Publication: Distinct patterns of cytolytic T-cell activation by different tumour cells revealed by Ca2+ signalling and granule mobilization

Published in: Immunology, 2017, 150 (2), pp.199-212. ⟨10.1111/imm.12679⟩

Authors: Melissa Frick, Pierre Mouchacca, Grégory Verdeil, Yannick Hamon, Cyrille Billaudeau, Michel Buferne, Mathieu Fallet, Nathalie Auphan-Anezin, Anne-Marie Schmitt-Verhulst, Claude Boyer

Summary

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(35-43) peptide associated with H-2L(d), 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(d). 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 Ca2+ concentration ([Ca2+]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.

Link to Pubmed [PMID] – 27716898

Link to HAL – hal-01996182

Link to DOI – 10.1111/imm.12679