Project description:Radiotherapy, a treatment modality received by more than half of all cancer patients, remains one of the most effective approaches to achieve local tumour control. Despite increased accuracy driven by technological advances, healthy tissue injury due to off-target radiation exposure can still occur. In this study, we sought to understand the biological effect of radiation-mediated injury to the lung in the context of cancer metastasis, since we had previously reported that tissue regeneration is a feature of the metastatic microenvironment of this organ. We have exposed healthy mouse lung tissue to radiation prior to the induction of metastasis and observed a strong enhancement of cancer cell growth. Lung tissue was preconditioned into a profoundly tumour-supportive microenvironment governed by enhanced regenerative Notch signalling. Most importantly, we found that locally activated neutrophils were key drivers of these tissue perturbations, significantly increasing the metastatic proficiency of irradiated lung tissue and endowing arriving cancer cells with an augmented stemness phenotype. We show that by preventing neutrophil-dependent Notch activation in the irradiated tissue, we were able to significantly offset the radiation-enhanced metastases. Mechanistically, we identified the release of neutrophil granules as the effectors of the pro-tumorigenic preconditioning of the irradiated lung tissue. These findings not only reveal a novel tumour-supportive function of neutrophils in the context of tissue-injury, but also have important clinical implications by suggesting targeting their activity could maximise the success of radiotherapy for the treatment of cancer.
Project description:Radiotherapy is one of the most effective approaches to achieve tumor control in cancer patients, although healthy tissue injury due to off-target radiation exposure can occur. In this study, we used a model of acute radiation injury to the lung, in the context of cancer metastasis, to understand the biological link between tissue damage and cancer progression. We exposed healthy mouse lung tissue to radiation before the induction of metastasis and observed a strong enhancement of cancer cell growth. We found that locally activated neutrophils were key drivers of the tumor-supportive preconditioning of the lung microenvironment, governed by enhanced regenerative Notch signaling. Importantly, these tissue perturbations endowed arriving cancer cells with an augmented stemness phenotype. By preventing neutrophil-dependent Notch activation, via blocking degranulation, we were able to significantly offset the radiation-enhanced metastases. This work highlights a pro-tumorigenic activity of neutrophils, which is likely linked to their tissue regenerative functions.
Project description:We used our novel Cherry-niche system to specifically isolate cells from the metastatic niche of 4T1 lung metastasis and compared their profile with the one obtained isolating lungs cells distal from the tumour growth
Project description:Streptococcus agalactiae (Group B Streptococcus, GBS) can colonize the human vaginal tract leading to both superficial and serious infections in adults and neonates. To study bacterial colonization of the reproductive tract in a mammalian system, we employed a murine vaginal carriage model. Using RNASeq, the transcriptome of GBS growing in vivo during vaginal carriage was determined. Over one-quarter of the genes in GBS were found to be differentially regulated during in vivo colonization as compared to laboratory cultures. A two-component system (TCS) homologous to the staphylococcal virulence regulator SaeRS was identified as being up-regulated in vivo. One of the SaeRS targets, pbsP, a proposed GBS vaccine candidate, was shown to be important for colonization of the vaginal tract. A component of vaginal lavage fluid acted as a signal to turn on pbsP expression via SaeRS. These data demonstrate the ability to quantify RNA expression directly from the murine vaginal tract and identify novel genes involved in vaginal colonization by GBS. They also provide more information about the regulation of an important virulence and colonization factor of GBS, pbsP, by the TCS SaeRS.
Project description:Background & Aims: Immune checkpoint inhibitors combined with anti-angiogenic agents produces benefits in the treatment of advanced hepatocellular carcinoma (HCC). We investigated the efficacy and immunomodulatory activity of cabozantinib alone and combined with anti-PD1 in experimental models of HCC, and explored the potential target population that might benefit from this combination. Approach & Results: C57BL/6J mice bearing subcutaneous Hepa1-6 or Hep53.4 tumours received cabozantinib, anti-PD1, their combination or placebo. Tumour and blood samples were analysed by flow cytometry, immunohistochemistry, transcriptome and cytokine profiling. Cabozantinib-related effects were validated in a colorectal cancer PDX model. Transcriptomic data from three human HCC cohorts (Cohort 1: n=167, Cohort 2: n=57, TCGA: n=319) were used to cluster patients according to neutrophil features, and assess their impact on survival. The combination of cabozantinib and anti-PD1 showed increased anti-tumour efficacy compared to monotherapy and placebo (P<0.05). Cabozantinib alone significantly increased neutrophil infiltration and reduced CD8+PD1+ T cell proportions in the tumour, while the combination with anti-PD1 further stimulated both effects and significantly decreased T regulatory cell infiltration (all P<0.05). In blood, cabozantinib and especially combination increased the proportions of overall T cells (P<0.01) and memory/effector T cells (P<0.05), while lowering the neutrophil-to-lymphocyte ratio (P<0.001 for combination). Unsupervised clustering of human HCCs revealed that high tumour enrichment in neutrophil features observed with the treatment combination was linked to less proliferative phenotypes, and well-differentiated HCC with better prognosis. Neutrophil recruitment in both humans and mice was linked to CXCR2 ligands and CXCL12 (P<0.05). Conclusions: Cabozantinib in combination with anti-PD1 enhanced anti-tumour immunity by bringing together innate neutrophil-driven and adaptive immune responses, a mechanism of action which favours this approach for the treatment of HCC.
Project description:Background & Aims: Immune checkpoint inhibitors combined with anti-angiogenic agents produces benefits in the treatment of advanced hepatocellular carcinoma (HCC). We investigated the efficacy and immunomodulatory activity of cabozantinib alone and combined with anti-PD1 in experimental models of HCC, and explored the potential target population that might benefit from this combination. Approach & Results: C57BL/6J mice bearing subcutaneous Hepa1-6 or Hep53.4 tumours received cabozantinib, anti-PD1, their combination or placebo. Tumour and blood samples were analysed by flow cytometry, immunohistochemistry, transcriptome and cytokine profiling. Cabozantinib-related effects were validated in a colorectal cancer PDX model. Transcriptomic data from three human HCC cohorts (Cohort 1: n=167, Cohort 2: n=57, TCGA: n=319) were used to cluster patients according to neutrophil features, and assess their impact on survival. The combination of cabozantinib and anti-PD1 showed increased anti-tumour efficacy compared to monotherapy and placebo (P<0.05). Cabozantinib alone significantly increased neutrophil infiltration and reduced CD8+PD1+ T cell proportions in the tumour, while the combination with anti-PD1 further stimulated both effects and significantly decreased T regulatory cell infiltration (all P<0.05). In blood, cabozantinib and especially combination increased the proportions of overall T cells (P<0.01) and memory/effector T cells (P<0.05), while lowering the neutrophil-to-lymphocyte ratio (P<0.001 for combination). Unsupervised clustering of human HCCs revealed that high tumour enrichment in neutrophil features observed with the treatment combination was linked to less proliferative phenotypes, and well-differentiated HCC with better prognosis. Neutrophil recruitment in both humans and mice was linked to CXCR2 ligands and CXCL12 (P<0.05). Conclusions: Cabozantinib in combination with anti-PD1 enhanced anti-tumour immunity by bringing together innate neutrophil-driven and adaptive immune responses, a mechanism of action which favours this approach for the treatment of HCC.
Project description:Little is known about how commensal colonization controls neutrophil differentiation and functions. Using system immunology approaches we discovered commensal and infection induced changes in neutrophil proteomes. The identified differentially expressed genes were CRISPRed out in immortalized neutrophil progenitor cell lines transduced with lenti-guides. Analysis of maturation and bactericidal capacity of the generated CRISPRed clones ascribed a function to a currently unknown protein-termed Prenylcysteine oxidase 1 like (Pcyox1l). Pcyox1l deficient neutrophils show dramatic defects in longevity, autophagy, and bactericidal functions associated with reductions in SerpinB1a transcripts and protein. Metabolic labeling experiments revealed that Pcyox1l controls levels of protein prenylation, highlighting its key enzymatic function. The Pcyox1l deficiency phenotype is phenocopied by SerpinB1a deficiency in neutrophils signifying linked mechanisms. Commensal colonization increases Pcyox1l and SerpinB1a levels in polymorphonuclear leukocytes (PMNs) in specific pathogen free (SPF) mice when compared to germ free (GF) mice and, conversely, Pcyox1l KO mice demonstrated altered commensal microbiome and elevated susceptibility to bacterial infection. Cumulatively, our data highlight a novel metabolic pathway which is controlled by commensal colonization and governs neutrophil functionality, longevity, and bactericidal properties. In lieu with the impairment of neutrophil bactericidal functions, Pcyox1l KO mice showed elevated susceptibility to infection with the Gram-negative pathogen Pseudomonas aeruginosa
Project description:Cabozantinib enhances anti-PD1 efficacy and elicits a neutrophil-based immune response in murine models: implications for human HCC
Project description:Pre-metastatic niche (PMN) formation is a critical step in metastatic progression, yet the biological effect of subtherapeutic-dose of ionizing radiation (SDIR) following radiotherapy on this process remains unclear. Using a 4T1 breast cancer mouse model, we investigated the effects of SDIR (3×0.3 Gy) on lung PMN development and metastasis formation. Lung PMNs were exposed to SDIR on days 8–10 post-tumor induction, followed by mastectomy on day 18, and analyzed on day 24. SDIR significantly increased total metastatic volume (TMV) in lungs, suggesting an accelerated PMN formation. Mechanistically, SDIR upregulated Bv8 expression, enhanced neutrophil recruitment, and increased MMP9, S100A8, and IL-6 production in the PMN by day 11, though differences between irradiated and non-irradiated PMN were no longer evident by day 14. Notably, Bv8 inhibition prevented SDIR-induced neutrophil recruitment but did not reduce TMV, indicating additional mechanisms in SDIR-driven metastasis. Proteomic analysis revealed SDIR-induced metabolic reprogramming, extracellular matrix (ECM) remodeling, and upregulation of adhesion-related pathways, driving a microenvironment that accelerates tumor invasion and metastatic outgrowth. By demonstrating that SDIR reprograms the pre-metastatic lung microenvironment, this study highlights the need to integrate organ-specific radiation exposure into predictive models of metastasis and identifies metabolic and immune-stromal pathways as potential targets for therapeutic intervention.