathway and the extrinsic pathway. Through these pathways, it modulates various microenvironment factors such as inflammatory mediators and fibroblasts. An interesting yet‐to‐be resolved concept is whether the HCC‐promoting role of TGF‐β pathways is limited to a subset of HCC patients or it is involved in the whole process of HCC development. This review summarizes recent advancements to highlight the roles of circRNAs, lncRNAs, and TGF‐β in HCC.

Alarmin augments the antitumor immunity of lentiviral vaccine in ectopic, orthotopic and autochthonous hepatocellular carcinoma mice

It is a daunting therapeutic challenge to completely eradicate hepatocellular carcinoma (HCC) from patients. Alpha-fetoprotein (AFP) -based vaccines appear promising, however the efficacy needs to be improved.

Methods: Here, we explore if fusing high-mobility group nucleosome binding protein 1 (HMGN1), a potent immunoadjuvant, to AFP (lenti-HA) can augment the antitumor immunity of AFP-expressing lentiviral vector (lenti-AFP), a vehicle extensively employed for genetic immunization with high transduction efficacy and good safety profiles. The antitumor immunity of Lenti-HA was systemically assessed in ectopic, orthotopic and autochthonous HCC models.

Results: Lenti-HA elicited strong anti-HCC effects in mice and amplified the antitumor immunity of lenti-AFP by reducing effective dose 6-fold. Importantly, lenti-HA induced a robust antitumor immune response with prolonged survival rate and improved the immune and tumor microenvironment in mice with carcinogen-induced autochthonous HCC. Lenti-HA localized primarily to lymphoid organs with no preference for specific immune cell types. Activated dendritic cells (DCs), particularly CD103⁺CD11b^- DCs, were also actively recruited to lymph nodes in lenti-HA-treated HCC mice. Moreover, lenti-HA-transduced human DCs elicited stronger immune response than lenti-AFP against HCC cells in vitro.

Conclusion: Our study demonstrates that HMGN1 augments the antitumor immunity of AFP-expressing lentiviral vaccines in HCC mice and human cells in vitro and thus provides a new therapeutic strategy for HCC.

Frequency and Implications of myeloid-derived suppressor cells and lymphocyte subsets in Egyptian patients with hepatitis C virus-related hepatocellular carcinoma

BACKGROUND AND AIM

Myeloid-derived suppressor cells (MDSCs) play a pivotal role in tumor immunity and induction of immune tolerance to a variety of antitumor effectors, including T lymphocytes. Herein, we tried to evaluate the frequency and clinical significance of MDSCs and different lymphocyte subsets in hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC).

METHODS

Four groups were enrolled; chronic HCV (CHC; n = 40), HCV-related liver cirrhosis (n = 40), HCV-related HCC (HCV-HCC; n = 75), and healthy control group (n = 20). The percentage of peripheral lymphocytes subsets and total MDSCs with their main two subsets; monocytic (M-MDSCs) and granulocytic (G-MDSCs) was evaluated by flow cytometry.

RESULTS

The frequency of total MSDCs and M-MDSCs was significantly elevated in HCV-HCC especially patients with advanced stage HCC compared with those with early-stage HCC. The frequency of total MSDCs and M-MDSCs was positively correlated with ALT, AFP, and HCV viral load and negatively correlated with CD8⁺ T-cell frequency. CD4 ⁺ T cells were significantly decreased in HCV-HCC patients. The frequency of CD4 ⁺ T cells and CD8 ⁺ T cells was negatively correlated with AFP and AST, but not with albumin or HCV viral load.

CONCLUSION

Taken together, our data suggest that MDSCs, M-MDSCs, and lymphocyte subsets are associated with the development and progression of HCV-related HCC.

Rationally combining anti-VEGF therapy with checkpoint inhibitors in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a fatal disease with rising incidence in the world. For advanced HCC, sorafenib, a multikinase inhibitor, is the only systemic therapy with proven survival benefits. Sorafenib is a pan-VEGF receptor inhibitor, and thus many studies have focused its antivascular effects. But VEGF also acts as an immunosuppressive molecule. VEGF can inhibit maturation of dendritic cells, promote immune suppressive cell infiltration and enhance immune checkpoint molecules expression. On the other hand, potent VEGF inhibition may increase tumor hypoxia, which could hinder antitumor immunity or immunotherapy. Thus, achieving synergy when combining anti-VEGF therapy with immunotherapy may require proper polarization of the tumor microenvironment by dose titration or combination with other immunomodulating agents.

Improvement of the cytotoxic T lymphocyte response against hepatocellular carcinoma by transduction of cancer cells with an adeno-associated virus carrying the interferon-γ gene

Dendritic cell (DC)-based antigen-targeted immunotherapy may offer effective adjuvant therapy for hepatocellular carcinoma (HCC), in which cytotoxic T lymphocytes (CTLs) are key. However, in a number of cases, the activity of CTLs is completely inhibited due to the downregulated expression of major human leukocyte antigen (HLA) class I molecules by HCC cells. The aim of the present study was to overcome this issue. Hep3B cells were transduced by HCC‑specific recombinant adeno‑associated virus (rAAV) carrying human α‑fetoprotein promoter (AFPp) and the interferon‑γ (IFN‑γ) gene (rAAV/AFPp‑IFN‑γ). rAAV carrying the cytomegalovirus promoter (CMVp) and human α‑fetoprotein (AFP) gene (rAAV/CMVp‑AFP) was used to transduce professional antigen‑presenting DCs for the purpose of stimulating a CTL response. It was observed that transduction of DCs with rAAV/CMVp‑AFP resulted in: (i) AFP and interleukin‑12 expression; (ii) high expression levels of cluster of differentiation (CD)80, CD83, CD86, CD40, HLA‑death receptor and CD1a; (iii) T cell populations with marked IFN‑γ expression; (iv) a high percentage of CD69+/CD8+ T cells; and (v) the activity of CTLs against HLA‑A2‑expressing Hep3B cells. The transduction of Hep3B cells with rAAV/AFPp‑IFN‑γ resulted in: (i) IFN‑γ expression; (ii) upregulated expression of HLA‑A2; and (iii) an improved CTL response against HLA‑A2‑deficient Hep3B cells. rAAV/CMVp‑AFP‑transduced DCs elicited an AFP‑specific and HLA‑class I‑restricted CTL response against Hep3B cells. In conclusion, it was shown that the transduction of Hep3B with rAAV/AFPp-IFN-γ upregulated the expression of HLA-A2 and improved the sensitivity to CTL response.

Route of antigen delivery impacts the immunostimulatory activity of dendritic cell-based vaccines for hepatocellular carcinoma

Background

Dendritic cells (DC) are uniquely equipped to capture, process, and present antigens from their environment. The context in which an antigen is acquired by DC helps to dictate the subsequent immune response. Cancer vaccination promotes antitumor immunity by directing an immune response to antigens expressed by tumors. We have tested the tumor-associated antigen alpha-fetoprotein (AFP) as an immunotherapy target. The majority of hepatocellular carcinomas (HCC) upregulate and secrete this oncofetal antigen.

Methods

To develop cancer vaccines for HCC capable of promoting potent tumor-specific T cell responses, we tested adenovirally-encoded synthetic AFP, with or without its signal sequence, as well as protein forms of AFP and compared intracellular routing and subsequent antigen-specific CD8+ and CD4+ T cell responses.

Results

Surprisingly, the secreted form of antigen was superior for both CD4+ and CD8+ T cell activation. We also examined the mechanism through which AFP protein is endocytosed and trafficked in human DC. We identify the mannose receptor (MR/CD206) as the primary uptake pathway for both normal cord blood-derived AFP (nAFP) and tumor-derived AFP (tAFP) proteins. While in healthy donors, nAFP and tAFP were cross-presented to CD8+ T cells similarly and CD4+ T cell responses were dependent upon MR-mediated uptake. In HCC patient cells, tAFP was more immunogenic, and CD4+ T cell responses were not MR-dependent.

Conclusions

Secreted, cytoplasmically retained, and endocytosed forms of AFP utilize unique uptake and processing pathways, resulting in different immunologic responses from the induced antigen-specific CD4+ and CD8+ T cells and between healthy donors and HCC patients. Collectively, these data elucidate pathways of spontaneous and induced anti-tumor immunity in HCC patients to this secreted antigen.

Electronic supplementary material

The online version of this article (doi:10.1186/s40425-015-0077-x) contains supplementary material, which is available to authorized users.

Impaired function of CD4+ T follicular helper (Tfh) cells associated with hepatocellular carcinoma progression

Background and Aims

CD4+ T follicular helper (Tfh) cells, a new subset of immune cells, have been demonstrated to be involved in the development and prognosis of tumors. However, their functional role in human hepatocellular carcinoma (HCC) is relatively unknown, and the detailed mechanisms in HCC development remain to be described.

Methods

A total of 85 HCC patients with hepatitis B virus (HBV) infection, 25 HBV-relative liver cirrhosis (LC) patients, and 20 healthy controls (HC) were randomly enrolled. Flow cytometric analysis, immunohistochemical staining, and relative function (i.e., cytokine secretion, B cell maturation) assays were used to analyze the properties of CXCR5+CD4+ T cells. In addition, the relationship between the frequency of CXCR5+CD4+ T cells and overall survival rates or disease-free survival rates was also analyzed by the Kaplan-Meier method.

Results

The frequency of circulating CXCR5+CD4+ T cells was significantly decreased in HCC patients compared with HBV-relative liver cirrhosis (LC) patients and healthy controls, and the decrease in circulating CXCR5+CD4+ T cells correlated with disease progression. The proportion of infiltrated CXCR5+CD4+ T cells was significantly decreased in tumor regions compared with nontumor regions. Furthermore, compared with healthy controls, the function of circulating CXCR5+CD4+ T cells in HCC was impaired, with reduced IL-21 secretion and dysfunction in promoting B cell maturation. Importantly, follow-up data indicated that a decreased frequency of circulating CXCR5+CD4+ T cells was also associated with reduced disease-free survival time in HCC patients.

Conclusions

Impairment of CD4+ T follicular helper cells may influence the development of HBV-associated HCC. Decreased CD4+ T follicular helper cells may represent a potential prognostic marker and serve as a novel therapeutic target for HCC patients.

Correlation analysis of peripheral blood T cell subgroups, immunoglobulin and prognosis of early hepatocellular carcinoma after hepatectomy

To investigate the prediction value of preoperative changes in the immunological function for the prognosis of hepatocellular carcinoma (HCC) after hepatectomy, 158 cases of HCC patients who received liver resection in our hospital from 2009 to 2010 were enrolled in this study. Immune indices [CD3(+), CD4(+), CD8(+), CD19(+) and natural killer (NK), IgA, IgM, IgG], AFP level were calculated. The differences between preoperation and postoperation group, exclude were not both statistically significant (both P > 0.05), whereas IgA group was not (P < 0.05),The follow-up data showed that the 3-year recurrence rates of high level group on HBsAg, CD3, CD4, CD8, CD19 and IgGwerelarger than that of low level group,while the 3-year recurrence rates of high level group on AFP, NK, IgA and IgM smaller than that of low level group, and we found that CD3(+), CD4(+), CD8(+) and NK(+), CD19(+), HBsAg, IgA and IgG above were statistically different (P < 0.05), AFP and IgM were no difference with prognosis of HCC (P > 0.05).The markers level were not both statistically significant with age, gender, grade, tumor size (P > 0.05). Multiple logistic regression analysis indicated that CD4(+), CD8(+) and NK(+) were closely correlated with HCC postoperative survival rate (P < 0.05) (Y = 1.262×CD4(+)+1.448×CD8(+)-0.646×NK(+)). Construction of Cox's proportional hazards regression model showed IgA and IgG were correlated with HCC postoperative survival rate at a trend (P = 0.079) (Y = 127.9×IgG-28.7×IgM). Preoperative Immune indices (CD4(+), CD8(+), NK(+), IgA, IgG) were closely correlated with HCC survival rate and these were considerable predictive value for the malignantfeature and prognosis of HCC.

Tumor-derived α-fetoprotein impairs the differentiation and T cell stimulatory activity of human dendritic cells

Several tumor-derived factors have been implicated in dendritic cell (DC) dysfunction in cancer patients. α-fetoprotein (AFP) is an oncofetal Ag that is highly expressed in abnormalities of prenatal development and several epithelial cancers, including hepatocellular carcinoma (HCC). In HCC patients exhibiting high levels of serum AFP, we observed a lower ratio of myeloid/plasmacytoid circulating DCs compared with patients with low serum AFP levels and healthy donors. To test the effect of AFP on DC differentiation in vitro, peripheral blood monocytes from healthy donors were cultured in the presence of cord blood-derived normal AFP (nAFP) or HCC tumor-derived AFP (tAFP), and DC phenotype and function were assessed. Although the nAFP and tAFP isoforms only differ at one carbohydrate group, low (physiological) levels of tAFP, but not nAFP, significantly inhibited DC differentiation. tAFP-conditioned DCs expressed diminished levels of DC maturation markers, retained a monocyte-like morphology, exhibited limited production of inflammatory mediators, and failed to induce robust T cell proliferative responses. Mechanistic studies revealed that the suppressive activity of tAFP is dependent on the presence of low molecular mass (LMM) species that copurify with tAFP and function equivalently to the LMM fractions of both tumor and nontumor cell lysates. These data reveal the unique ability of tAFP to serve as a chaperone protein for LMM molecules, both endogenous and ubiquitous in nature, which function cooperatively to impair DC differentiation and function. Therefore, novel therapeutic approaches that antagonize the regulatory properties of tAFP will be critical to enhance immunity and improve clinical outcomes.

Transforming growth factor-β as a therapeutic target in hepatocellular carcinoma

Hepatocellular carcinoma arises in patients as a consequence of long-standing preexisting liver illnesses, including viral hepatitis, alcohol abuse, or metabolic disease. In such preexisting liver diseases, TGF-β plays an important role in orchestrating a favorable microenvironment for tumor cell growth and promoting epithelial-mesenchymal transition (EMT). TGF-β signaling promotes hepatocellular carcinoma progression by two mechanisms: first, via an intrinsic activity as an autocrine or paracrine growth factor and, second, via an extrinsic activity by inducing microenvironment changes, including cancer-associated fibroblasts, T regulatory cells, and inflammatory mediators. Although there is an increasing understanding on how TGF-β signaling is associated with tumor progression in hepatocellular carcinoma, it is not clear whether TGF-β signaling is limited to a certain subgroup of patients with hepatocellular carcinoma or is a key driver of hepatocellular carcinoma during the entire tumorigenesis of hepatocellular carcinoma. Inhibitors of the TGF-β signaling have been shown to block hepatocellular carcinoma growth and progression by modulating EMT in different experimental models, leading to the clinical investigation of the TGF-β inhibitor LY2157299 monohydrate in hepatocellular carcinoma. Preliminary results from a phase II clinical trial have shown improved clinical outcome and also changes consistent with a reduction of EMT.

Cellular immune suppressor mechanisms in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has been shown to induce several immune suppressor mechanisms in patients. Our laboratory has been investigating different cellular mechanisms of immune suppression in patients with HCC. These suppressor mechanisms range from CD4(+) regulatory T cells, functionally impaired dendritic cells, neutrophils, and monocytes to myeloid-derived suppressor cells. In vitro as well as in vivo studies have demonstrated that abrogation of the suppressor cells enhances or unmasks tumor-specific anti-tumor immune responses. We performed a literature search for immune suppressor cells in HCC, and here we provide a comprehensive summary of the latest studies in this field.

Effect of all-trans retinoic acid on the differentiation, invasion and metastasis of liver cancer HepG2 cells

AIM: To investigate the effect of all-trans retinoic acid (ATRA) on the differentiation, invasion and metastasis of liver cancer HepG2 cells.

METHODS: After HepG2 cells were treated with different concentrations of ATRA, the proliferation of HepG2 cells was evaluated by MTT assay; anchorage-dependent growth was evaluated by colony formation assay; AFP secretion was determined by ELISA; the transcription levels of Nanog and MMP-9 were assessed by RT-PCR, and their protein levels were assessed by Western blot; and cell invasion and migration were evaluated by scratch test and transwell assay.

RESULTS: ATRA suppressed the proliferation and anchorage-dependent growth of HepG2 in a dose- and time-dependent manner. ATRA induced cell differentiation and decreased AFP secretion in HepG2 cells (both P < 0.05). Treatment with ATRA down-regulated the mRNA and protein levels of Nanog and MMP-9 (within 24 hours) in a dose- and time-dependent manner. In addition, ATRA could inhibit the invasion and metastasis of HepG2 cells.

CONCLUSION: ATRA may induce cell differentiation, reduce cell invasion and migration and down-regulate the levels of Nanog in HepG2 cells.