Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Peptide specificity of cultured tumor-infiltrating lymphocytes (TIL) was systematically investigated in a group of HLA-A2.1+ metastatic melanoma patients consecutively referred to our department for surgical treatment. Seven samples from 6 patients were studied. All surgical specimens showed evidence of gp 100, MART-1/Melan-A and Tyrosinase gene expression as detectable by reverse PCR (rPCR). Cultured TIL from 2 patients displayed cytotoxic activity against autologous or HLA-matched EBV-transformed cells previously pulsed with MART-1/Melan-A27-35 peptide. In contrast, no CTL activity against gp100(280-288) or tyrosinase1-9 peptides could be observed. TIL were then repeatedly stimulated in vitro with the same peptides. After 6 restimulation courses at weekly intervals, specific recognition of gp100(280-288) and MART-1/Melan-A peptides was detectable in 3 and 5 TIL populations, respectively. In one case Tyrosinase1-9-specific CTL could be demonstrated. Two TIL populations from metastases resected from a melanoma patient at 6 months' distance showed a different peptide specificity pattern, and no specific CTL could be generated from simultaneously sampled peripheral blood mononuclear cells (PBMC). All peptide-specific CTL populations also displayed significant cytotoxic activity against HLA-A2.1 matched melanoma cell lines expressing the antigens under investigation. Our data indicate that CTL specific for MART-Melan-A27-35, gp100(280-288) or Tyrosinase1-9 peptides could be expanded with varying frequency from TIL derived from 4 out of 6 HLA-A2.1+ patients whose tumors expressed the genes encoding these tumor-associated antigens (TAA).
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PMID:Peptide-specific CTL in tumor infiltrating lymphocytes from metastatic melanomas expressing MART-1/Melan-A, gp100 and Tyrosinase genes: a study in an unselected group of HLA-A2.1-positive patients. 759 2

Four of ten HLA-A2-restricted melanoma specific CTL that were derived from tumor-infiltrating lymphocytes (TIL) and administered to patients recognized the gp100 melanoma Ag and nine of ten recognized the MART-1 Ag. Adoptive transfer of the four gp100-reactive CTL, but not the other TIL, resulted in tumor regression when infused into autologous patients along with IL-2. Tumor regression was thus correlated with the recognition of gp100 by the administered T cells (p = 0.0048). To identify the epitopes recognized by these four gp100-reactive CTL, 169 peptides containing HLA-A2.1 binding motifs were synthesized and screened for their recognition by TIL using cytotoxicity and IFN-gamma release assays. Five gp100 epitopes (two for TIL620, three for TIL660, one for TIL1143, and two for TIL1200) were recognized by CTL derived from different patients. Five of eight HLA-A2 binding melanoma epitopes (five gp100, one MART-1/Melan-A, two tyrosinase) had intermediate binding affinity to HLA-A2.1. These gp100 epitopes may be responsible for mediating tumor rejection in vivo and thus may be useful for the development of immunotherapies for patients with melanoma.
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PMID:Recognition of multiple epitopes in the human melanoma antigen gp100 by tumor-infiltrating T lymphocytes associated with in vivo tumor regression. 770 34

To determine whether T-cell-receptor (TCR) usage by T cells recognizing a defined human tumor antigen in the context of the same HLA molecule is conserved, we analyzed the TCR diversity of autologous HLA-A2-restricted cytotoxic T-lymphocyte (CTL) clones derived from five patients with metastatic melanoma and specific for the common melanoma antigen Melan-A/MART-1. These clones were first identified among HLA-A2-restricted anti-melanoma CTL clones by their ability to specifically release tumor necrosis factor in response to HLA-A2.1+ COS-7 cells expressing this tumor antigen. A PCR with variable (V)-region gene subfamily-specific primers was performed on cDNA from each clone followed by DNA sequencing. TCRAV2S1 was the predominant alpha-chain V region, being transcribed in 6 out of 9 Melan-A/MART-1-specific CTL clones obtained from the five patients. beta-chain V-region usage was also restricted, with either TCRBV14 or TCRBV7 expressed by all but one clone. In addition, a conserved TCRAV2S1/TCRBV14 combination was expressed in four CTL clones from three patients. None of these V-region genes was found in a group of four HLA-A2-restricted CTL clones recognizing different antigens (e.g., tyrosinase) on the autologous tumor. TCR joining regions were heterogeneous, although conserved structural features were observed in the complementarity-determining region 3 sequences. These results indicate that a selective repertoire of TCR genes is used in anti-melanoma responses when the response is narrowed to major histocompatibility complex-restricted antigen-specific interactions.
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PMID:Cytotoxic T-lymphocyte clones from different patients display limited T-cell-receptor variable-region gene usage in HLA-A2-restricted recognition of the melanoma antigen Melan-A/MART-1. 777 68

We and others have previously reported that melanoma-specific, cytotoxic T lymphocytes (CTL) define a minimum of six class I-presented peptide epitopes common to most HLA-A2+ melanomas. Here we show that three of these peptide epitopes are coordinately recognized by a CTL clone obtained by limiting dilution from the peripheral blood of an HLA-A2+ melanoma patient. Tandem mass spectrometry was used to characterize and sequence one of these three naturally processed melanoma peptides. One of the potential forms of the deduced peptide sequence (XXTVXXGVX, X = I or L) matches positions 32-40 of the recently identified melanoma gene MART-1/Melan-A. This peptide (p939; ILTVILGVL) binds to HLA-A2 with an intermediate-to-low affinity and is capable of sensitizing the HLA-A2+ T2 cell line to lysis by CTL lines and clones derived from five different melanoma patients. A relative high frequency of anti-p939-specific effector cells appear to be present in situ in HLA-A2+ melanoma patients, since p939 is also recognized by freshly isolated tumor infiltrating lymphocytes. p939 represents a good candidate for the development of peptide-based immunotherapies for the treatment of patients with melanoma.
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PMID:Mass spectrometric identification of a naturally processed melanoma peptide recognized by CD8+ cytotoxic T lymphocytes. 780 17

It has been reported previously that antitumor cytolytic T lymphocyte (CTL) clones can be isolated from blood lymphocytes of HLA-A2 melanoma patients, after stimulation in vitro with autologous tumor cells, and that some of these CTL clones lyse most HLA-A2 melanomas. A first antigen recognized by such CTL clones was previously shown to be encoded by the tyrosinase gene. We report here the identification of another gene that also directs the expression of an antigen recognized on most melanomas by CTL clones that are restricted by HLA-A2. The gene, designated Melan-A, is unrelated to any known gene. It is 18 kb long and comprises five exons. Like the tyrosinase gene, it is expressed in most melanoma tumor samples and, among normal cells, only in melanocytes.
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PMID:A new gene coding for a differentiation antigen recognized by autologous cytolytic T lymphocytes on HLA-A2 melanomas. 800 76

Experimental models of vaccination with tumor cells engineered to produce interleukin-4 (IL-4) have shown that the local release of this cytokine is associated with the development of antitumor immunity that may induce regression of established cancer. The aim of this study was to transduce a human melanoma cell line with the gene coding for human IL-4, and to analyze cytokine production, phenotypic characteristics, and antigen expression after transduction. A retroviral vector, constructed by inserting IL-4 cDNA into the LXSN vector, was used to infect the human melanoma cell line Me14932, known to express the MHC class I HLA-A2 and the melanoma-associated antigen Melan-A/MART-1, recognized by HLA-A2-restricted T-cells. The confluence of all G418-resistant cells (Me14932/IL-4) was then analyzed for proviral integration and IL-4 mRNA expression. Substantially stable IL-4 release was detected by ELISA in the supernatant of transduced cells, ranging from 1.6 to 4.6 ng/ml per 10(5) cells per 24 hr; such a cytokine displayed a specific biologic activity, as revealed by the stimulation of blast cell proliferation and the inhibition of lymphokine activated killer cell (LAK) induction by IL-2. After 200 Gy irradiation, IL-4 release remained detectable for 5 weeks, whereas cell proliferation ceased within 7 days. Morphology and immunophenotypic characteristics of the parental cell line (expression of MHC classes I and II, ICAM-1, LFA 3, melanoma-associated antigens, etc.) were retained by the IL-4 gene-transduced melanoma as assayed by microscopy and immunofluorescence; likewise, susceptibility to lysis by LAK cells as well as a T-cell clone recognizing the Melan-A/MART-1 antigen did not change. These results, together with the lack of replication-competent retrovirus, suggest that the Me14932/IL-4 cell line displays suitable characteristics for its use in the treatment of HLA-matched melanoma patients.
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PMID:A human melanoma cell line transduced with an interleukin-4 gene by a retroviral vector releases biologically active IL-4 and maintains the original tumor antigenic phenotype. 857 15

To determine whether HLA-A21 restricted melanoma Ags exist that are not expressed on normal melanocytes, a panel of 478 T cell clones from six HLA-A21+ patients was selected for HLA-A2 restricted lysis of autologous tumor and then tested for differential recognition of HLA-A2.1+ melanomas and normal melanocytes. Four subsets of clones were identified in the panel of 107 HLA-A2-restricted CTL clones. CTL clones from three of the four subsets did not lyse melanocytes, but recognized fresh HLA-A2.1+ melanomas and defined three classes of epitopes, including unique Ags, common melanoma Ags, and Ags shared with neoplastic cells of different histologic origin. These CTL clones did not recognize any of the 10 peptides selected for specific association to HLA-A2.1 and derived from Melan-A/Mart-1, tyrosinase, gp100, or MAGE-3 proteins. By contrast, the fourth subset of HLA-A2.1-restricted CTl clones recognized both melanoma and melanocytes. These CTL clones were directed to a peptide from either Melan-A/Mart-1, tyronise, or gp100. By a limiting dilution assay, designed to evaluate the frequency of HLA-A2-restricted CTL precursors (CTLp) directed to melanoma but not to melanocytes, such precursors were found in the peripheral blood or tumor site of five of six HLA-A2.1+ melanoma patients, and their frequency was much higher than the frequency of CTLp recognizing both tumor cells and the melanocytes. These results suggest that in melanoma patients most of the HLA-A2.1-restricted immune repertoire to melanoma is directly to epitopes expressed in the neoplastic but not in the normal cells of the melanocyte lineage.
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PMID:Cytotoxic T cells directed to tumor antigens not expressed on normal melanocytes dominate HLA-A2.1-restricted immune repertoire to melanoma. 859 64

Human melanoma represents the principal cause of death in patients with skin cancer in the United States and Europe. Tumour infiltrating lymphocytes recognizing melanoma have been used to identify the tumour antigens recognized by T-cells in the context of MHC class I or class II molecules. Such antigens include MAGE-1, MAGE-3, MART-1/Melan-A, gp100, tyrosinase, the tyrosinase-related antigen gp75, the antigen gp15 and the mutated CDK4 and beta-catenin gene-products. The identification of these T-cell epitopes provides us with novel reagents for the development of state-of-the-art treatments and for the (immuno-)monitoring of patients with melanoma. In order for treatments, including peptide-based vaccines, to be successful, several conceptual criteria must be met: (1) The patient's tumour must present the relevant epitope(s) integrated into the vaccine, (2) the tumour should express the appropriate restricting major histocompatibility complex (MHC) molecule(s) required for patient cytotoxic T lymphocyte (CTL) reactivity, and (3) the patient's T-cell repertoire should be able to react productively against the melanoma antigens present in the vaccine. Clinical trials implementing peptide-based vaccines or whole protein therapies have been initiated in the United States and Europe. We suggest that such treatments should include the careful monitoring of anti-tumour T-cell responses. This should include examination of melanoma antigen and MHC class I allele expression in the individual patient's tumour, assessment of the status of the peptide transporter molecules TAP1/TAP2 and evaluation of T-cell mediated immune responses reactive against peptides and autologous melanoma. Evaluation of clinical parameters (such as disease-free survival) in conjunction with an examination of immunological parameters may facilitate our understanding of the immune responses against T-cell antigens that are shared among melanoma and normal melanocytes, and may ultimately help to identify the most effective immunotherapy for patients with melanoma.
Melanoma Res 1996 Feb
PMID:New treatment options for patients with melanoma: review of melanoma-derived T-cell epitope-based peptide vaccines. 864 65

Recent progress in the structural identification of human melanoma antigens recognized by autologous cytotoxic T cells has led to the recognition of a new melanocyte differentiation antigen, Melan-A(MART-1). To determine the properties of the Melan-A gene product, Melan-A recombinant protein was produced in Escherichia coli and used to generate mouse monoclonal antibodies (mAbs). Two prototype mAbs, A103 and A355, were selected for detailed study. Immunoblotting results with A103 showed a 20-22-kDa doublet In Melan-A mRNA positive melanoma cell lines and no reactivity with Melan-A mRNA-negative cell lines. A355, in addition to the 20-22-kDa doublet, recognized several other protein species in Melan-A mRNA-positive cell lines. Immunocytochemical assays on cultured melanoma cells showed specific and uniform cytoplasmic staining in Melan-A mRNA-positive cell lines. Immunohistochemical analysis of normal human tissues with both mAbs showed staining of adult melanocytes and no reactivity with the other normal tissues tested. Analysis of 21 melanoma specimens showed homogenous staining of tumor cell cytoplasm in 16 of 17 Melan-A mRNA-positive cases and no reactivity with the three Melan-A mRNA-negative cases.
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PMID:Serological analysis of Melan-A(MART-1), a melanocyte-specific protein homogeneously expressed in human melanomas. 865 Jan 93

We applied an enzyme-linked immunospot (ELISPOT) assay for the detection and quantification of blood-derived CD8+ T cells recognizing peptide antigens presented by HLA-A2.1. CD8+ T lymphocytes were isolated from peripheral blood and were stimulated for 40 h with peptide-loaded A2.1-positive 0.174 x CEM.T2 cells. Tumor necrosis factor alpha (TNF-alpha) secreted by single T cells in response to antigen contact was trapped on nitrocellulose membranes precoated with anti-TNF-alpha antibodies and was then immunochemically visualized as spots. With this assay, up to 25% of cloned cytolytic T lymphocytes (CTL) were detected during the test period that recognized defined melanoma antigens in association with HLA-A2.1. CD8+ lymphocytes responsive to a known immunogenic HLA-A2.1-binding peptide from reverse transcriptase of the human immunodeficiency virus (HIV) were only detectable in HIV-infected patients, but not in anti-HIV-negative donors. T cells reacting with a peptide derived from a mutated cyclin-dependent kinase 4 (CDK4-R24C) were exclusively detected among CD8+ lymphocytes isolated from blood of the patient, whose melanoma had previously been found to carry the CDK4-R24C allele. T cells responding to HLA-A2.1-associated peptides of normal melanocyte differentiation antigens tyrosinase and Melan-A/MART-1 were found at low frequencies in almost all donors tested, which might reflect a natural autoimmunity to these antigens. However, in a melanoma patient we found a few days after surgery of melanoma metastases high frequencies of T cells against Melan-A/MART-1 and tyrosinase peptides (up to 38 per 10(5) CD8+ T cells), which gradually decreased during the following months. In an HIV-infected patient with progressive disease we observed a loss of T cells reactive with the HIV reverse transcriptase peptide. These observations provide evidence that peptide-dependent TNF-alpha spot formation in vitro resulted from previous antigen exposure in vivo. Therefore, the TNF-alpha ELISPOT assay might be useful in monitoring antigen-specific T lymphocyte responses during the natural course of diseases as well as during therapeutic interventions aiming at the induction of protective T cell immunity. In addition, it might help to identify immunodominant T cell epitopes.
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PMID:Detection and quantification of blood-derived CD8+ T lymphocytes secreting tumor necrosis factor alpha in response to HLA-A2.1-binding melanoma and viral peptide antigens. 866 32


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