Human Melanoma-Reactive CD4+ and CD8+ CTL Clones Resist Fas Ligand-Induced Apoptosis and Use Fas/Fas Ligand-Independent Mechanisms for Tumor Killing This information is current as of September 29, 2021. Licia Rivoltini, Marina Radrizzani, Paola Accornero, Paola Squarcina, Claudia Chiodoni, Arabella Mazzocchi, Chiara Castelli, Paolo Tarsini, Vincenzo Viggiano, Filiberto Belli, Mario P. Colombo and Giorgio Parmiani J Immunol 1998; 161:1220-1230; ; Downloaded from http://www.jimmunol.org/content/161/3/1220 References This article cites 60 articles, 32 of which you can access for free at: http://www.jimmunol.org/content/161/3/1220.full#ref-list-1 http://www.jimmunol.org/ Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists by guest on September 29, 2021 • Fast Publication! 4 weeks from acceptance to publication *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 1998 by The American Association of Immunologists All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. Human Melanoma-Reactive CD41 and CD81 CTL Clones Resist Fas Ligand-Induced Apoptosis and Use Fas/Fas Ligand-Independent Mechanisms for Tumor Killing1 Licia Rivoltini,2* Marina Radrizzani,* Paola Accornero,* Paola Squarcina,* Claudia Chiodoni,* Arabella Mazzocchi,* Chiara Castelli,* Paolo Tarsini,* Vincenzo Viggiano,† Filiberto Belli,‡ Mario P. Colombo,* and Giorgio Parmiani* 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 Fas1 lymphocytes. In this study, we report that tumor-specific T lymphocytes isolated from tumor lesions by repeated in vitro TCR stimulation with relevant Ags Downloaded from (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, CD41 and CD81 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 metallo- http://www.jimmunol.org/ protease 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 FasL1 melanoma cells. These results demonstrate that CD41 and CD81 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. The Journal of Immunology, 1998, 161: 1220–1230. umor cells can express antigenic determinants that are Particularly, one of the enigmas of tumor immunology is why detected by specific CD41 and CD81 T lymphocytes in the immune system generally fails to eliminate antigenic tumor T an MHC-restricted fashion, thus stimulating cytotoxic ac- cells or to slow down disease progression. This phenomenon, iden- by guest on September 29, 2021 tivity and cytokine release (1). Based on these observations, the tified as tumor immune escape, has been associated with the ability identification of the human tumor Ags recognized by these T cells of cancer cells to take advantage of a variety of strategies for is progressing at an accelerating pace (1). The genes reported to evading immune detection and/or killing. Deficiencies in quantity, encode tumor epitopes belong to different groups, including tumor- processing, presentation, or affinity may reduce the immunogenic- specific Ags, mutated proteins, and normal self molecules (2). In ity of certain tumor Ags (7), and loss of MHC expression, fre- the latter, T cell reactivity can be viewed as a sort of autoreactive quently observed in cancer cells, can make them completely un- phenomenon that escaped peripheral tolerance (3). The large detectable by T cells (8). Lack of expression of costimulatory amount of information collected in the last few years on the nature molecules on the neoplastic cells can lead to anergy of tumor- of Ags and epitopes recognized by T lymphocytes on cancer cells reactive CTL (9), and a similar effect can be mediated by immu- is presently supporting worldwide efforts aimed at identifying ef- nosuppressive factors released by cancer cells at the tumor site fective and widely applicable protocols of immune therapy of (10). Altogether, these factors may contribute in making a tumor cancer (4–6). lesion an immune privileged-like site that Ag-specific T cells can However, the functional interactions occurring in vivo between hardly access. the immune system and the cancer process are just starting to be Recently, a further mechanism potentially used by tumor cells to understood, and little information is still available on the rules neutralize host immune response has been identified as involving governing host immune responses directed against tumor cells. Fas-FasL3 interaction (11, 12). These proteins are key molecules in normal immune development, homeostasis, and functions (13). Li- gation of FasL to its Fas receptor induces programmed cell death (or apoptosis) and plays important immunologic roles, such as im- Divisions of *Experimental Oncology D, †Medical Oncology B, and ‡Surgical On- mune response termination, T cell activation-induced cell death, cology B, Istituto Nazionale Tumori, Milan, Italy clonal downsizing, and control of peripheral tolerance to self Ags Received for publication December 12, 1997. Accepted for publication April 2, 1998. (14). Based on these features, a central role of Fas-FasL has also The costs of publication of this article were defrayed in part by the payment of page been hypothesized recently in the maintenance of immune privi- charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. lege in certain vital organs, such as eye, central nervous system, 1 This work was supported in part by grants from Italian Association for Cancer and testis (15), and dysfunctions in Fas-mediated apoptosis have Research (Milan, Italy) and Istituto Superiore di Sanita`(Rome, Italy). 2 Address correspondence and reprint requests to Dr. L. Rivoltini, Division of Ex- perimental Oncology D, Istituto Nazionale Tumori, Via Venezian 1, 20133 Milan, 3 Abbreviations used in this paper: FasL, Fas ligand; CsA, cyclosporin A; LCL, lym- Italy. phoblastoid cell line; TBS, Tris-buffered saline; TIL, tumor-infiltrating lymphocytes. Copyright © 1998 by The American Association of Immunologists 0022-1767/98/$02.00 The Journal of Immunology 1221 been associated with autoimmunity in both animal models and and BS239-CD4 recognized an unknown Ag specifically expressed on au- humans (13, 14). Additionally, Fas-FasL interaction is also utilized tologous melanoma cells and presented in the context of HLA-DR1 or 10 by cytotoxic T cells as a death pathway for target killing, second- (our unpublished observations). The Th1 clone 103 has been described previously (27). ary to granule exocytosis in CD81 effectors, but essential for cy- 1 As for the tumor lines, MeBS, Me1340, Me23682, Me97620, totoxic CD4 cells (16, 17). Me1402/R, and Me37041 were established in our laboratory from mela- Although Fas has been reported to be broadly expressed in dif- noma lesions (either s.c. or visceral metastases, or invaded lymph nodes). ferent tissues, FasL was conventionally thought to be a selective BS-LCL, a B lymphoblastoid cell line, was obtained by infecting B cells from patient BS with EBV. 501 mel, GDNmel, and 624.28 mel were kindly marker of cells belonging to the immunologic compartment (13). provided by Dr. F. M. Marincola (Surgery Branch, National Institutes of However, it has been observed recently that nonimmunologic Health, Bethesda, MD) (28). 256 mel and 272 mel were a kind gift from cells, such as tumor cells, can indeed acquire FasL expression and Dr. D. Rimoldi (Ludwig Institute of Cancer Research, Lausanne, Switzer- use it for delivering death signals to activated, Fas1 T cells (12, 18, land). A375 mel, HS695 mel, and RPMI 7951 mel were purchased from 19). At the same time, tumor cells seem to be spared from their American Type Culture Collection (Rockville, MD). All of these cell lines, including Jurkat and K562, were maintained in 10% FCS/RPMI 1640. own weapon, due to their resistance to Fas-induced cell death that Normal melanocytes were kindly provided by Dr. M. Herlyn (Wistar In- additionally preserves them from undergoing apoptosis-mediated stitute, Philadelphia, PA). killing by