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Upregulation of T cell immunoglobulin-3 (TIM-3) has been associated with negative regulation of the immune response in chronic infection and cancer, including lymphoma. Here, we investigated the possible correlation between TIM-3 expression byex vivocytotoxic T cells (CTL) from follicular lymphoma (FL) biopsies and their functional unresponsiveness that could limit the favorable impact of CTL on disease progression. We report a high percentage of CD8+TIM-3+T cells in lymph nodes of FL patients. When compared to their CD8+TIM-3−counterparts, CD8+TIM-3+T cells exhibited defective cytokine production following TCR engagement. Furthermore, CD8+TIM-3+T cells displayex vivomarkers of lytic granule release and remain unresponsive to further TCR-induced activation of the lytic machinery. Although confocal microscopy showed that TIM-3 expression on CD8+T cells correlated with minor alterations of immunological synapse, a selective reduction of ERK signaling in CD8+TIM-3+T cells was observed by phospho-flow analysis. Finally, short relapse-free survival despite rituximab(R)-chemotherapy was observed in patients with high content of TIM-3+cells and a poor infiltrate of granzyme B+T cells in FL lymph nodes. Together, our data indicate that, besides selective TCR early signaling defects, TIM-3 expression correlates with unresponsiveness ofex vivoCD8+T cells in FL. They show that scores based on the combination of exhaustion and cytolytic markers in FL microenvironment might be instrumental to identify patients at early risk of relapses following R-chemotherapy. [ABSTRACT FROM PUBLISHER]

The article discusses a study on whether melanoma cells create defense mechanisms from ultrarapid lytic granule secreted by cytotoxic T lymphocytes (CTLs). It uses single-cell time-lapse microscopy to analyze subcellular events in melanoma cells which shows that an intracellular Ca2+ wave is initiated by target cell perforation upon CTL attack. It concludes that Ca2+ triggered lysosomal use to the synapse upon attack with unpredicted defensive topology in melanoma nodules.

Human cytotoxic T lymphocytes (CTLs) exhibit ultrarapid lytic granule secretion, but whether melanoma cells mobilize defense mechanisms with commensurate rapidity remains unknown. We used single-cell time-lapse microscopy to offer high spatiotemporal resolution analyses of subcellular events in melanoma cells upon CTL attack. Target cell perforation initiated an intracellular Ca 2+ wave that propagated outward from the synapse within milliseconds and triggered lysosomal mobilization to the synapse, facilitating membrane repair and conferring resistance to CTL induced cytotoxicity. Inhibition of Ca 2+ flux and silencing of synaptotagmin VII limited synaptic lysosomal exposure and enhanced cytotoxicity. Multiplexed immunohistochemistry of patient melanoma nodules combined with automated image analysis showed that melanoma cells facing CD8 + CTLs in the tumor periphery or peritumoral area exhibited significant lysosomal enrichment. Our results identified synaptic Ca 2+ entry as the definitive trigger for lysosomal deployment to the synapse upon CTL attack and highlighted an unpredicted defensive topology of lysosome distribution in melanoma nodules.

Upregulation of T cell immunoglobulin-3 (TIM-3) has been associated with negative regulation of the immune response in chronic infection and cancer, including lymphoma. Here, we investigated the possible correlation between TIM-3 expression by ex vivo cytotoxic T cells (CTL) from follicular lymphoma (FL) biopsies and their functional unresponsiveness that could limit the favorable impact of CTL on disease progression. We report a high percentage of CD8 + TIM-3 + T cells in lymph nodes of FL patients. When compared to their CD8 + TIM-3 - counterparts, CD8 + TIM-3 + T cells exhibited defective cytokine production following TCR engagement. Furthermore, CD8 + TIM-3 + T cells display ex vivo markers of lytic granule release and remain unresponsive to further TCR-induced activation of the lytic machinery. Although confocal microscopy showed that TIM-3 expression on CD8 + T cells correlated with minor alterations of immunological synapse, a selective reduction of ERK signaling in CD8 + TIM-3 + T cells was observed by phospho-flow analysis. Finally, short relapse-free survival despite rituximab(R)-chemotherapy was observed in patients with high content of TIM-3 + cells and a poor infiltrate of granzyme B + T cells in FL lymph nodes. Together, our data indicate that, besides selective TCR early signaling defects, TIM-3 expression correlates with unresponsiveness of ex vivo CD8 + T cells in FL. They show that scores based on the combination of exhaustion and cytolytic markers in FL microenvironment might be instrumental to identify patients at early risk of relapses following R-chemotherapy.