High numbers of granzyme B/CD8-positive tumour-infiltrating lymphocytes in nasopharyngeal carcinoma biopsies predict rapid fatal outcome in patients treated with curative intent

Prognostic value of tumour-stroma ratio in nasopharyngeal carcinoma: a two-center retrospective study

BACKGROUND

Tumour-stroma ratio (TSR) is the proportion of tumour cells relative to surrounding stroma. This study aimed to investigate the prognostic impact of TSR, and to construct a prognostic nomogram in patients with nasopharyngeal carcinoma (NPC).

METHODS

Clinico-pathological data of 206 patients treated at Guangzhou Institute of Cancer Research, the Affiliated Cancer Hospital, Guangzhou Medical University for NPC were used as the training cohort. Assessment of TSR was performed on haematoxylin and eosin-stained slides and the correlation of TSR with survival outcomes was examined. A nomogram model comprising TSR was established and the clinical performance was evaluated by concordance index (C-index), calibration curve, time-dependent area under the curve (tAUC), and decision curve analysis (DCA). External validation was performed using cohort from Sun Yat-sen University Cancer Center (n = 343).

RESULTS

High stroma ratio was proved to be an adverse prognostic factor for OS. A prognostic model integrating T stage, N stage and TSR for individual prediction of survival was constructed and graphically represented as a nomogram. Calibration curves indicated good agreement between the nomogram and actual observations. Moreover, the nomogram outperformed the commonly used staging systems. In addition, the nomogram could successfully classified patients into three different risk groups. The external validation cohort supported these findings.

CONCLUSIONS

TSR is a strong and independent prognostic factor for NPC patients. A nomogram that integrated T stage, N stage and TSR could serve as a precise and convenient model of risk stratification in predicting the prognosis of patients with NPC.

The biological function of Serpinb9 and Serpinb9-based therapy

Recent breakthroughs in discovering novel immune signaling pathways have revolutionized different disease treatments. SERPINB9 (Sb9), also known as Proteinase Inhibitor 9 (PI-9), is a well-known endogenous inhibitor of Granzyme B (GzmB). GzmB is a potent cytotoxic molecule secreted by cytotoxic T lymphocytes and natural killer cells, which plays a crucial role in inducing apoptosis in target cells during immune responses. Sb9 acts as a protective mechanism against the potentially harmful effects of GzmB within the cells of the immune system itself. On the other hand, overexpression of Sb9 is an important mechanism of immune evasion in diseases like cancers and viral infections. The intricate functions of Sb9 in different cell types represent a fine-tuned regulatory mechanism for preventing immunopathology, protection against autoimmune diseases, and the regulation of cell death, all of which are essential for maintaining health and responding effectively to disease challenges. Dysregulation of the Sb9 will disrupt human normal physiological condition, potentially leading to a range of diseases, including cancers, inflammatory conditions, viral infections or other pathological disorders. Deepening our understanding of the role of Sb9 will aid in the discovery of innovative and effective treatments for various medical conditions. Therefore, the objective of this review is to consolidate current knowledge regarding the biological role of Sb9. It aims to offer insights into its discovery, structure, functions, distribution, its association with various diseases, and the potential of nanoparticle-based therapies targeting Sb9.

Digital Spatial Profiling Identifies the Tumor Periphery as a Highly Active Biological Niche in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is characterized by a high degree of intratumoral heterogeneity (ITH). Besides genomic ITH, there is considerable functional ITH, which encompasses spatial niches with distinct proliferative and signaling activities. The full extent of functional spatial heterogeneity in ccRCC is incompletely understood. In the present study, a total of 17 ccRCC tissue specimens from different sites (primary tumor, n = 11; local recurrence, n = 1; distant metastasis, n = 5) were analyzed using digital spatial profiling (DSP) of protein expression. A total of 128 regions of interest from the tumor periphery and tumor center were analyzed for the expression of 46 proteins, comprising three major signaling pathways as well as immune cell markers. Results were correlated to clinico-pathological variables. The differential expression of granzyme B was validated using conventional immunohistochemistry and was correlated to the cancer-specific patient survival. We found that a total of 37 proteins were differentially expressed between the tumor periphery and tumor center. Thirty-five of the proteins were upregulated in the tumor periphery compared to the center. These included proteins involved in cell proliferation, MAPK and PI3K/AKT signaling, apoptosis regulation, epithelial-to-mesenchymal transition, as well as immune cell markers. Among the most significantly upregulated proteins in the tumor periphery was granzyme B. Granzyme B upregulation in the tumor periphery correlated with a significantly reduced cancer-specific patient survival. In conclusion, this study highlights the unique cellular contexture of the tumor periphery in ccRCC. The correlation between granzyme B upregulation in the tumor periphery and patient survival suggests local selection pressure for aggressive tumor growth and disease progression. Our results underscore the potential of spatial biology for biomarker discovery in ccRCC and cancer in general.

Naproxen chemoprevention induces proliferation of cytotoxic lymphocytes in Lynch Syndrome colorectal mucosa

Background

Recent clinical trial data from Lynch Syndrome (LS) carriers demonstrated that naproxen administered for 6-months is a safe primary chemoprevention that promotes activation of different resident immune cell types without increasing lymphoid cellularity. While intriguing, the precise immune cell types enriched by naproxen remained unanswered. Here, we have utilized cutting-edge technology to elucidate the immune cell types activated by naproxen in mucosal tissue of LS patients.

Methods

Normal colorectal mucosa samples (pre- and post-treatment) from a subset of patients enrolled in the randomized and placebo-controlled 'Naproxen Study' were obtained and subjected to a tissue microarray for image mass cytometry (IMC) analysis. IMC data was processed using tissue segmentation and functional markers to ascertain cell type abundance. Computational outputs were then used to quantitatively compare immune cell abundance in pre- and post-naproxen specimens.

Results

Using data-driven exploration, unsupervised clustering identified four populations of immune cell types with statistically significant changes between treatment and control groups. These four populations collectively describe a unique cell population of proliferating lymphocytes within mucosal samples from LS patients exposed to naproxen.

Conclusions

Our findings show that daily exposure of naproxen promotes T-cell proliferation in the colonic mucosa, which paves way for developing combination of immunoprevention strategies including naproxen for LS patients.

Clinical relevance of PD-1 positive CD8 T-cells in gastric cancer

BACKGROUND

We evaluated the relevance of PD-1⁺CD8⁺ T-cells in gastric cancer (GC) including prognostic significance, association with chemotherapy and immunotherapy sensitivity and correlations with the tumor microenvironment (TME).

METHODS

Discovery cohort: GC samples were evaluated for AE1/3, CD8, PD-1, Ki-67 and Granzyme-B expression with fluorescence-based multiplex immunohistochemistry (mIHC). Validation cohorts: we analyzed bulk RNAseq GC datasets from TCGA, the "3G" chemotherapy trial and an immunotherapy phase 2 trial. The cox proportional hazards model was used to identify factors that influenced overall survival (OS). To study the TME, we analyzed single-cell RNAseq performed on GCs.

RESULTS

In the discovery cohort of 350 GCs, increased PD-1 expression of CD8 T-cells was prognostic for OS (HR 0.822, p = 0.042). PD-1 expression in CD8 T-cells highly correlated with cytolytic [Granzyme-B⁺] (r = 0.714, p < 0.001) and proliferative [Ki-67⁺] (r = 0.798, p < 0.001) activity. Analysis of bulk RNAseq datasets showed tumors with high PD-1 and CD8A expression levels had improved OS when treated with immunotherapy (HR 0.117, p = 0.036) and chemotherapy (HR 0.475, p = 0.017). Analysis of an scRNAseq dataset of 152,423 cells from 40 GCs revealed that T-cell and NK-cell proportions were higher (24% vs 18% and 19% vs 15%, p < 0.0001), while macrophage proportions were lower (7% vs 11%, p < 0.0001) in CD8PD-1_high compared to CD8PD-1_low tumors.

CONCLUSION

This is one of the largest GC cohorts of mIHC combined with analysis of multiple datasets providing orthogonal validation of the clinical relevance of PD-1⁺CD8⁺ T-cells being associated with improved OS. CD8PD-1_high tumors have distinct features of an immunologically active, T-cell inflamed TME.

Epstein–Barr Virus Epithelial Cancers—A Comprehensive Understanding to Drive Novel Therapies

Epstein–Barr virus (EBV) is a ubiquitous oncovirus associated with specific epithelial and lymphoid cancers. Among the epithelial cancers, nasopharyngeal carcinoma (NPC), lymphoepithelioma-like carcinoma (LELC), and EBV-associated gastric cancers (EBVaGC) are the most common. The role of EBV in the pathogenesis of NPC and in the modulation of its tumour immune microenvironment (TIME) has been increasingly well described. Much less is known about the pathogenesis and tumour–microenvironment interactions in other EBV-associated epithelial cancers. Despite the expression of EBV-related viral oncoproteins and a generally immune-inflamed cancer subtype, EBV-associated epithelial cancers have limited systemic therapeutic options beyond conventional chemotherapy. Immune checkpoint inhibitors are effective only in a minority of these patients and even less efficacious with molecular targeting drugs. Here, we examine the key similarities and differences of NPC, LELC, and EBVaGC and comprehensively describe the clinical, pathological, and molecular characteristics of these cancers. A deeper comparative understanding of these EBV-driven cancers can potentially uncover targets in the tumour, TIME, and stroma, which may guide future drug development and cast light on resistance to immunotherapy.

Granzyme B in Inflammatory Diseases: Apoptosis, Inflammation, Extracellular Matrix Remodeling, Epithelial-to-Mesenchymal Transition and Fibrosis

Inflammation is strictly interconnected to anti-inflammatory mechanisms to maintain tissue homeostasis. The disruption of immune homeostasis can lead to acute and chronic inflammatory diseases, as cardiovascular, pulmonary, metabolic diseases and cancer. The knowledge of the mechanisms involved in the development and progression of these pathological conditions is important to find effective therapies. Granzyme B (GrB) is a serine protease produced by a variety of immune, non-immune and tumor cells. Apoptotic intracellular and multiple extracellular functions of GrB have been recently identified. Its capability of cleaving extracellular matrix (ECM) components, cytokines, cell receptors and clotting proteins, revealed GrB as a potential multifunctional pro-inflammatory molecule with the capability of contributing to the pathogenesis of different inflammatory conditions, including inflammaging, acute and chronic inflammatory diseases and cancer. Here we give an overview of recent data concerning GrB activity on multiple targets, potentially allowing this enzyme to regulate a wide range of crucial biological processes that play a role in the development, progression and/or severity of inflammatory diseases. We focus our attention on the promotion by GrB of perforin-dependent and perforin-independent (anoikis) apoptosis, inflammation derived by the activation of some cytokines belonging to the IL-1 cytokine family, ECM remodeling, epithelial-to-mesenchymal transition (EMT) and fibrosis. A greater comprehension of the pathophysiological consequences of GrB-mediated multiple activities may favor the design of new therapies aim to inhibit different inflammatory pathological conditions such as inflammaging and age-related diseases, EMT and organ fibrosis.

Secretome analysis reveals upregulated granzyme B in human androgen-repressed prostate cancer cells with mesenchymal and invasive phenotype

Epithelial-mesenchymal transition (EMT) is a critical early step in cancer metastasis and a complex process that involves multiple factors. In this study, we used proteomics approaches to investigate the secreted proteins (secretome) of paired human androgen-repressed prostate cancer (ARCaP) cell lines, representing the epithelial (ARCaP-E) and mesenchymal (ARCaP-M) phenotypes. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses showed high levels of proteins involved in bone remodeling and extracellular matrix degradation in the ARCaP-M cells, consistent with the bone metastasis phenotype. Furthermore, LC-MS/MS showed a significantly higher level of the serine protease granzyme B (GZMB) in ARCaP-M conditioned media (CM) compared to that of ARCaP-E. Using quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) to detect mRNA and Western blot to detect protein expression, we further demonstrated that the GZMB gene was expressed by ARCaP-M and the protein was secreted extracellularly. ARCaP-M cells with GZMB gene knockdown using small interfering RNA (siRNA) have markedly reduced invasiveness as demonstrated by the Matrigel invasion assay in comparison with the scrambled siRNA negative control. This study reports that GZMB secretion by mesenchymal-like androgen-repressed human prostate cancer cells promotes invasion, suggesting a possible extracellular role for GZMB in addition to its classic role in immune cell-mediated cytotoxicity.

Epitelial-to-mesenchimal transition and invasion are upmodulated by tumor-expressed granzyme B and inhibited by docosahexaenoic acid in human colorectal cancer cells

BACKGROUND

Granzyme B (GrB) is a serine protease, traditionally known as expressed by cytotoxic lymphocytes to induce target cell apoptosis. However, it is emerging that GrB, being also produced by a variety of normal and neoplastic cells and potentially acting on multiple targets, might represent a powerful regulator of a wide range of fundamental biological processes. We have previously shown that GrB is expressed in urothelial carcinoma tissues and its expression is associated to both pathological tumor spreading and EMT. We have also shown that docosahexaenoic acid (DHA), a dietary ω-3 polyunsaturated fatty acid with anti-tumor activity, while inhibiting urothelial and pancreatic carcinoma cell invasion also inhibited their GrB expression in vitro. In this study, we characterized a panel of colorectal carcinoma (CRC) cells, with different invasive capabilities, for GrB expression and for the contribution of GrB to their EMT and invasive phenotype. In addition, we investigated the effect of DHA on CRC cell-associated GrB expression, EMT and invasion.

METHODS

The expression levels of GrB and EMT-related markers were evaluated by Western blotting. GrB knockdown was performed by Stealth RNAi small interfering RNA silencing and ectopic GrB expression by transfection of human GrB vector. Cell invasion was determined by the BioCoat Matrigel invasion chamber test.

RESULTS

GrB was produced in 57.1% CRC cell lines and 100% CRC-derived Cancer Stem Cells. Although GrB was constitutive expressed in both invasive and noninvasive CRC cells, GrB depletion in invasive CRC cells downmodulated their invasion in vitro, suggesting a contribution of GrB to CRC invasiveness. GrB loss or gain of function downmodulated or upmodulated EMT, respectively, according to the analysis of cancer cell expression of three EMT biomarkers (Snail1, E-cadherin, N-cadherin). Moreover, TGF-β1-driven EMT was associated to the enhancement of GrB expression in CRC cell lines, and GrB depletion led to downmodulation of TGF-β1-driven EMT. In addition, DHA inhibited GrB expression, EMT and invasion in CRC cells in vitro.

CONCLUSIONS

These findings present a novel role for GrB as upmodulator of EMT in CRC cells. Moreover, these results support the use of DHA, a dietary compound without toxic effects, as adjuvant in CRC therapy.

Functional characterization of TRPM7 in nasopharyngeal carcinoma and its knockdown effects on tumorigenesis

The aim of this study was to evaluate the association of functional expression of TRPM7 with nasopharyngeal carcinoma (NPC) growth. We examined the correlation of TRPM7 expression with cell growth and proliferation, cell cycle, and apoptosis in vitro in NPC cell lines and NPC tumorigenesis in mice by conducting experiments in mice and by further analyzing the tumor volume and growth. We further explored to see whether there is any positive correlation with the TRPM7 knockdown in NPC cells with their sensitivity to radiation. We found that the functional expression of TRPM7 in nasopharyngeal carcinoma is a critical requirement for physiological processes such as cell cycle, resistance to apoptosis, and cell proliferation. TRPM7 knockdown also enhanced sensitivity to radiotherapy of nasopharyngeal carcinoma. Moreover, we identified TRPM7 as a novel potential regulator of cell proliferation in NPC, through signal transducer and activator of transcription 3 (STAT3)-mediated signaling pathway and other anti-apoptotic factors. TRPM7 and STAT3 activation might be critical for the growth of NPC cells and could be an effective target for treatment of nasopharyngeal carcinoma.

Therapeutic implications of Epstein-Barr virus infection for the treatment of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is highly endemic in certain regions including the People’s Republic of China and Southeast Asia. Its etiology is unique and multifactorial, involving genetic background, epigenetic, and environment factors, including Epstein–Barr virus (EBV) infection. The presence of EBV in all tumor cells, aberrant pattern of antibodies against EBV antigens in patient sera, and elevated viral DNA in patient circulation as well as nasopharyngeal site underline the role of EBV during NPC development. In NPC tumors, EBV expresses latency type II, where three EBV-encoded proteins, Epstein–Barr nuclear antigen 1, latent membrane protein 1 and 2 (LMP1, 2), are expressed along with BamH1-A rightward reading frame 1, Epstein–Barr virus-encoded small nuclear RNAs, and BamH1-A rightward transcripts. Among all encoded proteins, LMP1 plays a central role in the propagation of NPC. Standard treatment of NPC consists of radiotherapy with or without chemotherapy for early stage, concurrent chemoradiotherapy in locally advanced tumors, and palliative systemic chemotherapy in metastatic disease. However, this standard care has limitations, allowing recurrences and disease progression in a certain proportion of cases. Although the pathophysiological link and molecular process of EBV-induced oncogenesis are not fully understood, therapeutic approaches targeting the virus may increase the cure rate and add clinical benefit. The promising results of early phase clinical trials on EBV-specific immunotherapy, epigenetic therapy, and treatment with viral lytic induction offer new options for treating NPC.

BamHI-A rightward frame 1, an Epstein-Barr virus-encoded oncogene and immune modulator

Epstein–Barr virus (EBV) causes several benign and malignant disorders of lymphoid and epithelial origin. EBV-related tumors display distinct patterns of viral latent gene expression, of which the BamHI-A rightward frame 1 (BARF1) is selectively expressed in carcinomas, regulated by cellular differentiation factors including ΔNp63α. BARF1 functions as a viral oncogene, immortalizing and transforming epithelial cells of different origin by acting as a mitogenic growth factor, inducing cyclin-D expression, and up-regulating antiapoptotic Bcl-2, stimulating host cell growth and survival. In addition, secreted hexameric BARF1 has immune evasive properties, functionally corrupting macrophage colony stimulating factor, as supported by recent functional and structural data. Therefore, BARF1, an intracellular and secreted protein, not only has multiple pathogenic functions but also can function as a target for immune responses. Deciphering the role of BARF1 in EBV biology will contribute to novel diagnostic and treatment options for EBV-driven carcinomas. Herein, we discuss recent insights on the regulation of BARF1 expression and aspects of structure-function relating to its oncogenic and immune suppressive properties. © 2013 The Authors. Reviews in Medical Virology published by John Wiley & Sons, Ltd.

Inhibition of Granzyme B by PI-9 protects prostate cancer cells from apoptosis

BACKGROUND

In order for tumors to grow and proliferate, they must avoid recognition by immune cells and subsequent death by apoptosis. Granzyme B (GrB), a protease located in natural killer cells, initiates apoptosis in target cells. Inhibition of GrB by PI-9, its natural inhibitor, can prevent apoptosis. Here we investigate whether PI-9 protects prostate cancer cells from apoptosis.

METHODS

The expression of PI-9 was quantified by qPCR in several prostate cancer cell lines, and GrB activity was tested in each cell line. PI-9 was overexpressed in LNCaP cells, which lack endogenous PI-9. Apoptosis was induced by natural killer cells in LNCaP cells that either contained or lacked PI-9, and the percent cell death was quantified. Lastly, PI-9 levels were examined by qPCR and immunohistochemistry in prostate tumor tissue.

RESULTS

Prostate cancer cell lines that expressed PI-9 could inhibit GrB. Overexpression of PI-9 protected LNCaP cells from natural killer cell-mediated apoptosis. Examination of the levels of PI-9 in tissue from prostate tumors showed that PI-9 could be upregulated in low grade tumors and stochastically dysregulated in high grade tumors. Additionally, PI-9 was found consistently in high grade prostatic intraepithelial neoplasia and atrophic lesions.

CONCLUSIONS

These results indicate that overexpression of PI-9 can protect prostate cancer cells from apoptosis, and this effect may occur in human prostate tumors. These findings imply that early prostatic inflammation may trigger this increase in PI-9. This suggests that PI-9 upregulation is needed early in tumor progression, before additional protective mechanisms are in place.

Host-tumor interactions in nasopharyngeal carcinomas

Like other human solid tumors, nasopharyngeal carcinoma (NPC) is a tissue and a systemic disease as much as a cell disease. Tumor cell population in NPC is highly heterogeneous. Heavy infiltration by non-malignant leucocytes results at least in part from the production of abundant inflammatory cytokines by the malignant epithelial cells. There is indirect evidence that interactions between stromal and malignant cells contribute to tumor development. Peripheral blood samples collected from NPC patients contain multiple products derived from the tumor, including cytokines, non-cytokine tumor proteins, tumor exosomes and viral nucleic acids. These products represent a potential source of biomarkers for assessment of tumor aggressiveness, indirect exploration of cellular interactions and monitoring of tumor response to therapeutic agents. Most NPC patients are immunocompetent with evidence of active humoral and cellular immune responses against EBV-antigens at the systemic level. Tumor development is facilitated by local immunosuppressive factors which are not fully understood. Local accumulation of regulatory T-cells is probably one important factor. At least two NPC tumor products are suspected to contribute to their expansion, the cytokine CCL20 and the tumor exosomes carrying galectin 9. In the future, new therapeutic modalities will probably aim at breaking immune tolerance or at blocking cellular interactions critical for tumor growth.

Density of CD4(+) and CD8(+) T lymphocytes in biopsy samples can be a predictor of pathological response to chemoradiotherapy (CRT) for rectal cancer

Background

Although preoperative radiotherapy (RT) is widely used as the initial treatment for locally advanced rectal cancer (RC) in the neoadjuvant setting, factors determining clinical response have not been adequately defined. Radiosensitivity has recently been shown to be greatly affected by immune function of the host.

Methods

In 48 cases of advanced RC, we retrospectively examined the density of tumor infiltrating CD4(+) and CD8(+) T cells using immunohistochemical staining of biopsy samples before CRT, and examined the correlation with tumor response.

Results

The numbers of both CD4(+) and CD8(+) tumor-infiltrating lymphocytes (TIL) in pre-CRT biopsy samples were strongly correlated with tumor reduction ratio evaluated by barium enema. Moreover, the densities of CD4(+) and CD8(+) TIL were significantly associated with histological grade after CRT. The density of CD8(+) TIL was an independent prognostic factor for achieving complete response after CRT.

Conclusions

In RC patients, T lymphocyte-mediated immune reactions play an important role in tumor response to CRT, and the quantitative measurement of TIL in biopsy samples before CRT can be used as a predictor of the clinical effectiveness of CRT for advanced RC.

The role of inflammation in the pathogenesis of non-small cell lung cancer

The link between chronic immune activation and tumorigenesis is well established. Compelling evidence has accumulated that histologic assessment of infiltration patterns of different host immune response components in non-small cell lung cancer specimens helps identify different prognostic patient subgroups. This review provides an overview of recent insights gained in the understanding of the role played by chronic inflammation in lung carcinogenesis. The usefulness of quantification of different populations of lymphocytes, natural killer cells, macrophages, and mast cells within the tumor microenvironment in non-small cell lung cancer is also discussed. In particular, the importance of assessment of inflammatory cell microlocalization within both the tumor islet and surrounding stromal components is emphasized.

Inflammation in gastric adenocarcinoma of the cardia: how do EBV infection, Her2 amplification and cancer progression influence tumor-infiltrating lymphocytes?

Tumor-infiltrating lymphocytes (TILs) in gastric adenocarcinoma show a strong compartmentalization with high numbers of lymphocytes in the stroma and low intraepithelial lymphocyte counts. Our previous study has shown stromal regulatory T cells (Treg) to be associated with a beneficial outcome in intestinal type cancer of the cardia. We undertook the present study to further evaluate the immunogenic and inflammatory environment in intestinal-type gastric adenocarcinoma of the cardia. We assessed CXCR3 expression, Epstein-Barr virus (EBV) status, Her2/ERBB2 status and overexpression/amplification using tissue microarrays (immunohistochemistry and in situ hybridization) of 52 patients. The data were correlated to different TIL subset counts (CD3, CD8, GranzymeB, FoxP3 and CD20) and to infiltrating histiocytes (CD68) both in the tumor and the surrounding stromal tissue that were reported earlier. Her2/ERBB2 overexpression/amplification showed no correlation to tumor stage. Moreover, for the first time, we show here that Her2/ERBB2 overexpression/amplification has no correlation to overall or subset-specific TIL infiltration. EBV infection was seen in four cases and showed a strong association with intratumoral CD8(+) T cell infiltration as well as a moderate correlation to stromal CD8(+) T cell accumulation. Intratumoral CD8(+) T cell infiltration was significantly correlated to intratumoral FoxP3(+) Treg infiltration, and to a lesser extent, to stromal FoxP3(+) Treg counts. Stromal CXCR3(+) T cell infiltration showed an inverse correlation to T category. This highlights the importance of stromal immune processes for cancer growth and suggests a subversion of Th1 immunoresponse in cancer progression and underlines the important role of inflammation for early carcinogenesis.

FOXP3+ regulatory T cells and tumoral indoleamine 2,3-dioxygenase expression predicts the carcinogenesis of intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND AND AIMS

FOXP3+ regulatory T cells (Tregs) play a central role in self-tolerance and suppress the effective antitumor immune response. A recent study revealed that indoleamine 2,3-dioxygenase (IDO)-mediated tryptophan depletion was able to affect local tumor-infiltrating lymphocytes. The aim of this study was to investigate the clinical significance of the tumor-infiltrating Tregs and tumoral IDO expression during the progression of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas.

METHODS

We investigated the prevalence and localization of FOXP3+ Tregs, CD8+ lymphocytes, and IDO expression in IPMNs by immunohistochemistry. We recruited 39 cases with IPMNs (IPMA: adenoma, n = 11; IPMB: borderline malignancy, n = 9; IPMC: noninvasive carcinoma, n = 7; I-IPMC: invasive IPMC, n = 12).

RESULTS

The prevalence of Tregs increased step by step during the carcinogenesis of IPMNs (Kruskal-Wallis test: p < 0.0001). IDO expression in the tumor was observed in 5 cases with IPMNs (IPMC, n = 1; I-IPMC, n = 4). IDO expression in the tumor was positively correlated with the prevalence of Tregs in IPMNs.

CONCLUSIONS

FOXP3+ Tregs play a role in controlling the immune surveillance against IPMNs at the premalignant stage. IDO expression in the tumor is one of the late-stage phenomena of multistage carcinogenesis of IPMNs.

Increase of programmed death-1-expressing intratumoral CD8 T cells predicts a poor prognosis for nasopharyngeal carcinoma

Intratumoral cytotoxic T lymphocytes are critical for controlling tumor recurrence, and programmed death-1 (PD-1) is a recognized marker of T-cell dysfunction. We analyzed this marker and its binding ligands in nasopharyngeal tumor tissue and non-cancerous nasopharyngeal control tissue to retrospectively evaluate the correlation between its expression and the post-treatment outcome of nasopharyngeal carcinoma patients. Using double immunofluorescence staining, we found that the expression of PD-1 in CD8 T cells in tumor tissue was significantly higher than in control tissue (mean: 28.4 vs 3.9%, P<0.0001). Although the expression rate of PD-1 in intratumoral CD8 cells was not associated with the other clinicopathological parameters examined, the higher expression rate in this subset of T cells significantly correlated with a poorer prognosis of overall survival, disease-free survival, and locoregional recurrence-free survival of the cancer patients (P=0.05, 0.007, and 0.004, respectively). Multivariate analysis confirmed it as an independent risk factor for death, treatment failure, and local recurrence of nasopharyngeal carcinoma. On the other hand, the expression of PD-1 in CD4 T cells and of its ligands in epithelial and stromal cells was not significantly different between tumor and control tissue, and its expression was not associated with clinical outcome of the cancer patients. We propose that PD-1 expression in CD8 cells reflects the selective suppression of cytotoxic lymphocytes in the tumor microenvironment and predicts recurrence of nasopharyngeal carcinoma after conventional therapies.

CD8+ tumor-infiltrating lymphocytes predict favorable prognosis in malignant pleural mesothelioma after resection

Defects in human leukocyte antigen (HLA) class I expression may allow tumor cells to escape immune recognition. T cell infiltration is associated with a good prognosis in many cancers. However, the role of HLA class I expression and tumor-infiltrating lymphocytes (TILs) in malignant pleural mesothelioma (MPM) has not been fully analyzed. In the present study, we investigated the immune profiles and conducted outcome analyses of MPM patients. HLA class I expression and TILs (CD4(+), CD8(+), and NK cells) were detected by immunohistochemistry in a series of 44 MPM cases. To detect HLA class I expression, specimens were stained with the anti-pan HLA class I monoclonal antibody EMR8-5. The expression of HLA class I was positive in all patients. There was no case that showed negative HLA class I expression. The density of CD4(+) and CD8(+) TILs were strongly correlated (R = 0.76, p < 0.001). A high density of CD8(+) TILs was a significantly better prognostic factor for the survival of patients with extrapleural pneumonectomy (p < 0.05). Multivariate analysis revealed that a high density of CD8(+) TILs is an independent prognostic factor for patients who underwent extrapleural pneumonectomy. The presence of intratumoral CD8(+) T cells was correlated with an improved clinical outcome, raising the possibility that CD8(+) T cells might play a pivotal role in the antitumor immune response against MPMs. Thus, the stimulation of CD8(+) lymphocytes might be an efficacious immunotherapy for MPM patients.

Endogenous latent membrane protein 1 in Epstein-Barr virus-infected nasopharyngeal carcinoma cells attracts T lymphocytes through upregulation of multiple chemokines

Tumor-infiltrating T lymphocytes are considered to facilitate development of Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC), but how EBV in NPC tumor cells directs T cell infiltration remains unclear. Here we compare EBV-infected NPC cells with and without spontaneous expression of viral latent membrane protein 1 (LMP1) and find that culture supernatants of LMP1-positive NPC cells exert enhanced chemoattraction to primary T cells. Knockdown of endogenous LMP1 in the cells suppresses the chemotactic activity. Endogenous LMP1 in NPC cells upregulates multiple chemokines, among which MIP-1alpha, MIP-1beta and IL-8 contribute to T cell chemotaxis. We further reveal that LMP1-induced production of MIP-1alpha and MIP-1beta in NPC cells requires not only two carboxyl-terminal activation regions of LMP1 but also their downstream NF-kappaB and JNK pathways. This study corroborates that endogenous LMP1 in EBV-infected NPC cells induces multiple chemokines to promote T cell recruitment and perhaps other pathogenic events in NPC.

Novel approach to the formulation of an Epstein-Barr virus antigen-based nasopharyngeal carcinoma vaccine

Epstein-Barr virus (EBV) is associated with several malignant diseases including nasopharyngeal carcinoma (NPC), a common neoplasm throughout southeast Asia. Radiotherapy and chemotherapy can achieve remission, but a reemergence of disease is not uncommon. Therefore, there is a need for specific therapies that target the tumor through the recognition of EBV antigens. In NPC, latent membrane protein 1 (LMP1) and LMP2 offer the best opportunity for specific targeting since they are typically expressed and T-cell determinants in each of these proteins have been defined. We have attempted to maximize the opportunity of incorporating every possible CD4 and CD8 determinant in a single formulation. We have achieved this by generating a scrambled protein incorporating random overlapping peptide sets from EBNA1, LMP1, and LMP2, which was then inserted into a replication-deficient strain of adenovirus (adenovirus scrambled antigen vaccine [Ad-SAVINE]). This report describes the construction of this Ad-SAVINE construct, its utility in generating LMP1 and LMP2 responses in healthy individuals as well as NPC patients, and its capacity to define new epitopes. This formulation could have a role in NPC immunotherapy for all ethnic groups since it has the potential to activate all possible CD4 and CD8 responses within EBNA1 and LMPs.

Different subsets of tumor infiltrating lymphocytes correlate with NPC progression in different ways

Background

Increasing amounts of evidence indicate that tumor infiltrating lymphocytes (TIL) are correlated with the prognosis of cancer patients. This study focuses on the association between the densities of tumor infiltrating cytotoxic T lymphocytes (CTL), activated CTL, regulatory T lymphocytes (Treg) and Th17 lymphocytes, and the prognosis and clinicopathological features of nasopharyngeal carcinoma (NPC) patients.

Results

Double immunohistochemical staining was performed in 106 biopsy specimens from newly diagnosed NPC patients. Prognostic values of infiltrating lymphocyte densities were evaluated by Kaplan-Meier analysis and Cox regression. The density of CD8+ TIL was positively correlated with lymph node metastasis, while the density of Foxp3⁺ TIL was negatively associated with T stage (P < 0.05). For survival evaluation, the density of Foxp3⁺ TIL or Foxp3⁺ TIL combined with GrB⁺ TIL together was associated with better overall survival (OS) and progression-free survival (PFS) (P < 0.01) in all patients and in the patients with late-stage diseases (Stages III and IV, P < 0.01). Meanwhile a low density of CD8⁺TIL or high ratio of FOXP3⁺TIL to CD8⁺TIL was correlated with better PFS in early stage patients (Stages I and II, P < 0.05). No significant association was found between IL-17⁺ TIL and clinicopathological characteristic or survival of NPC patients.

Conclusions

Our study identifies for the first time the tumor infiltrating Foxp3⁺ TIL as an independent favorable factor in the prognosis of NPC patients, especially for the patients with late-stage diseases.

Liver tumor infiltrating lymphocytes: Comparison of hepatocellular and cholangiolar carcinoma

AIM: To investigate the role of tumor infiltrating lymphocytes (TIL) in primary hepatocellular and cholangiolar carcinomas of the liver.

METHODS: Immunohistochemical analysis was performed including antibodies to CD3, CD4, CD8, CD20, CD56 and TIA-1 in formalin-fixed and paraffin-embedded tissue of 35 liver resection specimens of hepatocellular or cholangiocellular carcinomas. Semiquantitative evaluation was performed with emphasis on the area of the tumor itself and of the tumor/liver interface.

RESULTS: All hepatocellular carcinomas showed infiltration of lymphocytes predominantly around the tumor in the tumor/liver interface consisting mainly of CD3+ CD4+ T lymphocytes [164.3/10 high power fields (HPF)] and in the tumor itself of CD8+ cells (54.9/10 HPF). Cholangiocarcinomas contained a heterogeneous amount of TIL, composed mainly of CD3+ T cells with a predominance of CD8+ cells in the tumor tissue (52.6/10 HPF) and of CD4+ cells in the interface region (223.1/10 HPF). CD56+ cells of the innate immune system were scarce. There was no significant difference between hepatocellular or cholangiolar carcinoma. No correlation with the clinicopathological data was seen.

CONCLUSION: Liver TIL consists of intratumoral CD8+ T cells and peritumoral CD4+ T cells independent of histogenetic origin. Different functions of lymphocytes in these regions seem possible.

An immunohistochemical study of the inflammatory infiltrate associated with nasal carcinoma in dogs and cats

The aims of this study were to characterize the inflammatory infiltrate associated with nasal carcinoma in dogs and cats and to determine whether this differed between the two species or with different types of carcinoma. Sections from fixed tissue biopsy samples of intranasal carcinoma from 31 dogs and six cats were labelled immunohistochemically to detect expression of the T-lymphocyte marker CD3, class II molecules of the major histocompatibility complex (MHC II), the myelomonocytic antigen MAC387 and immunoglobulin (Ig) G, IgA and IgM within the cytoplasm of plasma cells. All canine carcinomas were heavily infiltrated by MAC387(+) neutrophils, with smaller numbers of MAC387(+) macrophages. T cells were particularly prominent in the infiltrate associated with transitional carcinoma, and in such tumours were frequently mixed with MHC II(+) cells having macrophage or dendritic cell morphology. IgG(+) and IgA(+) plasma cells were detected at the peripheral margins of all types of canine carcinoma. In contrast, feline intranasal carcinoma was invariably associated with a marked infiltration of CD3(+) T cells. The feline tumour infiltrates contained sparse neutrophils and macrophages and few IgG(+) and IgA(+) plasma cells. These findings suggest that qualitatively different immune responses are induced in response to specific types of canine intranasal carcinoma, and that the canine and feline immune response to these neoplasms is also distinct.

Increase in tumour-infiltrating lymphocytes with regulatory T cell immunophenotypes and reduced zeta-chain expression in nasopharyngeal carcinoma patients

The pathological significance of the mechanisms of tumour immune-evasion and/or immunosuppression, such as loss of T cell signalling and increase in regulatory T cells (T(regs)), has not been well established in the nasopharyngeal carcinoma (NPC) microenvironment. To evaluate the T(reg) immunophenotypes in tumour-infiltrating lymphocytes (TILs), we performed a double-enzymatic immunostaining for detection of forkhead box P3 (FoxP3) and other markers including CD4, CD8, and CD25 on 64 NPC and 36 non-malignant nasopharyngeal (NP) paraffin-embedded tissues. Expression of CD3 zeta and CD3 epsilon was also determined. The prevalence of CD4(+)FoxP3(+) cells in CD4(+) T cells and the ratio of FoxP3(+)/CD8(+) were increased significantly in NPC compared with those in NP tissues (P < 0.001 and P = 0.025 respectively). Moreover, the ratio of FoxP3(+)/CD25(+)FoxP3(-) in NPC was significantly lower than that in NP tissues (P = 0.005), suggesting an imbalance favouring activated phenotype of T cells in NPC. A significant negative correlation between the abundance of FoxP3(+) and CD25(+)FoxP3(-) cells (P < 0.001) was also identified. When histological types of NPC were considered, a lower ratio of FoxP3(+)/CD25(+)FoxP3(-) was found in non-keratinizing and undifferentiated carcinomas. Increased CD4(+)FoxP3(+)/CD4(+) proportion and FoxP3(+)/CD8(+) ratio were associated with keratinizing squamous cell carcinoma. A reduced expression of CD3 zeta in TILs was found in 20.6% of the NPC tissues but none of the NP tissues. These data provide evidence for the imbalances of T(reg) and effector T cell phenotypes and down-regulation of signal-transducing molecules in TILs, supporting their role in suppression of immune response and immune evasion of NPC.

Characterising the local immune responses in cervical intraepithelial neoplasia: a cross-sectional and longitudinal analysis

INTRODUCTION

Immunological competence influences the progression of cervical intraepithelial neoplasia (CIN) to invasive cancer. Information on the local immunological changes during the natural course of CIN is central for the development of new therapies.

OBJECTIVE

This study defines the populations of tissue-infiltrating immune cells in a cross-sectional cohort of different grades of CIN and also in a longitudinal cohort of regressing, persistent and progressing low-grade (LG)-CIN.

DESIGN

A cohort of 125 women with LG cytological atypia was recruited, of which 64/125 (51%) women with LG-CIN were followed prospectively for 1 year. Paraffin-embedded entry and exit cervical biopsies were used for immunohistochemistry analysis (CD4, CD8, CD56, FOXP3, CD1a and granzyme B).

RESULTS

At recruitment, 74/125 (59%), 39/125 (31%) and 12/125 (10%) women referred with LG smears had histologically proven LG-CIN, high-grade (HG) and normal biopsies, respectively. Seventeen of 64 (24.6%) women with LG-CIN progressed to HG-CIN within 1 year. In both LG-CIN and HG-CIN, the predominant intraepithelial cell population were cytotoxic T cells, while CD4+ and FOXP3+ T cells predominated the stromal compartment. Women with LG-CIN who later on regressed displayed a significantly higher number of cytotoxic (granzyme B+) cells in their entry samples. In addition, the ratio between CD8+ cells and granzyme B+ cells was close to 1, suggesting that all infiltrating CD8+ T cells were highly active. In contrast, this ratio was three-fold lower in women, in whom the lesions persisted or progressed.

CONCLUSIONS

This study suggests that the early infiltration of lesions by highly cytotoxic effector cells protects against progression.

Multiple roles of LMP1 in Epstein-Barr virus induced immune escape

The life cycle of Epstein-Barr virus (EBV) is intriguing in that the virus resides within the immune system and utilizes distinct latency expression programs to establish a persistent infection yet escaping elimination. To achieve this EBV has hijacked cellular signaling pathways to its own benefit, but deregulated viral gene expression can turn into oncogenesis. EBV like many other persistent herpes viruses has evolved ingenious tricks to evade the immune system in part by mimicking host gene function(s). Latent membrane protein 1 (LMP1) mimics CD40 signaling as part of its "normal" biological function and when deregulated, functions as a viral oncogene. LMP1 also affects cell-cell contact, cytokine and chemokine production, Ag presentation and is secreted in the extracellular milieu via immunogenic exosomes. Thus, besides its well-known growth promoting properties LMP1 modulates immune responses. Herein we discuss current knowledge regarding the role of LMP1 in immune evasion of EBV and how this strategy for establishment of persistence contributes to immune escape of EBV+ tumors.

High levels of granzyme B expression in invasive cervical carcinoma correlates to poor response to treatment

The present study assessed, in cervical carcinoma, expression levels of seven immune response genes and sought correlation to response to treatment. The expression levels of CD28, CTLA4, ICOS, ICOSL, CD80 and CD86 and granzyme B genes were assessed by real-time RT-PCR in pre-treatment tumor fragments. During the six-month follow-up after treatment, 8 patients presented tumor and 10 survived free of tumor. The only gene whose expression levels were higher in patients with poor outcome (p = 0.03) was granzyme B. Further evaluation, in adequately powered prospective studies is warranted to confirm the data and to translate this observation to the clinical setting.

Epstein-Barr virus lytic transactivator Zta enhances chemotactic activity through induction of interleukin-8 in nasopharyngeal carcinoma cells

Epstein-Barr virus (EBV)-associated, undifferentiated type of nasopharyngeal carcinoma (NPC) is characterized by intensive leukocyte infiltration. Interaction between the infiltrating cells and the tumor cells has been considered crucial for NPC development. Recruitment of the infiltrates can be directed by certain chemokines present in the NPC tissues. It is unknown whether and how EBV lytic infection regulates expression of the chemokines. Using an antibody array, we first found that several chemokines secreted from EBV-infected NPC cells are increased upon EBV reactivation into the lytic cycle, and interleukin-8 (IL-8) is the chemokine upregulated most significantly and consistently. Further studies showed that the EBV lytic transactivator Zta is a potent inducer of IL-8 in NPC cells, augmenting secreted and intracellular IL-8 proteins, as well as IL-8 RNA. Zta upregulates Egr-1, a cellular transcription factor that has been involved in upregulation of IL-8, but the Zta-induced IL-8 expression is independent of Egr-1. The ability of Zta to transactivate the IL-8 promoter is important for the induction of IL-8, and we have identified two Zta-responsive elements in the promoter. Zta can bind to these two elements in vitro and can also be recruited to the IL-8 promoter in vivo. DNA-binding-defective Zta mutants can neither activate the IL-8 promoter nor induce IL-8 production. In addition, Zta-expressing NPC cells exert enhanced chemotactic activity that is mainly mediated by IL-8. Since IL-8 may contribute to not only leukocyte infiltration but also multiple oncogenic processes, the present study provides a potential link between EBV lytic infection and pathogenesis of NPC.

Immunologic markers of cancer progression and prognosis

During the past decade, significant progress has been made in understanding the interactions between the immune system and cancer. The re-emergence of cancer immunosurveillance and immunoediting concepts has provided an understanding of several immunologic markers that are associated with cancer progression and prognosis. Recent studies have attempted to define the critical role of tumor infiltration by lymphocytes as a reflection of a tumor-related immune response. More recently, there has been an improved ability to demonstrate distinct subsets of tumor-infiltrating lymphocytes (TILs) in different tumor compartments. Several of these studies indicate that the presence of TILs may be associated with improved clinical outcome in several human cancers. However, this improved clinical outcome is dependent upon the intratumoral balance and quality of TILs, or infiltration of regulatory T cells or myeloid-derived suppressor cells. Immunologic markers have an important role in demonstrating intermediate end points of a therapeutic intervention and ultimately may be useful in predicting clinical outcomes. These markers are important to the development of successful immunotherapy strategies in cancer.

Expression of RANTES and MCP-1 in epithelial cells is regulated via LMP1 and CD40

Epstein-Barr virus (EBV)-associated undifferentiated nasopharyngeal carcinoma (NPC) is characterized by a prominent nonneoplastic lymphoid stroma. The functional role of these inflammatory cells and the mechanism of their recruitment are not fully understood. In B-cells, the EBV-encoded latent membrane protein 1 (LMP1) can induce the expression of chemokines in an NF-kappaB dependent manner. We now show that LMP1 can induce the expression of RANTES and MCP-1 in an epithelial cell line, and that this effect is partially reversible by an inhibitor of NF-kappaB. Since tumor cells of virtually all NPCs show CD40 expression while many cases are LMP1-negative at the protein level, we also investigated the effect of CD40 signaling and demonstrate that CD40 stimulation can transiently induce RANTES and MCP-1 expression in LMP1-negative epithelial cells. In in situ hybridization only rare tumor cells showed expression of these chemokines unrelated to LMP1 expression, a pattern consistent with transient induction through CD40 signaling. Since RANTES and MCP-1 were also detected in the neoplastic cells of oral squamous cell carcinomas lacking a lymphoid stroma it remains uncertain to what extent these CC chemokines contribute to the attraction of inflammatory cells into the NPC microenvironment.

Tumor-infiltrating cytotoxic T cells but not regulatory T cells predict outcome in anal squamous cell carcinoma

PURPOSE

Tumor-infiltrating lymphocytes (TIL) are a possible prognostic factor in solid tumors. Cytotoxic TILs are generally considered as prognostically favorable, whereas regulatory T cells (Treg) may have adverse effects by virtue of their ability to inhibit effector cells. We have evaluated the effect of T-cell subsets on survival in patients with anal squamous cell carcinoma following radiochemotherapy.

METHODS

Biopsy specimens from 38 patients with anal carcinomas were evaluated using tissue microarrays and immunohistochemistry for the presence of tumor-infiltrating immune cells using CD3, CD4, CD8, and CD68 antibodies. Treg were identified using an antibody directed against the transcription factor FoxP3, and granzyme B served as a marker for cytotoxic cells. Intratumoral immune cells were enumerated using a semiautomatic image analysis program. Prognostic effect of TIL subsets was evaluated by the log-rank test comparing no evidence of disease survival for groups with high and low numbers using median values as cutoff.

RESULTS

CD3+ and CD4+ TILs influenced no evidence of disease survival: 3-year rates for patients with low numbers were 89% and 95%, respectively, and 54% (P = 0.02) and 48%, (P = 0.01), respectively, in cases with high numbers. Large numbers of tumor-infiltrating granzyme B+ cytotoxic cells had a significant negative prognostic effect (P = 0.008), whereas no effect was observed for Treg.

CONCLUSIONS

TILs were identified as negative prognostic indicators in anal squamous cell carcinomas with granzyme B+ cytotoxic cells showing highest effect on outcome. This is possibly explained by the selection of therapy-resistant tumor cell clones. No prognostic influence of Treg was found. Knowledge of local immune responses is important for the development of immunotherapeutic strategies.

Phosphatidylinositol 3-Kinase/Akt Activation by Integrin-Tumor Matrix Interaction Suppresses Fas-Mediated Apoptosis in T Cells

It has recently become apparent that the microenvironment made up of the extracellular matrix may affect cell signaling. In this study, we evaluated Fas-triggered apoptosis in T cells in contact with tumor cells, which resembles the cell-to-cell interactions found in tumor regions. Jurkat cells were less susceptible to the Fas-mediated apoptosis when cocultured with U118, HeLa, A549, and Huh-7 tumor cells. This was indicated by less plasma membrane alteration, an amelioration of the loss of mitochondria membrane potential, a decrease in caspase-8 and caspase-3 activation, a decrease in DNA fragmentation factor-45/35 cleavage, and a reduction in the breakage of DNA when compared with Jurkat cells cultured alone. In contrast, the tumor cell lines MCF-7 and HepG2 produced no such protective effect. This protective event was independent of the expression of Fas ligand on the tumor cells. Interrupting the beta integrins-matrix interaction diminished the coculture effect. In Jurkat cells, cell matrix contact reduced the assembly of the Fas death-inducing signaling complex and Bcl-x(L) cleavage, but enhanced the phosphorylation of ERK1/2, p38 MAPK, and Akt. Only PI3K inhibitor, but not kinase inhibitors for MEK, ERK1/2, p38 MAPK, JNK, protein kinase C, and protein kinase A, completely abolished this tumor cell contact-associated protection and in parallel restored Fas-induced Bcl-x(L) cleavage as well as decreasing the phosphorylation of Bad at serine 136. Together, our results indicate that stimulation of the beta integrin signal of T cells by contact with tumor cells may trigger a novel protective signaling through the PI3K/Akt pathway of T cells against Fas-mediated apoptosis.

Ectopic expression of the serine protease inhibitor PI9 modulates death receptor-mediated apoptosis

Apoptosis is a highly controlled process, whose triggering is associated with the activation of caspases. Apoptosis can be induced via a subgroup of the tumor necrosis factor (TNF) receptor superfamily, which recruit and activate pro-caspase-8 and -10. Regulation of apoptosis is achieved by several inhibitors, including c-FLICE-inhibitory protein, which prevents apoptosis by inhibiting the pro-apoptotic activation of upstream caspases. Here we show that the human intracellular serine protease inhibitor (serpin), protease inhibitor 9 (PI9), inhibits TNF-, TNF-related apoptosis-inducing ligand- and Fas ligand-mediated apoptosis in certain TNF-sensitive cell lines. The reactive center P1 residue of PI9 was required for this inhibition since PI9 harboring a Glu --> Ala mutation in its reactive center failed to impair death receptor-induced cell death. This suggests a classical serpin-protease interaction. Indeed, PI9 inhibited apoptotic death by directly interacting with the intermediate active forms of caspase-8 and -10. This indicates that PI9 can regulate pro-apoptotic apical caspases.

FOXP3+ regulatory T cells affect the development and progression of hepatocarcinogenesis

PURPOSE

Tumor-infiltrating lymphocytes represent the host immune response to cancer. CD4+CD25+FOXP3+ regulatory T cells (Tregs) suppress the immune reaction. The aim of the present study was to investigate the clinicopathologic significance and roles of Tregs and CD8+ T cells during hepatocarcinogenesis.

EXPERIMENTAL DESIGN

We examined the infiltration of FOXP3+ Tregs and CD8+ T cells in the tumor stroma and nontumorous liver parenchyma using 323 hepatic nodules including precursor lesions, early hepatocellular carcinoma (HCC), and advanced HCC, along with 39 intrahepatic cholangiocarcinomas and 59 metastatic liver adenocarcinomas. We did immunohistochemical comparative studies.

RESULTS

The prevalence of Tregs was significantly higher in HCC than in the nontumorous liver (P<0.001). The patient group with a high prevalence of Tregs infiltrating HCC showed a significantly lower survival rate (P=0.007). Multivariate analysis revealed that the prevalence of Tregs infiltrating HCC was an independent prognostic factor. The prevalence of Tregs increased in a stepwise manner (P<0.001) and that of CD8+ T cells decreased during the progression of hepatocarcinogenesis (P<0.001). Regardless of the presence of hepatitis virus infection or histopathologic evidence of hepatitis, the prevalence of Tregs was significantly increased in nontumorous liver bearing primary hepatic tumors.

CONCLUSIONS

Tregs play a role in controlling the immune response to HCC during the progression of hepatocarcinogenesis. It has been suggested that primary hepatic cancers develop in liver that is immunosuppressed by a marked infiltration of Tregs. A high prevalence of Tregs infiltrating HCC is thought to be an unfavorable prognostic indicator.

Epstein–Barr virus: the future for screening, treatment and monitoring of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is often not diagnosed until an advanced stage of the disease, and has a poor 5-year survival with current therapies. Thus, screening programs to identify high-risk patients at early disease stages are essential to improve patient outcomes, most likely through using Epstein–Barr virus (EBV) DNA monitoring in conjunction with tumor-specific markers. EBV-specific cytotoxic T lymphocytes (CTLs) have been utilized successfully for long-term regression of EBV-associated B-cell lymphomas, such as post-transplant lymphoproliferative disease. This strategy has recently been adapted to raise latent membrane proteins 1 and 2, and EBV nuclear antigen 1-specific CD8+ and CD4+ T cells to target EBV proteins expressed in NPC tumors. Future challenges will be focused on developing multiple-target therapies, including improving CTL persistence and tumor specificity. Understanding the role of EBV infection and protein expression in NPC will be pivotal in the development of screening protocols and novel treatments, including vaccines.

Expression of the apoptosis inhibitor protease inhibitor 9 predicts clinical outcome in vaccinated patients with stage III and IV melanoma

PURPOSE

There have been reports of successful treatment of metastatic melanoma patients with active specific immunotherapy (ASI) using irradiated autologous tumor cell vaccination. It is still unknown why some patients respond and others do not. Tumor cells can evade the immune system, for example through interference with antigen presentation by down-regulation of MHC molecules or expressing proteins interfering with cytotoxic lymphocyte-induced apoptosis like the granzyme B antagonist protease inhibitor 9 (PI-9).

EXPERIMENTAL DESIGN

PI-9 expression was detected in melanoma cell lines. To investigated if PI-9 is important in the response to ASI, paraffin-embedded tissues from stage III or IV melanoma patients were stained.

RESULTS

PI-9 is expressed in melanoma cells and expression in metastasized melanoma cells is, in this group of patients, an adverse prognostic marker with regard to overall and disease-free survival. Moreover, loss of MHC-1 expression frequently occurs during tumor progression but is not associated with poor clinical outcome. Interestingly, melanoma patients with a favorable clinical outcome after ASI therapy usually have high percentages of activated (granzyme B-positive) tumor-infiltrating lymphocytes at time of first diagnosis and low percentages of activated lymphocytes at time of recurrent tumor.

CONCLUSIONS

Expression of PI-9 in metastatic melanoma cells is associated with unfavorable clinical outcome whereas MHC-1 down-regulation is not. Although it cannot be proven that PI-9 expression is directly responsible for failure of immunotherapy, these data suggest that expression of PI-9 could be an important immune escape mechanism and that modulation of this inhibitor may enhance the efficacy of immunotherapy.

Absence of caspase 3 activation in neoplastic cells of nasopharyngeal carcinoma biopsies predicts rapid fatal outcome

Poor prognosis in nasopharyngeal carcinoma patients may result from resistance to the apoptosis-inducing effect of radio- and/or chemotherapy. Apoptosis depends on proper activation of caspase 3, resulting in cleavage of key proteins like PARP-1. To investigate whether disruption of the apoptosis pathway results in therapy-resistant tumour cells, we investigated whether absence of caspase 3 activation in tumour biopsies of nasopharyngeal carcinoma patients is related to poor clinical outcome. Moreover, we investigated whether absence of caspase 3 activation is related to loss of procaspase 3 expression or expression of the apoptosis regulators p53, bcl-2 and XIAP. We studied 36 Indonesian nasopharyngeal carcinoma patients without evidence of distant metastases who were treated with curative intent by radiotherapy only. Activation of caspase 3 and expression of the different markers were determined using specific antibodies. Levels of caspase 3 activation were determined by quantifying positively staining tumour cells. Nasopharyngeal carcinoma-derived C15 and C17 tumour cells were used as control. Absence of caspase 3 activation was strongly related to a poor clinical response to radiotherapy and to a higher T and N stage, resulting in a particularly poor clinical outcome with regard to progression-free (P<0.0001) and overall survival time (P<0.0001). Absence of caspase 3 activation was significantly correlated to loss of expression of procaspase 3 (P=0.04). In nasopharyngeal carcinoma patients treated with curative intent, absence of active caspase 3-positive neoplastic cells predicts rapid fatal outcome, and is associated with poor response to radiotherapy and high T and N stage at time of presentation.

The granzyme B inhibitor proteinase inhibitor 9 (PI9) is expressed by human mast cells

The activity of granzyme B, a main effector molecule of cytotoxic T lymphocytes (CTL) and natural killer cells, is regulated by the human intracellular serpin proteinase inhibitor 9 (PI9). This inhibitor is particularly expressed by CTL and dendritic cells, in which it serves to protect these cells against endogenous and locally released granzyme B. Moreover, PI9 expression by neoplastic cells may constitute one of the mechanisms for tumors to escape immune surveillance. Here we show that PI9 is also expressed by human mast cells. In immunohistochemical studies using a PI9-specific monoclonal antibody, strong cytoplasmic staining for PI9 was found in normal mast cells in various tissues throughout the body. In addition, in 80% of all cases of cutaneous and systemic mastocytosis tested the majority of the mast cells expressed PI9. As an in vitro model for PI9 expression by mast cells, we studied expression by the human mast cell line HMC-1. Stimulation of HMC-1 with PMA and the calcium ionophore A23187 resulted in a marked increase of PI9 expression. Thus, PI9 is expressed by activated mast cells. We suggest that this expression serves to protect these cells against apoptosis induced by granzyme B released during initiation of the local inflammatory response.

Expression of the interferon-inducible chemokine IP-10 (CXCL10), a chemokine with proposed anti-neoplastic functions, in Hodgkin lymphoma and nasopharyngeal carcinoma

Hodgkin lymphoma (HL) and nasopharyngeal carcinoma (NPC) are characterized by their association with Epstein-Barr virus (EBV) and an abundant infiltrate of reactive lymphoid cells. The presence of this lymphoid stroma may influence the effect of anti-viral immunotherapy. The interferon-inducible chemokine IP-10 has anti-neoplastic effects in several model systems mediated by T-cells expressing the CXCR3 chemokine receptor. Using in situ hybridization, it is shown that IP-10 is expressed in neoplastic cells of HL and correlates both with the mixed cellularity histotype and with EBV infection. IP-10 expression was also detected in tumour cells of most NPCs as well as in EBV-negative squamous cell carcinomas of the tongue. Thus, in carcinomas, IP-10 expression showed no correlation with EBV infection. Numerous CXCR3-positive lymphocytes were detected in the lymphoid stroma of HL and NPC, raising the possibility of a Th1-predominant immune response in these cases. In view of the proposed anti-neoplastic functions of IP-10 and CXCR3-positive lymphocytes, these findings are unexpected and raise the possibility that endogenous IP-10 expression in the context of human tumours may not exert the anti-tumour effects ascribed to it by in vitro experiments.

Treatment of nasopharyngeal carcinoma with Epstein-Barr virus--specific T lymphocytes

Conventional treatment for nasopharyngeal carcinoma (NPC) frequently fails and is accompanied by severe long-term side effects. Since virtually all undifferentiated NPCs are associated with Epstein-Barr virus (EBV), this tumor is an attractive candidate for cellular immunotherapy targeted against tumor-associated viral antigens. We now demonstrate that EBV-specific cytotoxic T-cell (CTL) lines can readily be generated from individuals with NPC, notwithstanding the patients' prior exposure to chemotherapy/radiation. A total of 10 patients diagnosed with advanced NPC were treated with autologous CTLs. All patients tolerated the CTLs, although one developed increased swelling at the site of pre-existing disease. At 19 to 27 months after infusion, 4 patients treated in remission from locally advanced disease remain disease free. Of 6 patients with refractory disease prior to treatment, 2 had complete responses, and remain in remission over 11 to 23 months after treatment; 1 had a partial remission that persisted for 12 months; 1 has had stable disease for more than 14 months; and 2 had no response. These results demonstrate that administration of EBV-specific CTLs to patients with advanced NPC is feasible, appears to be safe, and can be associated with significant antitumor activity.