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: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:Pathways that stimulate β-cell regeneration remain of great clinical interest, yet effective therapeutic avenues that promote survival or reconstitution of β-cell mass remain elusive. Utilizing a mouse model with inducible β-cell apoptosis followed by adiponectin-mediated regeneration, we aimed to identify key molecules boosting β-cell viability. Within the regenerating pancreatic islets, we examined changes within the transcriptome, and observed an extensive upregulation of genes encoding proteins involved in lipid transport and metabolism. The most prominent targets were further confirmed by quantitative PCR and immunofluorescence. Among the upstream regulators predicted by pathway analysis of the transcriptome, we detected enhanced levels of two key transcription factors, HNF4α and PPARα. Enhanced leptin levels in circulation may also contribute to the anti-lipotoxic program in islets. In summary, our data suggest that improving local lipid metabolism as an important anti-lipotoxic phenomenon to boost β-cell regeneration, primarily mediated by adiponectin’s action on the β-cells directly as well as on the adipocyte. RNA profiles of pancreatic islets isolated from PANIC-ATTAT mice crossed with adiponectin wild-type (P-Adn+/+) or the overexpressing transgene (P-AdnTg/+) at 5 weeks after initial dimerizer administration.
Project description:Current chemotherapy or immunotherapy regimens for pancreatic cancer are limited. Although minimally invasive irreversible electroporation (IRE) ablation is a promising option for unresectable pancreatic cancers, the typical immunosuppressive tumour microenvironment promotes immune evasion and rapid tumour recurrence. Thus, triggering efficient amplification of endogenous adaptive antitumour immunity is critical for improving immunotherapy after ablation therapy. Here, we developed a hydrogel microsphere vaccine as an immune amplifier for post-ablation cancer immunotherapy. The vaccine acts as a general immune amplifier to trigger a rocket-like amplification of the cDC1-mediated antigen cross-presentation cascade, resulting in dramatic amplification of the antitumour immunity of endogenous CD8+ T cells. We also showed that the hydrogel microsphere vaccine promoted the transformation of pancreatic cancer from "cold" to "hot" tumours in a safe and efficient manner, significantly increased the survival of mice bearing orthotopic pancreatic tumours, and induced strong systemic antitumour immunity, which inhibited the growth of distant metastases.
Project description:Pathways that stimulate β-cell regeneration remain of great clinical interest, yet effective therapeutic avenues that promote survival or reconstitution of β-cell mass remain elusive. Utilizing a mouse model with inducible β-cell apoptosis followed by adiponectin-mediated regeneration, we aimed to identify key molecules boosting β-cell viability. Within the regenerating pancreatic islets, we examined changes within the transcriptome, and observed an extensive upregulation of genes encoding proteins involved in lipid transport and metabolism. The most prominent targets were further confirmed by quantitative PCR and immunofluorescence. Among the upstream regulators predicted by pathway analysis of the transcriptome, we detected enhanced levels of two key transcription factors, HNF4α and PPARα. Enhanced leptin levels in circulation may also contribute to the anti-lipotoxic program in islets. In summary, our data suggest that improving local lipid metabolism as an important anti-lipotoxic phenomenon to boost β-cell regeneration, primarily mediated by adiponectin’s action on the β-cells directly as well as on the adipocyte.
Project description:The CD155/TIGIT axis can be co-opted during immune evasion in chronic viral infections and cancer. Pancreatic adenocarcinoma (PDAC) is a highly lethal malignancy, and immune-based strategies to combat this disease have been largely unsuccessful to date. We corroborate prior reports that a substantial portion of PDAC harbors predicted high affinity MHC class I-restricted neoepitopes and extend these findings to advanced/metastatic disease. Using two novel preclinical models of neoantigen-expressing PDAC, we demonstrate that intratumoral neoantigen-specific CD8+ T cells adopt multiple states of dysfunction, which are similar to tumor-infiltrating lymphocytes of human PDAC patients. Mechanistically, genetic and/or pharmacologic modulation of the CD155/TIGIT axis was sufficient to promote immune evasion in autochthonous neoantigen-expressing PDAC. Finally, we demonstrate that the CD155/TIGIT axis is critical to maintain immune evasion in PDAC and uncover a combination immunotherapy (TIGIT/PD-1 co-blockade plus CD40 agonism) that elicits profound anti-tumor responses in preclinical models, now poised for clinical evaluation.