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Castelli C, Tarsini P, Mazzocchi A, Rini F, Rivoltini L, Ravagnani F, Gallino F, Belli F, Parmiani G. Novel HLA-Cw8-Restricted T Cell Epitopes Derived from Tyrosinase-Related Protein-2 and gp100 Melanoma Antigens. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.3.1739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The identification of T cell epitopes presented by alternative HLA-B and -C alleles may provide a means to counteract the tumor escape mechanism based on the selection of tumor cells no longer susceptible to HLA-A-restricted T cell recognition. Several T cell clones and lines were obtained from T lymphocytes purified from melanoma-infiltrated or noninfiltrated lymph nodes of a patient who remained disease free 8 yr after surgery. Selected T cells recognized the autologous melanoma as evaluated by direct cytolysis and production of cytokines. These effectors were directed against the tyrosinase-related protein-2 (TRP-2) and gp100 melanoma epitopes restricted by HLA-Cw8. The nonamer and decamer peptides containing the sequence ANDPIFVVL (residues 387–395) of TRP-2 and the octamer, nonamer, and decamer peptides containing the sequence SNDGPTLI (residues 71–78) of gp100 reconstituted the epitope for TRP-2- and gp100-specific T cell lines and clones, respectively. However, only the nonameric form of TRP-2 and the nonameric and octameric forms of gp100 were able to induce peptide-specific T cells recognizing the autologous tumor in an HLA-class I-restricted fashion from PBMC of the melanoma patient studied. Together these data indicate that HLA-Cw8 can restrict the recognition of gp100 and TRP-2 epitopes by CTL, and that such peptides could stimulate a patient’s PBL, suggesting that these Ags could have contributed to a systemic immunity against melanoma.
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Affiliation(s)
| | | | | | | | | | | | - Francesco Gallino
- ‡Surgical Oncology B, Istituto Nazionale Tunori, Milan, Italy
- Divisions of
| | - Filiberto Belli
- ‡Surgical Oncology B, Istituto Nazionale Tunori, Milan, Italy
- Divisions of
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Rivoltini L, Radrizzani M, Accornero P, Squarcina P, Chiodoni C, Mazzocchi A, Castelli C, Tarsini P, Viggiano V, Belli F, Colombo MP, Parmiani G. Human Melanoma-Reactive CD4+ and CD8+ CTL Clones Resist Fas Ligand-Induced Apoptosis and Use Fas/Fas Ligand-Independent Mechanisms for Tumor Killing. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.3.1220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Tumor cells have been shown recently to escape immune recognition by developing resistance to Fas-mediated apoptosis and acquiring expression of Fas ligand (FasL) molecule that they may use for eliminating activated Fas+ lymphocytes. In this study, we report that tumor-specific T lymphocytes isolated from tumor lesions by repeated in vitro TCR stimulation with relevant Ags (mostly represented by normal self proteins, such as MART-1/Melan A and gp100) can develop strategies for overcoming these escape mechanisms. Melanoma cells (and normal melanocytes) express heterogeneous levels of Fas molecule, but they result homogeneously resistant to Fas-induced apoptosis. However, CD4+ and CD8+ CTL clones kill melanoma cells through Fas/FasL-independent, granule-dependent lytic pathway. In these lymphocytes, Ag/MHC complex interaction with TCR does not lead to functional involvement of FasL, triggered, on the contrary, by T cell activation with nonspecific stimuli such as PMA/ionomycin. Additionally, melanoma cells express significant levels of FasL (detectable on the cell surface only after treatment with metalloprotease inhibitors), although to a lesser extent than professional immune cells such as Th1 clones. Nevertheless, antimelanoma CTL clones resist apoptosis mediated by FasL either in soluble form or expressed by Th1 lymphocytes or FasL+ melanoma cells. These results demonstrate that CD4+ and CD8+ antimelanoma T cell clones can be protected against Fas-dependent apoptosis, and thus be useful reagents of immunotherapeutic strategies aimed to potentiate tumor-specific T cell responses.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Filiberto Belli
- ‡Surgical Oncology B, Istituto Nazionale Tumori, Milan, Italy
- Divisions of
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