Distinct patterns of cytolytic T-cell activation by different tumour cells revealed by Ca 2+ signalling and granule mobilization

• Published in: Immunology 2017-02, Vol.150 (2), p.199-212
• Main Authors: Frick, Melissa, Mouchacca, Pierre, Verdeil, Grégory, Hamon, Yannick, Billaudeau, Cyrille, Buferne, Michel, Fallet, Mathieu, Auphan-Anezin, Nathalie, Schmitt-Verhulst, Anne-Marie, Boyer, Claude
• Format: Article
• Language: English
• Subjects: Animals; Antigens, Neoplasm - genetics; Antigens, Neoplasm - metabolism; Calcium Signaling; Cell Line, Tumor; Cytotoxicity, Immunologic; Exocytosis; Histocompatibility Antigen H-2D - metabolism; Humans; Intercellular Adhesion Molecule-1 - metabolism; Lymphocyte Activation; Lymphocyte Function-Associated Antigen-1 - metabolism; Mastocytoma - immunology; Melanoma - immunology; Mice; Peptide Fragments - metabolism; Secretory Vesicles - metabolism; T-Cell Antigen Receptor Specificity; T-Lymphocytes, Cytotoxic - immunology
• ISSN: 0019-2805; 1365-2567
• DOI: 10.1111/imm.12679

Cancer-germline genes in both humans and mice have been shown to encode antigens susceptible to targeting by cytotoxic CD8 T effector cells (CTL). We analysed the ability of CTL to kill different tumour cell lines expressing the same cancer-germline gene P1A (Trap1a). We previously demonstrated that CTL expressing a T-cell receptor specific for the P1A peptide associated with H-2L , although able to induce regression of P1A-expressing P815 mastocytoma cells, were much less effective against P1A-expressing melanoma cells. Here, we analysed parameters of the in vitro interaction between P1A-specific CTL and mastocytoma or melanoma cells expressing similar levels of the P1A gene and of surface H-2L . The mastocytoma cells were more sensitive to cytolysis than the melanoma cells in vitro. Analysis by video-microscopy of early events required for target cell killing showed that similar patterns of increase in cytoplasmic Ca concentration ([Ca ]i) were induced by both types of P1A-expressing tumour cells. However, the use of CTL expressing a fluorescent granzyme B (GZMB-Tom) showed a delay in the migration of cytotoxic granules to the tumour interaction site, as well as a partially deficient GZMB-Tom exocytosis in response to the melanoma cells. Among surface molecules possibly affecting tumour-CTL interactions, the mastocytoma cells were found to express intercellular adhesion molecule-1, the ligand for LFA-1, which was not detected on the melanoma cells.