epiglucan and Sepsis

Sepsis is a life-threatening condition caused by an abnormal immune response induced by infection with no approved or specific therapeutic options. We present our perspectives for the therapeutic management of sepsis through a four-way approach: (1) infection control through immune enhancement; (2) immune suppression during the initial hyper-inflammatory phase; (3) balanced immune-modulation to counter the later immune-paralysis phase; and (4) advantageous effects on metabolic and coagulation parameters throughout. COVID-19 is a virus-triggered, accelerated sepsis-like reaction that is associated with the rapid progress of an inflammatory cascade involving a cytokine storm and multiorgan failure. Here, we discuss the potential of the biological response modifiers, β-glucans (BRMGs), in the management of sepsis based on their beneficial effects on inflammatory-immune events in COVID-19 clinical studies. In COVID-19 patients, apart from metabolic regulation, BRMGs, derived from a black yeast,

Topics: beta-Glucans; C-Reactive Protein; COVID-19; Glucans; Humans; Immunologic Factors; Interleukin-6; Sepsis

Sepsis is a life-threatening response to systemic infection. In addition to frank gastrointestinal (GI) rupture/puncture, sepsis can also be exacerbated by translocation of pathogen-associated molecular patterns (PAMPs) from the GI tract to the systemic circulation (gut origin of sepsis). In the human gut, Gram-negative bacteria and Candida albicans are abundant, along with their major PAMP components, endotoxin (LPS) and (1 → 3)-β-D-glucan (BG). Whereas the influence of LPS in bacterial sepsis has been studied extensively, exploration of the role of BG in bacterial sepsis is limited. Post-translocation, PAMPs enter the circulation through lymphatics and the portal vein, and are detoxified and then excreted via the liver and the kidney. Sepsis-induced liver and kidney injury might therefore affect the kinetics and increase circulating PAMPs. In this article, we discuss the current knowledge of the impact of PAMPs from both gut mycobiota and microbiota, including epithelial barrier function and the "gut-liver-kidney axis," on bacterial sepsis severity.

Topics: Animals; Bacterial Infections; beta-Glucans; Candida; Gastrointestinal Tract; Humans; Intestinal Mucosa; Kidney; Lipopolysaccharides; Liver; Pathogen-Associated Molecular Pattern Molecules; Proteoglycans; Sepsis

Topics: beta-Glucans; Biomarkers; DNA, Fungal; Fungemia; Galactose; Humans; Immunocompromised Host; Mannans; Neoplasms; Sepsis

To investigate whether (1 → 3)-β-d-Glucan (BDG)-guidance shortens time to antifungal therapy and thereby reduces mortality of sepsis patients with high risk of invasive Candida infection (ICI).. Multicenter, randomized, controlled trial carried out between September 2016 and September 2019 in 18 intensive care units enrolling adult sepsis patients at high risk for ICI. Patients in the control group received targeted antifungal therapy driven by culture results. In addition to targeted therapy, patients in the BDG group received antifungals if at least one of two consecutive BDG samples taken during the first two study days was ≥ 80 pg/mL. Empirical antifungal therapy was discouraged in both groups. The primary endpoint was 28-day-mortality.. 339 patients were enrolled. ICI was diagnosed in 48 patients (14.2%) within the first 96 h after enrollment. In the BDG-group, 48.8% (84/172) patients received antifungals during the first 96 h after enrollment and 6% (10/167) patients in the control group. Death until day 28 occurred in 58 of 172 patients (33.7%) in the BDG group and 51 of 167 patients (30.5%) in the control group (relative risk 1.10; 95% confidence interval, 0.80-1.51; p = 0.53). Median time to antifungal therapy was 1.1 [interquartile range (IQR) 1.0-2.2] days in the BDG group and 4.4 (IQR 2.0-9.1, p < 0.01) days in the control group.. Serum BDG guided antifungal treatment did not improve 28-day mortality among sepsis patients with risk factors for but unexpected low rate of IC. This study cannot comment on the potential benefit of BDG-guidance in a more selected at-risk population.

Topics: Adult; Antifungal Agents; beta-Glucans; Candidiasis, Invasive; Glucans; Humans; Sensitivity and Specificity; Sepsis

The time to diagnosis of invasive Candida infection (ICI) is often too long to initiate timely antifungal therapy in patients with sepsis. Elevated serum (1,3)-β-D-glucan (BDG) concentrations have a high diagnostic sensitivity for detecting ICI. However, the clinical significance of elevated BDG concentrations is unclear in critically ill patients. The goal of this study is to investigate whether measurement of BDG in patients with sepsis and a high risk for ICI can be used to decrease the time to empiric antifungal therapy and thus, increase survival.. This prospective multicenter open randomized controlled trial is being conducted in 19 German intensive care units. All adult patients with severe sepsis or septic shock and an increased risk for ICI are eligible for enrolment. Risk factors are total parenteral nutrition, previous abdominal surgery, previous antimicrobial therapy, and renal replacement therapy. Patients with proven ICI or those already treated with systemic antifungal substances are excluded. Patients are allocated to a BDG or standard care group. The standard care group receives targeted antifungal therapy as necessary. In the BDG group, BDG serum samples are taken after randomization and 24 h later. Antifungal therapy is initiated if BDG is ≥80 pg/ml in at least one sample. We plan to enroll 312 patients. The primary outcome is 28-day mortality. Other outcomes include antifungal-free survival within 28 days after enrolment, time to antifungal therapy, and the diagnostic performance of BDG compared to other laboratory tests for early ICI diagnosis. The statistical analysis will be performed according to the intent-to-treat principle.. Because of the high risk of death, American guidelines recommend empiric antifungal therapy in sepsis patients with a high risk of ICI despite the limited evidence for such a recommendation. In contrast, empiric antifungal therapy is not recommended by European guidelines. BDG may offer a way out of this dilemma since BDG potentially identifies patients in need of early antifungals. However, the evidence for such an approach is inconclusive. This clinical study will generate solid evidence for health-care providers and authors of guidelines for the use of BDG in critically ill patients.. Clinicaltrials.gov, NCT02734550 . Registered 12 April 2016.

Topics: Antifungal Agents; Bacteriological Techniques; beta-Glucans; Biomarkers; Candida; Candidiasis, Invasive; Early Diagnosis; Female; Germany; Humans; Male; Multicenter Studies as Topic; Predictive Value of Tests; Prospective Studies; Proteoglycans; Randomized Controlled Trials as Topic; Reproducibility of Results; Sepsis; Severity of Illness Index; Time Factors; Time-to-Treatment; Up-Regulation

Aging plays a critical role in the incidence and severity of infection, with age emerging as an independent predictor of mortality in sepsis. Trained immunity reprograms immunocytes to respond more rapidly and effectively to pathogens and serves as a potential approach to improve immune function in aging and/or sepsis. However, there is very little data on trained immunity in the aging immune system or in the presence of sepsis. We examined the impact of β-glucan induced innate immune training on monocytes from aging healthy humans (>60 years old) as well as sepsis patients. We observed increased metabolic capacity, upregulated cytokine secretion, increased H3K27 acetylation, and upregulation of crucial intracellular signaling pathways in trained monocytes from healthy aging subjects. The response to trained immunity in healthy aging monocytes was equivalent to the response of monocytes from younger,

Topics: beta-Glucans; Cytokines; Humans; Middle Aged; Monocytes; Sepsis; Signal Transduction

Topics: Animals; beta-Glucans; Caco-2 Cells; Candida; Colitis; Cytokines; Dextran Sulfate; Disease Models, Animal; Dysbiosis; Humans; Klebsiella pneumoniae; Mice; Mice, Inbred C57BL; Sepsis; Toll-Like Receptor 2

Bacterial infection remains the main cause of acute respiratory distress syndrome and is a leading cause of death and disability in critically ill patients. Here we report on the use of purified β-glucan (lentinan) extracts from Lentinus edodes (Shiitake) mushroom that can reduce infection by a multidrug-resistant clinical isolate of Klebsiella pneumoniae in a rodent pneumonia model, likely through immunomodulation. Adult male Sprague-Dawley rats were subjected to intra-tracheal administration of K. pneumoniae to induce pulmonary sepsis and randomized to three groups; vehicle control (Vehicle, n = 12), commercial lentinan (CL, n = 8) or in-house extracted lentinan (IHL, n = 8) were administered intravenously 1 h postinfection. Physiological parameters and blood gas analysis were measured, bacterial counts from bronchoalveolar-lavage (BAL) were determined, along with differential staining of white cells and measurement of protein concentration in BAL 48 h after pneumonia induction. Use of IHL extract significantly decreased BAL CFU counts. Both CL and IHL extractions reduced protein concentration in BAL. Use of IHL resulted in an improvement in physiological parameters compared to controls and CL. In conclusion, administration of lentinan to treat sepsis-induced lung injury appears safe and effective and may exert its effects in an immunomodulatory manner.

Topics: Animals; Anti-Bacterial Agents; beta-Glucans; Drug Resistance, Bacterial; Humans; Klebsiella pneumoniae; Lentinan; Lung Diseases; Male; Plant Extracts; Rats; Rats, Sprague-Dawley; Sepsis; Shiitake Mushrooms

Very high mortality rate in sepsis may be related to oxidative stress. This study was conducted on the rats to investigate the presence of oxidative stress and also the potential protective effects of the ß-glucan in the intra-abdominal sepsis model formed by cecal ligation-perforation (CLP).. In this study, 30 Male rats were equally divided into three groups as 'Sham', 'Sepsis' and 'ß-Glucan'. Only laparotomy was performed in the Sham group, and sepsis was induced by CLP in Sepsis and ß-Glucan groups. Following CLP, a single dose of 4 mg ß-glucan/kg was also intraperitoneally administered to the β-Glucan group. Blood and tissue (liver, lung and kidney) samples were taken from Sepsis and ß-Glucan groups after sepsis development determined at the end of the 48th hour, also from the Sham group. The levels of myeloperoxidase (MPO) and advanced oxidation protein products (AOPP) were determined in plasma samples, and the malondialdehyde (MDA) was measured in plasma and tissues.. MPO and AOPP were higher in both the Sepsis and ß-Glucan groups; however, plasma and tissue MDA levels were higher only in the Sepsis group than the Sham group (p<0.05). However, when compared to the Sepsis group, all parameters measured, except kidney MDA, were significantly lower in the ß-Glucan group (p<0.05).. To our knowledge, this is the first study to investigate the AOPP levels in the CLP sepsis model, ROS produced by the reaction of MPO derived from neutrophils may form oxidative damage to the proteins, compared to the lipids, and ß-glucan may be used as an alternative agent for sepsis treatment.

Topics: Advanced Oxidation Protein Products; Animals; beta-Glucans; Disease Models, Animal; Male; Malondialdehyde; Oxidative Stress; Protective Agents; Rats; Sepsis

In nonneutropenic intensive care unit (ICU) patients, current risk stratification scores lack specificity to reliably predict the risk of a prospective invasive candidiasis (IC). We aimed to explore possible associations of distinct immunological markers with different degrees of Candida affection in patients with abdominal sepsis.. The presented explorative, noninterventional diagnosis study recruited patients admitted to the surgical ICU at Heidelberg University Hospital with abdominal sepsis. Over 5 days, we determined white blood cell count, 1,3-β-D-glucan, and HLA-DR expression; the amount of Th1, Th17, regulatory T, T helper, and cytotoxic T cells; Dectin-1 and TLR2-expression; the amount of T, B, and NK cells; the ex vivo secretion of IL-8 upon stimulation with LPS, flagellin, and zymosan; and the distribution of distinct T-cell cytokines in a daily manner. On day 21, patients' Candida infection status was stratified in no colonization or IC, colonization or IC.. A total of 26 patients were included. On day 21, five patients showed no colonization or IC, in 13 patients a colonization was detected, and eight patients were diagnosed with IC. On study inclusion, the stratification groups showed comparable values in standard laboratory parameters and morbidity scores. Decreased B and NK cell counts, as well as reduced IL-8 secretion after ex vivo stimulation with LPS or flagellin seemed to be associated with a higher risk of subsequent Candida colonization. Even lower values could distinguish the therapy-relevant difference between prospective IC from colonization alone.. We were able to show distinct immune system impairments in early abdominal sepsis by specific immune-based measurements. A possible association of these impairments with a subsequent Candida affection is shown.

Topics: Adult; Aged; Aged, 80 and over; beta-Glucans; Candidiasis, Invasive; Female; Flow Cytometry; Humans; Intensive Care Units; Interleukin-2 Receptor alpha Subunit; Interleukin-7 Receptor alpha Subunit; Lectins, C-Type; Male; Middle Aged; Monocytes; Neutrophils; Sepsis; T-Lymphocytes, Cytotoxic; T-Lymphocytes, Helper-Inducer; T-Lymphocytes, Regulatory; Th1 Cells; Th17 Cells; Toll-Like Receptor 2; Toll-Like Receptor 9

Desirability of outcome ranking (DOOR) has been developed for assessing desirability of outcome in interventional studies. However, its possible use in observational studies of the diagnosis and early treatment of infectious diseases has not been explored so far, and it might introduce interesting features in specific scenarios. This was a post hoc analysis of a prospective observational study in intensive care unit patients with sepsis and at risk of candidemia. The probabilities that a randomly selected patient would have a more, less, and equally cost-effective early therapeutic choice following a BDG-based diagnostic strategy rather than the empirical administration of antifungals to all patients were calculated using DOOR methods. The probability of a more cost-effective therapeutic choice following the BDG-based rather than the empirical strategy was 67.81% (95% CI 67.32-68.30), whereas the probabilities of a less and equally cost-effective early therapeutic choice were 19.68% (95% CI 19.27-20.10) and 12.50% (95% CI 12.16-12.85), respectively. The application of DOOR methods to observational studies focused on diagnosis and early treatment is a novel field that could merit further investigation.

Topics: Antifungal Agents; Antigens, Fungal; beta-Glucans; Candidemia; Cost-Benefit Analysis; Disease Management; Fungi; Humans; Intensive Care Units; Prospective Studies; Sepsis; Treatment Outcome

We investigated the influence of spontaneous gut leakage upon polymicrobial sepsis in a lupus model with Fc gamma receptor IIb-deficient (FcGRIIb-/-) mice aged 8 and 40 weeks, as representing asymptomatic and symptomatic lupus, respectively. Spontaneous gut leakage, determined by (i) the presence of FITC-dextran, (ii) elevated serum endotoxin, and (iii) elevated serum (1→3)-β-D-glucan (BG), was demonstrated in symptomatic lupus but not in the asymptomatic group. In parallel, spontaneous gut leakage, detected by elevated serum BG without fungal infection, was demonstrated in patients with active lupus nephritis. Gut leakage induced by dextran sulfate solution (DSS) or endotoxin administration together with BG or endotoxin alone, but not BG alone, enhanced the severity of cecal ligation and puncture (CLP) sepsis more prominently in 8-week-old FcGRIIb-/- mice. Additionally, the bone marrow-derived macrophages of FcGRIIb-/- mice produced higher cytokine levels when coexposed to endotoxin and BG, when compared to wild-type mice. In summary, spontaneous gut leakage was demonstrated in symptomatic FcGRIIb-/- mice and the induction of gut permeability worsened sepsis severity. Gut translocation of endotoxin and BG had a minor effect on wild-type mice, but the synergistic effect of BG and endotoxin was prominent in FcGRIIb-/- mice. The data suggest that therapeutic strategies addressing gut leakage may be of interest in sepsis conditions in patients with lupus.

Topics: Adult; Animals; beta-Glucans; Cytokines; Dextran Sulfate; Disease Models, Animal; Endotoxins; Female; Gastrointestinal Tract; Humans; Lupus Erythematosus, Systemic; Lupus Nephritis; Macrophages; Mice; Permeability; Proteoglycans; Receptors, IgG; Sepsis; Survival Analysis

Ganoderma lingzhi (reishi) (GL) is a widely used medicinal mushroom in the treatment of several diseases, including metabolic syndrome and cancer. We recently performed autodigestion of GL and found enhanced release of hypotensive peptides and immunomodulating beta-1,3-glucan. In the present study, we examined the protective effects of G. lingzhi and its autodigested product (AD-GL) against gut inflammation and endogenous sepsis induced in mice by the oral administration of indomethacin (IND). Gut inflammation was assessed by measuring the lengths of the intestines and colon, and sepsis was evaluated by the survival period. G. lingzhi and AD-GL were mixed with animal feed (2.5%) that was available ad libitum during the experimental period. The murine model was established by the repeated oral administration of IND (once a day, 5 mg/kg from day 0). On day 3, the lengths of the small intestine and colon were measured, and the average lengths of the intestines were significantly shorter in the control and G. lingzhi-administered groups than in the AD-GL-administered group. This finding suggests that AD-GL protected against gut inflammation due to IND-induced ulceration and subsequent microbial translocation. Furthermore, the median numbers of survival days in the control group, the G. lingzhi group, and the AD-GL group were 5, 6, and 11, respectively. The concentrations of the inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin-6, in the blood were significantly reduced in the mice administered AD-GL. In the in vitro cell culture, G. lingzhi and AD-GL fractions released a significantly higher concentration of TNF-α from the spleen, and the splenocytes of mice administered AD-GL hot water extract showed a greater potential to produce cytokines in response to pathogen-associated molecular patterns. These results strongly suggest the protection of the gut mucosa from inflammation, and therefore the prevention of sepsis, by the administration of AD-GL. Autodigestion appears to be a promising protocol that enhances the usefulness of G. lingzhi as a functional food.

Topics: Animals; beta-Glucans; Cells, Cultured; Cytokines; Fungal Polysaccharides; Gastrointestinal Diseases; Gene Expression Regulation; Indomethacin; Inflammation; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Reishi; Sepsis; Spleen

Candida albicans is the most common fungus in the human intestinal microbiota but not in mice. To make a murine sepsis model more closely resemble human sepsis and to explore the role of intestinal C. albicans, in the absence of candidemia, in bacterial sepsis, live- or heat-killed C. albicans was orally administered to mice at 3h prior to cecal ligation and puncture (CLP). A higher mortality rate of CLP was demonstrated with Candida-administration (live- or heat-killed) prior to CLP. Fecal Candida presented only in experiments with live-Candida administration. Despite the absence of candidemia, serum (1→3)-β-D-glucan (BG) was higher in CLP with Candida-administration than CLP-controls (normal saline administration) at 6h and/or 18h post-CLP. Interestingly, fluconazole attenuated the fecal Candida burden and improved survival in mice with live-Candida administration, but not CLP-control. Microbiota analysis revealed increased Bacteroides spp. and reduced Lactobacillus spp. in feces after Candida administration. Additionally, synergy in the elicitation of cytokine production from bone marrow-derived macrophages, in vitro, was demonstrated by co-exposure to heat-killed E. coli and BG. In conclusion, intestinal abundance of fungi and/or fungal-molecules was associated with increased bacterial sepsis-severity, perhaps through enhanced cytokine elicitation induced by synergistic responses to molecules from gut-derived bacteria and fungi. Conversely, reducing intestinal fungal burdens decreased serum BG and attenuated sepsis in our model.

Topics: Administration, Oral; Animals; beta-Glucans; Blood Bactericidal Activity; Candida albicans; Cecum; Cytokines; Disease Models, Animal; Escherichia coli; Feces; Gastrointestinal Microbiome; Ligation; Macrophages; Male; Mice, Inbred ICR; Punctures; Sepsis; Survival Analysis; Time Factors

Systemic infections caused by extraintestinal pathogenic Escherichia coli (ExPEC) have emerged as the most common community-onset bacterial infections and are major causes of nosocomial infections worldwide. The management of ExPEC infections has been complicated by the heterogeneity of ExPEC strains and the emergence of antibiotic resistance, thus their prevention through vaccination would be beneficial. The protective efficacy of four common ExPEC antigen candidates composed of common pilus antigens EcpA and EcpD and iron uptake proteins IutA and IroN, were tested by both active and passive immunization in lethal and non-lethal murine models of sepsis. Additionally, antibody raised to a synthetic form of a conserved surface polysaccharide, β-(1-6)-linked poly-N-acetylglucosamine (dPNAG) containing 9 monomers of (non-acetylated) glucosamine (9GlcNH2) conjugated to tetanus toxoid TT (9GlcNH2-TT) was tested in passive immunization protocols. Active immunization of mice with recombinant antigens EcpA, EcpD, IutA, or IroN elicited high levels of total IgG antibody of IgG1/IgG2a isotypes, and were determined to be highly protective against E. coli infection in lethal and non-lethal sepsis challenges. Moreover, passive immunization against these four antigens resulted in significant reductions of bacteria in internal organs and blood of the mice, especially when the challenge strain was grown in iron-restricted media. Inclusion of antibodies to PNAG increased the efficacy of the passive immunization under conditions where the challenge bacteria were grown in LB medium but not in iron-restricted media. The information and data presented are the first step toward the development of a broadly protective vaccine against sepsis-causing E. coli strains.

Topics: Animals; Antibodies, Bacterial; Antigens, Bacterial; beta-Glucans; Escherichia coli Infections; Escherichia coli Proteins; Escherichia coli Vaccines; Female; Fimbriae Proteins; Immunization, Passive; Immunoglobulin G; Mice; Molecular Chaperones; Rabbits; Receptors, Cell Surface; Sepsis; Vaccines, Conjugate

To determine the effects of a strategy that uses serum (1,3)-β-d-glucan (BDG) results for antifungal treatment of ICU patients at high risk of invasive candidiasis.. Adult patients admitted to the ICU from January 2012 to June 2014 were included if they exhibited sepsis at the time of BDG testing and they met Candida score components ≥3. A retrospective analysis of collected data was performed.. In total, 198 patients were studied. Of 63 BDG-positive patients, 47 with candidaemia and 16 with probable Candida infection, all [31.8% (63/198)] received antifungal therapy. Of 135 BDG-negative patients, 110 [55.5% (110/198)] did not receive antifungal therapy, whereas 25 [12.6% (25/198)] were initially treated. Overall, antifungal therapy was started in 88 cases (44.4%), mostly with echinocandins. Antifungals were discontinued in 14 of 25 patients, as negative BDG results became available, and in 16 BDG-false-positive patients for whom subsequent findings allowed candidaemia (and other forms of invasive candidiasis) to be ruled out. Candidaemia was diagnosed only in one patient who did not receive prior antifungal therapy. The median antifungal therapy duration in candidaemic patients differed significantly from that in non-candidaemic patients [14 (IQR, 6-18) days versus 4 (IQR, 3-7) days; P < 0.001]. Using this approach, antifungal therapy was avoided in ∼73% of potentially treatable patients and it was shortened in another ∼20%.. This study supports the use of serum BDG results in the management of systemic antifungal drug prescription in septic patients. These findings need to be confirmed in additional studies.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antifungal Agents; Antigens, Fungal; beta-Glucans; Candidiasis, Invasive; Critical Illness; Female; Humans; Male; Middle Aged; Proteoglycans; Retrospective Studies; Sepsis; Young Adult

Gastrointestinal (GI) leakage is believed to exacerbate sepsis and new, validated markers of GI barrier performance might benefit clinical decision-making. Serum (1→3)-β-D-glucan (BG) was evaluated as a potential GI leakage marker. Serum BG was tested in several mouse models of GI leakage, including dextran sulfate solution (DSS) administration, endotoxin (LPS) injection, and cecal ligation and puncture sepsis (CLP). Serum BG titer was also evaluated in patients with sepsis and septic shock, for comparison.With 0.75% DSS administration, BG increased only after oral administration of heat-killed C. albicans, but increased spontaneously with 1.5% DSS. In the LPS and CLP models, BG increased as early as 1 h and at 12 h after LPS administration and surgery, respectively. GI leakage was confirmed by orthogonal validation methods including FITC-dextran oral administration in the DSS, LPS, and CLP models and, in the DSS model, with urine sucralose after oral administration and serum endotoxemia. IL-6 increased in parallel with serum BG. Serum BG or IL-6, at 18 h, anticipated sepsis mortality in the CLP model.Analysis of serum BG from patients with febrile neutropenic sepsis (N = 49) and febrile non-neutropenic sepsis (N = 39) demonstrated BG elevation. Patients with bacterial septic shock had serum BG titers similar to levels observed in invasive fungal disease, regardless of febrile neutropenia. Serum BG was lower in less severe cases of bacterial sepsis. Elevated serum IL-6 was associated with GI leakage and elevated serum BG.Serum BG may have potential as a sepsis/septic shock biomarker and further study in this context is warranted.

Topics: Animals; beta-Glucans; Candida albicans; Disease Models, Animal; Feces; Gastrointestinal Tract; Humans; Male; Mice; Pilot Projects; Proteoglycans; Sepsis; Shock, Septic

To study the differences of monocyte activation by albicans and non-albicans species of Candida and its change in sepsis, peripheral blood mononuclear cells were isolated from 17 healthy volunteers and 26 patients with severe sepsis/shock, and incubated in the absence/presence of heat-killed (HK) isolates of four different Candida species and purified β-D-glucan from C.albicans. Experiments were repeated in the presence and absence of inhibitors of intracellular activation pathways. Expression of annexin V on cells membranes of monocytes and lymphocytes, cytoplasmic activity of caspase-3, and DNA fragmentation of monocytes were studied. Membrane expression of annexin V on viable monocytes of healthy volunteers decreased significantly after incubation with C.albicans but not with non-albicans species. The decrease was dose-dependent from the Candida inoculum and by the concentration of β-D-glucan. A relationship with inhibition of apoptosis was found as the activity of caspase-3 activity, and the level of DNA fragmentation were also decreased. Incubation in the absence/presence of inhibitors showed that the decrease by annexin V expression resulted by activation of the dectin-1 pathway and Raf-1 by β-D glucan. The decrease of annexin V(+)/PI(-) expression was not shown on monocytes of patients with severe sepsis/shock, where no effect of inhibitors was found. Decrease of annexin V binding on monocytes can be viewed as a selective response to C.albicans partly effected through activation of dectin-1. This response is down-regulated after a septic insult.

Topics: Aged; Aged, 80 and over; Annexins; beta-Glucans; Candida albicans; Cell Adhesion; Cells, Cultured; Down-Regulation; Female; Humans; Male; Middle Aged; Monocytes; Sepsis

Innate immune memory is the phenomenon whereby innate immune cells such as monocytes or macrophages undergo functional reprogramming after exposure to microbial components such as lipopolysaccharide (LPS). We apply an integrated epigenomic approach to characterize the molecular events involved in LPS-induced tolerance in a time-dependent manner. Mechanistically, LPS-treated monocytes fail to accumulate active histone marks at promoter and enhancers of genes in the lipid metabolism and phagocytic pathways. Transcriptional inactivity in response to a second LPS exposure in tolerized macrophages is accompanied by failure to deposit active histone marks at promoters of tolerized genes. In contrast, β-glucan partially reverses the LPS-induced tolerance in vitro. Importantly, ex vivo β-glucan treatment of monocytes from volunteers with experimental endotoxemia re-instates their capacity for cytokine production. Tolerance is reversed at the level of distal element histone modification and transcriptional reactivation of otherwise unresponsive genes. VIDEO ABSTRACT.

Topics: beta-Glucans; Cell Differentiation; DNA Methylation; Epigenomics; Gene Regulatory Networks; Histone Code; Humans; Immune Tolerance; Immunity, Innate; Immunologic Memory; Lipopolysaccharides; Macrophages; Monocytes; Sepsis; Transcription, Genetic

The diagnosis of neonatal invasive fungal disease (IFD) is difficult and often delayed. The platelet parameters and (1, 3)-β-D-Glucan (BG) may be useful for diagnosing IFD, but their diagnostic performance are not well characterized in neonates. We studied 63 preterm infants with IFD, 160 preterm infants without sepsis (preterm control), and 41 preterm infants with bacterial sepsis. Platelet parameters at the first day of onset of IFD and at the fourteenth day after antifungal treatment were evaluated. Serum BG was measured. Platelet count (PC), plateletcrit (PCT), and platelet distribution width (PDW) values were significantly lower, and mean platelet volume (MPV) values significantly higher in the IFD versus preterm control infants. PC and PCT values were much lower in infants with IFD versus bacterial sepsis, and there were significant differences in BG value between the two groups. After 14 days of antifungal treatment, significant elevations in PC, PCT, PDW and reductions in MPV levels in IFD group were observed. Receiver operating characteristic (ROC) curves showed that PC and PCT were strong predictors of IFD. The PC and PCT cut-offs for predicting IFD were 119.5 (sensitivity 78%, specificity 95%) and 0.21 (sensitivity 83%, specificity 85%), respectively. There were significant differences in PC and PCT levels between deceased and survived patients. The PC and PCT cut-offs for predicting deceased IFD were 39 (sensitivity 62%, specificity 86%) and 0.04 (sensitivity 50%, specificity 95%), respectively. The sensitivity in diagnosing IFD by a BG cutoff of ≥10 pg/ml was 68.3% and specificity was 75.6%. PC and PCT levels in the BG ≥400 pg/ml group were significantly lower compared to the BG<400 pg/ml group. Platelet parameters and BG could be useful biomarkers for the diagnosis and prognosis of neonatal IFD.

Topics: beta-Glucans; Biomarkers; Blood Platelets; Case-Control Studies; Female; Fluconazole; Humans; Infant, Newborn; Infant, Premature; Male; Mean Platelet Volume; Mycoses; Platelet Count; Prognosis; ROC Curve; Sensitivity and Specificity; Sepsis

Epigenetic reprogramming of myeloid cells, also known as trained immunity, confers nonspecific protection from secondary infections. Using histone modification profiles of human monocytes trained with the Candida albicans cell wall constituent β-glucan, together with a genome-wide transcriptome, we identified the induced expression of genes involved in glucose metabolism. Trained monocytes display high glucose consumption, high lactate production, and a high ratio of nicotinamide adenine dinucleotide (NAD(+)) to its reduced form (NADH), reflecting a shift in metabolism with an increase in glycolysis dependent on the activation of mammalian target of rapamycin (mTOR) through a dectin-1-Akt-HIF-1α (hypoxia-inducible factor-1α) pathway. Inhibition of Akt, mTOR, or HIF-1α blocked monocyte induction of trained immunity, whereas the adenosine monophosphate-activated protein kinase activator metformin inhibited the innate immune response to fungal infection. Mice with a myeloid cell-specific defect in HIF-1α were unable to mount trained immunity against bacterial sepsis. Our results indicate that induction of aerobic glycolysis through an Akt-mTOR-HIF-1α pathway represents the metabolic basis of trained immunity.

Topics: Aerobiosis; Animals; beta-Glucans; Candida albicans; Candidiasis; Disease Models, Animal; Epigenesis, Genetic; Female; Glucose; Glycolysis; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Immunity, Innate; Immunologic Memory; Male; Mice; Mice, Inbred C57BL; Monocytes; Sepsis; Staphylococcal Infections; Staphylococcus aureus; TOR Serine-Threonine Kinases; Transcriptome

Topics: Aged; beta-Glucans; Biomarkers; Cardiopulmonary Bypass; Elective Surgical Procedures; Female; Humans; Male; Middle Aged; Monitoring, Intraoperative; Proteoglycans; Sepsis

Sepsis is characterized by systemic immune activation and neutrophil-mediated endothelial barrier integrity compromise, contributing to end-organ dysfunction. Studies evaluating endothelial barrier dysfunction induced by neutrophils from septic patients are lacking, despite its clinical significance. We hypothesized that septic neutrophils would cause characteristic patterns of endothelial barrier dysfunction, distinct from experimental stimulation of normal neutrophils, and that treatment with the immunomodulatory drug β-glucan would attenuate this effect.. Blood was obtained from critically ill septic patients. Patients were either general surgery patients (Primary Sepsis (PS)) or those with sepsis following trauma (Secondary Sepsis (SS)). Those with acute respiratory distress syndrome (ARDS) were identified. Healthy volunteers served as controls. Neutrophils were purified and aliquots were untreated, or treated with fMLP or β-glucan. Endothelial cells were grown to confluence and activated with tissue necrosis factor (TNF)-α . Electric Cell-substrate Impedance Sensing (ECIS) was used to determine monolayer resistance after neutrophils were added. Groups were analyzed by two-way analysis of variance (ANOVA).. Neutrophils from all septic patients, as well as fMLP-normal neutrophils, reduced endothelial barrier integrity to a greater extent than untreated normal neutrophils (normalized resistance of cells from septic patients at 30 mins = 0.90 ± 0.04; at 60 mins = 0.73 ± 0.6 and at 180 mins = 0.56 ± 0.05; p < 0.05 vs normal). Compared to untreated PS neutrophils, fMLP-treated PS neutrophils caused further loss of barrier function at all time points; no additive effect was noted in stimulation of SS neutrophils beyond 30 min. Neutrophils from ARDS patients caused greater loss of barrier integrity than those from non-ARDS patients, despite similarities in age, sex, septic source, and neutrophil count. Neutrophils obtained after resolution of sepsis caused less barrier dysfunction at all time points. β-glucan treatment of septic patients' neutrophils attenuated barrier compromise, rendering the effect similar to that induced by neutrophils obtained once sepsis had resolved.. Neutrophils from septic patients exert dramatic compromise of endothelial barrier integrity. This pattern is mimicked by experimental activation of healthy neutrophils. The effect of septic neutrophils on the endothelium depends upon the initial inflammatory event, correlates with organ dysfunction and resolution of sepsis, and is ameliorated by β-glucan.

Topics: Adult; beta-Glucans; Cell Culture Techniques; Critical Illness; Endothelium, Vascular; Female; Humans; Male; Middle Aged; Neutrophils; Prospective Studies; Sepsis

Diagnosis of invasive fungal disease (IFD) in patients under intensive care is challenging. Circulating biomarkers, (1,3)-β-D-glucan (BG) and galactomannan (GM), were prospectively assessed in 98 critically ill patients at risk of IFD. There were 11 cases of invasive aspergillosis (IA; 4 proven and 7 probable), 9 cases of proven invasive candidiasis (IC), 1 case of mixed proven IC and probable IA, 1 case of proven zygomycosis, and 1 case of mixed mycelial proven IFD. In all IA cases there was no significant difference when the area under the receiver operating characteristic curve (AUC) of GM (0.873 [95%CI, 0.75-0.99]) and BG (0.856 [95% CI, 0.71-0.99]) were compared (p = 0.871). The AUC for BG in IC and for the rest of the IFD cases was 0.605 (95% CI, 0.39-0.82) and 0.768 (95% CI, 0.63-0.90) respectively. Positive BG (40%) predated blood culture (n = 3) and abdominal pus (n = 1) a mean of 3.25 days before Candida was grown. In patients with IFD caused by molds, BG appeared a mean of 5.65 days before culture results. For the diagnosis of patients at risk of IC, BG has shown a high NPV (94.5%), with positive results also predating blood cultures in 30% of patients. In conclusion, early BG results permit a timely initiation of antifungal therapy in patients at risk of IFD.

Topics: Adult; Aged; Aged, 80 and over; beta-Glucans; Critical Illness; Female; Galactose; Humans; Male; Mannans; Middle Aged; Mycoses; Prospective Studies; Proteoglycans; ROC Curve; Sepsis

Sepsis is defined as a systemic response of organisms to microorganisms and toxins. Sepsis is associated with the enhanced generation of reactive oxygen metabolites, leading to multiple organ dysfunctions. β-glucan is accepted to be one of the most powerful immune response modifiers. The aim of this study was to investigate the putative protective effect of β-glucan on changes of iron and malondialdehyde (MDA) levels in various tissue and blood after experimental sepsis in rats. Sepsis was induced by cecal ligation and perforation (CLP) in 32 male Wistar albino rat. To evaluate this, rats were divided into four groups as sham operated, β-glucan treated sham operated, CLP and β-glucan treated CLP. Sixteen hours after operation, rats were decapitated and MDA and iron levels were measured in the liver, kidney, heart, diaphragm tissues and blood. Also, whole tissue histopathology was evaluated by a light microscope. The results demonstrate that sepsis significantly decreased iron levels of all tissues and blood. The decrease in tissue iron levels and the increase MDA levels demonstrate the role of trace elements and free radicals in sepsis-induced tissue damage. Our results indicate that the given dose of β-glucan was probably insufficient to prevent sepsis-induced organ injury.

Topics: Animals; Antioxidants; beta-Glucans; Hepatocytes; Iron; Kidney; Lipid Peroxidation; Liver; Male; Malondialdehyde; Rats; Rats, Wistar; Sepsis; Thiobarbituric Acid Reactive Substances; Tissue Distribution; Trace Elements

Clinical trials with biological modifiers targeting specific inflammatory mediators associated with severe sepsis have shown no or limited survival benefit. The approach taken in studies reported here was to limit the point source of intra-abdominal infection by potentiating innate immune function, thereby lessening the severity of sepsis and improving survival. Soluble beta-glucans, glucose polymers of the fungal cell wall, have been shown to stimulate innate immune host defense in animal and human studies when administered prior to an infectious challenge. We evaluated the effects of poly-(1,6)-β-d-glucopyranosyl-(1,3)-β-d-glucopyranose glucan (PGG glucan) on overall survival when administered intraperitoneally after the onset of polymicrobial infection by cecal ligation and puncture (CLP). Since gender-dependent differences in host immune response to infection have been reported, male and female mice were prospectively stratified for PGG glucan treatment. Outbred CD-1 mice were administered 10 mg/kg of body weight PGG glucan or the polysaccharide control, dextran, 1 h after CLP. Six hours after CLP, blood samples were obtained for cytokine measurements. Surprisingly, a gender-dependent effect on the response to PGG glucan was revealed. PGG glucan enhanced survival in female mice over a 10-day period, but survival in males was improved for only 24 h. In female mice, PGG glucan reduced interleukin-6 (IL-6) and IL-10 levels and reduced the bacterial burden in the liver. Ovariectomy abrogated the response to PGG glucan. Together, the translational potential of these findings is the indicated use of PGG glucan given locally, rather than intravenously, for improved source control during the management of sepsis. This therapy does not require prophylactic beta-glucan administration.

Topics: Animals; Bacterial Infections; Bacterial Load; beta-Glucans; Female; Immunologic Factors; Injections, Intraperitoneal; Interleukin-10; Interleukin-6; Liver; Male; Mice; Sepsis; Sex Factors; Survival Analysis; Time Factors

The culture-independent serum (1→3)-β-D-glucan (BG) detection test may allow early diagnosis of invasive fungal disease, but its clinical usefulness needs to be firmly established. A prospective single-center observational study was conducted to compare the diagnostic value of BG assay, Candida score (CS), and colonization index in intensive care unit (ICU) patients at risk for Candida sepsis.. Of 377 patients, consecutively admitted to ICU for sepsis, 95 patients having an ICU stay of more than five days were studied. Blood specimens for fungal culture and BG measurement were obtained at the onset of clinical sepsis. For CS and colonization index calculations, surveillance cultures for Candida growth, and/or clinical data were recorded.. Sixteen (16.8%) patients were diagnosed with proven invasive fungal infection, 14 with candidiasis (13 candidemia and 1 mediastinitis) and 2 with pulmonary aspergillosis or fusariosis. Of 14 invasive Candida-infection patients, 13 had a serum sample positive for BG, 10 had a CS value ≥ 3, and 7 a colonization index ≥ 0.5. In the 12 candidemic patients, a positive BG result was obtained 24 to 72 hrs before a culture-documented diagnosis of invasive candidiasis. The positive and negative predictive values for the BG assay were higher than those of CS and colonization index (72.2% versus 57.1% and 27.3%; and 98.7% versus 97.2% and 91.7%, respectively).. A single-point BG assay based on a blood sample drawn at the sepsis onset, alone or in combination with CS, may guide the decision to start antifungal therapy early in patients at risk for Candida infection.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; beta-Glucans; Candida; Candidemia; Colony Count, Microbial; Early Diagnosis; Female; Humans; Intensive Care Units; Male; Middle Aged; Prospective Studies; Sepsis; Young Adult

Invasive candidiasis is a frequent life-threatening complication in critically ill patients. Early diagnosis followed by prompt treatment aimed at improving outcome by minimizing unnecessary antifungal use remains a major challenge in the ICU setting. Timely patient selection thus plays a key role for clinically efficient and cost-effective management. Approaches combining clinical risk factors and Candida colonization data have improved our ability to identify such patients early. While the negative predictive value of scores and predicting rules is up to 95 to 99%, the positive predictive value is much lower, ranging between 10 and 60%. Accordingly, if a positive score or rule is used to guide the start of antifungal therapy, many patients may be treated unnecessarily. Candida biomarkers display higher positive predictive values; however, they lack sensitivity and are thus not able to identify all cases of invasive candidiasis. The (1→3)-β-D-glucan (BG) assay, a panfungal antigen test, is recommended as a complementary tool for the diagnosis of invasive mycoses in high-risk hemato-oncological patients. Its role in the more heterogeneous ICU population remains to be defined. More efficient clinical selection strategies combined with performant laboratory tools are needed in order to treat the right patients at the right time by keeping costs of screening and therapy as low as possible. The new approach proposed by Posteraro and colleagues in the previous issue of Critical Care meets these requirements. A single positive BG value in medical patients admitted to the ICU with sepsis and expected to stay for more than 5 days preceded the documentation of candidemia by 1 to 3 days with an unprecedented diagnostic accuracy. Applying this one-point fungal screening on a selected subset of ICU patients with an estimated 15 to 20% risk of developing candidemia is an appealing and potentially cost-effective approach. If confirmed by multicenter investigations, and extended to surgical patients at high risk of invasive candidiasis after abdominal surgery, this bayesian-based risk stratification approach aimed at maximizing clinical efficiency by minimizing health care resource utilization may substantially simplify the management of critically ill patients at risk of invasive candidiasis.

Topics: beta-Glucans; Candida; Candidemia; Female; Humans; Male; Sepsis

Sepsis is associated with the development of progressive damage in multiple organ systems. The beneficial effect of glucans has been attributed to modulation of immune function and enhances defense against bacterial, viral, fungal, and parasitic infections. The aim of this study was to investigate the putative protective effect of ß-glucan on changes of trace element levels in various tissues after experimental sepsis in rats. Sepsis was induced by cecal ligation and perforation (CLP) in 28 male Wistar albino rats. To evaluate this, rats were divided into four groups as sham operated, ß-glucan treated sham operated, CLP, and ß-glucan treated CLP. Sixteen hours after operation, rats were decapitated and zinc (Zn) and copper (Cu) levels were determined in the liver, kidney, heart, diaphragm, and lung tissues. The results demonstrate that sepsis significantly decreased zinc and copper levels of all tissues. The decrease in tissue zinc and copper levels demonstrates the role of trace elements in sepsis-induced tissue damage. Our results indicated that ß-glucan administration did not return the zinc and copper levels to the control group level, and it seems likely that the given dose of ß-glucan was insufficient to prevent sepsis-induced organ injury.

Topics: Animals; beta-Glucans; Copper; Diaphragm; Heart; Intestinal Perforation; Kidney; Ligation; Liver; Lung; Male; Myocardium; Rats; Rats, Wistar; Sepsis; Trace Elements; Zinc

Procalcitonin serum level has been recommended as a new marker of bacterial infectious diseases. The aim of this prospective, multicenter study was to determine the clinical usefulness of procalcitonin in differentiating patients with sepsis from those with severe sepsis. Eighty-two patients were enrolled: 20 without systemic inflammatory response syndrome (SIRS), 9 with SIRS, 34 with sepsis, and 19 with severe sepsis. The patients with severe sepsis had significantly higher procalcitonin levels (median, 36.1 ng/ml) than those with sepsis (median, 0.6 ng/ml). With a procalcitonin cutoff value of 2.0 ng/ml, sensitivity for the detection of severe sepsis and specificity for the detection of sepsis were 94.7% and 78.1%, respectively. A good correlation was found between the serum procalcitonin level and the Sepsis-Related Organ Failure Assessment (SOFA) score (r = 0.680), although no correlation was found between the C-reactive protein (CRP) level and the SOFA score. In conclusion, the procalcitonin serum level may be useful not only for aiding the diagnosis of sepsis but also for discriminating between sepsis and severe sepsis.

Topics: APACHE; beta-Glucans; Biomarkers; C-Reactive Protein; Calcitonin; Calcitonin Gene-Related Peptide; Endotoxins; Glycoproteins; Humans; Interleukin-6; Predictive Value of Tests; Prospective Studies; Protein Precursors; Sepsis; Severity of Illness Index

Sepsis is one of the most important risk factors in acute respiratory distress syndrome (ARDS). beta-Glucan is a potent reticuloendothelial modulating agent, the immunobiological activity of which is mediated in part by an increase in the number and function of macrophages. In this study, we investigated the putative protective role of beta-glucan against sepsis-induced lung injury. Sepsis was induced by cecal ligation and puncture (CLP) in Wistar rats. The control group received saline, and the treatment groups received beta-glucan or beta-glucan + beta-1,3-D-glucanase. Five hours thereafter, plasma tumor necrosis factor (TNF) alpha, interleukin (IL) 1beta, and IL-6 levels were determined. Presence of lung injury was determined via lung tissue myeloperoxidase (MPO) activity, intercellular adhesion molecule (ICAM) 1 levels, and histopathological examination at 18 h after CLP. In a separate set of experiments, survival was monitored for 7 days after CLP. beta-Glucan treatment led to a significant increase in survival rate (63% in glucan-treated rats vs 38% in saline-treated rats). Administration of the beta-glucan inhibitor abrogated beta-glucan's survival benefit (50%). After CLP, plasma TNF-alpha, IL-1beta, and IL-6 concentrations were increased in control animals. When beta-glucan was administered, it completely blocked the elevation of TNF-alpha, IL-1beta, and IL-6. Administration of beta-1,3-D-glucanase suppressed glucan-induced decrease in cytokines. Animals treated with beta-glucan showed a significant reduction in lung injury score, a marked decrease in ICAM-1 expression, and a significant decrease in MPO levels. In contrast, beta-1,3-D-glucanase caused a significantly increased MPO and ICAM-1 levels in the lung. These data reveal that beta-glucan treatment improved the course of CLP-induced peritonitis and attenuated the lung injury. Administration of beta-glucanase inhibited the beta-glucan activity and resulted in enhanced lung injury.

Topics: Animals; beta-Glucans; Cytokines; Disease Models, Animal; Inflammation Mediators; Male; Random Allocation; Rats; Rats, Wistar; Respiratory Distress Syndrome; Sepsis

Understanding the biological mediators involved in the complex inflammatory response of sepsis and acute lung injury offers the possibility of future investigations targeting treatment based on these mediators. This study investigated whether macrophage activator beta-glucan has a protective effect on acute lung injury in an experimental model of sepsis.. Experimental study in an experimental research center.. 30 rats randomized into three groups (sham, sepsis, and beta-glucan).. Cecal ligation and puncture were performed in the beta-glucan and sepsis groups. The beta-glucan group was given a single intraperitoneal dose of beta-glucan (4 mg/kg) following cecal ligation.. Rats treated with beta-glucan had fewer circulating neutrophils, more blood monocytes, and higher serum interleukin 6 levels than septic animals. The percentages of neutrophils and lymphocytes from the bronchoalveolar lavage fluid and the myeloperoxidase activity measured in the lung tissue were lower in the beta-glucan group than in the sepsis group. Less alveolar hemorrhage and neutrophil infiltration were observed in lungs from animals in the beta-glucan group in the septic groups.. In this rat model of intra-abdominal sepsis beta-glucan treatment partially protected against secondary lung injury, decreased lung hemorrhages, and lung neutrophilia. These results suggest that beta-glucan protects against sepsis-associated lung damage.

Topics: Analysis of Variance; Animals; beta-Glucans; Bronchoalveolar Lavage Fluid; Immunologic Factors; Interleukin-6; Leukocyte Count; Lung; Male; Peroxidase; Rats; Rats, Wistar; Respiratory Distress Syndrome; Sepsis; Survival Analysis

Sepsis leads to various organ damage and dysfunction. One of the underlying mechanisms is thought to be the oxidative damage due to the generation of free radicals. In this study, we investigated the putative protective role of beta-glucan against sepsis-induced oxidative organ damage. Sepsis was induced by caecal ligation and puncture (CLP) in Wistar albino rats. Sham operated (control) and sepsis groups received saline or beta-glucan (50 mg/kg, po) once daily for 10 days and 30 min prior to and 6 h after the CLP. Sixteen hours after the surgery, rats were decapitated and the biochemical changes were determined in the brain, diaphragm, kidney, heart, liver and lung tissues using malondialdehyde (MDA) content - an index of lipid peroxidation - glutathione (GSH) levels - a key antioxidant - and myeloperoxidase (MPO) activity - an index of neutrophil infiltration. Serum TNF-alpha levels were assessed by RIA method. Tissues were also examined under light microscope to evaluate the degree of sepsis-induced damage. The results demonstrate that sepsis significantly decreased GSH levels and increased the MDA levels and MPO activity (p<0.05-p<0.001) causing oxidative damage. Elevated plasma TNF-alpha levels in septic rats significantly reduced to control levels in beta-glucan treated rats. Since beta-glucan administration reversed these oxidant responses, it seems likely that beta-glucan protects against sepsis-induced oxidative organ injury.

Topics: Animals; Antioxidants; beta-Glucans; Disease Models, Animal; Female; Glutathione; Male; Malondialdehyde; Peroxidase; Rats; Rats, Wistar; Sepsis; Tumor Necrosis Factor-alpha

We examined the effect of modulating phosphoinositide 3-kinase (PI3K) activity in a murine model of cecal ligation and puncture-induced polymicrobial sepsis. Inhibition of PI3K activity with wortmannin increased serum cytokine levels and decreased survival time in septic mice. We have reported that an immunomodulator, glucan phosphate, induces protection in murine polymicrobial sepsis. We observed that glucan stimulated tissue PI3K activity, which positively correlated with increased survival in septic mice. We investigated the effect of PI3K inhibition on survival in septic mice treated with glucan. Treatment of mice with the PI3K inhibitors, wortmannin and LY294002, completely eliminated the protective effect of glucan, indicating that protection against septic mortality was mediated through PI3K. Inhibition of PI3K resulted in increased serum levels of IL1-beta, IL-2, IL-6, IL-10, IL-12, and TNF-alpha in septic mice. Apoptosis is thought to play a central role in the response to septic injury. We observed that inhibition of PI3K activity in septic mice resulted in increased splenocyte apoptosis and a change in the anatomic distribution of splenocyte apoptosis. We conclude that PI3K is a compensatory mechanism that suppresses proinflammatory and apoptotic processes in response to sepsis and/or inflammatory injury. Thus, PI3K may play a pivotal role in the maintenance of homeostasis and the integrity of the immune response during sepsis. We also observed that glucan phosphate decreased septic morbidity and mortality through a PI3K-dependent mechanism. This suggests that stimulation of the PI3K pathway may be an effective approach for preventing or treating sepsis and/or septic shock.

Topics: Androstadienes; Animals; Apoptosis; beta-Glucans; Cecum; Chromones; Cytokines; Disease Susceptibility; Enzyme Inhibitors; Glucans; Immunity, Innate; Injections, Intraperitoneal; Ligation; Male; Mice; Mice, Inbred ICR; Morpholines; Organ Specificity; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Punctures; Sepsis; Signal Transduction; Spleen; Survival Analysis; Wortmannin

To determine whether there was a correlation between induction of polymicrobial sepsis, modulation of tissue Toll-like receptor (TLR) gene, and protein expression and survival outcome.. Prospective, randomized animal study.. University medical school research laboratory.. Age- and weight-matched ICR/HSD mice.. Sepsis was induced by cecal ligation and puncture (CLP). No-surgery and sham (laparotomy)-operated mice were controls. We also examined tissue TLR2 and TLR4 messenger RNA and TLR4 protein levels in mice treated with an immunomodulator that increases survival in polymicrobial sepsis. In the immunomodulator study, mice were treated with glucan phosphate (50 mg/kg, intraperitoneally) 1 hr before CLP. No-surgery, sham surgery, glucan + no-surgery, sham surgery + glucan, and CLP groups were employed as controls.. Total RNA was isolated from liver, lung, and spleen at 0, 1, 3, 6, 8, and 24 hrs after CLP. TLR gene expression was assessed by reverse transcription-polymerase chain reaction. Tissue TLR4 protein levels were evaluated at 24 hrs by Western blot and immunohistochemistry. CLP sepsis increased (p <.05) liver and lung TLR2 and TLR4 gene expression compared with controls. TLR4 protein concentrations also were increased. Increased TLR2/4 gene and TLR4 protein expression correlated with mortality. Immunoprophylaxis with glucan phosphate increased (p <.001) long-term survival (20% vs. 70%) but inhibited (p <.05) CLP-induced increases in tissue TLR2 and TLR4 messenger RNA expression as well as TLR4 protein expression.. Early increases in TLR2/4 gene and TLR4 protein expression correlated with mortality, whereas blunting TLR gene and protein expression correlated with improved long-term survival. This suggests that early up-regulation of tissue TLR2/4 may play a role in the proinflammatory response and pathophysiology of polymicrobial sepsis.

Topics: Adjuvants, Immunologic; Analysis of Variance; Animals; beta-Glucans; Gene Expression Regulation; Glucans; Liver; Lung; Male; Membrane Glycoproteins; Mice; Mice, Inbred ICR; Proportional Hazards Models; Random Allocation; Receptors, Cell Surface; RNA, Messenger; Sepsis; Survival Analysis; Time Factors; Toll-Like Receptor 2; Toll-Like Receptor 4; Toll-Like Receptors

Topics: Adjuvants, Immunologic; Animals; beta-Glucans; Gene Expression Regulation; Glucans; Membrane Glycoproteins; Mice; Receptors, Cell Surface; Sepsis; Toll-Like Receptors

Soluble beta-1,3-glucan has been demonstrated to protect against infection and shock in rats and mice, and clinical studies suggest that administration of soluble glucans to trauma/surgical patients decreases septic complications and improves survival. However, little is known about the precise mechanisms by which glucans influence the state of activation of blood cells, which are responsible for the fulminant cytokine production and the activation of the coagulation system observed in serious gram-negative infection. We studied therefore the effect of an underivatized, soluble yeast beta-1,3-glucan and lipopolysaccharide (LPS), either alone or in combination, on tumor necrosis factor-alpha (TNFalpha), interleukin-6 (IL-6), IL-8 and IL-10 secretion and monocyte tissue factor (TF) expression in human whole blood. As expected, LPS induced the secretion of substantial amounts of all measured parameters, whereas only minor amounts of TNFalpha, IL-6, and IL-10 were induced by beta-glucan itself. However, beta-glucan itself induced the production of significant amounts of IL-8 and TF. Soluble beta-1,3-glucan had a strong synergistic effect on the LPS-induced secretion of IL-8, IL-10, and on monocyte TF activity, but not on TNFalpha and 1L-6 production. On the other hand, soluble beta-glucan strongly primed LPS stimulation of all parameters, including TNFalpha and IL-6. beta-Glucan also induced detectable neutrophil degranulation within 15 min, whereas a response to LPS was first detected after 90 min. In conclusion, soluble beta-1,3-glucan upregulated leukocyte activity, both on its own and in concert with LPS.

Topics: beta-Glucans; Biomarkers; Blood Coagulation; Cytokines; Glucans; Humans; In Vitro Techniques; Indicators and Reagents; Lipopolysaccharides; Platelet Activation; Sepsis; Thromboplastin

Growing evidence supports the role of transcription factor activation in the pathophysiology of inflammatory disorders, sepsis, ARDS, SIRS, and shock. Kinase mediated phosphorylation of IkappaBalpha is a crucial step in the NFkappaB activation pathway. We investigated IKBalpha phosphorylation in murine liver and lung extracts after cecal ligation and puncture (CLP) in the presence and absence of a glucan ligand. ICR mice were subjected to CLP. Unoperated and sham-operated mice served as the controls. Glucan phosphate (50 mg/kg) was administered 1 h before or 15 min after CLP. CLP increased hepatic and pulmonary levels of phospho-IkappaBalpha by 48-192%. Pre- or post-treatment with glucan phosphate decreased (P < 0.05) tissue phospho-IkappaBalpha levels in CLP mice. Phospho-IkappaBalpha in the glucan-CLP group were not significantly different from the unoperated controls. To investigate mechanisms we examined IKKbeta kinase activity, IkappaBalpha phosphorylation and degradation, and NFkappaB activity in a murine macrophage cell line, J774a.1, treated with LPS (1 microg/mL) and/or glucan phosphate (1 microg/mL) for up to 120 min. The glucan ligand blunted LPS-induced IKKbeta kinase activity, phosphorylation and degradation of IkappaBalpha, and NFkappaB nuclear binding activity. The data indicate that one mechanism by which (1-->3)-beta-D-glucan may alter the response to endotoxin or polymicrobial sepsis involves modulation of IKK3 kinase activity with subsequent decreases in IkappaBalpha phosphorylation and NFkappaB activation.

Topics: Animals; beta-Glucans; Cell Line; Cell Nucleus; Cells, Cultured; Cytosol; DNA-Binding Proteins; Gene Expression Regulation; Glucans; I-kappa B Kinase; I-kappa B Proteins; Intestinal Perforation; Ligands; Lipopolysaccharides; Liver; Lung; Macrophages; Male; Mice; Mice, Inbred ICR; NF-kappa B; NF-KappaB Inhibitor alpha; Phosphorylation; Protein Processing, Post-Translational; Protein Serine-Threonine Kinases; Sepsis; Shock, Septic

Recent data implicate the activation of nuclear factor-kappa B (NF-kappa B) and nuclear factor interleukin 6 (NF-IL6) as important steps in the pathophysiologic mechanisms of adult respiratory distress syndrome and systemic inflammatory response syndrome.. This study evaluated the effect of immunomodulating polysaccharides on transcription factor activation, cytokine expression, and mortality in a murine cecal ligation and puncture (CLP) model. ICR/HSD mice were treated with glucan (50 mg/kg) 1 hour before or 15 minutes after CLP. Liver and lung tissue were harvested at 3 hours and mortality trends were observed for 20 days.. CLP increased liver and lung NF-kappa B and NF-IL6 nuclear binding activity as well as tumor necrosis factor-alpha and interleukin 6 messenger RNA levels at 3 hours. Pretreatment or posttreatment with glucans inhibited tissue NF-kappa B and NF-IL6 nuclear binding activity and tissue cytokine messenger RNA levels. Prophylaxis with glucan phosphate or scleroglucan increased (P < .001) long-term survival (20% CLP vs 65% glucan phosphate, 75% scleroglucan). Posttreatment with glucan phosphate also increased (P < .05) long-term survival (20% vs 65%).. Pretreatment or posttreatment with biologic response modifiers decreased tissue transcription factor nuclear binding activity and cytokine message in liver and lung of septic mice. Inhibiting early transcription factor activation and cytokine message expression correlates with improved outcome in polymicrobial sepsis as denoted by increased long-term survival.

Topics: Animals; beta-Glucans; CCAAT-Enhancer-Binding Proteins; DNA-Binding Proteins; Glucans; Interleukin-6; Male; Mice; Mice, Inbred ICR; NF-kappa B; Nuclear Proteins; RNA, Messenger; Sepsis; Tumor Necrosis Factor-alpha

Two immunomodulating polysaccharides, poly-(1-6)-beta-glucotriosyl-(1-3)-beta-glucopyranose (PGG)-glucan and Bacteroides fragilis polysaccharide A (PS A), were evaluated for the prevention of mortality and abscess formation associated with experimental intraabdominal sepsis. Prophylactic treatment with a combination of these compounds significantly reduced mortality (8% vs. 44% in the saline-treated control group) and the incidence of abscesses (30% vs. 100% in the saline-treated control group) after challenge with rat cecal contents. These compounds were also effective when administered therapeutically after bacterial contamination of the peritoneal cavity. PS A treatment conferred long-term protection against abscess formation and resulted in significantly fewer total aerobes and anaerobes in the peritoneal fluid of animals challenged with cecal contents. These data demonstrate the usefulness of two immunomodulatory polysaccharides in preventing experimental intraabdominal sepsis in the absence of antimicrobial therapy and may represent a new adjunct to antibiotic regimens currently used to prevent clinical cases of this disease.

Topics: Abdominal Abscess; Adjuvants, Immunologic; Animals; Bacteroides fragilis; Bacteroides Infections; beta-Glucans; Disease Models, Animal; Glucans; Male; Peritoneal Cavity; Polysaccharides, Bacterial; Rats; Rats, Wistar; Sepsis

Previous studies have established the efficacy of soluble polymers of poly-(1-6)-beta-glucotriosyl-(1-3)-beta-glucopyranose (PGG) glucan, a biological-response modifier, in protecting against mortality associated with experimentally induced peritonitis in a rat model. PGG glucan-treated animals showed increases in total leukocyte counts and enhanced bacterial clearance from blood. To further explore the mechanisms) by which this agent confers protection, studies were performed to examine whether protection could be transferred from PGG glucan-treated animals to naive recipients via spleen cells (SC), SC lysates, or serum. Passive-transfer experiments indicated that the responsible factor(s) was transferable by whole SC and SC lysates, as well as by peripheral leukocytes or serum from animals treated with PGG glucan. The transferable factor(s) was resistant to pronase and trypsin digestion, was heat stable at 56 or 80 degrees C, and was not removed by NH4SO4 precipitation. The protective effect of PGG glucan was abrogated by treatment with indomethacin, a potent inhibitor of prostaglandin synthesis. Administration of a purified prostaglandin extract from the sera of PGG glucan-treated animals protected against mortality in the peritonitis model. Furthermore, treatment of rats with exogenous synthetic prostaglandin E2 also conferred protection against mortality. These results suggest that the protective effect exhibited by PGG glucan in the rat peritonitis model is mediated, at least in part, by prostaglandins.

Topics: Adjuvants, Immunologic; Animals; beta-Glucans; Dinoprostone; Glucans; Immunotherapy, Adoptive; Indomethacin; Male; Prostaglandins; Rats; Rats, Wistar; Sepsis

The emergence of multiple antibiotic-resistant microorganisms has led to a search for alternatives to traditional therapeutic regimens. PGG glucan is a soluble beta-glucan immunomodulator that selectively enhances the microbicidal activities of neutrophils and macrophages without stimulating proinflammatory cytokine production. In the present studies, we examined the ability of PGG glucan to act in concert with antibiotics to decrease mortality in a rat model of intraabdominal sepsis using antibiotic-resistant bacteria as infectious inocula. Results of these studies demonstrated that prophylaxis with PGG glucan in combination with antibiotics provided enhanced protection against lethal challenge with Esherichia coli or Staphylococcus aureus as compared with the use of antibiotics alone.

Topics: Adjuvants, Immunologic; Animals; Anti-Bacterial Agents; beta-Glucans; Drug Resistance, Microbial; Drug Therapy, Combination; Escherichia coli; Escherichia coli Infections; Glucans; Rats; Sepsis; Staphylococcal Infections; Staphylococcus aureus

Topics: Adjuvants, Immunologic; beta-Glucans; Cytokines; Glucans; Humans; Postoperative Complications; Sepsis

Beta-1,3-D-polyglucose derivatives protect mice against otherwise lethal bacterial infections. This protective effect has been considered to be mediated through mononuclear phagocytes. By using radioactive labelling, we localized the beta-1,3-D-polyglucose derivatized microbeads (GDM) during the period following injection. The GDM was recovered mainly in the milky spots of the omentum. In animals treated with GDM, the total white cell number was significantly increased in peritoneal fluid of mice before and after challenge with E. coli. Bacterial counts in peritoneal fluid of GDM treated animals declined to zero after 24 h. In untreated animals there was a slight increase in bacterial counts until the animals died after about 12 h. Mouse peritoneal macrophages stimulated with GDM released significant amounts of IL-1 and PGE2. There was no significant release of TNF. Levels of IL-1 and PGE2 in peritoneal fluid increased significantly during the first 48 h after treatment with GDM. There was no increase of levels of TNF. After challenge with E. coli, the levels of IL-1, TNF, and PGE2 were significantly lower compared with control animals. In untreated animals the levels of IL-1 and TNF remained elevated until the animals died after about 12 h. These studies demonstrate that the raised levels of arachidonic acid metabolites after pretreatment with GDM or AG seems to inhibit the otherwise lethal elevation of IL-1 and TNF in body fluids which is seen in untreated animals.

Topics: Adjuvants, Immunologic; Animals; beta-Glucans; Cells, Cultured; Cytokines; Dinoprostone; Dose-Response Relationship, Immunologic; Escherichia coli; Female; Glucans; Interleukin-1; Leukocyte Count; Macrophages; Mice; Mice, Inbred Strains; Peritoneum; Sepsis; Tumor Necrosis Factor-alpha

The influences of pretreatment with beta-1,3-D-polyglucose derivatives on levels of cytokines and arachidonic acid metabolites in body fluids in experimental peritonitis in mice are reported. Peritonitis was induced by an intraperitoneal injection of 10(8) live Escherichia coli. Pretreated animals survived the infection, untreated animals died about 12 h after inoculation with E. coli. Levels of IL-1 in plasma and peritoneal fluid, measured by cytotoxicity assay of the HT-2 cell line, increased significantly during the first 48 h after intraperitoneal treatment with beta-1,3-D-polyglucose-derivatized microbeads (GDM) or soluble, aminated beta-1,3-D-polyglucose (AG). After subsequent challenge with E. coli, the levels of IL-1 were significantly lower than in untreated animals. There was no increase in levels of TNF after treatment with GDM or AG, measured by cytotoxicity assay of the WEHI clone 13 cell line. After challenge with E. coli, TNF in plasma and peritoneal fluid was significantly lower compared with untreated animals. Both PGE2 and LTB4, measured by radioimmunoassay kits, were increased in peritoneal fluid after treatment with GDM and AG. After challenge with E. coli, PGE2 and LTB4 in peritoneal fluid increased to about half the concentration of infected control animals. Intraperitoneal injection of indomethacin to pretreated animals resulted in increased levels of IL-1 and TNF and decreased levels of PGE2 following challenge with E. coli. The levels of IL-1 and TNF remained elevated until the animals died after about 12 h. These studies demonstrate that the raised levels of arachidonic acid metabolites after pretreatment with GDM or AG seem to inhibit the otherwise lethal elevation of IL-1 and TNF in body fluids which is seen in untreated animals.

Topics: Animals; Arachidonic Acids; Ascitic Fluid; beta-Glucans; Cytokines; Dinoprostone; Escherichia coli Infections; Female; Glucans; Indomethacin; Interleukin-1; Leukocyte Count; Leukotriene B4; Mice; Mice, Inbred CBA; Sepsis; Tumor Necrosis Factor-alpha

Beta-1,3-D-polyglucose derivatives protect mice against otherwise lethal bacterial infections. This protective effect has previously been considered to be mediated through mononuclear phagocytes. We have now investigated the cellular composition in blood and peritoneal fluid after administration of the beta-1,3-D-polyglucose before and after challenge with Escherichia coli. In animals treated with beta-1,3-D-polyglucose derivatives, the total white cell number was significantly increased in both blood and peritoneal fluid before and after challenge with E. coli. The increased total cell number was mainly the result of raised levels of granulocytes. The effects of beta-1,3-D-polyglucose-derivatized microbeads (GDM) and soluble aminated beta-1,3-D-polyglucose (AG) were similar. Bacterial counts in peripheral blood in GDM- and AG-treated animals increased with 6 h after challenge and approached zero after 24 h. In untreated animals the bacterial counts increased gradually until the animals died after about 12 h. Bacterial counts in peritoneal fluid of GDM- and AG-treated animals declined to zero after 24 h. In untreated animals there was a slight increase in bacterial counts until the animals died after about 12 h. By using radioactive labelling, we localized the bacterial as well as the beta-1,3-D-polyglucose derivatives during the period following injection. Particle-bound beta-1,3-D-polyglucose was recovered mainly in the milky spots of the omentum. A conspicuous number of bacteria were also recovered in the milky spots. The soluble aminated beta-1,3-D-polyglucose was recovered mainly in the liver. However, on a weight basis, the greatest concentration of radioactivity was in the milky spots.

Topics: Animals; Ascitic Fluid; beta-Glucans; Colony Count, Microbial; Escherichia coli Infections; Female; Glucans; Immunity, Innate; Leukocyte Count; Mice; Mice, Inbred C3H; Mice, Inbred CBA; Microspheres; Omentum; Peritoneal Diseases; Sepsis