Microbial Translocation Research Articles

Indole-3-propionic acid, a product of intestinal flora, inhibits the HDAC6/NOX2 signaling and relieves doxorubicin-induced cardiomyocyte damage.

The heart failure-gut hypothesis indicates that damage to intestinal mucosa leads to increased microbial translocation, resulting in alterations in metabolites entering the blood circulation. This process promotes the development of heart failure. This study aimed to reveal the involvement of indole-3-propionic acid (IPA), a microbiota-derived tryptophan metabolite, in heart failure. Human cardiomyocytes AC16 was treated with doxorubicin to induce in vitro heart failure model, the influences of IPA on the cellular viability, apoptosis, inflammation and oxidative stress were evaluated. Molecular docking and western blotting were used to initially illustrate the potential relationship between IPA and HDAC6. Through HDAC6 overexpression, its mediating role in the regulatory mechanism of IPA in the above aspects was further investigated. IPA was found to reduce the apoptosis, inflammation and oxidative stress in doxorubicin-treated cells. The visualized structure displayed that IPA bound to HDAC6 and that IPA reduced HDAC6 level. Additionally, HDAC6 overexpression reversed the regulation of IPA in the above aspects, indicating the HDAC6/NOX2 signals mediated the mechanism of IPA. Together, the present study revealed that IPA reduced oxidative stress, inflammatory response and apoptosis in cardiomyocytes via inhibiting the HDAC6/NOX2 signaling. The findings suggest that gut microbiota metabolites have potential in the treatment of heart failure.

Serum TGF-β1 and CD14 Predicts Response to Anti-TNF-α Therapy in IBD.

Tumor necrosis factor-alpha (TNF-α) agonists revolutionized therapeutic algorithms in inflammatory bowel disease (IBD) management. However, approximately every third IBD patient does not respond to this therapy in the long term, which delays efficient control of the intestinal inflammation. We analyzed the power of serum biomarkers to predict the failure of anti-TNF-α. We collected serum of 38 IBD patients at therapy prescription and 38 weeks later and analyzed them with relation to therapy response (no-, partial-, and full response). We used enzyme-linked immunosorbent assay to quantify 16 biomarkers related to gut barrier (intestinal fatty acid-binding protein, liver fatty acid-binding protein, trefoil factor 3, and interleukin (IL)-33), microbial translocation, immune system regulation (TNF-α, CD14, lipopolysaccharide-binding protein, mannan-binding lectin, IL-18, transforming growth factor-β1 (TGF-β1), osteoprotegerin (OPG), insulin-like growth factor 2 (IGF-2), endocrine-gland-derived vascular endothelial growth factor), and matrix metalloproteinase system (MMP-9, MMP-14, and tissue inhibitors of metalloproteinase-1). We found that future full-responders have different biomarker profiles than non-responders, while partial-responders cannot be distinguished from either group. When future non-responders were compared to responders, their baseline contained significantly more TGF-β1, less CD14, and increased level of MMP-9, and concentration of these factors could predict non-responders with high accuracy (AUC = 0.938). Interestingly, during the 38 weeks, levels of MMP-9 decreased in all patients, irrespective of the outcome, while OPG, IGF-2, and TGF-β1 were higher in non-responders compared to full-responders both at the beginning and the end of the treatment. The TGF-β1 and CD14 can distinguish non-responders from responders. The changes in biomarker dynamics during the therapy suggest that growth factors (such as OPG, IGF-2, and TGF-β) are not markedly influenced by the treatment and that anti-TNF-α therapy decreases MMP-9 without influencing the treatment outcome.

#4884 DISRUPTION OF THE INTESTINAL MUCOSAL BARRIER IN CHRONIC KIDNEY DISEASE IS RELATED TO REDUCED EXPRESSION OF THE TIGHT JUNCTIONS' COMPONENTS

Abstract Background and Aims Patients with chronic kidney disease (CKD) present evidence of systemic inflammation without clinical infection. This is partly attributed to intestinal barrier dysfunction resulting in increased gut permeability with microbial and endotoxin translocation. However, the potential mechanism(s) implicated in increased gut permeability remain unclear. In this study, we investigated several parameters of the intestinal barrier in patients with CKD of various stages. Methods Thirty-three patients with CKD were prospectively enrolled. Patients were divided in stage I-IV CKD (group A, n = 17, 9 of them with IgA nephropathy) or end-stage kidney disease (ESKD) (group B, n = 16) and were compared with 11 healthy controls (group C). Duodenal biopsies from all subjects, obtained by endoscopy, were examined histologically for evaluation of the villous length and apoptotic bodies in cryptal epithelium. Intraepithelial CD3+ T-lymphocytes, expression of occludin and claudin-1 in the intestinal epithelium were evaluated by immunohistochemistry. Circulating endotoxin concentration was measured by enzyme-linked immunosorbent assay and cytokine levels [interleukin (IL)-1β, IL-6, IL-8, IL-10, TNF-a] by flow cytometry. Results Patients in groups A and B presented significantly higher serum endotoxin, IL-8 and IL-10 levels compared to controls (p<0.01, both groups). Patients in group B presented additionally significantly higher IL-6 levels compared to controls (p<0.01). Occludin expression was significantly decreased in groups A and B compared to group C (p<0.0001 and p<0.001, respectively). Interestingly, in CKD patients (groups A and B) a gradient of occludin expression along the length of the villi, from crypt to tip was recorded with greater loss of its expression at villous tip. Claudin-1 expression was significantly decreased in crypts in groups A and B compared to group C (p<0.0001 and p<0.01 respectively). Endotoxin concentrations were inversely correlated with intestinal occludin (p<0.0001) and claudin-1 (p<0.01) expression and positively correlated with serum IL-6 (p<0.05) and IL-8 (p<0.001) levels. Subgroup analysis for patients with IgA nephropathy showed similar histological findings for occludin and claudin-1 expression as well as for serum endotoxin levels. Conclusion Decreased enterocytes’ occludin and claudin-1 expression, might represent an important mechanism of intestinal barrier disruption and increased gut permeability in patients with CKD.

#2511 ASSOCIATION OF CONSTIPATION, MICROBIAL TRANSLOCATION, AND INFLAMMATION IN HD PATIENTS

Abstract Background and Aims Increased gut permeability and intestinal dysbiosis may contribute to chronic inflammation, leading to accelerated atherosclerosis and cardiovascular complications in patients on haemodialysis (HD). Constipation is highly prevalent in HD patients and growing evidence suggested constipation can aggravate gut microbiota dysbiosis and gut inflammation. The aim of this study was to evaluate the association between markers of microbial translocation, intestinal permeability and inflammation in HD patients with and without constipation. Method A cross-sectional, observational study was conducted and 200 stable prevalent HD were enrolled. Serum zonulin, eotaxin-1, amyloid A, intestinal fatty acid-binding protein (iFABP), IL-6, endotoxin core antibodies (EndoCAb) and lipopolysaccharide binding protein (LBP) levels were measured. Functional constipation was defined according to the Rome IV criteria. Results Serum levels of zonulin and eotaxin-1 but not LPS, endo-Cab IgG, amyloid A and IL-6 were significantly higher in HD patients with constipation than in non-constipated HD controls. The multiple logistic regression analysis in constipated HD patients after adjustment for age, and BMI demonstrated that serum zonulin and eotaxin-1 were independently associated with constipation with an odds ratio (OR) of 1.24 (95% CI = 1.09-1.42, p = 0.0016) and 1.02 (95% CI = 1.01-1.03, p = 0.0001), respectively. Conclusion We demonstrate that there was association between serum eotaxin-1 and zonulin levels in constipated HD patients. This may indicates that increased intestinal inflammation or intestinal permeability in these patients but the significance of these findings need further investigation.

Biohybrids: Textile fibres provide scaffolds and highways for microbial translocation.

Introduction: Living materials (biohybrids, textile-microbial hybrids, hybrid living materials) have gained much attention in recent years with enormous potential for applications in biomedical science, the built environment, construction and architecture, drug delivery and as environmental biosensors. Living materials contain matrices which incorporate microorganisms or biomolecules as the bioactive components. A cross-disciplinary approach, operating at the intersection of creative practice and scientific research, incorporated textile technology and microbiology to demonstrate textile fibres providing microbial scaffolds and highways during this study. Methods: The study evolved from previous research which showed bacteria utilising the water layer surrounding fungal mycelium for motility, termed the 'fungal highway', which led to the investigation of the directional dispersal of microbes across a range of fibre types (natural and synthetic). The application of the study centred around the potential for biohybrids to be used as a biotechnology to improve oil bioremediation through seeding of hydrocarbon-degrading microbes into polluted environments via fungal or fibre highways, therefore treatments in the presence of crude oil were tested. Furthermore, from a design perspective, textiles have huge potential to act as a conduit for water and nutrients, essential to sustain microorganisms within living materials. Using the moisture absorption properties of natural fibres, the research explored how to engineer variable liquid absorption rates using cellulosics and wool to produce shape-changing knitted fabrics suitable for adaptation to oil spill capture. Results: At a cellular scale, confocal microscopy provided evidence to show that bacteria were able to utilise a water layer surrounding the fibres, supporting the hypothesis that fibres can aid bacterial translocation through their use as 'fibre highways'. A motile bacterial culture, Pseudomonas putida, was shown to translocate around a liquid layer surrounding polyester, nylon, and linen fibres, yet no evidence of translocation was apparent on silk or wool fibres, suggesting microbes elicit different responses to specific fibre types. Findings showed that translocation activity around highways did not diminish in the presence of crude oil, known to contain an abundance of toxic compounds, in comparison to oil-free controls. A design series demonstrated the growth of fungal mycelium (Pleurotus ostreatus) through knitted structures, highlighting the ability for natural fabrics to provide a scaffold to support microbial communities whilst retaining the ability to undergo environmentally responsive shape-change. A final prototype, Ebb&Flow, demonstrated the potential to scale up the responsive capacities of the material system using locally produced UK wool. The prototype conceptualised both the uptake of a hydrocarbon pollutant by fibres, and the translocation of microbes along fibre highways. Discussion: The research works towards facilitating the translation of fundamental science and design into biotechnological solutions that can be used in real world applications.

High-throughput proteomic analysis reveals systemic dysregulation in virally suppressed people living with HIV.

People living with HIV (PLHIV) on antiretroviral therapy (ART) exhibit persistent immune dysregulation and microbial dysbiosis, leading to the development of cardiovascular diseases (CVD). We initially compared plasma proteomic profiles between 205 PLHIV and 120 healthy controls (HCs) and validated the results in an independent cohort of 639 PLHIV and 99 HCs. Differentially expressed proteins (DEPs) were then associated to microbiome data. Finally, we assessed which proteins were linked with CVD development in PLHIV. Proximity extension assay technology was utilized to measure 1472 plasma proteins. Markers of systemic inflammation (CRP, D-Dimer, IL6, sCD14, and sCD163) and microbial translocation (IFABP) were measured by ELISA, and gut bacterial species were identified using shotgun metagenomic sequencing. Baseline CVD data were available for all PLHIV, and 205 PLHIV were recorded for the development of CVD during a 5-year follow-up. PLHIV on ART displayed systemic dysregulation of protein concentrations compared to HCs. Most of the DEPs originated from the intestine and lymphoid tissues, while they enriched in immune- and lipid metabolism-related pathways. Furthermore, we observed that DEPs originating from the intestine were associated with specific gut bacterial species. Finally, we identified upregulated proteins in PLHIV (GDF15, PLAUR, RELT, NEFL, COL6A3, and EDA2R), unlike most markers of systemic inflammation, associated with the presence and risk of developing CVD in 5-year follow-up. Our findings suggest a systemic dysregulation of protein concentrations in PLHIV, of which some proteins were associated with CVD development. Most of DEPs originated from the gut and were related to specific gut bacterial species. Cohorts included in this study are part of the Human Functional Genomics Project (HFGP) (www.humanfunctionalgenomics.org). The 2000HIV Human Functional Genomics Partnership Program is registered at ClinicalTrials.gov: (ID: NCT03994835). The 200HIV and 2000HIV studies are supported by the AIDS-fonds (#P-29001, Netherlands) and a ViiV healthcare grant (A18-1052), respectively; The ViiV healthcare grant was awarded to A.V., M.G.N., L.A.B.J., and Q.d.M; The Spinoza Prize (NWO SPI94-212) and ERC Advanced grant (no. 833247) were awarded to M.G.N; The Indonesia Endowment Fund for Education (LPDP) given by the Ministry of Finance of the Republic of Indonesia was awarded to N.V.

Increased Microbial Translocation is a Prognostic Biomarker of Different Immune Responses to ART in People Living with HIV.

Microbial translocation (MT) is a characteristic of human immunodeficiency virus (HIV) infection. Whether MT is also a biomarker of different immune responses to antiretroviral therapy (ART) received by people living with HIV (PLWH) is not known. We examined the presence of MT in a cohort of 33 HIV-infected immunological responders (IRs) and 28 immunological non-responders (INRs) (≥500 and <200 cluster of differentiation (CD)4+ T-cell counts/µL after 2 years of HIV-1 suppression, respectively) with no comorbidities. Plasma samples were used to measure the circulating levels of MT markers. All enrolled study participants had received 2 years of viral-suppression therapy. Levels of lipopolysaccharide (P = 0.0185), LPS-binding protein (P < 0.0001), soluble-CD14 (P < 0.0001), and endogenous endotoxin-core antibody (P < 0.0001) at baseline were significantly higher in INRs than in IRs and were associated with an increased risk of an immunological non-response, whereas the level of intestinal fatty acid-binding protein did not show this association. Analysis of receiver operating characteristic (ROC) curves demonstrated the utility of these individual microbial markers in discriminating INRs after ART in people living with HIV with high sensitivity, specificity, and area under the ROC curve. INRs in HIV infection are characterized by increased MT at baseline. These markers could be used as a rapid prognostic tool for predicting immune responses in people infected with the HIV.

Pyroptotic MAITs link microbial translocation with severity of alcohol-associated liver disease.

Mucosal-associated invariant T cells (MAITs) are markedly reduced in patients with alcohol-associated liver disease (ALD); however, the potential mechanism underlying MAITs' loss remains elusive. Hence, we aimed to explore what induced MAITs' loss and its clinical significance. The characteristics of pyroptotic MAITs were evaluated in a cohort of patients with ALD, including 41 patients with alcohol-associated liver cirrhosis (ALC) and 21 patients with ALC complicated with severe alcoholic hepatitis (ALC + SAH). In patients with ALD, blood MAITs were significantly decreased, hyperactivated, and displayed enhanced cell death through pyroptosis. The frequencies of pyroptotic MAITs increased with disease severity in patients with ALC and patients with ALC + SAH. These frequencies were negatively associated with the frequencies of MAITs and positively correlated with the levels of MAITs' activation, plasma levels of intestinal fatty acid-binding protein (a marker of intestinal enterocyte damage), soluble CD14, lipopolysaccharide-binding protein, and peptidoglycan recognition proteins (surrogate markers of microbial translocation). Pyroptotic MAITs were also found in the liver of patients with ALD. Interestingly, MAITs underwent further activation and pyroptosis in vitro under stimulation by Escherichia coli or direct bilirubin. Notably, blocking IL-18 signaling reduced the activation and frequencies of pyroptotic MAITs. The loss of MAITs in patients with ALD is, at least in part, due to cell death from pyroptosis and is associated with the severity of ALD. Such increased pyroptosis may be affected by dysregulated inflammatory responses to intestinal microbial translocation or direct bilirubin.

THU-243 - Long-term benefit of direct-acting antivirals on gut dysbiosis and microbial translocation in HCV-infected patients with and without HIV coinfection

THU-243 - Long-term benefit of direct-acting antivirals on gut dysbiosis and microbial translocation in HCV-infected patients with and without HIV coinfection

TOP-078 - Pyroptotic MAITs link microbial translocation with severity of alcohol-related liver disease

TOP-078 - Pyroptotic MAITs link microbial translocation with severity of alcohol-related liver disease

Long-term dasatinib plus quercetin effects on aging outcomes and inflammation in nonhuman primates: implications for senolytic clinical trial design.

Cellular senescence increases with aging and results in secretion of pro-inflammatory factors that induce local and systemic tissue dysfunction. We conducted the first preclinical trial in a relevant middle-aged nonhuman primate (NHP) model to allow estimation of the main translatable effects of the senolytic combination dasatinib (D) and quercetin (Q), with and without caloric restriction (CR). A multi-systemic survey of age-related changes, including those on immune cells, adipose tissue, the microbiome, and biomarkers of systemic organ and metabolic health are reported. Age-, weight-, sex-, and glycemic control-matched NHPs (D + Q, n = 9; vehicle [VEH] n = 7) received two consecutive days of D + Q (5mg/kg + 50mg/kg) monthly for 6months, where in month six, a 10% CR was implemented in both D + Q and VEH NHPs to induce equal weight reductions. D + Q reduced senescence marker gene expressions in adipose tissue and circulating PAI-1 and MMP-9. Improvements were observed in immune cell types with significant anti-inflammatory shifts and reductions in microbial translocation biomarkers, despite stable microbiomes. Blood urea nitrogen showed robust improvements with D + Q. CR resulted in significant positive body composition changes in both groups with further improvement in immune cell profiles and decreased GDF15 (p = 0.05), and the interaction of D + Q and CR dramatically reduced glycosylated hemoglobin A1c (p = 0.03). This work indicates that 6months of intermittent D + Q exposure is safe and may combat inflammaging via immune benefits and improved intestinal barrier function. We also saw renal benefits, and with CR, improved metabolic health. These data are intended to provide direction for the design of larger controlled intervention trials in older patients.

Chemotherapy induced peripheral neuropathy (CIPN) and biomarkers of gut microbial translocation in long-term survivors of testicular germ cell tumors.

e17032 Background: Survivors of testicular germ cell tumors (GCT) may suffer from long-term treatment induced peripheral neuropathy. We hypothesized markers of gut microbial translocation after chemotherapy and/or radiotherapy may be contributing factors of peripheral neuropathy. Methods: GCT survivors (N = 194) from National Cancer Institute of Slovakia completed the EORTC QLQ Chemotherapy-Induced Peripheral Neuropathy (CIPN20) questionnaires during their annual follow-up visit at 10-year median (range 2-25). Biomarkers of gut microbial translocaion and dysbiosis (GMT) lipopolysaccharide (LPS), high mobility group box-1 (HMGB-1), d-lactate and sCD14 were measured from peripheral blood obtained during the same visit. Upon obtaining the scores from questionnaires per recommended guidelines, each score was correlated with biomarkers of GMT scored as as high or low (above and below median). Survivors were treated with orchiectomy only (N = 30), cisplatin-based chemotherapy (N = 135), radiotherapy to the retroperitoneum (N = 14) or both chemotherapy and radiotherapy (N = 10). Results: GCT survivors with higher vs lower plasma levels of HMGB-1 had worse overall CIPN20 score (median ± SD = 18 229.0 ± 13 644.2 vs 17 387.0 ± 5106.6 p = 0.048). Patients with higher vs lower plasma HMGB-1 also had worse motor function (9.0 ± 1.8 vs 8.0 ± 2.3, p = 0.036). Sensory and autonomy subscales of CIPN20 qestionaire did not show significant association with HMGB-1 (both P &gt; 0.05). There was no significant difference in CIPN20 symptom burden associated with LPS, d-lactate and sCD14 (all P &gt; 0.05). Conclusions: HMGB-1 may serve as a promising biomarker of CIPN20 in long-term cancer survivors. Proinflammatory pathways are suggested as underlying mechanism of CIPN. Furhter research and larger patient cohorts are needed to explore the pathogenesis of CIPN in GCT survivors.

Translocation of bacterial LPS is associated with self-reported cognitive abilities in men living with HIV receiving antiretroviral therapy

BackgroundGut damage allows translocation of bacterial lipopolysaccharide (LPS) and fungal β-D-glucan (BDG) into the blood. This microbial translocation contributes to systemic inflammation and risk of non-AIDS comorbidities in people living with HIV, including those receiving antiretroviral therapy (ART). We assessed whether markers of gut damage and microbial translocation were associated with cognition in ART-treated PLWH.MethodsEighty ART-treated men living with HIV from the Positive Brain Health Now Canadian cohort were included. Brief cognitive ability measure (B-CAM) and 20-item patient deficit questionnaire (PDQ) were administered to all participants. Three groups were selected based on their B-CAM levels. We excluded participants who received proton pump inhibitors or antiacids in the past 3 months. Cannabis users were also excluded. Plasma levels of intestinal fatty acid binding protein (I-FABP), regenerating islet-derived protein 3 α (REG3α), and lipopolysaccharides (LPS = were quantified by ELISA, while 1–3-β-D-glucan BDG) levels were assessed using the Fungitell assay. Univariable, multivariable, and splines analyses were performed.ResultsPlasma levels of I-FABP, REG3α, LPS and BDG were not different between groups of low, intermediate and high B-CAM levels. However, LPS and REG3α levels were higher in participants with PDQ higher than the median.Multivariable analyses showed that LPS association with PDQ, but not B-CAM, was independent of age and level of education. I-FABP, REG3α, and BDG levels were not associated with B-CAM nor PDQ levels in multivariable analyses.ConclusionIn this well characterized cohort of ART-treated men living with HIV, bacterial but not fungal translocation was associated with presence of cognitive difficulties. These results need replication in larger samples.

Increase in gut permeability and oxidized ldl is associated with post-acute sequelae of SARS-CoV-2.

Post-acute sequelae of SARS-CoV-2 (PASC) is marked by persistent or newly developing symptoms beyond 4 weeks of infection. Investigating gut integrity, oxidized lipids and inflammatory markers is important for understanding PASC pathogenesis. A cross-sectional study including COVID+ with PASC, COVID+ without PASC, and COVID-negative (COVID-) participants. We measured plasma markers by enzyme-linked immunosorbent assay to assess intestinal permeability (ZONULIN), microbial translocation (lipopolysaccharide-binding protein or LBP), systemic inflammation (high-sensitivity C-reactive protein or hs-CRP), and oxidized low-density lipoprotein (Ox-LDL). 415 participants were enrolled in this study; 37.83% (n=157) had prior COVID diagnosis and among COVID+, 54% (n=85) had PASC. The median zonulin among COVID- was 3.37 (IQR: 2.13, 4.91) mg/mL, 3.43 (IQR: 1.65, 5.25) mg/mL among COVID+ no PASC, and highest [4.76 (IQR: 3.2, 7.35) mg/mL] among COVID+ PASC+ (p<.0001). The median ox-LDL among COVID- was 47.02 (IQR: 35.52, 62.77) U/L, 57.24 (IQR: 40.7, 75.37) U/L among COVID+ No PASC, and the highest [76.75 (IQR: 59.95, 103.28) U/L] among COVID+ PASC+ (p<.0001). COVID+ PASC+ was positively associated with zonulin (p=0.0002) and ox-LDL (p<.0001), and COVID- was negatively associated with ox-LDL (p=0.01), compared to COVID+ No PASC. Every unit increase in zonulin was associated with 44% higher predicted odds of having PASC [aOR: 1.44 (95%CI: 1.1, 1.9)] and every one-unit increase in ox-LDL was associated with more than four-fold increased odds of having PASC [aOR: 2.44 (95%CI: 1.67, 3.55)]. PASC is associated with increased gut permeability and oxidized lipids. Further studies are needed to clarify whether these relationships are causal which could lead to targeted therapeutics.

Autoimmunity: A New Focus on Nasal Polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) has long been considered a benign, chronic inflammatory, and hyperplastic disease. Recent studies have shown that autoimmune-related mechanisms are involved in the pathology of nasal polyps. Activated plasma cells, eosinophils, basophils, innate type 2 lymphocytes, mast cells, and proinflammatory cytokine in polyp tissue indicate the mobilization of innate and adaptive immune pathways during polyp formation. The discovery of a series of autoantibodies further supports the autoimmune nature of nasal polyps. Local homeostasis dysregulation, infection, and chronic inflammation may trigger autoimmunity through several mechanisms, including autoantigens overproduction, microbial translocation, molecular mimicry, superantigens, activation or inhibition of receptors, bystander activation, dysregulation of Toll-Like Receptors (TLRs), epitope spreading, autoantigens complementarity. In this paper, we elaborated on the microbiome-mediated mechanism, abnormal host immunity, and genetic changes to update the role of autoimmunity in the pathogenesis of chronic rhinosinusitis with nasal polyps.

Impacts of plasma microbial lipopolysaccharide translocation on B cell perturbations and anti-CD4 autoantibody production in people with HIV on suppressive antiretroviral therapy

Background. Up to 20% of people with HIV (PWH) who undergo virologically suppressed antiretroviral therapy (ART) fail to experience complete immune restoration. We recently reported that plasma anti-CD4 IgG (antiCD4IgG) autoantibodies from immune non-responders specifically deplete CD4 + T cells via antibody-dependent cytotoxicity. However, the mechanism of antiCD4IgG production remains unclear.Methods. Blood samples were collected from 16 healthy individuals and 25 PWH on suppressive ART. IgG subclass, plasma lipopolysaccharide (LPS), and antiCD4IgG levels were measured by ELISA. Gene profiles in B cells were analyzed by microarray and quantitative PCR. Furthermore, a patient-derived antiCD4IgG–producing B cell line was generated and stimulated with LPS in vitro. B cell IgG class switch recombination (CSR) was evaluated in response to LPS in splenic B cells from C57/B6 mice in vitro.Results. Increased plasma anti-CD4 IgGs in PWH were predominantly IgG1 and associated with increased plasma LPS levels as well as B cell expression of TLR2, TLR4, and MyD88 mRNA in vivo. Furthermore, LPS stimulation induced antiCD4IgG production in the antiCD4IgG B cell line in vitro. Finally, LPS promoted CSR in vitro.Conclusion. Our findings suggest that persistent LPS translocation may promote anti-CD4 autoreactive B cell activation and antiCD4IgG production in PWH on ART, which may contribute to gradual CD4 + T cell depletion. This study suggests that reversing a compromised mucosal barrier could improve ART outcomes in PWH who fail to experience complete immune restoration.

Probiotics, prebiotics, and synbiotics in nonalcoholic fatty liver disease and alcohol-associated liver disease.

The use of probiotics, prebiotics, and synbiotics has become an important therapy in numerous gastrointestinal diseases in recent years. Modifying the gut microbiota, this therapeutic approach helps to restore a healthy microbiome. Nonalcoholic fatty liver disease and alcohol-associated liver disease are among the leading causes of chronic liver disease worldwide. A disrupted intestinal barrier, microbial translocation, and an altered gut microbiome metabolism, or metabolome, are crucial in the pathogenesis of these chronic liver diseases. As pro-, pre-, and synbiotics modulate these targets, they were identified as possible new treatment options for liver disease. In this review, we highlight the current findings on clinical and mechanistic effects of this therapeutic approach in nonalcoholic fatty liver disease and alcohol-associated liver disease.

Toll-like receptor 2 activation in monocytes contributes to systemic inflammation and alcohol-associated liver disease in humans.

In the context of gut leakiness and translocation of microbial products in alcohol-associated liver disease (ALD), it is possible that systemic and liver inflammation involve the activation of circulating monocyte through gut-derived factors. We explored the association between monocytes, microbial translocation, systemic inflammation, and ALD. Patients with alcohol use disorder following a rehabilitation program were compared with healthy controls. We determined the circulating number and proportion of monocyte subsets by FACS. The activation of signaling pathways by gut-derived microbes was analyzed by quantitative PCR in isolated monocytes. Cytokines secretion by monocytes and phagocytosis were assessed in vitro. Serum microbial translocation markers and cytokines were measured by ELISA and multiplex assay, respectively. ALD severity and liver inflammatory responses were analyzed in liver biopsies by various methods. In patients with alcohol use disorder, the number of blood monocytes increased compared with controls. Monocytes from patients with alcohol use disorder upregulated IL-1β and IL-8 together with toll-like receptor 2 and downstream AP-1, while fungal sensor CARD9 was downregulated. IL-1β and IL-8 were actively secreted upon stimulation in vitro with the toll-like receptor 2 ligand peptidoglycan. Exposure with Escherichia coli confirmed preserved bacterial phagocytic activity. In contrast, Candida albicans stimulation leads to downregulation of IL-1β and TNFα compared with controls. Systemic cytokines and monocyte changes correlated with microbial translocation. Hepatic IL-1β and IL-8 increased with ALD severity together with liver macrophage activation and upregulation of chemokines involved in monocyte attraction. Our results point to the contribution of activated monocytes to systemic inflammation and ALD. Monocytes likely infiltrate the liver, transform into monocyte-derived macrophages and release IL-1β and IL-8 in response to peptidoglycan and toll-like receptor 2 activation.

Galectin-9 mediates gut-associated inflammation and disruption of tight junctions

Abstract Background: High levels of Galectin-9 (Gal-9), a β-galactoside-binding mammalian lectin, are associated with systemic inflammation in chronic viral infections like HIV, despite viral suppression by ART. Gut-systemic microbial translocation is a major contributor of persistent inflammation. Whether Gal-9 influences the integrity of the gut during viral infections remains unknown. Objective: Here we investigated the impact of Gal-9 in the interplay between gut-systemic microbial translocation in the setting of well-treated chronic HIV infection. Method: We assessed the levels of Gal-9 and sCD14 in the plasma of people with HIV on ART (PWH; n=25) and people without HIV (PWOH; n=15) by ELISA. The integrity of the gut epithelium in the presence and absence of rGal-9 was assessed in the HT-29 cell line by immunofluorescence. TNFa was used as a positive control to disrupt gut integrity. The levels of TNFa were measured by qPCR. Non parametric tests were used in the analysis. Results: Plasma Gal-9 and sCD14 were elevated in PWH compared to PWOH (all p&amp;lt;0.0001). Further, high Gal-9 levels correlated with high sCD14 in both the PWH (r=0.43, p=0.0317) and PWOH (r=0.79, p=0.0006) groups. Immunofluorescence revealed disruption of the Claudin tight junctions in vitroafter 24 hrs of rGal-9 treatment. rGal-9 also induced a 6-fold increase in the expression of TNFα in HT-29 cells. Conclusion: Our results show that Gal-9 is associated with markers of gut-systemic microbial translocation irrespective of HIV status and given the direct effects of rGal-9 on tight junction barrier function, targeting Gal-9 either by exploiting its secretory pathways or competitive blockade may serve as a novel therapeutic approach to control gut-associated inflammation.

Effect of HCV treatment with DAAs on serum intestinal fatty acid binding protein (I-FABP) as a marker of intestinal permeability in HCV/HIV co-infected patients

BackgroundHCV and HIV co-infected patients develop cirrhosis more rapidly than HCV mono-infection. Intestinal injury and microbial translocation are postulated mechanisms for the rapid progression of cirrhosis.AimStudy the effect of HCV treatment with DAAs on serum intestinal fatty acid binding protein (I-FABP) as a marker of intestinal injury in HCV/HIV co-infected patients and its relation to hepatic fibrosis. Comparing the level of I-FABP in HCV mono-infection and HCV/HIV co-infection was a secondary aim.MethodsI-FABP levels were measured in 50 non-cirrhotic HCV/HIV co-infected patients pre- and post-HCV treatment (SVR 12) (25 patients were HIV treatment naive, and 25 patients were on HAART) and in 25 chronic HCV patients as a control group. Hepatic fibrosis was assessed by FIB4 score, APRI score, and transient elastography.ResultsHCV/HIV co-infected patients had significantly higher levels of I-FABP compared to the HCV-mono-infected patients (P = 0.001). After HCV treatment in HCV/HIV co-infected patients, I-FABP level was significantly elevated (P < 0.001) and was positively correlated with baseline FIB4 values and serum ALT levels (r = 0.283, P-value = 0.047) and (r = 0.340, P-value = 0.016), respectively.ConclusionHCV/HIV co-infection is associated with significantly higher intestinal injury and subsequent hepatic fibrosis than HCV mono-infection. HIV infection is associated with intestinal epithelial injury and microbial translocation and may play a role in the persistence of systemic inflammation after HCV eradication.