Project description:Third dataset release from the Immunological Proteome Resource (ImmPRes). This dataset contains the study focussing on the effect of Hypoxia in Cytotoxic CD8+ Lymphocytes.
Project description:While some of the inflammatory mechanisms driving hepatocellular carcinoma (HCC) had been proposed, the regulators of anti-cancer immunity in HCC remain poorly understood. We found that IL-27 receptor (IL-27R) signaling promotes HCC development in vivo. High IL-27EBI3 or IL-27RA expression correlated with poor prognosis for patients with HCC. Loss of IL-27R suppressed HCC in vivo in two different models of hepatocarcinogenesis. Mechanistically, IL-27R signaling within the tumor microenvironment restrains the cytotoxicity of innate cytotoxic lymphocytes. IL-27R ablation enhanced the accumulation and activation, while depletion or functional impairment of innate cytotoxic cells abrogated the effect of IL-27R disruption. Pharmacological neutralization of IL-27 signaling increased infiltration of innate cytotoxic lymphocytes with upregulated cytotoxic molecules and reduced HCC development. Our data reveal an unexpected role of IL-27R signaling as an immunological checkpoint regulating innate cytotoxic lymphocytes and promoting HCC of different etiologies, thus indicating a therapeutic potential for IL-27 pathway blockade in HCC
Project description:Cytotoxic T lymphocytes (CTL) kill malignant and infected cells via cytotoxic proteins such as granzyme B (GzmB) that are released into the immunological synapse in the form of ~110 nm supramolecular attack particles (SMAPs). However, it is not known where SMAPs are stored in the cell and how they are released. To address this, we utilized knock-in mice to label fusogenic cytotoxic granules with synaptobrevin2-mRFP. We identified two classes of fusion-competent granules, single core granules (SCG) and multi core granules (MCG), with different diameter, morphology, and protein composition. Functional analyses demonstrate that both classes of granules fuse with the plasma membrane at the IS. SCG fusion resulted in rapid dispersal of GzmB. MCG labelled with the SMAP marker thrombospondin-1 and their fusion events resulted in deposition of SMAPs. The CTL attack strategy thus includes SCG fusion to disperse immediately active cytotoxic proteins and parallel MCG fusion to deposit concentrated latent SMAPs onto the target.
Project description:This project explores the effects of Cdc42 gene-knock in effector cytotoxic T lymphocytes (CTLs). Effector CTLs were differentiated from OTI TCR transgenic mice for 5 days in vitro, then nucleofected with CRISPR/Cas9 RNPs targeting Cdc42 or non-targeting sequence.
Project description:Evasion from immunity is a major obstacle for achievement of successful cancer immunotherapy. Hybrids derived from cell-cell fusion is a theory associated with tumor heterogeneity and progression by conferring novel properties to tumor cells, such as drug resistance or metastatic capacity; however, its impact on immune evasion remains still unknown. Here, we investigated the potency of hybrids in immune evasion using tumor-macrophage hybrids. Hybrids were established by co-culture of a melanoma cell line, A375 and type 2 macrophages. The hybrids showed higher migration ability and higher tumorigenicity than those of the parental melanoma cells. We found that the hybrids were less sensitive to T cell receptor (TCR) specific for NY-ESO-1 transduced T cells (TCR-T cells) than parental melanoma cells, although hybrids and parental melanoma cells showed equivalent NY-ESO-1 expression. An in vitro tumor heterogeneity model revealed that TCR-T cells preferentially killed parental cells than hybrids and the survival rate of hybrids were higher than that in parental cells indicating hybrids evade from killing by TCR-T cells efficiently. A single cell analysis data set revealed that a few macrophage cells expressed melanoma differentiation antigens including gp100, MART-1 and tyrosinase, indicating hybrids exist in primary melanoma, and number of potential hybrids were corelated with poorer response to immune checkpoint blockade. These results provide evidence that melanoma-macrophage fusion has a role in tumor heterogeneity and immune evasion.
Project description:The cytotoxic activity of lymphocytes is particularly dependent on the regulated and polarised delivery of lytic granules to infected or malignant cells. Although genetic and mechanistic studies have identified a number of factors that regulate exocytosis in cytotoxic lymphocytes, a systematic mapping of the relevant factors and their relationships is lacking. Here, using a genome-scale CRISPR knockout screen in human natural killer cells, we characterise a complex genetic network regulating cytotoxic granule exocytosis, with lipid metabolism and protein lipidation among the most prominent pathways. By combining global protein lipidation and membrane lipid composition studies, we further uncover the critical role of ZDHHC17 in SNAP23 palmitoylation and targeting of palmitoylated SNAP23 to the membrane for cytotoxic granule fusion and release. Using ODYA-17 labelling of Ctrl and sgZDHHC17 NK-92 cells followed by pulldown and proteomic analysis, we investigated the palmitoylome of the NK-92 model cell line. By comparing the abundance of ODYA-17 labelled proteins in the lysates of Ctrl and sgZDHHC17 NK-92 cells, we defined the molecules that depend on the activity of the palmitoyl transferase ZDHHC17.
Project description:Regulated exocytosis controls key cellular functions ranging from neurotransmitter release to the secretion of immune mediators and its disruption is associated with numerous pathologies. The cytotoxic activity of lymphocytes is particularly dependent on regulated and polarized lytic granule delivery towards infected or malignant cells. Although genetic and mechanistic studies have identified factors regulating exocytosis in cytotoxic lymphocytes, a systematic mapping of the relevant factors and their relationships is lacking. Through a genome-scale CRISPR knockout screen in a human natural killer cell line, we characterized a complex genetic network regulating cytotoxic granule exocytosis, with lipid metabolism and protein lipidation amongst the most prominent pathways. By combining global protein lipidation and membrane lipid composition studies, we found that ZDHHC17 drives palmitoylation of the core SNARE complex protein SNAP23 to target cytotoxic granules to GM1-rich lipid rafts whose assembly is controlled by serine palmitoyltransferase.
Project description:We investigated transcriptional changes in MAZR-, Runx3- and MAZR/Runx3-deficient cytotoxic T lymphocytes (CTLs). This analysis revealed that MAZR plays a compensatory role in the Runx3-dependent transcriptional program of CTL differentiation.
Project description:Effector cytotoxic T lymphocytes (CTLs) are critical for ridding the body of infected or cancerous cells. Recognition of an antigenic ligand by the CTL’s T cell receptor (TCR) triggers a signalling cascade that ultimately results in the targeted release of cytolytic granules and/or secretion of cytokines and chemokines to alert and recruit additional immune cells. These signalling cascades are capable of initiating transcription, translation, and cytoskeletal rearrangements. While previous work has demonstrated how translation and intracellular reorganisation contribute to CTL effector responses, the role of transcription is less well studied. To address this, we examined the impact of blocking transcription on the CTL proteome during TCR stimulation. These data demonstrated a strong transcriptional requirement for expression of cytokines and chemokines but not cytolytic molecules. Together with functional studies, these data reveal differential molecular control of the cell-cell communication and cytolytic functions of effector CTLs. CTLs exhibit complete and persistent priming for cytolytic activity prior to target cell encounter, but they require de novo transcription to recruit additional immune cells that amplify the response.