Hepatoid adenocarcinoma-Clinicopathological features and molecular characteristics

Hepatoid adenocarcinoma (HAC) is a rare, malignant, extrahepatic tumor with histologic features similar to those of hepatocellular carcinoma. HAC is most often associated with elevated alpha-fetoprotein (AFP). HAC can occur in multiple organs, including the stomach, esophagus, colon, pancreas, lungs, and ovaries. HAC differs greatly from typical adenocarcinoma in terms of its biological aggression, poor prognosis, and clinicopathological characteristics. However, the mechanisms underlying its development and invasive metastasis remain unclear. The purpose of this review was to summarize the clinicopathological features, molecular traits, and molecular mechanisms driving the malignant phenotype of HAC, in order to support the clinical diagnosis and treatment of HAC.

HCC biomarkers - state of the old and outlook to future promising biomarkers and their potential in everyday clinical practice

Hepatocellular carcinoma (HCC) is one of the most common and deadly tumors worldwide. Management of HCC depends on reliable biomarkers for screening, diagnosis, and monitoring of the disease, as well as predicting response towards therapy and safety. To date, imaging has been the established standard technique in the diagnosis and follow-up of HCC. However, imaging techniques have their limitations, especially in the early detection of HCC. Therefore, there is an urgent need for reliable, non/minimal invasive biomarkers. To date, alpha-fetoprotein (AFP) is the only serum biomarker used in clinical practice for the management of HCC. However, AFP is of relatively rather low quality in terms of specificity and sensitivity. Liquid biopsies as a source for biomarkers have become the focus of clinical research. Our review highlights alternative biomarkers derived from liquid biopsies, including circulating tumor cells, proteins, circulating nucleic acids, and exosomes, and their potential for clinical application. Using defined combinations of different biomarkers will open new perspectives for diagnosing, treating, and monitoring HCC.

Differential Virus-Specific IFN-Gamma Producing T Cell Responses to Marek's Disease Virus in Chickens With B19 and B21 MHC Haplotypes

Marek’s disease virus (MDV), the etiologic agent for Marek’s disease (MD), causes a deadly lymphoproliferative disease in chickens. Causes of the well-documented association between genetically defined lines of chicken and resistance to MD remain unknown. Here, the frequencies of IFN-gamma producing pp38 and MEQ-specific T cell responses were determined in line N (B21 haplotype; MD-resistant) and line P2a (B19 haplotype, MD-susceptible) chickens after infection with vaccine and/or virulent (RB1B) strains of MDV using both standard ex vivo and cultured chIFN-gamma ELISPOT assays. Notably, MDV infection of naïve and vaccinated MD-resistant chickens induced higher frequencies of IFN-gamma producing MDV-specific T cell responses using the cultured and ex vivo ELISPOT assay, respectively. Remarkably, vaccination did not induce or boost MEQ-specific effector T cells in the susceptible chickens, while it boosted both pp38-and MEQ-specific response in resistant line. Taken together, our results revealed that there is a direct association between the magnitude of T cell responses to pp38 and MEQ of MDV antigens and resistance to the disease.

Immunotherapy in hepatocellular cancer

Hepatocellular carcinoma is a major global healthcare problem. It is closely related to chronic liver inflammation triggered by viral and non-viral insults, that can lead to exhaustion of effector T-cells. Furthermore, immune cells within the normal liver itself tend to be more immune tolerant in order to support the essential function of liver as the first processing station of molecules absorbed in the gastrointestinal tract. Dysregulation of the immune system is a hallmark of hepatocellular carcinoma. Immune checkpoint inhibitors targeting the programmed death-1 axis have shown promise as monotherapy in the management of advanced disease, but still most patients do not benefit from treatment. Most recently, combinatorial strategies with other immune checkpoint inhibitors or agents targeting the second hallmark of hepatocellular carcinoma, i.e., the activation of the vascular epithelial growth factor axis have been studied. In this paper, we review the current immunotherapy approaches for hepatocellular carcinoma and discuss novel immunotherapy approaches and optimal patient selection.

A novel α-fetoprotein-derived helper T-lymphocyte epitope with strong immunogenicity in patients with hepatocellular carcinoma

α-Fetoprotein (AFP) is considered a good target for immunotherapy strategies against hepatocellular carcinoma (HCC); however, no immunodominant AFP-derived MHC class II-restricted helper T-lymphocyte (HTL) epitope has been reported. Therefore, we identified novel AFP-derived HTL epitopes possessing high immunogenicity. HTL epitopes were predicted using the online service, and peptides were subsequently synthesized. Four newly synthesized peptides showed positive reactivity in >20% patients on ELISPOT using peripheral blood mononuclear cells (PBMCs). Among these, the highest rate was shown by AFP₁ (MKWVESIFLIFLLNFTESRT), which also showed the highest positive rate in cell proliferation assays. Binding assays demonstrated that AFP₁ had strong binding properties toward MHC molecules. Further, blocking assays performed using an anti-HLA-DR antibody showed that immune response decreased, confirming the binding of AFP₁ to HLA-DR molecules. Furthermore, the survival rates of patients with stages II–IV HCC indicated that T cell response against AFP₁ led to significantly greater survival that of patients without T cell response. When evaluating immune response against AFP₁ before and after HCC treatment, an increase in the frequency of peptide-specific T cells was observed after treatment in patients with HLA-DRB1*1502, *0405, and *0901 alleles. In conclusion, the identified epitopes may be useful for immunotherapy strategies against HCC.

[The role of alpha-fetoprotein in regulation of the cytokine profile of activated T-helpers and their conversion in Th17 phenotype]

We studied the effect of the native (non-recombinant) alpha-fetoprotein (AFP) on differentiation, proliferation, and cytokine profile of activated helper T cells 17 (Th17). The object of the study was a culture of isolated by immunomagnetic separation helper T cells (CD4+), induced into the Th17 phenotype by using TCR-activator and proinflammatory cytokines (IL-1β and IL-6). AFP had not significant effect on the frequency of Th17 cells (ROR-γτ+) in the helper T cell culture, and did not affect proliferation of these cells, as measured by Ki-67 expression. Evaluation of the cytokine profile of culture supernatants by using the Luminex xMAP technology, revealed that AFP did not affect the levels of IL-4, IL-5, IL-7, IL-8, IL-10, IL-17, IFN-γ and TNF-α, but at concentrations of 50 IU/ml and 100 IU/ml it increased IL-2 production by activated helper T cells. At the same time, AFP suppressed the synthesis of G-CSF and GM-CSF (10 IU/ml), but stimulated the production of CCL4/MIP-1β (100 IU/ml) and CCL2/MCP-1 chemokines (10 IU/ml and 50 IU/ml).

More Than a Tumor Marker…A Potential Role for Alpha-Feto Protein in Inflammatory Bowel Disease

BACKGROUND

Human alpha-fetoprotein (hAFP) is a glycoprotein derived from the gut entoderm and expressed sequentially by cells of the yolk sac, fetal liver, and gastrointestinal tract. By adulthood, serum levels of alpha-fetoprotein (AFP) are undetectable in healthy, nonpregnant adults. Despite the clinical utilities of AFP monitoring in pregnancy and malignancy, much remains to be determined regarding its potential physiological functions.

METHODS

We focused on literature related to AFP's immunoregulatory role and its ability to modulate disease activity both in animal models of autoimmune disorders and in human clinical studies.

RESULTS

Evidence suggests that AFP plays an important role in immunoregulation by inducing T-cell suppressor activity, downregulating dendritic-like cell antigen expression, and impairing the function of macrophages. Studies evaluating AFP and its effects in rodent models of autoimmune diseases have shown that AFP is associated with downregulation of inflammation. Observations in studies of pregnant patients with immune-mediated inflammatory diseases have also described potential correlations between AFP expression and disease activity during different stages of pregnancy and postpartum.

CONCLUSIONS

We propose further prospective evaluations of AFP expression during pregnancy in inflammatory bowel disease patients to further correlate with disease activity and consider the potential of AFP as a novel therapeutic agent.

Characterization of alpha-fetoprotein effects on dendritic cell and its function as effector immune response activator

Tumor antigen alpha-fetoprotein (AFP) can promote immune tolerance toward tumor cells by inducing regulatory functions of the immune system. The purpose of this study was to characterize the effects of AFP on dendritic cells (DC) in their antitumor immune response stimulation and subsequent immune tolerance toward tumor cells. Monocytes were cultured in medium with GM-CSF and IL-4 and incubated for 6 days to generate immature DC (imDC). AFP was added into the treatment group at the beginning of the monocyte-derived DC culture. Mature DC (mDC) were generated by an addition of lipopolysaccharide (LPS) into the culture and incubation for another 48 hours. We observed that the addition of AFP in early DC culture was able to decrease the binding of LPS onto imDC surface, which lowered the strength of stimulation and consequently the maturity of DC. As expected, the expression of mDC surface markers, which are known to be crucial in effector cell proliferation and activation such as HLA-DR, CD40, CD80, CD83, and CD86, were confirmed to be reduced on AFP-exposed DC. DC potential in stimulating proliferation of CD4⁺ T cells was decreased, in line with the reduction of surface markers’ expression. Additionally, an increased secretion of cytokine TGF-β by DC was observed. In summary, AFP inhibited the effector immune responses while increasing the regulatory immune responses in DC. This might lead to tolerance toward antigens and tumor cell survival, such as in cases of hepatocellular carcinoma patients with high levels of AFP.

Elevated Serum Level of IL-35 Associated with the Maintenance of Maternal-Fetal Immune Tolerance in Normal Pregnancy

Objectives

IL-35 is a novel inhibitory cytokine. In this study, we investigate the serum levels of inhibitory cytokines IL-35, IL-10 and TGF-β in both normal pregnancies and non-pregnant females, and whether IL-35 is associated with the pathogenesis of recurrent spontaneous abortion. We also try to elucidate the relationships of IL-35 with estrogen and alpha-fetoprotein (AFP).

Methods

The levels of IL-35, IL-10, TGF-β, estradiol (E2), unconjugated estriol (uE3) and AFP were analyzed in 120 normal pregnancies, 40 women suffering recurrent spontaneous abortion, 40 postpartum healthy women and 40 non-pregnant women by enzyme-linked immunosorbent assay (ELISA). The correlations between inhibitory cytokines, estrogen and AFP were assessed with the Spearman rank correlation coefficient.

Results

Data are expressed as median and percentiles (Q1, Q3).The level of serum IL-35 in normal pregnancies was significantly higher than that in non-pregnant women [333.6 (59.32, 1391) pg/mL vs. 123.9 (8.763, 471.7) pg/mL; P < 0.001]. A significantly higher level of TGF-β was observed in the first trimester only as compared to non-pregnant women [473.4 (398.0, 580.5) pg/mL vs. 379.7 (311.0, 441.3) pg/mL, P < 0.01]. The difference in serum IL-10 level between pregnant women and non-pregnant women was not significant [8.602 (5.854, 12.89) pg/mL vs. 9.339 (5.691, 12.07) pg/mL; P > 0.05]. The level of serum IL-35 in recurrent spontaneous abortion was significantly lower than that in normal early pregnancy [220.4 (4.951, 702.0) pg/mL vs. 386.5 (64.37, 1355) pg/mL; P < 0.05]. The higher IL-35 level in first trimester pregnant women correlated with E2 (r = 0.3062, P < 0.01) and AFP (r = 0.3179, P < 0.01).

Conclusion

Serum levels of IL-35 increased in normal pregnancy and decreased in recurrent spontaneous abortion. Increased IL-35 correlated with estrogen and AFP levels in early pregnancy. IL-35 is becoming recognized as an active player in the maintenance of a successful pregnancy, but this is not the case for IL-10 or TGF-β.

Potential synergistic anti-tumor activity between lenalidomide and sorafenib in hepatocellular carcinoma

BACKGROUND AND AIM

The immune modulatory drug lenalidomide has shown promising anti-tumor activity in a clinical trial of patients with advanced hepatocellular carcinoma (HCC). The present study explored whether lenalidomide can enhance the anti-tumor activity of sorafenib, the standard molecular targeted therapy for HCC.

METHODS

The anti-tumor efficacy of single-agent or combination treatment was measured by change in tumor volume and animal survival using an orthotopic liver cancer model. Distribution of T-cell subpopulations in tumor-infiltrating lymphocytes (TILs) and splenocytes derived from tumor-implanted mice was measured by flow cytometry. Depletion of relevant T-cell subpopulations or cytokines was done by co-administration of relevant antibodies with study drug treatment. Tumor cell apoptosis and tumor angiogenesis were measured by transferase deoxytidyl uridine end labeling assay and immunohistochemical study, respectively.

RESULTS

Combination of sorafenib and lenalidomide produced significant synergistic anti-tumor efficacy in terms of tumor growth delay and animal survival. This synergistic effect was associated with a significant increase in interferon-γ expressing CD8(+) lymphocytes in TILs and a significantly higher number of granzyme- or perforin-expressing CD8(+) T cells, compared with vehicle- or single-agent treatment groups. Combination treatment significantly increased apoptotic tumor cells and vascular normalization in tumor tissue. The synergistic anti-tumor effect was abolished after CD8 depletion.

CONCLUSIONS

Lenalidomide can enhance the anti-tumor effects of sorafenib in HCC through its immune modulatory effects, and CD8(+) TILs play an important role in the anti-tumor synergism.

Tumour immunogenicity, antigen presentation and immunological barriers in cancer immunotherapy

Since the beginning of the 20^th century, scientists have tried to stimulate the anti-tumour activities of the immune system to fight against cancer. However, the scientific effort devoted on the development of cancer immunotherapy has not been translated into the expected clinical success. On the contrary, classical anti-neoplastic treatments such as surgery, radiotherapy and chemotherapy are the first line of treatment. Nevertheless, there is compelling evidence on the immunogenicity of cancer cells, and the capacity of the immune system to expand cancer-specific effector cytotoxic T cells. However, the effective activation of anti-cancer T cell responses strongly depends on efficient tumour antigen presentation from professional antigen presenting cells such as dendritic cells (DCs). Several strategies have been used to boost DC antigen presenting functions, but at the end cancer immunotherapy is not as effective as would be expected according to preclinical models. In this review we comment on these discrepancies, focusing our attention on the contribution of regulatory T cells and myeloid-derived suppressor cells to the lack of therapeutic success of DC-based cancer immunotherapy.

Cytokine Gene Expression in CD4 Positive Cells of the Japanese Pufferfish, Takifugu rubripes

CD4⁺ T (Th) cells are a central component of the adaptive immune response and are divided into distinct sets based on their specific cytokine production pattern. Several reports have suggested that fish possess Th subset activity similar to that of mammals. The aim of the present study was to isolate CD4⁺ T cells from the blood of Japanese pufferfish, Fugu rubripes, and to characterize their cytokine expression profile. We produced a specific antibody against Fugu CD4 and performed cell sorting with the magnetic activated cell sorting system. Sorted Fugu CD4⁺ cells were characterized by morphology and expression analysis of cell marker genes. Fugu CD4⁺ cells expressed T-cell marker genes but not macrophage or B-cell marker genes. In addition, peripheral blood lymphocytes were stimulated with lipopolysaccharide (LPS), polycytidylic acid (polyI:C), concanavalin A (ConA) prior to sorting, and then Multiplex RT-PCR was used to examine the expression of Th cytokines by the stimulated Fugu CD4⁺ cells. LPS and polyI:C stimulation upregulated the expression of Th1, Th17 and Treg cytokines and downregulated the expression of Th2 cytokines. ConA stimulation upregulated the expression of all Th cytokines. These results suggest that fish exhibit the same upregulation of Th-specific cytokine expression as in mammals.

Alpha-fetoprotein: a renaissance

Alpha-fetoprotein (AFP) is a major mammalian embryo-specific and tumor-associated protein that is also present in small quantities in adults at normal conditions. Discovery of the phenomenon of AFP biosynthesis in carcinogenesis by G. Abelev and Yu. Tatarinov 50 years ago, in 1963, provoked intensive studies of this protein. AFPs of some mammalian species were isolated, purified and physico-chemically and immunochemically characterized. Despite the significant success in study of AFP, its three-dimensional structure, mechanisms of receptor binding along with a structure of the receptor itself and, what is the most important, its biological role in embryo- and carcinogenesis remain still obscure. Due to difficulties linked with methodological limitations, research of AFP was to some extent extinguished by the 1990 s. However, over the last decade a growing number of investigations of AFP and its usage as a tumor-specific biomarker have been observed. This was caused by the use of new technologies, primarily, computer-based and genetic engineering approaches in studying of this very important oncodevelopmental protein. Our review summarizes efforts of different scientific groups throughout the world in studying AFP for 50 years with emphasis on detailed description of recent achievements in this field.

Surgical treatment for large hepatocellular carcinoma: does size matter?

Despite significant progress in the management of hepatocellular carcinoma (HCC), patients with large HCC (defined as >10 cm) continue to present a significant challenge. The goal of this paper is to review the existing literature regarding large HCC, with emphasis on identifying the issues and challenges involved in approaching these tumours surgically. A computerized search was made of the Medline database from January 1992 to December 2010. The MESH heading 'large' or 'huge' in combination with the keyword 'hepatocellular carcinoma' was used. After excluding further studies that identified 'large' HCC as less than 10 cm and/or sequential publications with overlapping patient populations, the search produced a study population of 22 non-duplicated papers, reporting on a total of 5223 patients with HCC tumours >10 cm. Regarding resection for large HCC, the overall 5-year survival in these studies ranged from 25% to 45%, with few outliers on both sides, whereas in most studies, the 5-year disease-free survival ranged between 15% and 35%, with the only exception being studies with patients with single lesions and no cirrhosis showing disease-free survival of 41% and 56%, respectively. Risk factors identified included vascular invasion, cirrhosis, high level of alpha-fetoprotein and the presence of multiple lesions. Finally, liver transplantation, although an attractive concept, did not appear to offer a survival benefit in any of the studies. In conclusion, identifying the risk factors that affect the outcome in patients undergoing surgery for large HCC is critical. The reason is that surgical resection can have excellent outcomes in carefully selected patients.

α-Fetoprotein impairs activation of natural killer cells by inhibiting the function of dendritic cells

α-Fetoprotein (AFP) is a tumour-associated antigen in hepatocellular carcinoma (HCC). The biological properties of AFP have been identified in its regulatory effects on immune responses of T cells and B cells. However, AFP effects on natural killer (NK) cells are still unclear. In this study, we examined the immunoregulation of AFP on NK activity. The cytolytic activity against K562 cells and Huh7 cells of NK cells co-cultured with AFP-treated dendritic cells (DCs) (AFP-DCs) was lower than that with albumin-treated DCs (Alb-DCs). Direct addition of AFP to NK cells did not alter the cytolytic activity of NK cells. Adding AFP inhibited the interleukin (IL)-12 production of DCs after stimulation with lipopolysaccharide (LPS) [Toll-like receptor (TLR)-4 ligand], or Poly(I:C) (TLR-3 ligand), but not IL-18 production. The mRNAs of IL-12p35 and IL-12p40 were significantly inhibited in AFP-DCs compared with Alb-DCs, but those of TLR-4 or TLR-3 were not. Transwell experiments revealed that soluble factors derived from DCs played roles in inhibition of the ability of activating NK cells by AFP-DCs. Adding the neutralizing antibody of IL-12 to NK cells co-cultured with Alb-DCs resulted in a decrease of cytolytic activity to the levels of NK cells co-cultured with AFP-DCs. Adding IL-12 to NK cells co-cultured with AFP-DCs resulted in an increase of cytolytic activity to the levels of NK cells co-cultured with Alb-DCs. These demonstrated that the impairment of IL-12 production from AFP-DCs resulted in inhibition of the ability of the activation of NK cells by DCs, and thus suggests a role of AFP in HCC development.

Lack of ex vivo peripheral and intrahepatic α-fetoprotein-specific CD4+ responses in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies with a poor prognosis and limited therapeutic options that is often characterized by the expression of the tumor-associated antigen α-fetoprotein (AFP). CD4+ helper T cells are important in generating potent anticancer immunity as they prime and expand CD8+ T-cell memory and may also have direct antitumor activity. However, very little information is currently available about the relative frequency, immunodominance and peripheral versus intratumoral distribution of AFP-specific CD4+ T-cell responses in patients with HCC. We, therefore, analyzed AFP-specific CD4+ responses in blood and tumor tissue of patients with HCC by using overlapping peptides spanning the entire AFP protein and novel sensitive approaches such as antigen-specific upregulation of CD154. We found that AFP-specific CD4+ T-cell responses were not detectable in the peripheral blood ex vivo. However, after in vitro stimulation, AFP-specific CD4+ T-cell responses were detectable in a large fraction of patients targeting different previously unreported epitopes with no clear immunodominance. These results indicate that AFP-specific CD4+ T-cell responses are not completely deleted but only present at very low frequencies. Importantly, AFP-specific CD4+ T-cell responses were also rarely detectable in tumor tissue, suggesting that the relative absence of these cells in the circulation ex vivo is not due to a rapid accumulation to the tumor side. Taken together, these results suggest that the lack of sufficient CD4+ T-cell help, especially within the tumor tissue, may be one central mechanism responsible for the failure of AFP-specific immune responses to control HCC progression.

Induction of latency-associated peptide (transforming growth factor-β(1)) expression on CD4+ T cells reduces Toll-like receptor 4 ligand-induced tumour necrosis factor-α production in a transforming growth factor-β-dependent manner

CD4(+) T cells expressing the latent form of transforming growth factor-β [latency-associated peptide (LAP) (TGF-β(1))] play an important role in the modulation of immune responses. Here, we identified a novel peptide ligand (GPC(81-95) ) with an intrinsic ability to induce membrane-bound LAP (TGF-β(1)) expression on a subpopulation of human CD4(+) T cells (using flow cytometry; ranging from 0·8% to 2·6%) and stimulate peripheral blood mononuclear cells to release LAP (TGF-β(1) ) (using ELISPOT assay; ranging from 0·03% to 0·16%). In spite of this low percentage of responding cells, GPC(81-95) significantly reduced Toll-like receptor 4 ligand-induced tumour necrosis factor-α production in a TGF-β(1) - and CD4(+) T-cell-dependent manner. The results demonstrate that GPC(81-95) is a useful tool to study the functional properties of a subpopulation of LAP (TGF-β(1))(+) CD4(+) T cells and suggest a pathway that can be exploited to suppress inflammatory response.

Expansion of interferon-gamma-producing multifunctional CD4+ T-cells and dysfunctional CD8+ T-cells by glypican-3 peptide library in hepatocellular carcinoma patients

Glypican-3 is a promising target for immunotherapy for hepatocellular carcinoma, but limited data exist regarding its immunogenicity in patients with diverse HLA types, immunogenicity for CD4(+) T-cells, and the impact of inhibitory co-stimulation on glypican-3-specific T-cells. Using a 15mer overlapping peptide library for glypican-3, PBMC from patients with HCC were assessed ex vivo and after short-term in vitro expansion for tumor antigen-specific T-cell responses with and without blockade of PD-1/PD-L1 and CTLA-4 signaling. Glypican-3-specific T-cells were undetectable ex vivo, but primarily IFNγ(+)TNFα(+) CD4(+) T-cells expanded with short-term in vitro stimulation in 10/19 (52%) patients. Glypican-3-specific CD8(+) T-cells predominantly produced TNFα, but did not secrete IFNγ nor degranulate. CTLA-4 and PD-1 blockade minimally impacted the cytokine secretion and proliferation of glypican-3-specific T-cells. These data suggest that CD8(+) T-cell-directed tumor vaccines in HCC may have limited potential for efficacy unless optimal co-stimulation conditions can be identified but CD4(+)-directed vaccines merit consideration.

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

The presence of CD8 T cell responses to tumor associated antigens have been reported in patients with different malignancies. However, there is very little information on a comparable CD8 and CD4 T cell response to a tumor antigen in liver cancer patients. Here, we re-examine the kinetic and the pattern of T helper 1 and cytotoxic T lymphocyte responses to alpha-fetoprotein (AFP), a tumor rejection antigen in hepatocellular carcinoma (HCC). Then, we discuss the possibility of using AFP-based immunotherapy in combination with necrotizing treatments in HCC patients.

Cell-mediated immune responses to alpha-fetoprotein and other antigens in hepatocellular carcinoma

Cell-mediated immune responses play an important role in the control of tumour growth. CD4 and CD8 T cells recognise tumour antigens presented via major histocompatibility complex molecules of antigen presenting cells and develop into effector cells with the ability to identify and kill tumour cells. Here, we re-examine the adaptive immune response to tumour antigens expressed by hepatocellular carcinoma (HCC) and discuss approaches that could be applied in future T-cell-based immunotherapy schedules to induce a potent and effective antitumour immunity. Moreover, we discuss cytotoxic T lymphocyte and Th1 responses to tumour antigens in patients with HCC and evaluate the effects of conventional treatments on antitumour T-cell responses.

Expansion of anti-AFP Th1 and Tc1 responses in hepatocellular carcinoma occur in different stages of disease

Background:

α-Fetoprotein (AFP) is a tumour-associated antigen in hepatocellular carcinoma (HCC) and is a target for immunotherapy. However, there is little information on the pattern of CD4 (Th1) and CD8 (Tc1) T-cell response to AFP in patients with HCC and their association with the clinical characteristics of patients.

Methods:

We therefore analysed CD4 and CD8 T-cell responses to a panel of AFP-derived peptides in a total of 31 HCC patients and 14 controls, using an intracellular cytokine assay for IFN-γ.

Results:

Anti-AFP Tc1 responses were detected in 28.5% of controls, as well as in 25% of HCC patients with Okuda I (early tumour stage) and in 31.6% of HCC patients with stage II or III (late tumour stages). An anti-AFP Th1 response was detected only in HCC patients (58.3% with Okuda stage I tumours and 15.8% with Okuda stage II or III tumours). Anti-AFP Th1 response was mainly detected in HCC patients who had normal or mildly elevated serum AFP concentrations (P=0.00188), whereas there was no significant difference between serum AFP concentrations in these patients and the presence of an anti-AFP Tc1 response. A Th1 response was detected in 44% of HCC patients with a Child–Pugh A score (early stage of cirrhosis), whereas this was detected in only 15% with a B or C score (late-stage cirrhosis). In contrast, a Tc1 response was detected in 17% of HCC patients with a Child–Pugh A score and in 46% with a B or C score.

Conclusion:

These results suggest that anti-AFP Th1 responses are more likely to be present in patients who are in an early stage of disease (for both tumour stage and liver cirrhosis), whereas anti-AFP Tc1 responses are more likely to be present in patients with late-stage liver cirrhosis. Therefore, these data provide valuable information for the design of vaccination strategies against HCC.

alpha-Fetoprotein as a modulator of the pro-inflammatory response of human keratinocytes

BACKGROUND AND PURPOSE

The immunomodulatory effects of alpha-fetoprotein (AFP) on lymphocytes and macrophages have been described in vitro and in vivo. Recombinant forms of human AFP have been proposed as potential therapeutic entities for the treatment of autoimmune diseases. We examined the effects of embryonic and recombinant human AFP on the spontaneous, UVA- and cytokine-induced pro-inflammatory responses of human keratinocytes.

EXPERIMENTAL APPROACH

Cultures of primary and immortalized human keratinocytes (HaCaT) and human blood T lymphocytes were used. The effects of AFP on cytokine expression were studied by bioplexed elisa and quantitative reverse transcriptase polymerase chain reaction assay. Kinase and nuclear factor kappa B (NFkappaB) phosphorylation were quantified by intracellular elisa. Nuclear activator protein 1 and NFkappaB DNA binding activity was measured by specific assays. Nitric oxide and H(2)O(2) production and redox status were assessed by fluorescent probe and biochemical methods.

KEY RESULTS

All forms of AFP enhanced baseline expression of cytokines, chemokines and growth factors. AFP dose-dependently increased tumour necrosis factor alpha-stimulated granulocyte macrophage colony stimulating factor and interleukin 8 expression and decreased tumour necrosis factor alpha-induced monocyte chemotactic protein 1 and IP-10 (interferon gamma-produced protein of 10 kDa) expression. AFP induced a marked activator protein 1 activation in human keratinocytes. AFP also increased H(2)O(2) and modulated nitrite/nitrate levels in non-stimulated keratinocytes whereas it did not affect these parameters or cytokine release from UVA-stimulated cells. Phosphorylation of extracellular signal-regulated kinase (ERK1/2) and Akt1 but not NFkappaB was activated by AFP alone or by its combination with UVA.

CONCLUSIONS AND IMPLICATIONS

Exogenous AFP induces activation of human keratinocytes, with de novo expression of a number of pro-inflammatory mediators and modulation of their pro-inflammatory response to cytokines or UVA. AFP may modulate inflammatory events in human skin.

Alpha-fetoprotein (AFP)-derived peptides as epitopes for hepatoma immunotherapy: a commentary

The various immunological roles of human alpha-fetoprotein (HAFP), and its correlation with hepatomas, that is, hepatocellular carcinomas (HCCs), are not often addressed together in biomedical reports considering that HAFP is an established biomarker for hepatomas. Studies reporting measurement of HAFP serum levels in hepatoma patients in basic/clinical research settings has greatly increased over the years. Recent reports have now expanded our base knowledge in the mounting of an immune response against AFP, a self antigen, during hepatoma tumorigenesis. Advances in the detection and identification of AFP-derived peptide epitopes are opening new vistas of knowledge regarding the immunological role of AFP-peptides as T cell stimulating antigens in the course of hepatoma growth and progression. The present commentary addresses HAFP-derived peptides as immunologic responders in HCC and their use in the study and generation of AFP-peptide sensitized T cells directed against hepatoma cells. Attempts were further made to relate the AFP-derived peptide epitopes to T cell activities during the course of hepatoma immunotherapies and to profile the traits and properties of the peptides themselves. Hence, the present commentary was divided into two sections; (1) the characterization, properties, and traits of AFP peptide epitopes, and (2) the use of AFP-derived peptides in the therapeutic induction of T cells primed against hepatoma cells using both in vivo and in vitro models.

Immunomodulation of EAE by alpha-fetoprotein involves elevation of immune cell apoptosis markers and the transcription factor FoxP3

Alpha-fetoprotein (AFP) is an immunomodulatory glycoprotein associated with the normal growth of the mammalian fetus. Ws have shown that treatment with recombinant human AFP (rhAFP) reduced lymphocyte reactivity and the extent of neuroinflammation in mice with experimental autoimmune encephalomyelitis (EAE). In the present study we found involvement of AFP in immune cell apoptosis, attesting to its possible mechanism of action. AFP increased the expression of the Bax, Bid, Bad and ApaF genes in peripheral lymphocytes, together with an enhanced expression of Caspase-3, Fas, FasL and TRAIL among infiltrating immune cells. The induction of apoptosis markers was accompanied with an increased expression of Foxp3 in lymph node cells, as well as accumulation of CD4+Foxp3+ regulatory T cells in the CNS. Overall, these immunological alterations gave rise to a milder disease and accelerated remission rate. Our results suggest a new role for AFP in controlling the autoimmune inflammation associated with EAE.

Comprehensive analysis of the alpha-fetoprotein-specific CD8+ T cell responses in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide, with a poor prognosis and limited therapeutic options. Therefore, the development of novel therapeutic strategies is of high priority. alpha-Fetoprotein (AFP) is overexpressed in the majority of HCCs. Priming of immune responses against AFP results in significant protective antitumoral T cell responses in the mouse model. Little information is available about the hierarchy, breadth, frequency, and peripheral versus intrahepatic distribution of AFP-specific CD8(+) T cell responses in patients with HCC. To address these important issues we comprehensively analyzed CD8(+) T cell responses against full-length AFP in peripheral blood, tumor liver tissue, and nontumor liver tissue from patients with HCC using overlapping AFP peptides. The AFP-specific CD8(+) T cell response was also tested in peripheral blood and liver from patients chronically infected with hepatitis C virus (HCV) and compared to the HCV-specific CD8(+) T cell response. The majority of patients with HCC showed AFP-specific responses, with many responses directed against previously unreported epitopes. These responses were primarily detectable in the HCC tissue and mainly targeted the C-terminus of AFP. Interestingly, AFP-specific T cells were not only found in patients with HCC but also in patients with chronic HCV infection, other liver diseases, and less frequently in healthy subjects.

CONCLUSION

In patients with HCC, a high frequency of AFP-specific CD8(+) T cells directed against different epitopes suggest that AFP has a strong and broad immunogenicity. Further, CD8(+) T cells specific for the self-antigen AFP are present in the normal T cell repertoire and are not centrally or peripherally deleted. Our results provide support for strategies to boost AFP-specific CD8(+) T cell responses in patients with HCC but also demonstrate a diversity of immune responses that may be needed for protection.