Search results for "gp100 Melanoma Antigen"
showing 6 items of 6 documents
Melanomas resist T-cell therapy through inflammation-induced reversible dedifferentiation.
2012
Adoptive cell transfer therapies (ACTs) with cytotoxic T cells that target melanocytic antigens can achieve remissions in patients with metastatic melanomas, but tumours frequently relapse. Hypotheses explaining the acquired resistance to ACTs include the selection of antigen-deficient tumour cell variants and the induction of T-cell tolerance. However, the lack of appropriate experimental melanoma models has so far impeded clear insights into the underlying mechanisms. Here we establish an effective ACT protocol in a genetically engineered mouse melanoma model that recapitulates tumour regression, remission and relapse as seen in patients. We report the unexpected observation that melanoma…
Rapid High Efficiency Sensitization of CD8+ T Cells to Tumor Antigens by Dendritic Cells Leads to Enhanced Functional Avidity and Direct Tumor Recogn…
2003
Abstract Myeloid-origin dendritic cells (DCs) can develop into IL-12-secreting DC1 or non-IL-12-secreting DC2 depending on signals received during maturation. Through rapid culture techniques that prepared either mature, CD83+ DC1 or DC2 from CD14+ monocytes in only 2 days followed by a single 6–7 day DC-T cell coculture, we sensitized normal donor CD8+ T cells to tumor Ags (HER-2/neu, MART-1, and gp100) such that peptide Ag-specific lymphocytes constituted up to 16% of the total CD8+ population. Both DC1 and DC2 could sensitize CD8+ T cells that recognized peptide-pulsed target cells. However, with DC2, a general decoupling was observed between recognition of peptide-pulsed T2 target cells…
Primary oral melanoma : a histopathological and immunohistochemical study of 22 cases of Latin America
2011
Objective: The aim of this study was to analyze the histopathological and immunohistochemical characteristics of 22 cases of primary oral melanomas (OM). Study Design: Twenty two cases of primary oral melanoma were analyzed by description of their histopathological features and immunohistochemical study using the antibodies S-100, HMB-45, Melan-A and Ki-67. Results: The mean age was 58 years and 14 cases were female. The main affected sites were the hard palate, followed by the upper gingiva. Microscopically, 15 cases presented level III of invasion, 2 cases were amelanotic and 13 showed a mixed epithelioid and plasmacytoid or spindle cells composition. Some cases showed necrosis, perivascu…
Cytolytic T cell reactivity against melanoma-associated differentiation antigens in peripheral blood of melanoma patients and healthy individuals
1996
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…
Generation of CD8+T cells expressing two additional T-cell receptors (TETARs) for personalised melanoma therapy
2015
Adoptive T-cell therapy of cancer often fails due to the tumor cells' immune escape mechanisms, like antigen loss or down-regulation. To anticipate immune escape by loss of a single antigen, it would be advantageous to equip T cells with multiple specificities. To study the possible interference of 2 T-cell receptors (TCRs) in one cell, and to examine how to counteract competing effects, we generated TETARs, CD8(+) T cells expressing two additional T-cell receptors by simultaneous transient transfection with 2 TCRs using RNA electroporation. The TETARs were equipped with one TCR specific for the common melanoma antigen gp100 and one TCR recognizing a patient-specific, individual mutation of…
Inverse relationship of melanocyte differentiation antigen expression in melanoma tissues and CD8+ cytotoxic-T-cell responses: evidence for immunosel…
1996
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…