Inhibition of CCL20 increases mortality in models of mouse sepsis with intestinal apoptosis

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.

Dietary Lactobacillus-Derived Exopolysaccharide Enhances Immune-Checkpoint Blockade Therapy

Microbes and their byproducts have been reported to regulate host health and immune functions. Here we demonstrated that microbial exopolysaccharide produced by Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1 (EPS-R1) induced CCR6+ CD8+ T cells of mice and humans. In mice, ingestion of EPS-R1 augmented antitumor effects of anti-CTLA-4 or anti-PD-1 monoclonal antibody against CCL20-expressing tumors, in which infiltrating CCR6+ CD8+ T cells were increased and produced IFNγ accompanied by a substantial immune response gene expression signature maintaining T-cell functions. Of note, the antitumor adjuvant effect of EPS-R1 was also observed in germ-free mice. Furthermore, the induction of CCR6 expression was mediated through the phosphorylated structure in EPS-R1 and a lysophosphatidic acid receptor on CD8+ T cells. Overall, we find that dietary EPS-R1 consumption induces CCR6+ CD8+ T cells in Peyer's patches, favoring a tumor microenvironment that augments the therapeutic effect of immune-checkpoint blockade depending on CCL20 production by tumors.

SIGNIFICANCE

Gut microbiota- and probiotic-derived metabolites are attractive agents to augment the efficacy of immunotherapies. Here we demonstrated that dietary consumption of Lactobacillus-derived exopolysaccharide induced CCR6+ CD8+ T cells in Peyer's patches and improved the tumor microenvironment to augment the therapeutic effects of immune-checkpoint blockade against CCL20-producing tumors. See related commentary by Di Luccia and Colonna, p. 1189. This article is highlighted in the In This Issue feature, p. 1171.

Nitidine chloride exerts anti-inflammatory action by targeting Topoisomerase I and enhancing IL-10 production

In the effort to identify natural products that regulate immunity and inflammation, we found that nitidine chloride (NC), an alkaloid from herb Zanthoxylum nitidum, enhanced IL-10 production in lipopolysaccharide (LPS)-stimulated myeloid cells. While NC was shown to be capable of inhibiting topoisomerase I (TOP1), NC analogs that could not inhibit TOP1 failed to increase IL-10 production. Moreover, medicinal TOP1 inhibitors TPT and SN-38 also augmented IL-10 production significantly, whereas knockdown of TOP1 prevented NC, TPT, and SN-38 from enhancing IL-10 expression. Thus, NC promoted IL-10 production by inhibiting TOP1. In LPS-induced endotoxemic mice, NC and TOP1 inhibitors increased IL-10 production, suppressed inflammatory responses, and reduced mortality remarkably. The anti-inflammatory activities of TOP1 inhibition were markedly reduced by IL-10-neutralizing antibody and largely absent in IL-10-deficient mice. In LPS-stimulated RAW264.7 cells and in peritoneal macrophages from endotoxemic mice, NC and TOP1 inhibitors significantly enhanced the activation of Akt, a critical signal transducer for IL-10 production, and inhibition of Akt prevented these compounds from enhancing IL-10 production and ameliorating endotoxemia. These data indicated that NC and TOP1 inhibitors are able to exert anti-inflammatory action through enhancing Akt-mediated IL-10 production and may assist with the treatment of inflammatory diseases.

Vitamin E-Coated Polysulfone Membrane-Based Hemodiafiltration Attenuates Inflammation in a Rat Model of Lipopolysaccharide-Induced Systemic Inflammation

BACKGROUND

Acute blood purification (ABP) therapy is used regularly in the clinical setting and reportedly alleviates organ failure associated with severe systemic inflammatory responses, leading to reduced mortality. The present study aimed to determine whether there is a difference in efficacy between polysulfone (PS) membranes, which are currently used regularly in the clinical setting, and vitamin E-coated polysulfone (VEPS) membranes, which are anticipated to exhibit the antioxidant and anti-inflammatory properties of vitamin E.

METHODS

Male Wistar rats (n=15/group) were intravenously administered 10 mg/kg of lipopolysaccharide (LPS) to establish a systemic inflammatory response model. Six hours after LPS administration, hemodiafiltration (HDF) was performed for 30 minutes using a PS or VEPS membrane under general anesthesia. Blood was collected at various time points, lung tissue was evaluated histologically, and 24-hour survival was assessed.

RESULTS

The rats in the VEPS group tended to have a higher survival rate than those in the PS group when undergoing HDF, although the difference was not significant. With respect to lung tissue, the inflammatory response was suppressed to a greater extent in the VEPS group than the PS group. Serum interleukin (IL)-6 levels were reduced at an early stage, plasma antioxidant activity was increased, and oxidative stress was reduced in the VEPS group compared to the PS group.

CONCLUSION

Relative to PS membrane-based HDF, the survival rate tended to improve and inflammation was subdued earlier due to the antioxidant activity and early attenuation of inflammation associated with VEPS membrane-based HDF.

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

BACKGROUND

Chemokine ligand 20 (CCL20) is a chemokine released by mainly liver and blood leucocytes. Particularly under pro-inflammatory circumstances it triggers chemotaxis of lymphocytes and dendritic cells via activating receptor chemokine receptor 6 (CCR6) that is specific to it. In experimental sepsis models, the chemokine-receptor pair has been identified as a potential pathophysiological axis affecting mortality.

OBJECTIVE

Measurement of CCL20 and CCR6 plasma levels in septic patients compared with postsurgical, nonseptic patients.

DESIGN

Case control study.

SETTING

Surgical ICUs of the Department of Anaesthesiology, General Hospital of Vienna, Vienna, Austria.

PATIENTS

Plasma levels were measured in 46 patients with sepsis, severe sepsis or septic shock according to current American College of Chest Physicians/Society of Critical Care Medicine criteria at the day of sepsis onset. Plasma levels in 36 postsurgical controls without sepsis admitted to the ICU were investigated. Plasma concentrations were determined by using commercially available ELISA kits. Data are given as median and interquartile range (IQR).

MAIN OUTCOME MEASURES

CCL20 and CCR6 plasma levels.

RESULTS

CCL20 plasma levels were significantly increased in the sepsis group: 220.9 pg ml (IQR, 72.8 to 540.1) compared with the ICU controls: 37.0 pg ml (IQR 6.5 to 83.6) (P < 0.0001). Significantly elevated CCR6 levels were found in the sepsis group: 2.47 ng ml (IQR 0.92 to 5.54) compared with the controls: 0.59 ng ml (IQR 0.17 to 1.48) (P < 0.0001). Both CCL20 and CCR6 correlated with the maximum sequential organ failure assessment score (CCL20: P < 0.0001, CCR6: P < 0.0001). Length of ICU admission depended significantly on the logarithm of CCR6 (P = 0.008) and sequential organ failure assessment maximum (P < 0.0001).

CONCLUSION

There were early increased plasma concentrations of CCL20 and CCR6 in patients with sepsis. CCL20 and CCR6 correlate with severity of illness in ICU patients. Levels of CCR6 predicted the length of patients' admission.

Dietary Omega-3 Fatty Acids Increase Survival and Decrease Bacterial Load in Mice Subjected to Staphylococcus aureus-Induced Sepsis

Sepsis caused by Staphylococcus aureus is increasing in incidence. With the alarming use of antibiotics,S. aureus is prone to become methicillin resistant. Antibiotics are the only widely used pharmacological treatment for sepsis. Interestingly, mice fed high-fat diet (HFD) rich in polyunsaturated fatty acids have better survival of S. aureus-induced sepsis than mice fed HFD rich in saturated fatty acids (HFD-S). To investigate what component of polyunsaturated fatty acids, i.e., omega-3 or omega-6 fatty acids, exerts beneficial effects on the survival of S. aureus-induced sepsis, mice were fed HFD rich in omega-3 or omega-6 fatty acids for 8 weeks prior to inoculation with S. aureus Further, mice fed HFD-S were treated with omega-3 fatty acid metabolites known as resolvins. Mice fed HFD rich in omega-3 fatty acids had increased survival and decreased bacterial loads compared to those for mice fed HFD-S after S. aureus-induced sepsis. Furthermore, the bacterial load was decreased in resolvin-treated mice fed HFD-S after S. aureus-induced sepsis compared with that in mice treated with vehicle. Dietary omega-3 fatty acids increase the survival of S. aureus-induced sepsis by reversing the deleterious effect of HFD-S on mouse survival.

Dietary polyunsaturated fatty acids increase survival and decrease bacterial load during septic Staphylococcus aureus infection and improve neutrophil function in mice

Severe infection, including sepsis, is an increasing clinical problem that causes prolonged morbidity and substantial mortality. At present, antibiotics are essentially the only pharmacological treatment for sepsis. The incidence of resistance to antibiotics is increasing; therefore, it is critical to find new therapies for sepsis. Staphylococcus aureus is a major cause of septic mortality. Neutrophils play an important role in the defense against bacterial infections. We have shown that a diet with high levels of dietary saturated fatty acids decreases survival in septic mice, but the mechanisms behind this remain elusive. The aim of the present study was to investigate how the differences in dietary fat composition affect survival and bacterial load after experimental septic infection and neutrophil function in uninfected mice. We found that, after S. aureus infection, mice fed a polyunsaturated high-fat diet (HFD-P) for 8 weeks had increased survival and decreased bacterial load during sepsis compared with mice fed a saturated high-fat diet (HFD-S), similar to mice fed a low-fat diet (LFD). Uninfected mice fed HFD-P had a higher frequency of neutrophils in bone marrow than mice fed HFD-S. In addition, mice fed HFD-P had a higher frequency of neutrophils recruited to the site of inflammation in response to peritoneal injection of thioglycolate than mice fed HFD-S. Differences between the proportion of dietary protein and carbohydrate did not affect septic survival at all. In conclusion, polyunsaturated dietary fat increased both survival and efficiency of bacterial clearance during septic S. aureus infection. Moreover, this diet increased the frequency and chemotaxis of neutrophils, key components of the immune response to S. aureus infections.

Comparison of bioactivities of talactoferrin and lactoferrins from human and bovine milk

OBJECTIVES

Lactoferrin (Lf) is an iron-binding glycoprotein present in high concentration in human milk. It is a pleiotropic protein and is involved in diverse bioactivities, such as stimulation of cell proliferation and differentiation, immune competence, antimicrobial activities, anti-infection, and anticancer activities. Lf has been shown to be partly resistant to proteolysis in the gastrointestinal tract and may thus play important roles in the intestine and liver during infancy. Talactoferrin alfa (TLf) is a recombinant human Lf shown to protect against sepsis and necrotizing enterocolitis as well as cancer. Because bovine Lf (bLf) and human Lf have different amino acid composition and all 3 Lfs differ in glycosylation, they may have different functions/potency. The objective of the present study was to investigate and compare bioactivities of TLf and Lfs from human and bovine milk and thus to provide a better understanding of the bioactivities of different forms of Lf and their potential applications.

METHODS

In the present study, Caco-2 and C3A cells were used as intestine and liver models to evaluate internalization of Lfs by intestine and liver cells, effects of Lfs on cell proliferation and differentiation, growth of enteropathogenic Escherichia coli (EPEC), chemokine (C-C motif) ligand 20 (CCL20) secretion, and transforming growth factor (TGF)-β1 expression. In addition, HT-29 cells were used as a colon cancer cell model to examine the effects of Lfs on apoptosis.

RESULTS

All Lfs significantly enhanced cell proliferation and differentiation, apoptosis, CCL20 secretion, and TGF-β1 expression. They also markedly suppressed growth of EPEC. Compared with bLf, TLf showed stronger effects on suppression of EPEC growth and enhancement of TGF-β1 secretion, whereas bLf exhibited more potent effects on cell differentiation, apoptosis, and CCL20 secretion.

CONCLUSIONS

Our results demonstrate that TLf has several bioactivities similar to human Lf and bLf from milk and may play critical roles in immune and intestinal development in infants as well as having anti-cancer activities in adults. TLf and bLf may be used for different applications owing to their various potencies. TLf may preferentially be used for anti-bacterial applications, whereas bLf may be used for cancer therapy because it exhibits stronger effects on CCL20 secretion, cell differentiation, and apoptosis.