Increased Production Of TNF-α Research Articles

An in vitro comparison of the toxicological profiles of ground tire particles (TP) and actual tire and road wear particles (TRWP) emissions

There is currently limited data on the potential effects of tire and road wear particles (TRWP) on human health. TRWP include tire fragments, but also road wear materials, dust, adsorbed gaseous pollutants and different types of inclusions that could affect their hazard profiles. Due to their availability and lower complexity, ground tire particles (TP) are often used in toxicological studies. However, this makes it difficult to draw firm conclusions about the potential hazard of actual TRWP. Here, we compared the in vitro toxicological profile of ground TP and actual TRWP emissions of similar size collected from road traffic. For this purpose, TP and TRWP were separately incubated with alveolar macrophages for 24 h, and the cellular response was evaluated in terms of cytotoxicity, proinflammatory response and oxidative stress. Both TP and TRWP induced neither significant cytotoxicity nor oxidative stress, but triggered a concentration-dependent proinflammatory response, as evidenced by increased TNF-α production. The level of TNF-α production was slightly higher with TRWP than with TP, independent of the particle dose. All in all, the pulmonary toxicity of TRWP could be due primarily to the tire tread inclusions and only marginally to other particle components (i.e. road wear materials, dust …). Although these preliminary results need to be confirmed by further analysis, they could be useful for tire manufacturers in the production of safer-by-design tires.

Arginine-specific gingipains (RgpA/RgpB) knockdown modulates neutrophil machinery

ABSTRACT Background Gingipains are important virulence factors present in Porphyromonas gingivalis. Arginine-specific gingipains (RgpA and RgpB) are critically associated with increased proteolytic activity and immune system dysfunction, including neutrophilic activity. In this study, we assessed the impact of gingipains (RgpA and RgpB) on neutrophil function. Methods Peripheral blood samples were obtained; neutrophils were isolated and incubated with P. gingivalis A7436, W50, and the double RgpA/RgpB double knockout mutant E8 at MOI 20 for 2 hours. Neutrophil viability was assessed by Sytox staining. Phagocytic capacity and apoptosis were measured by flow cytometry. Superoxide release was measured by superoxide dismutase and cytochrome c reduction assay. Gene expression of TLR2, p47-phox, p67-phox, and P2 × 7was measured by qPCR. Inflammatory cytokine and chemokine production was measured by IL-1β, IL-8, RANTES, and TNF-α in cell supernatants. Results Neutrophil TLR2 gene expression was reduced in the absence of RgpA/RgpB (p < 0.05), while superoxide production was not significantly impacted. RgpA/RgpB−/− significantly impaired neutrophil phagocytic function (p < 0.05) and increased TNF-α production when compared with the wild-type control (p < 0.05). Neutrophil apoptosis was not altered when exposed to RgpA/RgpB−/− E8 (p > 0.05). Conclusion These data suggest that arginine-specific gingipains (RgpA/RgpB) can modulate neutrophil responses against P. gingivalis infection.

TNF-α signals through ITK-Akt-mTOR to drive CD4+ T cell metabolic reprogramming, which is dysregulated in rheumatoid arthritis.

Upon activation, T cells undergo metabolic reprogramming to meet the bioenergetic demands of clonal expansion and effector function. Because dysregulated T cell cytokine production and metabolic phenotypes coexist in chronic inflammatory disease, including rheumatoid arthritis (RA), we investigated whether inflammatory cytokines released by differentiating T cells amplified their metabolic changes. We found that tumor necrosis factor-α (TNF-α) released by human naïve CD4+ T cells upon activation stimulated the expression of a metabolic transcriptome and increased glycolysis, amino acid uptake, mitochondrial oxidation of glutamine, and mitochondrial biogenesis. The effects of TNF-α were mediated by activation of Akt-mTOR signaling by the kinase ITK and did not require the NF-κB pathway. TNF-α stimulated the differentiation of naïve cells into proinflammatory T helper 1 (TH1) and TH17 cells, but not that of regulatory T cells. CD4+ T cells from patients with RA showed increased TNF-α production and consequent Akt phosphorylation upon activation. These cells also exhibited increased mitochondrial mass, particularly within proinflammatory T cell subsets implicated in disease. Together, these findings suggest that T cell-derived TNF-α drives their metabolic reprogramming by promoting signaling through ITK, Akt, and mTOR, which is dysregulated in autoinflammatory disease.

Sub-acute oral exposure to lowest observed adverse effect level of nivalenol exacerbates atopic dermatitis in mice via direct activation of mitogen-activated protein kinase signal in antigen-presenting cells.

This study investigated the immunotoxic effects of the mycotoxin nivalenol (NIV) using antigen-presenting cells and a mouse model of atopic dermatitis (AD). In vitro experiments were conducted using a mouse macrophage cell line (RAW 264.7) and mouse dendritic cell line (DC 2.4). After cells were exposed to NIV (0.19-5µmol) for 24h, the production of pro-inflammatory cytokines (IL-1β, IL-6, and TNFα) was quantified. To further investigate the inflammatory cytokine production pathway, the possible involvement of mitogen-activated protein kinase (MAPK) pathways, such as ERK1/2, p-38, and JNK, in NIV exposure was analyzed using MAPK inhibitors and phosphorylation analyses. In addition, the pro-inflammatory effects of oral exposure to NIV at low concentrations (1 or 5ppm) were evaluated in an NC/Nga mouse model of hapten-induced AD. In vitro experiments demonstrated that exposure to NIV significantly enhanced the production of TNFα. In addition, it also directly induced the phosphorylation of MAPK, indicated by the inhibition of TNFα production following pretreatment with MAPK inhibitors. Oral exposure to NIV significantly exacerbated the symptoms of AD, including a significant increase in helper T cells and IgE-produced B cells in auricular lymph nodes and secretion of pro-inflammatory cytokines, such as IL-4, IL-5, and IL-13, compared with the vehicle control group. Our findings indicate that exposure to NIV directly enhanced the phosphorylation of ERK1/2, p-38, and JNK, resulting in a significant increase in TNFα production in antigen-presenting cells, which is closely related to the development of atopic dermatitis.

EXTH-18. DEVELOPMENT OF A TRANSGENIC MOUSE MODEL ENABLING COMPARATIVE ANALYSIS OF CHIMERIC ANTIGEN RECEPTOR (CAR)-EXPRESSING IMMUNE CELL POPULATIONS FOR CANCER IMMUNOTHERAPY

Abstract We reported the creation of C57BL/6J-background transgenic (Tg) mice carrying the anti-epidermal growth factor receptor (EGFR)vIII-CAR with CD3z-CD28-4-1BB downstream of a Lox-Stop-Lox cassette in the Rosa26 locus. Breeding these mice with CD4-Cre Tg allows rigorous and reproducible evaluation of CAR-T cell therapy in syngeneic models (Chuntova et al. Neuro-Onc 2022). As the extension of the approach, we crossed the EGFRvIII-CAR Tg mice with mice carrying Vav-Cre, which allowed the expression of anti-EGFRvIII CAR in all hematopoietic cells. In particular, we evaluated CAR-T, CAR-NKT, CAR-NK cells, and CAR-macrophages. CAR-NK cells displayed a robust antigen-specific cytolytic activity against EGFRvIII-expressing SB28 cells, comparable to CAR-T cells in vitro and mice bearing intracerebral EGFRvIII-expressing SB28 gliomas. Remarkably, CAR-NKT cells produced higher levels of inflammatory cytokines when co-cultured with EGFRvIII-expressing SB28 cells, such as IFN-g, Perforin, IL4, and IL17. On the other hand, despite their in vitro cytotoxic effects against SB28 cells, CAR-NK cells failed to mediate a therapeutic response in mice bearing intracerebral glioma. Future studies will be directed at improving the in vivo persistence of CAR-NK cells using engineered cytokines, such as IL-2 superkine. In addition, we extensively investigated CAR-macrophages in vitro and in vivo. Unfortunately, we did not observe significant CAR-specific anti-tumor effects. Consequently, we modified the intracellular domain of CAR from CD3z-CD28-4-1BB to CD3z alone. This alteration led to increased TNF-α production through CAR signaling. This transgenic mouse model offers rigorous and reproducible evaluations of CAR-expressing hematopoietic cells. Furthermore, the model provides a platform for developing combination therapies, such as CAR-T plus CAR-NKT or CAR-T plus CAR-NK cells, with potential implications for enhanced cancer treatment strategies.

CD115+ monocytes protect microbially experienced mice against E. coli-induced sepsis

Uropathogenic E. coli (UPEC) is a primary organism responsible for urinary tract infections and a common cause of sepsis. Microbially experienced laboratory mice, generated by cohousing with pet store mice, exhibit increased morbidity and mortality to polymicrobial sepsis or lipopolysaccharide challenge. By contrast, cohoused mice display significant resistance, compared with specific pathogen-free mice, to a monomicrobial sepsis model using UPEC. CD115+ monocytes mediate protection in the cohoused mice, as depletion of these cells leads to increased mortality and UPEC pathogen burden. Further study of the cohoused mice reveals increased TNF-α production by monocytes, a skewing toward Ly6ChiCD115+ "classical" monocytes, and enhanced egress of Ly6ChiCD115+ monocytes from the bone marrow. Analysis of cohoused bone marrow also finds increased frequency and number of myeloid multipotent progenitor cells. These results show that a history of microbial exposure impacts innate immunity in mice, which can have important implications for the preclinical study of sepsis.

PDZ Peptide of the ZO-1 Protein Significantly Increases UTP-Induced MUC8 Anti-Inflammatory Mucin Overproduction in Human Airway Epithelial Cells.

Mucus hyperproduction and hypersecretion are observed often in respiratory diseases. MUC8 is a glycoprotein synthesized by epithelial cells and generally expressed in the respiratory track. However, the physiological mechanism by which extracellular nucleotides induce MUC8 gene expression in human airway epithelial cells is unclear. Here, we show that UTP could induce MUC8 gene expression through P2Y2-PLCβ3-Ca2+ activation. Because the full-length cDNA sequence of MUC8 has not been identified, a specific siRNA-MUC8 was designed based on the partial cDNA sequence of MUC8. siRNA-MUC8 significantly increased TNF-α production and decreased IL-1Ra production, suggesting that MUC8 may downregulate UTP/P2Y2-induced airway inflammation. Interestingly, the PDZ peptide of ZO-1 protein strongly abolished UTP-induced TNF-α production and increased IL-1Ra production and MUC8 gene expression. In addition, the PDZ peptide dramatically increased the levels of UTP-induced ZO proteins and TEER (trans-epithelial electrical resistance). These results show that the anti-inflammatory mucin MUC8 may contribute to homeostasis, and the PDZ peptide can be a novel therapeutic candidate for UTP-induced airway inflammation.

The use of alpha 1 thymosin as an immunomodulator of the response against SARS-Cov2

BackgroundSince the beginning of SARS-CoV2 pandemic, the mortality rate among elderly patients (60–90 years) has been around 50%, so age has been a determining factor of a worse COVID-19 prognosis. Associated with age, the thymic function involution and depletion plays an important role, that could be related to a dysregulated and ineffective innate and adaptive immune response against SARS-CoV2. Our study aims to further in vitro effect of human Thymosin-alpha-1 (α1Thy) treatment on the immune system in population groups with different thymic function levels in the scenario of SARS-CoV2 infection.ResultsActivation markers such as CD40, CD80 and TIM-3 were upregulated in α1Thy presence, especially in plasmacytoid dendritic cells (pDCs) and, with increased TNFα production was observed compared to untreated condition. Co-cultures of CD4 + and CD8 + T cells with DCs treated with α1Thy in response to SARS-CoV2 peptides showed a decrease in the cytokine production compared to the condition without α1Thy pre-treated. A decrease in CD40L activation co-receptor expression in CD8 + LTs was also observed, as well as an increase in PD1 in CD4 + TLs expression in both age groups. In fact, there are no age-related differences in the immunomodulatory effect of the hormone, and it seems that effector memory and terminally differentiated memory T lymphocyte subsets were the most actively influenced by the immunomodulatory α1Thy effect. Finally, the polyfunctionality measured in SARS-CoV2 Specific-T cells response was maintained in α1Thy presence in total and memory subpopulations CD4 + and CD8 + T-cells, despite decreased proinflammatory cytokines production.ConclusionThe hormone α1Thy could reduce, through the modulation of DCs, the amount of proinflammatory cytokines produced by T cells. Moreover, α1Thy improve lymphocyte functionality and could become a beneficial therapeutic alternative as an adjuvant in SARS-CoV2 treatment either in the acute phase after infection or reinfection. In addition, the effect on the T immune response means that α1Thy can be incorporated into the vaccination regimen, especially in the most immunologically vulnerable individuals such as the elderly.SubjectsThymosin alpha 1, Dendritic cells, SARS-CoV2-specific T cells response, Immunomodulation

Increased α-HB links colorectal cancer and diabetes by potentiating NF-κB signaling

Sufficient evidence has linked many different types of cancers and T2D through shared risk factors; however, the underlying mechanisms are not fully understood. α-Hydroxybutyrate (α-HB), a byproduct metabolite increased in diabetes and cancer, including colorectal cancer (CRC), triggers lactate dehydrogenase A (LDHA) nuclear translocation. Nuclear LDHA markedly extends NF-κB nuclear retention by interacting with phosphorylated p65, leading to an increase in TNF-α production, impaired insulin secretion and the exacerbation of azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced CRC and high-fat diet (HFD)-induced type 2 diabetes. Furthermore, metformin interrupted this process by inhibiting the transcription of FOXM1 and c-MYC, the resultant downregulation of LDHA expression and α-HB-induced LDHA nuclear translocation. Thus, the results reveal the elevated α-HB level could be a novel shared risk factor of linking CRC, diabetes and the use of metformin treatment, as well as highlight the importance of preventing NF-κB activation for protecting against cancer and diabetes.

Evaluation of the Effect of Cow’s Milk Kefir on Serum Tumor Necrosis Factor-alpha (TNF-α) and Expression of Inducible Nitric Oxide Synthase (iNOS) Gene in Liver Rats

TNF-α is a pro-inflammatory cytokine in insulin resistance. Cytokine-induced increase in TNF-α production by the iNOS pathway plays an important role in diabetes. This study was designed to determine the effect of cow's milk kefir as an antidiabetic and expression of the iNOS gene. Twenty-five Wistar rats were divided into 5 groups. Group cow’s milk kefir dose variation (50%, 75%, and 100%). This study showed that TNF-α levels in the DM control rat group were higher compared to other DM rat groups that were given cow’s milk kefir treatment. The cow's milk kefir treatment group (50%) had a higher average TNF-α content (146.3± 6.68) compared to the other two treatment groups given 75% cow's milk kefir (169.9± 6.39) and 100% cow's milk kefir (175.3± 4.66). There were differences in TNF-α levels between treatment groups (p=0.0013). The expression of the iNOS gene in the healthy control group was highest found in the M rat groupgiven 50% milk kefir and the lowest in the DM rat group given 100% milk kefir. There weresignificant differences in iNOS gene expression between groups (p = 0.0019). There was a significant difference between the DM rat group that was treated in the form of 50% group with DM Rats (positive controls) (p= 0.0048) and DM cow’s milk Kefir rats 75% milk with DM Rats (Positive controls) (p=0.0128). This study shows that there is an effect of cow's milk kefir as an antidiabetic on TNF-α and iNOS gene expression.

Stress granule activation attenuates lipopolysaccharide-induced cardiomyocyte dysfunction

BackgroundSepsis is the leading cause of death in intensive care units. Sepsis-induced myocardial dysfunction, one of the most serious complications of sepsis, is associated with higher mortality rates. As the pathogenesis of sepsis-induced cardiomyopathy has not been fully elucidated, there is no specific therapeutic approach. Stress granules (SG) are cytoplasmic membrane-less compartments that form in response to cellular stress and play important roles in various cell signaling pathways. The role of SG in sepsis-induced myocardial dysfunction has not been determined. Therefore, this study aimed to determine the effects of SG activation in septic cardiomyocytes (CMs).MethodsNeonatal CMs were treated with lipopolysaccharide (LPS). SG activation was visualized by immunofluorescence staining to detect the co-localization of GTPase-activating protein SH3 domain binding protein 1 (G3BP1) and T cell-restricted intracellular antigen 1 (TIA-1). Eukaryotic translation initiation factor alpha (eIF2α) phosphorylation, an indicator of SG formation, was assessed by western blotting. Tumor necrosis factor alpha (TNF-α) production was assessed by PCR and enzyme-linked immunosorbent assays. CMs function was evaluated by intracellular cyclic adenosine monophosphate (cAMP) levels in response to dobutamine. Pharmacological inhibition (ISRIB), a G3BP1 CRISPR activation plasmid, and a G3BP1 KO plasmid were employed to modulate SG activation. The fluorescence intensity of JC-1 was used to evaluate mitochondrial membrane potential.ResultsLPS challenge in CMs induced SG activation and resulted in eIF2α phosphorylation, increased TNF-α production, and decreased intracellular cAMP in response to dobutamine. The pharmacological inhibition of SG (ISRIB) increased TNF-α expression and decreased intracellular cAMP levels in CMs treated with LPS. The overexpression of G3BP1 increased SG activation, attenuated the LPS-induced increase in TNF-α expression, and improved CMs contractility (as evidenced by increased intracellular cAMP). Furthermore, SG prevented LPS-induced mitochondrial membrane potential dissipation in CMs.ConclusionSG formation plays a protective role in CMs function in sepsis and is a candidate therapeutic target.

Oxidative Stress, Cytotoxic and Inflammatory Effects of Azoles Combinatorial Mixtures in Sertoli TM4 Cells.

Triazole and imidazole fungicides are an emerging class of contaminants with an increasing and ubiquitous presence in the environment. In mammals, their reproductive toxicity has been reported. Concerning male reproduction, a combinatorial activity of tebuconazole (TEB; triazole fungicide) and econazole (ECO; imidazole compound) in inducing mitochondrial impairment, energy depletion, cell cycle arrest, and the sequential activation of autophagy and apoptosis in Sertoli TM4 cells (SCs) has recently been demonstrated. Given the strict relationship between mitochondrial activity and reactive oxygen species (ROS), and the causative role of oxidative stress (OS) in male reproductive dysfunction, the individual and combined potential of TEB and ECO in inducing redox status alterations and OS was investigated. Furthermore, considering the impact of cyclooxygenase (COX)-2 and tumor necrosis factor-alpha (TNF-α) in modulating male fertility, protein expression levels were assessed. In the present study, we demonstrate that azoles-induced cytotoxicity is associated with a significant increase in ROS production, a drastic reduction in superoxide dismutase (SOD) and GSH-S-transferase activity levels, and a marked increase in the levels of oxidized (GSSG) glutathione. Exposure to azoles also induced COX-2 expression and increased TNF-α production. Furthermore, pre-treatment with N-acetylcysteine (NAC) mitigates ROS accumulation, attenuates COX-2 expression and TNF-α production, and rescues SCs from azole-induced apoptosis, suggesting a ROS-dependent molecular mechanism underlying the azole-induced cytotoxicity.

AMPK reduces macrophage endotoxin tolerance through inhibition of TGF-β1 production and its signaling pathway.

Adenosine monophosphate-activated protein kinase (AMPK) is involved in suppression of the development of endotoxin tolerance, which is a driver of the immunosuppression induced by sepsis. However, the mechanism by which AMPK inhibits the development of endotoxin tolerance has not been clearly elucidated. Therefore, the present study was performed to investigate the mechanism by which the AMPK activator, metformin, inhibits the development of endotoxin tolerance. Lipopolysaccharide (LPS) increased the production of transforming growth factor (TGF)-β1 in macrophages, which was inhibited by metformin and resveratrol. Knockdown of AMPKα1 inhibited the suppressive effect of metformin on LPS-induced TGF-β1 production. TGF-β neutralizing antibody and TGF-β type I receptor inhibitor increased the production of TNF-α and IL-6 via LPS restimulation in tolerized macrophages. LPS increased Smad2 phosphorylation, but this was inhibited in cells treated with TGF-β neutralizing antibody or metformin. Smad2 knockdown inhibited the development of endotoxin tolerance, as evidenced by increased TNF-α production in response to LPS restimulation in tolerized macrophages. TGF-β1 expression was increased, and the levels of TNF-α and IL-6 production induced by LPS stimulation were decreased, in splenocytes of cecal ligation and puncture (CLP) model mice compared to sham-operated controls. However, metformin treatment suppressed the production of TGF-β1, and enhanced the production of TNF-α and IL-6 induced by LPS stimulation in splenocytes of CLP mice. These results indicated that AMPK activation inhibits LPS-induced TGF-β1 production and its signaling pathway, thus suppressing the development of endotoxin tolerance in macrophages.

Ablation of SYK Kinase from Expanded Primary Human NK Cells via CRISPR/Cas9 Enhances Cytotoxicity and Cytokine Production.

CMV infection alters NK cell phenotype and function toward a more memory-like immune state. These cells, termed adaptive NK cells, typically express CD57 and NKG2C but lack expression of the FcRγ-chain (gene: FCER1G, FcRγ), PLZF, and SYK. Functionally, adaptive NK cells display enhanced Ab-dependent cellular cytotoxicity (ADCC) and cytokine production. However, the mechanism behind this enhanced function is unknown. To understand what drives enhanced ADCC and cytokine production in adaptive NK cells, we optimized a CRISPR/Cas9 system to ablate genes from primary human NK cells. We ablated genes that encode molecules in the ADCC pathway, such as FcRγ, CD3ζ, SYK, SHP-1, ZAP70, and the transcription factor PLZF, and tested subsequent ADCC and cytokine production. We found that ablating the FcRγ-chain caused a modest increase in TNF-α production. Ablation of PLZF did not enhance ADCC or cytokine production. Importantly, SYK kinase ablation significantly enhanced cytotoxicity, cytokine production, and target cell conjugation, whereas ZAP70 kinase ablation diminished function. Ablating the phosphatase SHP-1 enhanced cytotoxicity but reduced cytokine production. These results indicate that the enhanced cytotoxicity and cytokine production of CMV-induced adaptive NK cells is more likely due to the loss of SYK than the lack of FcRγ or PLZF. We found the lack of SYK expression could improve target cell conjugation through enhanced CD2 expression or limit SHP-1-mediated inhibition of CD16A signaling, leading to enhanced cytotoxicity and cytokine production.

GARCINIA COWA ROXB. ETHANOL EXTRACT INHIBITS INFLAMMATION IN LPS-INDUCED RAW 264.7 MACROPHAGES

Objective: The purpose of this study was to examine the effect of Garcinia cowa Roxb. Ethanol (EGC) extract in LPS-induced Raw 264.7 macrophages by observing the release of Tumor Necrosis Factor (TNF) and Interleukin-6 (IL-6).&#x0D; Methods: Using the MTT method, a cell viability assay was performed to observe the cytotoxic effect on Raw 264.7 macrophages. For 24 h, Raw 264.7 macrophages were incubated with various EGC concentrations (100, 50, 10, 1 and 0.1 µg/ml). The medium was taken out after 48 h of incubation, and 100 µl of MTT 0.5 mg/ml was then added. 100 µl DMSO was used to dissolve the crystals and absorbance was measured using a microplate reader. To investigate the activity of EGC to LPS-induced Raw 264.7 macrophages, the ELISA method was used. Supernatant was obtained after treating Raw 264.7 macrophages with complete medium, EGC samples, and LPS (10 g/ml) for 24 h. IL-6 and TNF-α levels were assessed using supernatants with ELISA kit.&#x0D; Results: Cytotoxic effect of EGC to Raw 264.7 macrophages occurred at a concentration of 100 µg/ml with the cell viability value of 59.5%. At a concentration of 50 µg/ml, no cytotoxic effect occurred and the cell viability value was 105.5%. So, the higher concentration of EGC used for further investigation is 50 µg/ml. It was shown that the production of IL 6 was suppressed by EGC at a concentration of 12.5 µg/ml. The inhibition of TNF-α production was only seen at the concentration of 12.5, 25 and 50 µg/ml; there was an increase of TNF-α production.&#x0D; Conclusion: It can be concluded that EGC can be developed as a natural immunomodulator that can inhibit inflammation by suppressing IL-6 production to prevent immune system disorders.

The impact of BCG dose and revaccination on trained immunity

The innate immune system can display heterologous memory-like responses termed trained immunity after stimulation by certain vaccinations or infections. In this randomized, placebo-controlled trial, we investigated the modulation of Bacille Calmette-Guérin (BCG)-induced trained immunity by BCG revaccination or high-dose BCG administration, in comparison to a standard dose. We show that monocytes from all groups of BCG-vaccinated individuals exerted increased TNFα production after ex-vivo stimulation with various unrelated pathogens. Similarly, we observed increased amounts of T-cell-derived IFNγ after M. tuberculosis exposure, regardless of the BCG intervention. NK cell cytokine production, especially after heterologous stimulation with the fungal pathogen Candida albicans, was predominantly boosted after high dose BCG administration. Cytokine production capacity before vaccination was inversely correlated with trained immunity. While the induction of a trained immunity profile is largely dose- or frequency independent, baseline cytokine production capacity is associated with the magnitude of the innate immune memory response after BCG vaccination.

Type I IFN Signaling Is Essential for Preventing IFN-γ Hyperproduction and Subsequent Deterioration of Antibacterial Immunity during Postinfluenza Pneumococcal Infection.

Postinfluenza bacterial pneumonia is a significant cause of hospitalization and death in humans. The mechanisms underlying this viral and bacterial synergy remain incompletely understood. Recent evidence indicates that influenza-induced IFNs, particularly type I IFN (IFN-I) and IFN-γ, suppress antibacterial defenses. In this study, we have investigated the relative importance and interplay of IFN-I and IFN-γ pathways in influenza-induced susceptibility to Streptococcus pneumoniae infection. Using gene-deficient mouse models, as well as in vivo blocking Abs, we show that both IFN-I and IFN-γ signaling pathways contribute to the initial suppression of antibacterial immunity; however, IFN-γ plays a dominant role in the disease deterioration, in association with increased TNF-α production and alveolar macrophage (AM) depletion. We have previously shown that IFN-γ impairs AM antibacterial function and thereby acute bacterial clearance. The findings in this study indicate that IFN-γ signaling also impairs AM viability and αβ T cell recruitment during the progression of influenza/S. pneumoniae coinfection. Macrophages insensitive to IFN-γ mice express a dominant-negative mutant IFN-γR in mononuclear phagocytes. Interestingly, macrophages insensitive to IFN-γ mice exhibited significantly improved recovery and survival from coinfection, despite delayed bacterial clearance. Importantly, we demonstrate that IFN-I receptor signaling is essential for preventing IFN-γ hyperproduction and animal death during the progression of postinfluenza pneumococcal pneumonia.

Compartmentalized microfluidic device for in vitro co-culture of retinal cells.

The investigation is focused on the development of a compartmentalized microfluidic device for coculturing the cells of crucial retinal cellular layers and assessing cell-to-cell interactions. A perfusion-based microfluidic co-culture device was employed and computationally validated for determining the pressure drop and fluid flow rate within the device microchannels. Fabrication was performed using PDMS polymer and coating of fibronectin and collagen facilitated adherence of the cells over the glass surface. Microfluidic device successfully supported cell proliferation, under continuous perfusion of 1μlmin-1 flow rate. The barrier integrity of this coculture was confirmed by evaluating the permeability of fluorescently labeled molecules. The coculture expressed characteristic phenotypic protein markers like recoverin, PAX6, for retinal precursor cells, and RPE65 for retinal epithelial cells. The coculture also exhibited basal expression of TNF-α under normal conditions. Differentiated photoreceptor cells positively expressed rhodinherently possess sensitivity toward violet/blue light, which was validated in R28 cells by exposure to light having a wavelength of 405nm, which significantly decreased cell viability via increased TNF-α production and reduced rhodopsin expression. This proof-of-concept investigation proved the functionality of the retinal coculture, which may be used as an appropriate perfusion-based, preclinical tool for the evaluation of novel retinal drugs and delivery systems.

Increased TNF-α production in response to IL-6 in patients with systemic inflammation without infection.

Acute systemic inflammation can lead to life-threatening organ dysfunction. In patients with sepsis, systemic inflammation is triggered in response to infection, but in other patients, a systemic inflammatory response syndrome (SIRS) is triggered by non-infectious events. IL-6 is a major mediator of inflammation, including systemic inflammatory responses. In homeostatic conditions, when IL-6 engages its membrane-bound receptor on myeloid cells, it promotes pro-inflammatory cytokine production, phagocytosis, and cell migration. However, under non-physiologic conditions, such as SIRS and sepsis, leucocyte dysfunction could modify the response of these cells to IL-6. So, our aim was to evaluate the response to IL-6 of monocytes from patients diagnosed with SIRS or sepsis. We observed that monocytes from patients with SIRS, but not from patients with sepsis, produced significantly more TNF-α than monocytes from healthy volunteers, after stimulation with IL-6. Monocytes from SIRS patients had a significantly increased baseline phosphorylation of the p65 subunit of NF-κB, with no differences in STAT3 phosphorylation or SOCS3 levels, compared with monocytes from septic patients, and this increased phosphorylation was maintained during the IL-6 activation. We found no significant differences in the expression levels of the membrane-bound IL-6 receptor, or the serum levels of IL-6, soluble IL-6 receptor, or soluble gp130, between patients with SIRS and patients with sepsis. Our results suggest that, during systemic inflammation in the absence of infection, IL-6 promotes TNF-α production by activating NF-κB, and not the canonical STAT3 pathway.

Role of stress granule activation in cardiomyocyte function in sepsis

Sepsis is a life‐threatening organ dysfunction caused by a dysregulated host response to infection. It is the leading cause of mortality in Intensive Care Unit (ICU). Sepsis‐induced myocardial dysfunction (SIMD) is a major complication of the sepsis that contributes to high mortality of patients with sepsis. Stress granule (SG) is a cytoplasmic membraneless platform that is formed in response to cellular stresses. The role of SG in SIMD is unknown. The aim of present study is to understand whether activation of SG in cardiomyocytes (CM) plays a role in CM function in sepsis.MethodsCMs were treated with lipopolysaccharide (LPS). CM SG activation (eIF2α phosphorylation) and TNFα production were assessed with Western blot and ELISA, respectively. CM function was evaluated with intracellular cAMP. ISRIB or over‐expression of G3BP1 was employed interfering SG.ResultsChallenging CMs with LPS results in eIF2α phosphorylation, an increase in TNFα production, and a decrease in intracellular cAMP in response to dobutamine. Pharmacologically (ISRIB) or genetically inhibition (G3BP1 knock down) of SG leads to an exaggerated increase in TNFα expression. Further, SG inhibition results in enhanced decrease in CM function (decreased intracellular cAMP) in CM with LPS. Over‐expression of G3BP1 in CMs prevents LPS‐induced CM TNFα production and improves CM contractility.ConclusionOur results indicate that the cardiomyocyte stress granule activation plays a protective role of myocardial function in sepsis.