Project description:Pancreatic cancer (PC) is a devastating disease characterised by late diagnosis, genetic neoplastic heterogeneity, poor T-cell infiltration, a highly immunosuppressive tumour microenvironment, and metastatic spreading which results in poor clinical outcomes. Surgery remains the most effective treatment, although it is limited to a few patients. Local ablative techniques, such as radiofrequency ablation (RFA), have been proposed to control PC progression in patients with nonresectable tumours. However, the impact of these therapies on promoting the activation of the immune system and eliciting an effective anti-tumour immune response remains elusive. Whether local ablative techniques could overcome resistance to immunotherapy in PC is unknown. We enrolled a cohort of patients with non-resectable locally advanced pancreatic cancer and longitudinally evaluated the impact of local thermal ablation on circulating immunological parameters. Additionally, we used cancer cell lines derived from PC transgenic mouse models to establish a preclinical platform that recapitulates systemic and localised inflammation induced by RFA in vivo. Finally, we employed this preclinical experimental platform to evaluate the efficacy of the therapeutic treatments. Thermal ablation induced a short-term inflammatory process resulting in a systemic increase in myeloid cells as well as increased plasma levels of high mobility group box 1 molecule, which correlates with a better patient outcome. We performed thermal ablative procedures in mice bearing orthotopic PC and evaluated the therapeutic efficacy of thermal treatment alone or in combination with immune checkpoint-based immunotherapy through activation of a T lymphocyte-dependent anti-tumour immune response. We demonstrated that RFA synergises with immunotherapy to restrict tumour progression, significantly improving the overall survival of PC-bearing mice. Tumour immune landscape characterisation confirmed that RFA in combination with immunotherapy supported the sculpting of an immune hostile milieu towards an effective anti-tumour milieu characterised by an increased infiltration of cytotoxic T lymphocytes in spite of CD206-expressing tumour-associated macrophages. Our study confirmed that RFA enhances immunotherapy effectiveness by breaking tumour immune tolerance and unleashing the full cytotoxic abilities of tumour-specific T-cells. Thus, RFA can circumvent the current limitations of immunotherapy in patients with pancreatic cancer.

Project description:Plants have evolved a two-layered immune system that mainly includes pattern-triggered immunity (PTI) and effector-triggered immunity (ETI) against pathogen attack. PTI and ETI signaling are functionally linked, but also distinct due to specific perceived ligands and activation modes. Unraveling how PTI and ETI coordinate the immune responses against pathogens is crucial for understanding the regulatory mechanisms in plant immunity. To better understand the protein profiling and phosphorylation events during PTI and ETI, we employed integrated whole proteome and phosphoproteome analyses in the tomato-Pst pathosystem with different Pst DC3000 mutants that allow dissection of different layers of immune responses. A total of 225 proteins and 79 phosphopeptides were differentially regulated in tomato leaves during immune responses. Our proteomics results indicate that some overlapping immune responses are triggered by both PTI and ETI-inducing treatment, and ETI response is more robust than PTI response for most proteins. The change patterns of protein abundance and phosphorylation revealed some key regulators involved in Ca2+ signaling, mitogen-activated protein kinase cascades, and reversible protein phosphorylation, ROS and redox homeostasis, direct defense, transcription machinery and protein turnover, cell wall remodeling, hormone biosynthesis, as well as immune molecule accumulation, are modulated during PTI and/or ETI, suggesting their common or specific roles in plant immune responses. However, NAC domain protein and lipid particle serine esterase, two PTI-specific genes from previous transcriptomic work, have not been detected as differentially regulated in our proteomic analysis, and they were proved to be not PTI-specific inducible and therefore cannot be used as PTI-reporters through “overlapping circle” pattern assay. These results provide insights into the fine-tuned regulatory mechanisms between PTI and ETI in-Pst pathosystem, which will springboard further investigations into the sophisticated mechanisms in plant immunity.

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Immune Mechanisms After Radiofrequency Ablation of Pulmonary Metastases From Colorectal Cancer Origin

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