Plasma levels of chemokine ligand 20 and chemokine receptor 6 in patients with sepsis: A case control study

The Impact of Steatotic Liver Disease on Cytokine and Chemokine Kinetics During Sepsis

Metabolic dysfunction-associated steatotic liver disease (MASLD) has recently been linked with sepsis outcomes. However, the immune mechanisms by which MASLD aggravates sepsis severity are unknown. This prospective cohort study aimed to analyze serum cytokine and chemokine kinetics in patients with MASLD and community-acquired sepsis. Out of the 124 patients, 68 (55%) were diagnosed with MASLD. There were no differences in age, sex, comorbidities, baseline sepsis severity, or etiology between the groups. Serum concentrations of 27 cytokines and chemokines on admission and day 5 of hospitalization were analyzed using a multiplex bead-based assay. Patients with MASLD had significantly higher serum concentrations of IL17A, IL-23, IL-33, CXCL10 and TGF-β1. Different cytokine kinetics were observed; patients with MASLD had a decrease in IL-10, IL-23, CXCL10 and TGF-β1, and an increase in IL-33, CXCL5 and CXCL1 on day 5. In the non-MASLD group, there was a decrease in IFN-γ, IL-6, IL-23 and CCL20, and an increase in CCL11 and CXCL5. While TGF-β1 significantly increased in non-MASLD, in MASLD, it decreased on day 5. Kinetics of TGF- β1 and CCL11 were associated with mortality in patients with MASLD. In conclusion, MASLD is linked with distinct cytokine and chemokine profiles during sepsis.

Phenotypic Landscape of Immune Cells in Sepsis: Insights from High-Dimensional Mass Cytometry

Understanding the sepsis-induced immunological response can be facilitated by identifying phenotypic changes in immune cells at the single-cell level. Mass cytometry, a novel multiparametric single-cell analysis technique, offers considerable benefits in characterizing sepsis-induced phenotypic changes in peripheral blood mononuclear cells. Here, we analyzed peripheral blood mononuclear cells from 20 sepsis patients and 10 healthy donors using mass cytometry and employing 23 markers. Both manual gating and automated clustering approaches (PhenoGraph) were used for cell identification, complemented by uniform manifold approximation and projection (UMAP) for dimensionality reduction and visualization. Our study revealed that patients with sepsis exhibited a unique immune cell profile, marked by an increased presence of monocytes, B cells, and dendritic cells, alongside a reduction in natural killer (NK) cells and CD4/CD8 T cells. Notably, significant changes in the distributions of monocytes and B and CD4 T cells were observed. Clustering with PhenoGraph unveiled the subsets of each cell type and identified elevated CCR6 expression in sepsis patients' monocyte subset (PG#5), while further PhenoGraph clustering on manually gated T and B cells discovered sepsis-specific CD4 T cell subsets (CCR4low CD20low CD38low) and B cell subsets (HLA-DRlow CCR7low CCR6high), which could potentially serve as novel diagnostic markers for sepsis.

Prognostic Value of Macrophage Inflammatory Protein-3alpha (MIP3-Alpha) and Severity Scores in Elderly Patients with Sepsis

Objective

This study examines the effectiveness of MIP-3alpha and severity scores in determining the prognosis of elderly sepsis patients.

Methods

From October 2020 to April 2021, a total of 171 elderly sepsis patients were admitted to the Emergency Department of the Shijingshan Branch of Beijing Chaoyang Hospital, Capital Medical University. According to the 28-day mortality rate, they were divided into two groups: survivors (48 cases) and deaths (123 cases). At admission, severity scores which are the Sequential Organ Failure Assessment (SOFA) and the Acute Physiology and Chronic Health Evaluation II (APACHE II) were calculated. The logistic regression was used to analyze the independent risk factors associated with 28-day mortality in elderly sepsis patients. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to evaluate the value of MIP-3alpha, SOFA, and APACHE II in the evaluation of 28-day mortality in elderly sepsis patients.

Results

MIP-3alpha, SOFA and APACHE II of the death group were significantly higher than those of the survival group (P < 0.05). Multivariate logistic regression analysis showed that MIP-3alpha, SOFA, APACHE II, and systolic blood pressure (SBP) were independent risk factors for 28-day mortality of senile sepsis (P < 0.05). Analysis of the ROC curve revealed that MIP-3alpha, SOFA, APACHE II had predictive value for the 28-day prognosis of senile sepsis (all P < 0.01). Combing with MIP-3alpha and SOFA showed better predictive ability (Z1 = 3.733, Z2 = 2.996, both P < 0.01), compared to detecting MIP-3alpha and SOFA alone.

Conclusion

In senile sepsis, MIP-3alpha, SOFA, APACHE II and SBP are independent risk factors for 28-day mortality. The combination of MIP-3alpha and SOFA can further enhance the predictive value of 28-day mortality in patients with senile sepsis and provide some reference value for the evaluation and treatment of senile sepsis.

Targeting of G-protein coupled receptors in sepsis

The Third International Consensus Definitions (Sepsis-3) define sepsis as life-threatening multi-organ dysfunction caused by a dysregulated host response to infection. Sepsis can progress to septic shock-an even more lethal condition associated with profound circulatory, cellular and metabolic abnormalities. Septic shock remains a leading cause of death in intensive care units and carries a mortality of almost 25%. Despite significant advances in our understanding of the pathobiology of sepsis, therapeutic interventions have not translated into tangible differences in the overall outcome for patients. Clinical trials of antagonists of various pro-inflammatory mediators in sepsis have been largely unsuccessful in the past. Given the diverse physiologic roles played by G-protein coupled receptors (GPCR), modulation of GPCR signaling for the treatment of sepsis has also been explored. Traditional pharmacologic approaches have mainly focused on ligands targeting the extracellular domains of GPCR. However, novel techniques aimed at modulating GPCR intracellularly through aptamers, pepducins and intrabodies have opened a fresh avenue of therapeutic possibilities. In this review, we summarize the diverse roles played by various subfamilies of GPCR in the pathogenesis of sepsis and identify potential targets for pharmacotherapy through these novel approaches.

Recombinant Human Proteoglycan-4 Mediates Interleukin-6 Response in Both Human and Mouse Endothelial Cells Induced Into a Sepsis Phenotype

OBJECTIVES

Sepsis is a leading cause of death in the United States. Putative targets to prevent systemic inflammatory response syndrome include antagonism of toll-like receptors 2 and 4 and CD44 receptors in vascular endothelial cells. Proteoglycan-4 is a mucinous glycoprotein that interacts with CD44 and toll-like receptor 4 resulting in a blockade of the NOD-like receptor pyrin domain-containing-3 pathway. We hypothesized that endothelial cells induced into a sepsis phenotype would have less interleukin-6 expression after recombinant human proteoglycan 4 treatment in vitro.

DESIGN

Enzyme-linked immunosorbent assay and reverse transcriptase-quantitative polymerase chain reaction to measure interleukin-6 protein and gene expression.

SETTING

Research laboratory.

SUBJECTS

Human umbilical vascular endothelial cells, human lung microvascular endothelial cells, and transgenic mouse (wild type) (Cd44 +/+/Prg4 +/+), Cd44 -/- (Cd44 tm1Hbg Prg4 +/+), Prg4 GT/GT (Cd44 +/+ Prg4 tm2Mawa/J), and double knockout (Cd44 tm1Hbg Prg4 tm2Mawa/J) lung microvascular endothelial cells.

INTERVENTIONS

Cells were treated with 100 or 250 ng/mL lipopolysaccharide-Escherichia coli K12 and subsequently treated with recombinant human proteoglycan 4 after 30 minutes. Interleukin-6 levels in conditioned media were measured via enzyme-linked immunosorbent assay and gene expression was measured via reverse transcriptase-quantitative polymerase chain reaction with ΔΔ-Ct analysis. Additionally, human umbilical vascular endothelial cells and human lung microvascular endothelial cells were treated with 1:10 diluted plasma from 15 patients with sepsis in culture media. After 30 minutes, either 50 or 100 µg/mL recombinant human proteoglycan 4 was administered. Interleukin-6 protein and gene expression were assayed. Proteoglycan 4 levels were also compared between control and sepsis patient plasma.

MEASUREMENTS AND MAIN RESULTS

Human umbilical vascular endothelial cell, human lung microvascular endothelial cell, and mouse lung microvascular endothelial cell treated with lipopolysaccharide had significantly increased interleukin-6 protein compared with controls. Recombinant human proteoglycan-4 significantly reduced interleukin-6 in human and mouse endothelial cells. Interleukin-6 gene expression was significantly increased after lipopolysaccharide treatment compared with controls. This response was reversed by 50 or 100 µg/mL recombinant human proteoglycan-4 in 80% of sepsis samples in human umbilical vascular endothelial cells and in 60-73% in human lung microvascular endothelial cells. In Cd44 -/- genotypes of the mouse lung microvascular endothelial cells, recombinant human proteoglycan-4 significantly reduced interleukin-6 protein levels after lipopolysaccharide treatment, indicating that Cd44 is not needed for recombinant human proteoglycan-4 to have an effect in a toll-like receptor 4 agonist inflammation model. Patient sepsis samples had higher plasma levels of native proteoglycan-4 than controls.

INTERPRETATION AND CONCLUSIONS

Recombinant human proteoglycan-4 is a potential adjunct therapy for sepsis patients and warrants future in vivo model studies.

Outlining key inflammation-associated parameters during early phase of an experimental gram-negative sepsis model in rhesus macaques (Macaca mulatta)

The aim of this study was to identify inflammation-associated markers during the early phase of sepsis in rhesus macaque. Four rhesus macaques were given an intravenous dose of 1010 CFU/kg of E. coli. Blood samples were collected before, or 30 minutes, 2, 4, 6 and 8 hours after E. coli infusion. Physiological parameters, bacteremia, endotoxemia, C-reactive protein (CRP), procalcitonin (PCT), and plasma cytokines/chemokines were determined for each animal. Bacteremia was present in all animals from 30 minutes to 3 hours after E. coli infusion whereas endotoxin was detected during the full-time course. CRP and PCT levels remained at detectable levels during the whole experimental window suggesting an ongoing inflammatory process. Signature cytokines and chemokines such as TNF-α, MIP-1α, and MIP-1β peaked about 2 hours after E. coli infusion and decreased thereafter. Plasma IL-6, IL-12p40, IFN-γ, and IL-1Ra, as well as I-TAC, MIG, IP-10 and MCP-1, remained at detectable levels after 4 hours of E. coli infusion. This nonhuman primate model could be useful for the assessment of new therapeutics aiming to suppress key inflammatory markers throughout sepsis early phases.

Plasma Chemokine CCL2 and Its Receptor CCR2 Concentrations as Diagnostic Biomarkers for Breast Cancer Patients

The aim of this study was to investigate plasma levels and applicability of CCL2, CCR2, and tumor marker CA 15-3 in breast cancer (BC) patients and in relation to the control groups: patients with benign breast tumor and healthy subjects. Plasma levels of tested parameters were determined by enzyme-linked immunosorbent assay (ELISA) and CA 15-3 by Chemiluminescent Microparticle Immunoassay (CMIA). The median levels of CCL2 in entire group of BC were significantly higher compared to the control groups, similarly as median levels of CA 15-3. CCR2 is a negative marker whose levels were significantly lower in BC group compared to healthy women. The concentration of CCL2 in BC increases with advancing tumor stage, while a median level of CCR2 decreases with advancing stage. CCL2 showed the highest value of sensitivity (SE) (64.95%) in entire BC group and also in early stages of disease. The highest specificity (SP) was obtained by CA 15-3 (85.71%). The area under the ROC curve (AUC) of CCR2 (0.7304) was the largest of all the tested parameters (slightly lower than CA 15-3) in the entire BC group, but a maximum range was obtained for the combination of all tested parameters with CA 15-3 (0.8271). In early stages of BC the highest AUC of all tested parameters was observed in CCL2 or CCR2 (stage I: 0.6604 and 0.6564; respectively; stage II: 0.7768, respectively, for CCR2). The findings of this study suggest that there may be applicability of CCL2, CCR2 in diagnosis of BC patients, particularly in conjunction with CA 15-3.