Impact of antigen presentation on TCR modulation and cytokine release: implications for detection and sorting of antigen-specific CD8+ T cells using HLA-A2 wild-type or HLA-A2 mutant tetrameric complexes.

Abstract Soluble MHC class I molecules loaded with antigenic peptides are available either to detect and to enumerate or, alternatively, to sort and expand MHC class I-restricted and peptide-reactive T cells. A defined number of MHC class I/peptide complexes can now be implemented to measure T cell responses induced upon Ag-specific stimulation, including CD3/CD8/ζ-chain down-regulation, pattern, and quantity of cytokine secretion. As a paradigm, we analyzed the reactivity of a Melan-A/MART-1-specific and HLA-A2-restricted CD8+ T cell clone to either soluble or solid-phase presented peptides, including the naturally processed and presented Melan-A/MART-1 peptide AAGIGILTV or the peptide ana…

Identification of NY-ESO-1 epitopes presented by human histocompatibility antigen (HLA)-DRB4*0101-0103 and recognized by CD4(+) T lymphocytes of patients with NY-ESO-1-expressing melanoma

NY-ESO-1 is a member of the cancer-testis family of tumor antigens that elicits strong humoral and cellular immune responses in patients with NY-ESO-1–expressing cancers. Since CD4+ T lymphocytes play a critical role in generating antigen-specific cytotoxic T lymphocyte and antibody responses, we searched for NY-ESO-1 epitopes presented by histocompatibility leukocyte antigen (HLA) class II molecules. Autologous monocyte-derived dendritic cells of cancer patients were incubated with recombinant NY-ESO-1 protein and used in enzyme-linked immunospot (ELISPOT) assays to detect NY-ESO-1–specific CD4+ T lymphocyte responses. To identify possible epitopes presented by distinct HLA class II allele…

Identification of Point Mutations in Genes Coding for tum-Antigens. A Step Towards the Understanding of Mouse and Human Tumor-Specific Transplantation Antigens?

Most experimental tumors induced with chemical carcinogens or UV radiation express individually specific transplantation antigens that elicit a T cell-mediated immune rejection in the syngeneic animals (Prehn and Main 1957; Klein et al. 1960; Kripke 1981; Uyttenhove et al. 1983). The characterization of these transplantation antigens has proved very difficult and several different approaches have been followed. One involves the search for specific antibodies to isolate the antigen by immunoprecipitation. Unfortunately, tumors seldom elicit antibodies directed against their specific transplantation antigens. One notable exception is UV-induced tumor 1591, and the molecules that were isolated…

Spontaneous and antibody-dependent cellular immune reactions to ethanol-altered hepatoma cells

— Spontaneous cell-mediated cytotoxicity (SCMC), antibody-dependent cellular cytotoxicity (ADCC) and proliferative lymphocyte stimulation in alcoholic liver disease (ALD) were investigated. Peripheral blood lymphocytes (PBL) from eight patients with advanced ALD and nine normal controls were tested against hepatoma cells (PLC/PRF/5) as targets. Target cells were grown in either normal culture medium or medium supplemented with 1 and 5% ethanol, respectively, for 24 to 48 h. Ethanol-exposed hepatoma cells exhibited profound and characteristic morphological alterations. Ethanol preincubation, however, proved to be without effect on immune reactions. Provided that hepatoma cells are an appropr…

Frequency analysis of tumor-reactive cytotoxic T lymphocytes in peripheral blood of a melanoma patient vaccinated with autologous tumor cells

A limiting-dilution assay was developed and used to determine the frequency of autologous tumor-reactive cytotoxic T lymphocytes (CTL) in peripheral blood of a melanoma patient MZ2, who has been free of detectable disease since several years. In this patient, the frequencies of tumor-reactive CTL spontaneously varied only by a factor of 1.5. After vaccinations with autologous mutagenized and lethally irradiated tumor cells a two- to tenfold increase in frequencies of tumor-reactive CTL was found within the first 2 weeks. Thereafter, CTL frequencies returned to values measured prior to vaccinations. We conclude, that the limiting-dilution assay applied in this study can detect changes in the…

Stomach signet-ring cancer cell line (MZ-STO-1), established in tissue culture: Morphological characterization and antigenic profile

Abstract 5516: Therapeutic vaccination with the survivin-derived multi-epitope vaccine EMD640744 in patients with advanced solid tumors

Abstract Background: Survivin is a promising tumor-associated antigen for cancer immunotherapy that fulfills two major criteria for this purpose: (1) tumor cells depend on the actions of survivin (inhibition of apoptosis, unrestricted proliferation and angiogenesis); and (2) the protein has demonstrated immunogenicity in patients with different cancers. Here we report results of a first-in-man Phase I study with EMD640744, a cocktail of survivin-derived partially modified HLA class I-restricted peptides in Montanide® ISA 51 VG. Methods: This multicenter, open-label, parallel group, randomized study compared the immunologic efficacy, safety, tolerability and clinical activity of three dosage…

Strong immunogenic potential of a B7 retroviral expression vector: generation of HLA-B7-restricted CTL response against selectable marker genes.

The stimulation of a specific immune response is an attractive goal in cancer therapy. Gene transfer of co-stimulatory molecules and/or cytokine genes into tumor cells and the injection of these genetically modified cells leads to tumor rejection by syngeneic hosts and the induction of tumor immunity. However, the development of host immune response could be either due to the introduced immunomodulatory genes or due to vector components. In this study, human renal cell carcinoma cell lines were modified by a retrovirus to express the co-stimulatory molecule B7-1 together with the hygromycin/thymidine kinase fusion protein (HygTk) as positive and negative selection markers. These B7-1-transd…

Immunoselection in vivo: independent loss of MHC class I and melanocyte differentiation antigen expression in metastatic melanoma

Peptides derived from melanocyte differentiation antigens have been identified as targets for MHC class I-restricted cytolytic T lymphocytes (CTLs) in human melanoma Regression of antigen-expressing tumors as well as selection of antigen-loss variants in the presence of antigen-specific CTLs have previously been reported. In the present study, we determined the expression of the melanocyte differentiation antigens Melan A/MART-1 and tyrosinase by mRNA analysis and by immunohistochemical staining with the monoclonal antibodies (MAbs) A103 and T311. Co-expression of Melan A/MART-1 and tyrosinase was detected by both methods in 18/20 melanomas tested. However, immunohistochemistry provided add…

Antigen recognition by T cells: a strong sense of structure

Treatment of advanced pancreatic cancer with 5-fluorouracil, folinic acid and interferon alpha-2A: results of a phase II trial.

Interferon alpha-2a (IFN-alpha) and folinic acid (FA) have been shown to modulate the cytotoxic effects of 5-fluorouracil (5-FU) in the treatment of cancer. A phase II study was initiated to evaluate the effect of a combination of 5-FU/FA/IFN-alpha in patients with advanced pancreatic cancer. Sixty previously untreated patients with advanced adenocarcinoma of the pancreas were treated with 500 mg m-2 FU via an intravenous bolus 1 h after the initiation of a 2 h infusion of 500 mg m-2 FA. Before starting the FA infusion, 6 million units (MU) of IFN-alpha was administered subcutaneously. The treatment was repeated once a week. Of 57 evaluable patients, eight (14%) had a partial response (PR),…

Induction of primary NY-ESO-1 immunity: CD8+ T lymphocyte and antibody responses in peptide-vaccinated patients with NY-ESO-1+ cancers

Cancer–testis antigen NY-ESO-1 is one of the most immunogenic tumor antigens defined to date. Spontaneous humoral and CD8+ T-cell responses to NY-ESO-1 are detected in 40–50% of patients with advanced NY-ESO-1-expressing tumors. A clinical trial was initiated to study the immunological effects of intradermal vaccination with 3 HLA-A2-binding NY-ESO-1 peptides in 12 patients with metastatic NY-ESO-1-expressing cancers. Seven patients were NY-ESO-1 serum antibody negative, and five patients were NY-ESO-1 serum antibody positive at the outset of the study. Primary peptide-specific CD8+ T-cell reactions and delayed-type hypersensitivity responses were generated in four of seven NY-ESO-1 antibod…

A human renal cancer line as a new antigen source for the detection of antibodies to cytoplasmic and nuclear antigens in sera of patients with Wegener's granulomatosis.

Autoantibodies directed against cytoplasmic antigens of neutrophils (ANCA), especially proteinase 3 (C-ANCA), have proved to be a useful clinical tool to support the diagnosis or to monitor disease activity in Wegener's granulomatosis (WG). Till now, human neutrophil granulocytes have represented the major antigen source used to detect antibodies in WG by the immunofluorescence technique (IFT). We have tested serum samples of 164 patients with different connective tissue diseases (50 suffering from clinically active WG) performing IFT on a human renal cancer line (SK-RC11) and have found antibodies against the nuclear and cytoplasmic antigens in 39 patients. C-ANCA+ sera displayed a charact…

Cytoskeletal Heterogeneity of an Epithelioid Sarcoma with Expression of Vimentin, Cytokeratins, and Neurofilaments

We studied an unusual sarcoma with morphologic features diagnostic of epithelioid sarcoma by conventional light microscopy, transmission electron microscopy, and immunohistochemistry. The primary tumor, which was located in the deep soft tissues of the buttock of a 32-year-old woman, and its metastases to lymph nodes, liver, and lung were available for investigation. The histomorphological and ultrastructural appearance of the primary tumor and its metastatic deposits were typical of epithelioid sarcoma. Immunohistochemistry revealed a strong and uniform reactivity for vimentin in both the primary tumor and its metastases. In contrast, a marked cytoskeletal heterogeneity became evident for …

Chemotherapy with Idarubicin, Ara-C,VP-16, Amsacrine, Followed by G-CSF and Maintenance Immunotherapy with Interleukin-2 for Patients with High-Risk Acute Myeloid leukemia: a 3-Years Follow-Up

To improve the complete remission (CR) rate and to prolong CR duration in patients with advanced MDS, AML evolving from MDS, and secondary AML, a phase-III trial of aggressive chemotherapy followed by G-CSF was initiated in January 1992. Pts. achieving a CR were randomized to receive either high-dose or low-dose IL-2 to evaluate the potential of this cytokine to eliminate residual leukemic cells and to prolong the CR duration.

Induction of immunogenicity of a human renal-cell carcinoma cell line byTAP1-gene transfer

Reduced expression of the major-histocompatibility-complex(MHC)-class-I antigens has been demonstrated in renal-cell carcinoma (RCC), and appeared to be associated with deficiencies in the expression and function of different components of the MHC-class-I-antigen-processing pathway and poor recognition by cytotoxic T-lymphocytes (CTL). In order to investigate the role of peptide transporters for the immunogenic phenotype of RCC, tumor cells were stably transfected with the human TAP1A gene. While the TAP1 transfectants showed heterogeneous TAP1-transgene expression pattern of mRNA and protein, high TAP1 expression and a TAP-controlled increase in MHC-class-I surface expression could be achi…

Consensus nomenclature for CD8(+) T cell phenotypes in cancer

International audience; Whereas preclinical investigations and clinical studies have established that CD8+ T cells can profoundly affect cancer progression, the underlying mechanisms are still elusive. Challenging the prevalent view that the beneficial effect of CD8+ T cells in cancer is solely attributable to their cytotoxic activity, several reports have indicated that the ability of CD8+ T cells to promote tumor regression is dependent on their cytokine secretion profile and their ability to self-renew. Evidence has also shown that the tumor microenvironment can disarm CD8+ T cell immunity, leading to the emergence of dysfunctional CD8+ T cells. The existence of different types of CD8+ T…

Adjuvante und palliative Therapie kolorektaler Karzinome

Hepatocellular carcinoma after thorotrast exposure: establishment of a new cell line (Mz-Hep-1).

A human hepatoma cell line, associated with thorotrast exposure, from an hepatitis B marker-negative patient was established as a permanent cell line (Mz-Hep-1) in tissue culture. Histology of the primary tumor, as well as phase contrast, transmission and scanning electron microscopy of the cultured cells showed typical characteristics of liver cells. Mz-Hep-1 cells secreted complement components (C2, C3, C4), carcinoembryonic antigen, lactate dehydrogenase, chymotrypsin, haptoglobin and retinol-binding protein and expressed HLA-, transferrin-, blood group B-related determinants and complement component C5 and carcinoembryonic antigen on their cell surface. Mz-Hep-1 cells represent the firs…

Hepatocellular carcinoma: Biochemical and antigenic markers of three established cell lines

Induction of tumor-cell lysis by bi-specific antibody recognizing ganglioside GD2 and T-cell antigen CD3

Human tumor cells expressing ganglioside GD2 were lysed by various effector populations targeted with an anti-CD3-anti-GD2 bi-specific antibody (BAb CD3 x GD2). This antibody-heteroconjugate was prepared by chemically cross-linking the OKT-3 monoclonal antibody (MAb) reactive with CD3 antigen on T lymphocytes with the ganglioside MAb ME 361, which binds preferentially to the tumor-associated ganglioside GD2. The specificity of target-cell lysis by the cytotoxic T cells (CTL) was mediated by the specificity of the targeting antibody: GD2-negative cells were not lysed in the presence of the CD3 x GD2 BAb. A dose-dependent response was observed in a range of 10 to 10,000 ng/ml. In contrast, 2 …

Generation of cytotoxic T-cell responses with synthetic melanoma-associated peptidesin vivo: Implications for tumor vaccines with melanoma-associated antigens

Peptide epitopes derived from differentiation antigens of the melanocyte lineage have been identified in human melanomas and normal cultured melanocytes as targets for MHC-restricted cytotoxic T lymphocytes (CTL). Characterization of multiple CTL-defined antigenic determinants and the presence of corresponding precursor CTL open perspectives for the development of antigen-based vaccines. In the present study, we determined the CTL reactivity against melanoma-associated peptides derived from Melan A/MART-1, tyrosinase and gp100/Pmel17 in 10 HLA-A2+ melanoma patients and 10 healthy individuals. Then, we examined the immunological effects and toxicity of intradermal inoculation of synthetic me…

Cytotoxic T lymphocytes define multiple peptide isoforms derived from the melanoma-associated antigen MART-1/Melan-A

Peptides derived from the melanoma-associated MART-1/Melan-A antigen are currently implemented in immunotherapy for inducing or augmenting T-cell responses directed against peptides expressed by autologous tumor cells in HLA-A2+ patients with melanoma. Here, we describe the specificity of the T-cell clone SK29-FFM1.1, which secretes GM-CSF in response to a panel of synthetic MART-1/Melan-A-derived peptides, including the naturally presented ILTVILGVL32–40, but exhibits cytotoxicity and IFN-γ secretion exclusively to the MART-1/Melan-A derived peptide AAGIGILTV27–35. In addition, cytotoxic T-lymphocyte (CTL) clone SK29-FFM1.1 recognizes 3 different naturally processed and presented peptides …

Inverse relationship of melanocyte differentiation antigen expression in melanoma tissues and CD8+ cytotoxic-T-cell responses: evidence for immunoselection of antigen-loss variants in vivo.

Antigenic peptides derived from differentiation antigens of the melanocyte lineage were recently identified in human melanomas as targets for MHC-restricted cytotoxic T lymphocytes (CTL). CTL directed against peptides derived from the Melan A/MART-1, tyrosinase and gp100/Pmel17 antigens can be detected in melanoma patients and in healthy controls. The presence of defined antigenic peptides and corresponding precursor CTL in patients with metastatic melanoma opens perspectives for the development of antigen-specific tumor vaccines. In this study, we examined the expression of Melan A/MART-1, tyrosinase and gp100lPmel17 in fresh melanoma tissues of HLA-A2+ patients and the spontaneous CTL rea…

GD3 ganglioside: A marker for the diagnosis and treatment of neuroectodermal tumors?

Cellular and humoral immune responses against cancer: implications for cancer vaccines.

The key issue in tumor immunology is to identify antigens as target structures for a cancer-selective immunological attack in the tumor-bearing host, resulting in tumor rejection. There is a growing detailed understanding of structural and regulatory gene alterations giving rise to candidate rejection antigens and peptides in tumor cells. As well as reviewing the development of new adjuvant and recombinant vector systems, new approaches are suggested for the construction of cancer vaccines.

A phase II trial of chimeric monoclonal antibody G250 for advanced renal cell carcinoma patients.

Contains fulltext : 57114.pdf (Publisher’s version ) (Closed access) Chimeric monoclonal antibody G250 (WX-G250) binds to a cell surface antigen found on >90% of renal cell carcinoma (RCC). A multicentre phase II study was performed to evaluate the safety and efficacy of WX-G250 in metastatic RCC (mRCC) patients. In all, 36 patients with mRCC were included. WX-G250 was given weekly by intravenous infusion for 12 weeks. Patients with stable disease (SD) or response were eligible to receive additional treatment for 8 weeks. None of the 36 enrolled patients experienced any drug-related grade III or IV toxicity. Only three patients had grade II toxicity possibly related to the study medication.…

Classification of current anticancer immunotherapies.

© 2014. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Short Peptide Vaccine Induces CD4+ T Helper Cells in Patients with Different Solid Cancers.

Abstract Previous cancer vaccination trials often aimed to activate CD8+ cytotoxic T-cell (CTL) responses with short (8–10mer) peptides and targeted CD4+ helper T cells (TH) with HLA class II–binding longer peptides (12–16 mer) that were derived from tumor antigens. Accordingly, a study of immunomonitoring focused on the detection of CTL responses to the short, and TH responses to the long, peptides. The possible induction of concurrent TH responses to short peptides was widely neglected. In a recent phase I vaccination trial, 53 patients with different solid cancers were vaccinated with EMD640744, a cocktail of five survivin-derived short (9- or 10-mer) peptides in Montanide ISA 51VG. We m…

Gene transfer of the Co-stimulatory molecules B7-1 and B7-2 enhances the immunogenicity of human renal cell carcinoma to a different extent.

Stimulation of a specific antitumour immune response with recruitment and induction of T-cell effector functions represents an attractive concept in human cancer therapy. Different cytokines and the B7 co-stimulatory molecules are both able to provide proliferation and activation signals for T cells. In the present study, we first demonstrated the absence of both B7-1 and B7-2 expression in human renal cell carcinoma (RCC) cell lines. The lack of B7 expression was associated with a low or absent proliferative response of allogeneic and autologous T cells upon stimulation with tumour cells. In order to investigate the role of B7-1 and B7-2, the human RCC cell line, MZ1257RC, which expresses …

Cytolytic T-cell clones against an autologous human melanoma: specificity study and definition of three antigens by immunoselection.

Cytolytic T-lymphocyte (CTL) clones against an autologous melanoma (SK-MEL-29) were generated by mixed lymphocyte tumor culture and subsequent cloning of responder lymphocytes at limiting dilutions. These CTL clones lysed autologous melanoma but not autologous Epstein-Barr virus-transformed B cells and none of the allogeneic tumor targets included in the specificity analysis. The lysis of autologous melanoma targets could be inhibited by monoclonal antibodies against monomorphic HLA class I determinants. For proliferation of CTLs, the stimulation with the relevant target antigen on autologous tumor cells was essential. Immunoselection experiments carried out with two CTL clones revealed the…

Presence on a human melanoma of multiple antigens recognized by autologous CTL.

We derived from blood lymphocytes of a melanoma patient a large number of cytolytic T-cell clones directed against a cell line of the autologous tumor. Three distinct groups of antigens were recognized by these CTL on the autologous melanoma cells: group A consisted of stable antigens present on all sublines, whereas antigens B and C appeared unstable and were expressed by distinct sublines. In vitro immunoselections with various anti-A CTL clones were applied to the melanoma cells and variants resistant to 3 different CTL clones were obtained. These variants remained sensitive to other anti-A CTL clones, indicating that group A comprises at least 4 different antigens (D, E, F and A'). From…

Humoral immune responses of cancer patients against “Cancer-Testis” antigen NY-ESO-1: Correlation with clinical events

Humoral immune responses against the "Cancer-Testis" (CT) antigen NY-ESO-1 are frequently observed in patients with NY-ESO-1 expressing tumors. This is in contrast to other known tumor antigens (TA) defined by antibody or cytotoxic T cell (CTL) reactivity, i.e., MAGE-1, MAGE-3, SSX2, Melan A, and tyrosinase. No NY-ESO-1 antibody has been detected in healthy controls and patients with NY-ESO-1 negative tumors. In this study, we have assessed the NY-ESO-1 serum antibody response in patients with NY-ESO-1 positive tumors of different histological types and stages using Western blotting and an ELISA. Of the 12 patients analyzed, 10 had demonstrable NY-ESO-1 antibodies at the start of the study.…

New cell lines of gastric and pancreatic cancer: distinct morphology, growth characteristics, expression of epithelial and immunoregulatory antigens.

Two new cell lines from stomach cancers and one from a pancreatic carcinoma are presented. MZ-GC-1 was established from a hepatic metastasis of a well differentiated gastric adenocarcinoma. MZ-GC-2 was derived from ascites induced by a poorly differentiated gastric adenocarcinoma. MZ-PC-1 originated from the pleural effusion of a moderately well differentiated pancreatic ductal adenocarcinoma. MZ-GC-1 cells were adherent and partially polarized, connected tightly via desmosomes. In contrast MZ-GC-2 cells consisted of slightly adherent or floating subpopulations and displayed no desmosomes. MZ-PC-1 cells were adherent and showed polarized growth, connected by apical junctional complexes. Cel…

Hepatozelluläre Karzinommarker bei einem primären Gallenblasenkarzinom

Eine Adenokarzinomzellinie, Mz-ChA-2, konnte kurzlich aus einem primaren Gallenblasenkarzinom, das lokal in die Leber eingewachsen war, in Gewebekultur etabliert werden (1). Zyto- und Histomorphologie dieser Tumorzellinie in vitro und nach Transplantation auf Nacktmause entsprechen dem Primartumor der 65jahrigen Patientin. Im Serum wurden leicht erhohte AFP-Werte bestimmt, wahrend die CEA-Werte normal waren. Im Gewebekulturuberstand dieser neuen Tumorzellinie MZ-ChA-2 konnte AFP nachgewiesen werden. Auf klonaler Ebene zeigten sich erhebliche quantitative Schwankungen in der AFP-Synthese. CEA konnte im Gewebekulturuberstand nicht nachgewiesen werden, dem Serumbefund bei der Patientin entspre…

Biliary adenocarcinoma

Three human cell lines from adenocarcinomas of the extrahepatic biliary tract were established in permanent tissue culture. Mz-ChA-1 and Mz-ChA-2 were cultured from mechanically dissociated gallbladder adenocarcinoma metastases and SK-ChA-1 was grown from malignant ascites of a patient with primary adenocarcinoma of the extrahepatic biliary tree. Cell doubling times in tissue culture are 3-4 days for Mz-ChA-1 and approximately 2 days for Mz-ChA-2 and SK-ChA-1. All three tumour cell lines were successfully transplanted to nude mice, inducing progressive tumour growth. Histologically, nude mouse tumours resembled the original adenocarcinomas. In vitro formation of gland-like structures were r…

The differentiation antigen NY-BR-1 is a potential target for antibody-based therapies in breast cancer

Antibody-based cancer immunotherapy relies on the identification and characterization of target antigens and the development of potent antibodies recognizing the target. Here we report the expression analysis and molecular characterization of the differentiation antigen NY-BR-1, which we previously identified by using the SEREX (serological analysis of recombinant cDNA expression libraries) method. Corroborating methodologies, including mRNA quantitation and immunoblotting show that NY-BR-1 is strongly expressed in >70% of 129 breast tumors. Application of a NY-BR-1 specific antibody demonstrated NY-BR-1 expression in primary and metastastic breast cancers. In contrast, most of the breast c…

Analysis of antigens recognized on human melanoma cells by A2-restricted cytolytic t lymphocytes (CTL)

We have pursued our analysis of potential tumor-rejection antigens recognized on human melanoma by autologous cytolytic T lymphocytes (CTL). We reported previously that 3 distinct antigens (A,B,C) were recognized on melanoma cell line SK29-MEL in association with HLA-A2. Selection for melanoma-cell variants resistant to anti-A CTL revealed that antigen A consists of at least 2 determinants (Aa, Ab) which can be lost separately. Genetic linkage between Aa and Ab was suggested by concomitant loss of Aa and Ab in an immunoselected tumor-cell variant. This variant was also resistant to an autologous CTL clone restricted by HLA-B45, indicating that this CTL may also recognize a determinant of an…

Improved detection of melanoma antigen-specific T cells expressing low or high levels of CD8 by HLA-A2 tetramers presenting a Melan-A/Mart-1 peptide analogue

MHC class I tetramers containing peptide epitopes are sensitive tools for detecting antigen-specific CD8(+) T-cell responses. We demonstrate here that binding of HLA-A2 tetramers to CD8(+) T cells specific for the melanoma-associated antigen Melan-A/MART-1 can be fine-tuned by altering either the bound peptide epitope or residues in the alpha 3 domain of HLA-A2, which is important for CD8 binding. Antigen-specific T cells expressing high levels of CD8 could be detected using HLA-A2 tetramers containing the peptide AAGIGILTV, an epitope which is naturally processed and presented from Melan-A/MART-1. In contrast, low CD8-expressing, antigen-specific T cells could be detected efficiently only …

Lysis of human melanoma cells by autologous cytolytic T cell clones. Identification of human histocompatibility leukocyte antigen A2 as a restriction element for three different antigens.

From the peripheral blood of the melanoma patient (AV), we derived cytolytic T lymphocyte (CTL) clones that lysed the autologous tumor line SK-MEL-29, but not autologous EBV-B cells, K562, and other tumor targets. By immunoselection experiments it was shown that the CTL clones recognized at least three different antigens on the autologous tumor cells. We demonstrate here that these melanoma antigens are presented to the CTL in association with HLA-A2. First, HLA-A2-reactive pregnancy sera as well as an mAb against HLA-A2 inhibited the CTL lysis. Second, immunoselected melanoma subclones that were resistant to lysis by CTL clones against the three antigens described were found to lack expres…

Cellular immune response to human renal-cell carcinomas: Definition of a common antigen recognized by HLA-A2-restricted cytotoxic T-Lymphocyte (CTL) clones

Cytotoxic T lymphocyte (CTL) clones directed against autologous renal-cell carcinoma (RCC) cell lines were generated by mixed lymphocyte/tumor-cell culture (MLTC) using peripheral blood lymphocytes (PBL). A CD8+, CD4- CTL clone MZ1257-CTL 5/30 with high cytolytic activity for the autologous tumor cell line MZ1257-RCC was established. No lysis of the autologous EBV-transformed B lymphocytes (EBV-B) or K562 cells was observed. A panel of HLA-A2-matched allogeneic RCC lines was recognized by CTL 5/30. Further specificity analysis showed a cross-reactivity with HLA-A2-matched allogeneic tumor cells of various origins, especially melanoma. CTL 5/30 was also cross-reactive with several HLA-A2-pos…

Cytolytic T cell reactivity against melanoma-associated differentiation antigens in peripheral blood of melanoma patients and healthy individuals

Antigenic peptides derived from several differentiation antigens of the melanocyte lineage were recently identified in human melanomas as targets for HLA-A2.1-restricted cytotoxic T lymphocytes (CTLs). To examine their potential role in tumour-directed immune responses in vivo, we determined CTL reactivity against seven antigenic peptides derived from the Melan A/MART-1, tyrosinase and gp100/Pmel17 antigens in the peripheral blood of 10 HLA-A2+ healthy controls and 26 HLA-A2+ melanoma patients. The influenza matrix peptide (GILGFVFTL) presented by HLA-A2.1 was used as a control peptide. CTL reactivity was assessed in a mixed lymphocyte 'peptide' culture assay. Reactivity against Melan A/MAR…

Lysis of human pancreatic adenocarcinoma cells by autologous HLA-class I-restricted cytolytic T-lymphocyte (CTL) clones.

From the primary site of a pancreatic adenocarcinoma (patient BE) a permanent cell line (MZ-PC-2) was established in tissue culture. In the course of mixed lymphocyte-tumor-cell cultures (MLTC) with autologous blood-derived lymphocytes, we isolated CTL clones that lysed autologous tumor cells but not autologous EBV-transformed B cells (EBV-B) and not K562. Pre-treatment of MZ-PC-2 cells with IFN-gamma was required to obtain significant lysis in 4-hr cytotoxicity assays. IFN-gamma was superior to IFN-alpha in that respect. Among MLTC responder lymphocytes, tumor-reactive CTL proliferated more strongly in response to MZ-PC-2 cells treated with IFN-gamma than to untreated tumor cells. Three CT…

Recognition of human renal cell carcinoma and melanoma by HLA-A2-restricted cytotoxic T lymphocytes is mediated by shared peptide epitopes and up-regulated by interferon-gamma.

Cytotoxic T lymphocytes (CTL) have previously been isolated from peripheral blood of patients with renal cell carcinoma (RCC). The CD8-positive CTL line MZ1257-CTL-5 (CTL-5) has been shown to lyse autologous cultured RCC cells in an HLA-A2 restricted fashion. Allogeneic, HLA-A2-matched RCC and melanoma cell lines were also lysed by CTL-5, suggesting that melanoma and renal cancer share antigenic determinants. The aim of the study was to determine whether RCC and melanoma share peptide epitopes that are recognized by CTL-5 in the context of HLA-A2 molecules. Peptides were acideulated from various cell lines, separated by reversed phase high performance liquid chromatography (RP-HPLC), and as…

Granulocyte-macrophage-colony-stimulating factor enhances immune responses to melanoma-associated peptides in vivo.

Peptide epitopes derived from differentiation antigens of the melanocyte lineage were recently identified in human melanomas as targets for MHC-restricted cytotoxic T lymphocytes (CTL). The characterization of multiple CTL-defined antigenic determinants has opened possibilities of development of antigen-targeted vaccines. In the present study, we determined CTL reactivity against melanoma-associated peptides derived from Melan A/MART-1, tyrosinase, and gp100/Pmel17 in 3 HLA-A2+ melanoma patients. Then, we assessed the immune responses to synthetic melanoma-associated peptides injected intradermally. After 3 cycles of immunization with peptide alone, we used systemic GM-CSF as an adjuvant du…

T-lymphocytotoxicity in malignant melanoma: Induction with autologous mutagenized tumor cell clones

Clonal expansion of melan a-specific cytotoxic T lymphocytes in a melanoma patient responding to continued immunization with melanoma-associated peptides

Peptides derived from human tumor antigens have been used in a number of clinical trials to induce specific immune responses against autologous tumors in cancer patients. Although favorable clinical results were observed in single patients, immune responses correlating with tumor regression were either not detected or in case of responses, the T-cell specificity was difficult to demonstrate. In this study, we analyzed antigen-specific T-cell responses induced in the skin and in peripheral blood lymphocytes (PBL) in an HLA-A2-positive melanoma patient. The patient showed major regression of metastatic melanoma under continued immunization with peptides derived from the melanocyte differentia…

A gene encoding an antigen recognized by cytolytic T lymphocytes on a human melanoma.

Many human melanoma tumors express antigens that are recognized in vitro by cytolytic T lymphocytes (CTLs) derived from the tumor-bearing patient. A gene was identified that directed the expression of antigen MZ2-E on a human melanoma cell line. This gene shows no similarity to known sequences and belongs to a family of at least three genes. It is expressed by the original melanoma cells, other melanoma cell lines, and by some tumor cells of other histological types. No expression was observed in a panel of normal tissues. Antigen MZ2-E appears to be presented by HLA-A1; anti-MZ2-E CTLs of the original patient recognized two melanoma cell lines of other HLA-A1 patients that expressed the ge…

Production of stable cytolytic T-cell clones directed against autologous human melanoma

We have attempted to optimize the production of stable human cytolytic T lymphocyte clones directed against autologous melanoma cell lines. MLTC were restimulated every week with irradiated melanoma cells in medium containing human serum and IL-2. After 21 to 35 days, in 5 out of 6 patients, these cultures expressed a preferential cytolytic activity against the autologous melanoma cells, as compared to autologous EBV-B cells or NK target K562. Limiting dilution of MLTC responder cells was performed at times varying from days 7 to 28, in medium containing IL-2 and allogeneic EBV-B cells as feeders. Approximately 1% of these responder cells gave rise to CTL clones that lysed the autologous me…

Amino acid substitutions at position 97 in HLA-A2 segregate cytolysis from cytokine release in MART-1/Melan-A peptide AAGIGILTV-specific cytotoxic T lymphocytes.

CD8+ T lymphocytes recognize antigenic peptides presented by major histocompatibility complex (MHC) class I molecules. Individual peptide termini appear to be fixed at the C- and N-terminal ends. In contrast, central peptide side chains residues may point in different directions and exhibit limited flexibility, dependent on the MHC class I structural variation. For instance, position 97 in HLA-A201 has been shown to shift individual peptide species into different coordinations, one oriented towards the peptide N terminus, or more towards the C-terminal end. The conformational shape of such non-anchor peptide residues may affect the affinity of MHC/peptide/TCR interaction, resulting in quant…

Tumor associated antigens in human renal cell carcinoma: MHC restricted recognition by cytotoxic T lymphocytes.

Based on previous studies in human melanoma leading to the molecular cloning of genes encoding peptide antigens recognized by MHC-restricted cytotoxic T lymphocytes (CTL) we extended our efforts to renal cancer systems established in tissue culture. In two patients we obtained stable CD8+ CTL clones with high cytolytic activity for the corresponding autologous tumor cell line in vitro. Neither autologous EBV-transformed B lymphocytes or PHA-activated PBL nor natural killer targets K562 were lysed by these CTL clones. MZ1257-RCC CTL5-30 lysed autologous tumor cells as well as normal kidney cell cultures in an HLA-A2 restricted fashion. Further specificity analysis showed cross reactivity wit…