Project description:The dysregulated host response to infections can lead to sepsis, a complex disease characterized by a spectrum of clinical phenotypes associated with the host immune response variability and outcomes. This heterogeneity poses challenges for implementing specific therapeutic approaches. While clinical sepsis phenotypes are well distinguished, the mechanisms driving these heterogeneous responses remain poorly understood. Using an unbiased experimental approach, we analysed immune cell activation profiles in survived and non-survived CLP-septic to gain insights into the immunological mechanisms by which neutrophils contribute to the hyperinflammatory septic phenotype. Our finds reveal that non-survived septic mice exhibit increased frequencies of immature CXCR4+ PD-L1+ neutrophils and monocytes in the bloodstream, accompanied by an accumulation of trafficking-specific CXCR4+ PD-L1+ neutrophils into the lungs. The increased PD-L1 expression on CXCR4+ neutrophils is associated with increase of IFN-gamma signaling pathways. Additionally, the IFN-gamma and LPS promote an activation profile of CXCR4+ PD-L1+ neutrophils, exhibiting a phenotype associated with inflammation and organ damage. Notably, abrogating the IFN-gamma reduced susceptibility to CLP-sepsis and diminished PD-L1 expression on CXCR4+ neutrophils. This study provides molecular and functional insights into the immune cell activation profiles associated with the worsening of the septic hyperinflammatory phenotype experimental model. The CXCR4+ PD-L1+ neutrophils population and elevated plasmatic IFN-gamma levels highlighted here represent promising targets for therapeutic modulation in clinical sepsis hyperinflammatory phenotype.
Project description:Antibodies and derivative drugs targeting immune checkpoints have been approved for the treatment of several malignancies, but there are fewer responses in patients with pancreatic cancer. Here, we designed a nanobody molecule with bi-targeting on PD-L1 and CXCR4, as both targets are overexpressed in many cancer cells and play important roles in tumorigenesis. The nanobody sequences targeting PD-L1 and CXCR4 were linked by the (G4S)3 flexible peptide to construct the anti-PD-L1/CXCR4 bispecific nanobody. The bispecific nanobody was expressed in E. coli cells and purified by affinity chromatography. The purified nanobody was biochemically characterized by mass spectrometry, Western blotting and flow cytometry to confirm the molecule and its association with both PD-L1 and CXCR4. The biological function of the nanobody and its anti-tumour effects were examined.
Project description:Neutrophils are critical for effective anti-fungal immune responses. However, in fungal sepsis neutrophils undergo a phenotypical (Ly6G downregulation) and functional alteration (defective ROS production), impairing their anti-fungal capacity. Therefore we wish to characterize the neutrophils in septic mice transcriptionally to describe their role in driving sepsis. We included several control groups. Mice that lack T cells (TCRaKO mice) have increased resistance to the infection and their neutrophils appear unaltered. We identified G-CSF and DNA/histones to be responsible for affecting granulopoiesis, as rG-CSF and Clodronate liposomes combined expand Ly6Glow neutrohils in naive mice.
Project description:Peripheral blood neutrophils were isolated from septic patients and treated in vitro with LPS or HMGB1 Experiment Overall Design: 8 patients, each contributing a control, LPS-treated, and HMGB1-treated neutrophil sample.
Project description:The wide array of molecules carried by plasma regulates critical immune functions and constitutes valuable biomarkers and therapeutic targets. In recent years the introduction of “systems approaches” has provided investigators with powerful means for assessing immune responses in patient samples on a global scale. However, while the use of genome-wide profiling technologies has become widespread, measuring the plasma proteome still presents considerable challenges. An alternative approach that consists in measuring transcriptome responses in reporter cells exposed in vitro to patient plasma has been successfully employed in a limited number of studies. Here we devised such a “Transcriptomic Reporter Assay” system to assess the immunogenicity of plasma from septic patients and evaluate its potential for biomarker discovery. Sepsis is a common, severe systemic infectious process for which physicians still lack efficient diagnostic or prognostic tools. Of the three different cell reporter systems tested, neutrophils were identified as the most capable “plasma sensor”. Compared to peripheral blood mononuclear cells and dendritic cell preparations neutrophils were best able to discriminate between plasma from septic and control subjects and responded by upregulating a robust immune transcriptional program. Additionally, the amplitude of the neutrophil transcriptomic response was shown to be associated with disease severity in two additional sets of patients. Overall, our results demonstrate both the suitability and potential clinical relevance of a neutrophil reporter assay for assessing immunopathogenic processes in a complex and severe condition such as sepsis. Polymorphonuclear neutrophils (PMNs) were isolated from two healthy donors. Plasma samples were obtained from patients with culture-confirmed sepsis (n=12) and from uninfected controls (n=12). PMNs were cultured for 6 hours in medium alone, plasma from patients with sepsis, plasma from uninfected controls, and LPS using a final concentration of 20%. Transcriptional profiles were acquired using Illumina HumanHT12 V4 BeadChips.
Project description:The wide array of molecules carried by plasma regulates critical immune functions and constitutes valuable biomarkers and therapeutic targets. In recent years the introduction of “systems approaches” has provided investigators with powerful means for assessing immune responses in patient samples on a global scale. However, while the use of genome-wide profiling technologies has become widespread, measuring the plasma proteome still presents considerable challenges. An alternative approach that consists in measuring transcriptome responses in reporter cells exposed in vitro to patient plasma has been successfully employed in a limited number of studies. Here we devised such a “Transcriptomic Reporter Assay” system to assess the immunogenicity of plasma from septic patients and evaluate its potential for biomarker discovery. Sepsis is a common, severe systemic infectious process for which physicians still lack efficient diagnostic or prognostic tools. Of the three different cell reporter systems tested, neutrophils were identified as the most capable “plasma sensor”. Compared to peripheral blood mononuclear cells and dendritic cell preparations neutrophils were best able to discriminate between plasma from septic and control subjects and responded by upregulating a robust immune transcriptional program. Additionally, the amplitude of the neutrophil transcriptomic response was shown to be associated with disease severity in two additional sets of patients. Overall, our results demonstrate both the suitability and potential clinical relevance of a neutrophil reporter assay for assessing immunopathogenic processes in a complex and severe condition such as sepsis. Polymorphonuclear neutrophils (PMNs) were isolated a healthy donor. Plasma samples were obtained from a first set of patients with culture-confirmed sepsis (n=29) and from uninfected controls (n=17). PMNs were cultured for 6 h in medium alone, plasma from patients with sepsis, plasma from uninfected controls, and LPS using a final concentration of 20%. Transcriptional profiles were acquired using Illumina HumanHT12 V4 BeadChips.
Project description:The wide array of molecules carried by plasma regulates critical immune functions and constitutes valuable biomarkers and therapeutic targets. In recent years the introduction of âsystems approachesâ has provided investigators with powerful means for assessing immune responses in patient samples on a global scale. However, while the use of genome-wide profiling technologies has become widespread, measuring the plasma proteome still presents considerable challenges. An alternative approach that consists in measuring transcriptome responses in reporter cells exposed in vitro to patient plasma has been successfully employed in a limited number of studies. Here we devised such a âTranscriptomic Reporter Assayâ system to assess the immunogenicity of plasma from septic patients and evaluate its potential for biomarker discovery. Sepsis is a common, severe systemic infectious process for which physicians still lack efficient diagnostic or prognostic tools. Of the three different cell reporter systems tested, neutrophils were identified as the most capable âplasma sensorâ. Compared to peripheral blood mononuclear cells and dendritic cell preparations neutrophils were best able to discriminate between plasma from septic and control subjects and responded by upregulating a robust immune transcriptional program. Additionally, the amplitude of the neutrophil transcriptomic response was shown to be associated with disease severity in two additional sets of patients. Overall, our results demonstrate both the suitability and potential clinical relevance of a neutrophil reporter assay for assessing immunopathogenic processes in a complex and severe condition such as sepsis. Polymorphonuclear neutrophils (PMNs) were isolated a healthy donor. Plasma samples were obtained from a first set of patients with culture-confirmed sepsis (n=35) and from uninfected controls (n=19). PMNs were cultured for 6 h in medium alone, plasma from patients with sepsis, plasma from uninfected controls, and LPS using a final concentration of 20%. Transcriptional profiles were acquired using Illumina HumanHT12 V4 BeadChips.
Project description:The wide array of molecules carried by plasma regulates critical immune functions and constitutes valuable biomarkers and therapeutic targets. In recent years the introduction of “systems approaches” has provided investigators with powerful means for assessing immune responses in patient samples on a global scale. However, while the use of genome-wide profiling technologies has become widespread, measuring the plasma proteome still presents considerable challenges. An alternative approach that consists in measuring transcriptome responses in reporter cells exposed in vitro to patient plasma has been successfully employed in a limited number of studies. Here we devised such a “Transcriptomic Reporter Assay” system to assess the immunogenicity of plasma from septic patients and evaluate its potential for biomarker discovery. Sepsis is a common, severe systemic infectious process for which physicians still lack efficient diagnostic or prognostic tools. Of the three different cell reporter systems tested, neutrophils were identified as the most capable “plasma sensor”. Compared to peripheral blood mononuclear cells and dendritic cell preparations neutrophils were best able to discriminate between plasma from septic and control subjects and responded by upregulating a robust immune transcriptional program. Additionally, the amplitude of the neutrophil transcriptomic response was shown to be associated with disease severity in two additional sets of patients. Overall, our results demonstrate both the suitability and potential clinical relevance of a neutrophil reporter assay for assessing immunopathogenic processes in a complex and severe condition such as sepsis. Peripheral blood mononuclear cells (PBMCs) were isolated from two healthy donors. Plasma samples were obtained from patients with culture-confirmed sepsis (n=12) and from uninfected controls (n=12). PBMCs were cultured for 6 h in medium alone, plasma from patients with sepsis, plasma from uninfected controls, and LPS using a final concentration of 20%. Transcriptional profiles were acquired using Illumina HumanHT12 V4 BeadChips.
Project description:Severe infections and sepsis is an increasing clinical problem that cause prolonged morbidity and substantial mortality. At present, antibiotics are essentially the only pharmacological treatment for sepsis. The incidence of antibiotic resistance is increasing and it is therefore critical to find new therapies for sepsis. Staphylococcus aureus (S. aureus) is a major cause of septic mortality. Neutrophils play a major role in defense against bacterial infections. We have recently shown that a saturated high fat diet decreases survival in septic mice, but the mechanisms behind remain elusive. The aim of the present study was to investigate how the dietary fat composition affects survival and neutrophils function after experimental septic infection in mice. We found that, after S. aureus infection, mice fed polyunsaturated high fat diet (HFD/P) for 8 weeks had increased septic survival and decreased bacterial load compared with mice fed saturated HFD (HFD/S), and similar to that of mice given low fat diet (LFD). Furthermore, uninfected mice fed HFD/P had increased number of Ly6G+ neutrophils in bone marrow. In addition, mice fed HFD/P had a higher number Ly6G+ neutrophils recruited to the site of inflammation after peritoneal injection of thioglycollate. In conclusion, polyunsaturated dietary fat increased both survival and the efficiency of the bacterial clearance during septic S. aureus infection. Moreover, this diet enhanced the number and chemotaxis of neutrophils, a key component of the immune response to S. aureus infections. Mice (non-infected) fed saturated high fat diet, low fat diet, or polyunsaturated high fat diet