Search

Background Cancer-testis antigens (CTAs) and tumour-associated antigens (TAAs) are frequently expressed in hepatocellular carcinoma (HCC); however, the role of tumour-antigen-specific T cell immunity in HCC progression is poorly defined. We characterized CTA- and TAA-specific T cell responses in different HCC stages and investigated their alterations during HCC progression. Methods Fifty-eight HCC patients, 15 liver cirrhosis patients, 15 chronic hepatitis B patients and 10 heathy controls were enrolled in total. IFN-γ ELSPOT using CTAs, including MAGE-A1, MAGE-A3, NY-ESO-1, and SSX2, and two TAAs, SALL4 and AFP, was performed to characterize the T-cell immune response in the enrolled individuals. The functional phenotype of T cells and the responsive T cell populations were analyzed using short-term T-cell culture. Results T cell responses against CTAs and TAAs were specific to HCC. In early-stage HCC patients, the SALL4-specific response was the strongest, followed by MAGE-A3, NY-ESO-1, MAGE-A1 and SSX2. One-year recurrence-free survival after transcatheter arterial chemoembolization plus radiofrequency ablation treatment suggested the protective role of CTA-specific responses. The four CTA- and SALL4-specific T cell responses decreased with the progression of HCC, while the AFP-specific T cell response increased. A higher proportion of CD4+ T cells specific to CTA/SALL4 was observed than AFP-specific T cell responses. Conclusions The IFN-γ ELISPOT assay characterized distinct profiles of tumour-antigen-specific T cell responses in HCC patients. CTA- and SALL4-specific T cell responses may be important for controlling HCC in the early stage, whereas AFP-specific T cell responses might be a signature of malignant tumour status in the advanced stage. The application of immunotherapy at an early stage of HCC development should be considered.

Context: We previously reported a novel tumour associated antigen (TTA) with molecular weight around 48 kDa and identified the novel TTA as a fragment derived from human DNA-topoiomerase I (TOP1). We termed the novel TAA as TOPO48 and termed autoantibody against the TAA as anti-TOPO48 autoantibody. Objective: To explore the clinical significance of anti-TOPO48 autoantibody in patients with colorectal carcinoma (CRC). Materials and methods: Serum levels of the autoantibody in patients with CRC or benign tumours and healthy volunteers were measured with a specific ELISA. Results: CRC patients at early stage had higher frequency of positive levels of the autoantibody and CRC patients with positive autoantibody levels had higher overall survival rate than those with negative autoantibody levels. Conclusion: The autoantibody is a potential biomarker for early diagnosis and favourable prognosis of CRC.

Background: The production of autoantibodies against tumour-associated antigens (TAAs) is believed to reflect greater immunologic reactivity in cancer patients and enhanced immune surveillance for cancer cells. Over the past few decades, a number of different TAAs and their corresponding autoantibodies have been investigated. However, positive frequency of autoantibody detection in cancer patients has been relatively low. Here we describe a novel TAA that was a fragment derived from human DNA-topoiomerase I and an autoantibody against the novel TAA with relatively high positive frequency in the sera of early-stage non-small-cell lung cancer (NSCLC), gastric cancer (GC), colorectal cancer (CRC) and oesophageal squamous cell carcinoma (ESCC). Methods: Serologic enzyme-linked immunosorbent assay (ELISA) and western blot were used to discover a novel TAA with a molecular weight of 48 kDa separated by ion exchange chromatography. Autoantibody ELISA, immnohistochemistry and immunofluorescent staining, recombinant protein cloning/expression and western blot were used to identify the novel TAA. The association of the autoantibody against the novel TAA with early-stage carcinoma was explored by screening 203 stage I/II patients and 170 stage III/IV patients with NSCLC, GC, CRC or ESCC. Results: We identified the novel TAA as a fragment derived from human DNA-topoiomerase I (TOP1). We found that the novel TAA induced specific autoantibodies with a high prevalence that ranged from 58 to 72% in some of the most common types of cancer. We observed that the immune response against the novel TAA was associated with early stage ESCC, GC, CRC and NSCLC. Conclusions: The findings in this study suggest that the autoantibody against the novel TAA may be a potential biomarker for use in the early detection and diagnosis of cancer.

Background: The distinct expression pattern of tumour-associated antigens (TAAs) might be a critical reason for the inefficacy of immunity-based treatments and heterogeneous postsurgical recovery in patients with solid tumours, including hepatocellular carcinoma (HCC). However, little is known about the clinical value of the coexpression patterns of multiple TAAs. Methods: We determined the expression of multiple TAAs with identified immunogenicity (GPC3, AFP, SSX-2, NY-ESO-1, EpCAM, midkine) and the density of tumour-infiltrating immune cells by immunohistochemistry in a panel of 362 primary HCC patients. We evaluated the association between the TAAs, immune cell infiltration, clinicopathological parameters, and prognosis. Results: Patients who coexpressed more TAAs had better prognosis (P

Background & Aims: Chondroitin-glucuronate C5-epimerase is an enzyme that converts D-glucuronic acid to L-iduronic acid residues in dermatan sulphate biosynthesis. It is also identified to be a tumour-associated antigen recognized by cytotoxic T cells (CTLs) and its enhanced expression in many cancers has been reported. In the present study, we investigated the usefulness of this molecule as an immunotherapeutic target in hepatocellular carcinoma (HCC). Methods: The expression of chondroitin-glucuronate C5-epimerase in hepatoma cell lines and HCC tissues was confirmed by immunofluorescence and immunohistochemical analysis. CTL responses were investigated by several immunological techniques using peripheral blood mononuclear cells (PBMCs) or tumour-infiltrating lymphocytes. To determine the safety of immunotherapy using chondroitin-glucuronate C5-epimerase-derived peptide, 12 patients with HCC were administered s.c. vaccinations of the peptides and analysed. Results: Chondroitin-glucuronate C5-epimerase was expressed in HCC cell lines and human tissues including alpha-foetoprotein (AFP)-negative individuals. Chondroitin-glucuronate C5-epimerase-specific CTLs could be generated by stimulating PBMCs of HCC patients with peptides and they showed cytotoxicity against HCC cells expressing the protein. The frequency of CTL precursors investigated by enzyme-linked immunospot (ELISPOT) assay was 0-34 cells/3 × 10 5 PBMCs and the infiltration of interferon-gamma-producing CTLs into the tumour site was confirmed. In the vaccination study, no severe adverse events were observed and the peptide-specific CTLs were induced in 4 of 12 patients tested. Conclusions: Chondroitin-glucuronate C5-epimerase is a potential candidate for tumour antigen with immunogenicity and the peptides derived from this antigen could be useful in HCC immunotherapy. © 2012 John Wiley & Sons A/S.

Background: Identification of tumour-associated antigens (TAAs) that induce cytotoxic T lymphocytes (CTLs) specific to cancer cells is critical for the development of anticancer immunotherapy. In this study, we aimed at identifying a novel TAA of pancreatic cancer for immunotherapy. Methods: On the basis of the genome-wide cDNA microarray analysis, we focused on KIF20A (also known as RAB6KIFL/MKlp2) as a candidate TAA in pancreatic cancer cells. The HLA-A2 (A*02:01)-restricted CTL epitopes of KIF20A were identified using HLA-A2 transgenic mice (Tgm) and the peptides were examined to check whether they could generate human CTLs exhibiting cytotoxic responses against KIF20A+, HLA-A2+ tumour cells in vitro. Results: KIF20A was overexpressed in pancreatic cancer and in some other malignancies, but not in their non-cancerous counterparts and many normal adult tissues. We found that KIF20A-2 (p12–20, LLSDDDVVV), KIF20A-8 (p809–817, CIAEQYHTV), and KIF20A-28 (p284–293, AQPDTAPLPV) peptides could induce HLA-A2-restricted CTLs in HLA-A2 Tgm without causing autoimmunity. Peptide-reactive human CTLs were generated from peripheral blood mononuclear cells of HLA-A2+ healthy donors by in vitro stimulation with the three peptides, and those CTLs successfully exhibited cytotoxic responses to cancer cells expressing both KIF20A and HLA-A2. Conclusion: KIF20A is a novel promising candidate for anticancer immunotherapeutic target for pancreatic cancers.

In a phase II study, 43 renal cell carcinoma patients were treated with individualised doses of ABR-214936; a fusion of a Fab recognising the antigen 5T4, and Staphylococcal enterotoxin A. Drug was given intravenously on 4 consecutive days, treatment was repeated 1 month later. Treatment was associated with moderate fever and nausea, but well tolerated. Of 40 evaluable patients, 28 had disease control at 2 months, and at 4 months, one patient showed partial response (PR) and 16 patients stable disease. Median survival, with minimum follow-up of 26 months was 19.7 months with 13 patients alive to date. Stratification by the Motzer's prognostic criteria highlights prolonged survival compared to published expectation. Patients receiving higher drug exposure had greater disease control and lived almost twice as long as expected, whereas the low-exposure patients survived as expected. Sustained interleukin-2 (IL-2) production after a repeated injection appears to be a biomarker for clinical effect, as the induced-IL-2 level on the day 2 of treatment correlated with survival. The high degree of disease control and the prolonged survival suggest that this treatment can be effective. These findings will be used in the trial design for the next generation of drug, with reduced antigenicity and toxicity.

In the years following the discovery of techniques to generate a nearly limitless supply of monoclonal antibodies, much attention has been given to their use in the therapy of malignant diseases. During this time we have developed strategies that allow for the detection and also the irradication of malignant cells, not only from haematological malignancies, but also from solid tumours utilising naive, conjugated and designer antibodies. With the arrival of genetic engineering, antibodies have been manipulated in countless ways, not only with respect to their specificity, but their pharmacokinetics and pharmacodynamics may also be altered. A firm background, developed from years of in vivo studies, is now leading the field into a bright future. In the last few years, over 20 monoclonal antibodies (mAbs) have gained licence approval, not only in malignant indications. In this postgenomic era a multitude of technologies will allow us to rapidly identify, characterise and evaluate new targets. There is a deve...

Vaccines have classically been used for disease prevention. Modern clinical vaccines are continuously being developed for both traditional use as well as for new applications. Typically thought of in terms of infectious disease control, vaccination approaches can alternatively be adapted as a cancer therapy. Vaccines targeting cancer antigens can be used to induce anti-tumour immunity and have demonstrated therapeutic efficacy both pre-clinically and clinically. Various approaches now exist and further establish the tremendous potential and adaptability of anti-cancer vaccination. Classical strategies include ex vivo-loaded immune cells, RNA- or DNA-based vaccines and tumour cell lysates. Recent oncolytic virus development has resulted in a surge of novel viruses engineered to induce powerful tumour-specific immune responses. In addition to their use as cancer vaccines, oncolytic viruses have the added benefit of being directly cytolytic to cancer cells and thus promote antigen recognition within a highly immune-stimulating tumour microenvironment. While oncolytic viruses are perfectly equipped for efficient immunization, this complicates their use upon previous exposure. Indeed, the host’s anti-viral counter-attacks often impair multiple-dosing regimens. In this review we will focus on the use of oncolytic viruses for anti-tumour vaccination. We will explore different strategies as well as ways to circumvent some of their limitations.

International audience; Aims: Mucin 1 (MUC1) is an important tumour-associated antigen (TAA), both over-expressed and aberrantly glycosylated in adenocarcinomas. The objective of this study was to examine the MUC1-glycosylation status in primary ovarian adenocarcinomas and metastatic lesions. Methods and results: Paraffin-embedded tissue sections of 37 primary ovarian adenocarcinomas representing all histotypes (22 serous, 5 mucinous, 2 clear cell, 8 endometrioid), 4 serous borderline tumours with intraepithelial carcinoma, 7 sections of ovarian endometriosis and 13 metastatic lesions were analysed by immuno-histochemistry. Non-neoplastic ovarian surface epithelium and serous cystadenomas were used as controls. All epithelia expressed MUC1 protein. Of primary tumours, 76% expressed the differentiation-dependent glycoform and 84% the cancer-associated glycoform (Tn/Sialyl-Tn-epitopes). In metastatic lesions this was 77% and 85%, respectively. Notably, in 57% of ovarian endometriosis and 75% of intraepithelial lesions, the cancer-associated MUC1 epitopes were expressed, whereas normal ovarian surface epithelium and serous cystadenomas did not express these epitopes. Conclusions: The underglycosylated MUC1 epitopes are expressed by all histotypes of primary ovarian adenocarcinomas, by the vast majority of metastatic lesions and by ovarian cancer precursor lesions, whereas not by normal ovarian tissue. These results indicate that MUC1-associated Tn/STn-epitopes are important targets for immunotherapy and diagnostic imaging in ovarian cancer patients.

The CA 125 assay is used to monitor the course of disease in women with adenocarcinoma of the genital tract. We measured serum CA 125 levels longitudinally in three different groups of patients who had normal serum CA 125 levels (less than or equal to 16 U/ml) before extensive intraperitoneal abdominal surgery (group 1, second-look laparotomy in 28 women with ovarian cancer; group 2, radical hysterectomy in 42 patients with cervical cancer; group 3, 13 men and one woman who had aortic surgery for atherosclerotic occlusive disease or aneurysm formation). Following surgery, rising serum CA 125 levels were observed in 69 out of the 84 patients (82%), irrespective of the primary diagnosis, type of operation or sex. The highest levels were found during the second week after the operation (range 3-336 U/ml) and decreased gradually thereafter, to become normal at 8 weeks after surgery. It was concluded that abdominal surgery interferes with the specificity of CA 125 as a tumour marker during the early postoperative period.

Prognosis for patients suffering from malignant glioma has not substantially improved. Specific immunotherapy as a novel treatment concept critically depends on target antigens, which are highly overexpressed in the majority of gliomas, but the number of such antigens is still very limited. SOX2 was identified by screening an expression database for transcripts that are overexpressed in malignant glioma, but display minimal expression in normal tissues. Expression of SOX2 mRNA was further investigated in tumour and normal tissues by real-time PCR. Compared to cDNA from pooled normal brain, SOX2 was overexpressed in almost all (9 out of 10) malignant glioma samples, whereas expression in other, non-malignant tissues was almost negligible. SOX2 protein expression in glioma cell lines and tumour tissues was verified by Western blot and immunofluorescence. Immunohistochemistry demonstrated SOX2 protein expression in all malignant glioma tissues investigated ranging from 6 to 66% stained tumour cells. Human leucocyte antigen-A(*)0201-restricted SOX2-derived peptides were tested for the activation of glioma-reactive CD8+ cytotoxic T lymphocytes (CTLs). Specific CTLs were raised against the peptide TLMKKDKYTL and were capable of lysing glioma cells. The abundant and glioma-restricted overexpression of SOX2 and the generation of SOX2-specific and tumour-reactive CTLs may recommend this antigen as target for T-cell-based immunotherapy of glioma.

2527 Background: 5T4 is a tumour associated antigen that is widely expressed on the surface of most human adenocarcinomas, including colorectal, but rarely in normal cells. Modified Vaccinia Ankara (MVA) has been employed as a vaccine vector to deliver 5T4. Previously, MVA-5T4 has been evaluated in a phase I/II clinical trial in stage IV colorectal cancer patients. MVA-5T4 was shown to be safe and well tolerated and induced 5T4 specific immune responses in most patients. Furthermore, 5T4 specific antibody titres correlated with clinical benefit. Methods: Two open label phase II clinical trials were initiated in which patients with advanced colorectal cancer received MVA-5T4 in conjunction with either 5-FU/leukovorin and irinotecan (TV2-IFL; n=19 patients) or 5-FU/leukovorin and oxaliplatin (TV2-FOLFOX; n=17 patients). MVA-5T4 was administered up to 6 times, 2 prior to, 2 during and 2 post-chemotherapy. The primary objectives were to assess the safety and immunogenicity of MVA-5T4 given in combination with chemotherapy. Results: Recruitment to both trials is complete and MVA-5T4 was well tolerated in all ITT patients, with no serious adverse events being associated with MVA-5T4. 5T4-specific cellular and humoral immune responses were monitored before, during and after chemotherapy in all 23 per protocol patients (n=12 for TV2-IFL and n=11 for TV2-FOLFOX). Following vaccination, all 23 patients mounted 5T4 cellular and/or humoral responses. Immune responses were detectable during chemotherapy in the majority of patients. IFNγ ELISPOT responses to 5T4 peptides revealed precursor frequencies as high as 1 in 1000 PBMCs. Assessment of clinical responses in all PP patients demonstrated an overall response rate of 65% across both trials. Conclusions: MVA-5T4 is safe and well tolerated when administered in conjunction with IFL and FOLFOX chemotherapy regimens. Furthermore, 5T4 specific immune responses are induced in all per protocol patients and can be boosted or maintained during chemotherapy. Encouraging clinical responses have been observed and 5T4 immune responses shown to correlate with clinical benefit. [Table: see text]

MANY mouse and human tumours express major histocompatibility complex (MHC) class I-associated antigens that constitute targets for syngeneic cy to toxic T lymphocytes (CTL). Genes encoding such antigens were isolated from a mouse mastocytoma and from human melanomas by genetic methods1,2. Isolation and charac-terization of MHC class I-associated peptides has enabled specific anchor residues to be identified that are typical of peptides that bind to distinct class I molecules3. Moreover, CTL specific to particular MHC-peptide combinations have been used to identify naturally occurring antigenic peptides in cell extracts and enabled them to be sequenced directly4–6. Most known MHC ligands are of viral origin or are self peptides derived from normal proteins7. Here we use total acid extraction and repeated fractionation to isolate and sequence Lewis lung carcinoma (3LL)-specific pep-tide(s), which shows sequence homology to the connexin 37 protein. Synthetic octamers based on these sequences bind to 'empty' H-2Kb molecules on RMA-S cells, sensitize RMA-S cells to lysis by specific anti-3LL CTL, and induce anti-tumour CTL. The tumour-associated peptide originates from mutated connexin 37 expressed in 3LL.s

A radioimmunometric sandwich assay for the tumour-associated antigen defined by the monoclonal antibody (MAb) HMFG2, has been used to measure serum levels of the antigen in 76 healthy controls, 38 ovarian carcinoma patients pre-operatively, 98 patients 2 to 6 weeks after surgery and 36 patients at relapse or in complete remission at 12 months. HMFG2 antigen levels were elevated in 33% of stage-I and 62% of II-IV patients pre-operatively; they reflected bulk of disease post-surgically and were significantly higher in patients in relapse than in those who were in complete remission. HMFG2 antigen levels predicted the clinical course of disease in the majority of patients.

Xeno-antiserum specific for antigenic components of bronchogenic carcinoma was raised in rabbits, by passively immunizing them to normal human lung antigens at the same time as immunization with a tumour extract from a squamous-cell carcinoma. Antiserum so raised contained minimal quantities of anti-normal antibody which could be removed by a single absorption with glutaral-dehyde-insolubilized normal lung extract. When tested by quantitative complement fixation with a panel of tumour extracts from surgical specimens, it was found that the antiserum gave positive complement fixation with all squamous-cell carcinoma extracts tested, and with some of the extracts from bronchogenic carcinomas of differing pathological types. The antiserum was essentially negative for pooled extracts from normal lung, liver and spleen but gave a weak positive reaction with an extract of pooled foetal lung tissue.

Les taux seriques d'antigene CA 125 exprime par les cancers epitheliaux de l'ovaire ont ete doses chez 27 femmes menopausees presentant des tumeurs ovariennes et 16 temoins. On a observe des taux augmentes chez 9 (75%) des 12 patientes avec cancer ovarien; chez 3 patientes avec maladie au stade I les taux n'etaient pas augmentes. Aucune difference significative n'a ete trouvee pour les taux du sang veineux ovarien ou peripherique. Une baisse de taux d'antigene a ete observee 6-30 semaines apres intervention radicale et chimiotherapie cytostatique dans le groupe cancereux. Les resultats indiquent la valeur du dosage de CA 125 comme marqueur tumoral dans le suivi des cancers ovariens

The presence of Ca 125, an ovarian cancer-associated antigen, was assessed in serum from patients with liver diseases with (n = 26) and without (n = 26) ascites. Abnormal levels of serum CA 125 were observed in all patients with ascites and in 4 patients without ascites (15%). We conclude that CA 125 is a non-specific marker of ascites whatever the origin: ovarian carcinoma, cirrhosis or peritoneal inflammatory process.

Les auteurs rapportent deux techniques d'isolement de cellules hybrides humaines (cellules HeLa croisees avec des fibroblastes du derme) associees a des tumeurs radio-induites basees sur le fait que les cellules tumorales expriment selectivement une proteine de surface qui peut etre reconnue par un anticorps monoclonal. De telles techniques permettent un enrichisement rapide du milieu de culture

A tumour associated antigen, Tissue Polypeptide Antigen (TPA), has been evaluated in a study on patients suffering from small cell lung carcinoma. The results obtained indicate that TPA might be a useful tumour marker in the management of this disease. The study was performed on sera collected prior to therapy. The TPA levels were compared to stage of disease and to patient survival. It was found that TPA levels above 120 U/l are associated with increased probability for extensive disease. Patients with high serum TPA levels exhibit decreased survival. Also with respect to non-small cell lung cancer, high serum levels of TPA seem to correlate with high probability for extensive disease and decreased survival.

In this report we describe the preparation and partial characterization of a mono-specific anti-Wilms' antiserum raised in rabbits which had previously been injected normal kidney extracts in utero . The tumour associated antigen in Wilms' tumour does not appear to be oncofoetal antigen and it has also failed to react with feutin. It is possible that both our antiserum and that of Burtin and Gendron may be directed against a similar cell component.

TUMOUR-directed antibodies are found in the serum of patients suffering from malignant melanoma1–5, and so we have attempted to detect tumour-associated antigens in extracts from melanoma tumours and urine of patients.