Local Pro-inflammatory Response Research Articles

Anti-Glycation Properties of Zinc-Enriched Arthrospira platensis (Spirulina) Contribute to Prevention of Metaflammation in a Diet-Induced Obese Mouse Model.

Advanced glycation end products (AGEs) exert a key pathogenic role in the development of obesity and insulin resistance. Thanks to its abundance in bioactive compounds, the microalga Arthrospira platensis (spirulina, SP) is proposed as a nutritional supplement. Here, we investigated the potential anti-glycating properties of SP enriched with zinc (Zn-SP) and the following impact on diet-induced metabolic derangements. Thirty male C57Bl6 mice were fed a standard diet (SD) or a high-fat high-sugar diet (HFHS) for 12 weeks, and a subgroup of HFHS mice received 350 mg/kg Zn-SP three times a week. A HFHS diet induced obesity and glucose intolerance and increased plasma levels of pro-inflammatory cytokines and transaminases. Zn-SP administration restored glucose homeostasis and reduced hepatic dysfunction and systemic inflammation. In the liver of HFHS mice, a robust accumulation of AGEs was detected, paralleled by increased expression of the main AGE receptor (RAGE) and depletion of glyoxalase-1, whereas Zn-SP administration efficiently prevented these alterations reducing local pro-inflammatory responses. 16S rRNA gene profiling of feces and ileum content revealed altered bacterial community structure in HFHS mice compared to both SD and HFHS + Zn-SP groups. Overall, our study demonstrates relevant anti-glycation properties of Zn-SP which contribute to preventing AGE production and/or stimulate AGE detoxification, leading to the improvement of diet-related dysbiosis and metabolic derangements.

Development of Mass Spectrometry Imaging on skeletal muscle to characterize the local pro-inflammatory and pro-resolution lipid responses in a vaccination context

Vaccine reactogenicity is well documented at the clinical level but the mechanism involved at the local or systemic level are still poorly understood. Muscular tissue where most vaccines are administered is the first place of interaction between the vaccine formulation and the host's immune cells. So far, this site of vaccine administration is not well documented from a mechanistic standpoint. The study of early molecular events at the injection site is crucial to understand the local response to vaccines. In this paper, we report a standardized workflow, from the injection of vaccine formulations in rabbit muscle, to the analysis by desorption electrospray ionization and histology staining to understand the role of lipids involved in the inflammation and its resolution on striated muscular tissue. The analysis of lipid mediators was optimized at the site of needle insertion to allow the spatial comparison of cellular infiltrates at the injection site. We showed that lipids were distributed across the spatial tissue morphology in a time-dependent manner. The MS imaging applied to vaccinology could pave the way to a better understanding of vaccine reactogenicity and mechanism of action.

781TiP AGADIR: A basket multicenter open-label phase II study evaluating the first in class TLR7/8 agonist BDB001 in combination with atezolizumab and stereotactic body radiation therapy in patients with advanced solid tumors

Monotherapy response rates to PD1/PDL1 monoclonal antibodies remain low, and additional therapies are required to fully exploit their potential. In this regard, strategies that target tumor-resident innate immune cells and induce local tumor proinflammatory responses, which recruit CD8+ TILs, represent a promising approach. One strategy to turn an immunologically cold tumor hot is to promote activation of antigen presenting cells (APC) by targeting the endosomal TLRs TLR3, TLR7, TLR8, TLR9. The first in class TLR7/8 agonist BDB001 can activate both myeloid dendritic cell mDC (which express TLR8) and plasmacytoid dendritic cell pDC (which express TLR7 and TLR9). Targeting both TLR7 and TLR8 allows for a more potent activation signal capable of overriding other inhibitory mechanisms, including turning a « cold » tumor into a « hot » tumor. Stereotactic body radiation therapy (SBRT) can also promote an antitumor systemic response (“abscopal effect”) through T cell-mediated activation of the adaptive immune system. AGADIR is a multi-cohort single-arm phase 2, multicenter, open-label study investigating BDB001 with atezolizumab in patients with advanced cancers: pancreatic adenocarcinoma (pop 1), virus-associated tumors (pop 2), previously exposed to PD1/PDL1 antibodies non-small cell lung cancer (pop 3) and bladder cancer (pop 5), soft-tissue sarcomas (pop 4), triple-negative breast cancer (pop 6). This study will enroll ∼247 patients with no standard treatment options available and ECOG 0–1. BDB0001 is given IV on days 1, 8, and 15 of cycles 1 to 3 and on day 1 every 3 weeks therafter. Atezolizumab is given on day 1 every 3 weeks. SBRT of metastatic lesion will start at least one week after the first dose of atezolizumab. The primary endpoints are disease control rate within 24 weeks of treatment in populations 1, 2, 3, 5 and 6 and progression-free rate at 6 months for population 4 (RECIST 1.1). Secondary endpoints include toxicity, overall and progression-free survival. Pharmacodynamic and other biomarkers will be explored. The first patient received study drug on June 2022. NCT03915678, 16 April 2019. Institut Bergonié, Bordeaux, France.

Teriparatide therapy for medication-related osteonecrosis of the jaw: case report and literature review

Medication-related osteonecrosis of the jaw (MRONJ) is a recognised complication of antiresorptive therapy.[1][1] Emerging evidence suggests impaired epithelialisation post-dental surgery, local pro-inflammatory response and inhibition of angiogenesis in its pathogenesis.[2][2] Risk factors include

Inflammatory degranulation of the cardiac resident mast cells suppresses the pacemaking and affects activation pattern in the sinoatrial node

BackgroundMany bacterial and viral infections may cause sepsis or/and systemic or local proinflammatory responses that lead to life-threatening cardiovascular system failure. Severe bradycardia and/or bradyarrhythmias frequently accompany systemic inflammation and contribute to hemodynamic insufficiency. Markers for immunocompetent cells have been shown to be present in the tissue of the primary heart pacemaker, the sinoatrial node (SAN). However, the role of the resident cardiac immune cells in inflammation-induced bradycardia and SAN automaticity have still not been elucidated. Materials and methodsConfocal and bright field microscopy were used to identify toluidine blue-positive cells (TPC) in the SAN. Standard microelectrode technique and optical mapping were used to record action potentials (AP) and analyze activation pattern in the SAN tissue preparation from rats in presence of secretagogue C48/80. ResultsNumerous TPC, which exhibit toluidine-accumulating granules, typical for mast cells, are revealed in the SAN region of the right atrium. The activation and degranulation of the resident mast cells by C48/80 leads to biphasic changes of the pacemaker AP rate in the SAN – an initial acceleration is followed by rate reduction. The activation of the resident mast cells causes an increase of the primary activation area in the SAN that probably underlies the AP rate increase in response to C48/80. In addition, the application of C48/80 causes the primary/leading activation point migration in the SAN and AP rate decrease is probably mediated by the shift of the primary pacemaker site to the region surrounding the coronary sinus. Moreover, inexcitable zones and conduction blocks induced in the central SAN myocardium by C48/80 underlie the suppression of automaticity. ConclusionThe degranulation of resident mast cells affects the pacemaker cardiomyocytes’ ability to generate spontaneous AP in the SAN tissue and causes shift of the dominant pacemaker site. Therefore, the activation of the resident mast cells in the SAN can be considered as a new mechanism of inflammatory induced bradyarrhythmias.

Hype or hope of hyaluronic acid for osteoarthritis: Integrated clinical evidence synthesis with multi-organ transcriptomics.

BackgroundIntra-articular injections of hyaluronic acid (HA), the United States Food and Drug Administration approved treatment and widely utilized to delay or reserve the progression of the osteoarthritis (OA) involves. However, this treatment has shown controversial results through various clinical practice guidelines and meta-analysis evaluations, warrants more advanced researches on its safety and effectiveness.MethodsA novel strategy of integrating medical informatics and bioinformatics was utilized. An updated meta-analysis of 16 randomized controlled trials (RCTs) out of 1820 articles was conducted, in combination with a high throughput body-wide-organ-transcriptomic (BOT) RNA-sequencing (RNA-seq) and in vitro and vivo experiments to evaluate the effect of HA at local and systemic levels, revealing the underlying mechanism.ResultsA sensitivity analysis was performed restricting to high quality RCTs, no significant effect of HA treatment was found on pain relief and functional improvement. Descriptive analysis of RNA-seq using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed biological process related to innate immune responses and apoptosis; BOT analysis revealed differential gene expressions (DEGs) in cartilage, lymph node, spleen, kidney, and liver, with immune cell proliferation in immune-related organs. In vitro, HA-coated plates were shown to induce macrophage responses; in vivo histological images revealed knee joint, liver, and kidney with damaged/abnormal morphologies, while immune cell proliferation was observed in the lymph node and spleen and it was found that there was no significant difference in the treatment effect for OA animal model.ConclusionConclusively, integration of meta-analysis with bioinformatics analysis exhibited that HA induces inflammatory responses both locally and systematically and not benefit for OA treatment, thus limiting the regeneration and leading to some organ-specific pathogenesis. The strategy and findings will be of important for guiding future long-term clinical studies.The Translational potential of this articleThis study illustrated that the administered HA activated both systemic and local pro-inflammatory immune responses, possibly limiting its efficacy. This novel unique strategy proposed in this study can be utilized and adapted for future meta-analysis and bioinformatics study.

Effects of lipopolysaccharide exposure on the inflammatory response, butyrate flux, and metabolic function of the ruminal epithelium using an ex vivo model

Acidotic conditions in the rumen have been associated with compromised barrier function of the ruminal epithelium and translocation of microbe-associated molecular patterns (MAMP) such as lipopolysaccharide (LPS). Interaction of MAMP with the ruminal epithelium may also induce a local proinflammatory response. The aim of this study was to evaluate the potential proinflammatory response of the ruminal epithelium following LPS exposure in Ussing chambers, to investigate whether LPS exposure affects the flux and metabolism of butyrate. Ruminal epithelial tissue from 9 Holstein bull calves were mounted into Ussing chambers and exposed to 0, 10,000, 50,000, or 200,000 endotoxin units (EU)/mL LPS for a duration of 5 h. Radiolabeled 14C-butyrate (15 mM) was added to the mucosal buffer to assess the mucosal-to-serosal flux of 14C-butyrate. Additional Ussing chambers, without radioisotope, were exposed to either 0 or 200,000 EU/mL LPS and were used to measure the release of β-hydroxybutyrate (BHB) and IL1B into the buffer, and to collect epithelial tissue for analysis of gene expression. Genes associated with inflammation (TNF, IL1B, CXCL8, PTGS2, TGFB1, TLR2, TLR4), nutrient transport (MCT1, MCT4, SLC5A8, GLUT1), and metabolic function (ACAT1, BDH1, MCU, IGFBP3, IGFBP5) were selected and analyzed using quantitative real-time PCR. Butyrate flux was not significantly affected by LPS exposure; however, we detected a tendency for the mucosal-to-serosal butyrate flux to increase linearly with LPS dose. Bidirectional releases of BHB and IL1B were not affected by LPS exposure. Expression of PTGS2, TGFB1, TLR4, and MCU were downregulated following exposure to LPS ex vivo. We detected no effects on the expression of genes associated with nutrient transport. The results of the present study are interpreted to indicate that, although the inflammatory response of the ruminal epithelium was slightly suppressed, exposure to LPS may have altered metabolic function.

Dysbiosis of the gut microbiota maybe exacerbate orf pathology by promoting inflammatory immune responses

Orf is a contagious disease caused by the epitheliotropic orf virus (ORFV) that mainly affects goats and sheep. Orf occurs worldwide and can cause great losses to livestock production. Mounting evidence has shown that gut microbiota plays a pivotal role in shaping the immune responses of the host and thus affecting the infection process of a wide range of pathogens. However, it is unclear whether gut microbiota plays a role during orf development. In this study, we exploited asymptomatic ORFV-carrier goats to explore the potential effects of gut microbiota on orf pathogenesis. The results showed that antibiotics-induced gut microbiota disruption significantly aggravated orf, as indicated by the greater disease severity and higher percentage of animals manifesting clinical orf symptoms. Further analysis suggested IL-17-induced excessive neutrophil accumulation in the diseased lips was potentially responsible for the tissue pathology. In addition, skin γδT cells may be an important source of IL-17. In conclusion, our study showed that the gut microbiota of ORFV-carrier goats plays a central role in controlling inflammatory pathology during ORFV infection, partly through suppressing IL-17-mediated local proinflammatory immune responses. This finding can provide help for elucidating the pathogenesis of orf and also suggests an efficient strategy to minimize the inflammatory pathology by maintaining a healthy gut microbiota during orf development.

Extracellular Vesicles from Pseudomonas aeruginosa Suppress MHC-Related Molecules in Human Lung Macrophages.

Pseudomonas aeruginosa, a Gram-negative bacterium, is one of the most common pathogens colonizing the lungs of cystic fibrosis patients. P. aeruginosa secrete extracellular vesicles (EVs) that contain LPS and other virulence factors that modulate the host's innate immune response, leading to an increased local proinflammatory response and reduced pathogen clearance, resulting in chronic infection and ultimately poor patient outcomes. Lung macrophages are the first line of defense in the airway innate immune response to pathogens. Proper host response to bacterial infection requires communication between APC and T cells, ultimately leading to pathogen clearance. In this study, we investigate whether EVs secreted from P. aeruginosa alter MHC Ag expression in lung macrophages, thereby potentially contributing to decreased pathogen clearance. Primary lung macrophages from human subjects were collected via bronchoalveolar lavage and exposed to EVs isolated from P. aeruginosa in vitro. Gene expression was measured with the NanoString nCounter gene expression assay. DNA methylation was measured with the EPIC array platform to assess changes in methylation. P. aeruginosa EVs suppress the expression of 11 different MHC-associated molecules in lung macrophages. Additionally, we show reduced DNA methylation in a regulatory region of gene complement factor B (CFB) as the possible driving mechanism of widespread MHC gene suppression. Our results demonstrate MHC molecule downregulation by P. aeruginosa-derived EVs in lung macrophages, which is consistent with an immune evasion strategy employed by a prokaryote in a host-pathogen interaction, potentially leading to decreased pulmonary bacterial clearance.

Pairing Bacteroides vulgatus LPS Structure with Its Immunomodulatory Effects on Human Cellular Models.

The gut microbiota guide the development of the host immune system by setting a systemic threshold for immune activation. Lipopolysaccharides (LPSs) from gut bacteria are able to trigger systemic and local proinflammatory and immunomodulatory responses, and this capability strongly relies on their fine structures. Up to now, only a few LPS structures from gut commensals have been elucidated; therefore, the molecular motifs that may be important for LPS–mammalian cell interactions at the gut level are still obscure. Here, we report on the full structure of the LPS isolated from one of the prominent species of the genus Bacteroides, Bacteroides vulgatus. The LPS turned out to consist of a particular chemical structure based on hypoacylated and mono-phosphorylated lipid A and with a galactofuranose-containing core oligosaccharide and an O-antigen built up of mannose and rhamnose. The evaluation of the immunological properties of this LPS on human in vitro models revealed a very interesting capability to produce anti-inflammatory cytokines and to induce a synergistic action of MD-2/TLR4- and TLR2-mediated signaling pathways.

Successful Regulatory T Cell-Based Therapy Relies on Inhibition of T Cell Effector Function and Enrichment of FOXP3+ Cells in a Humanized Mouse Model of Skin Inflammation.

Background Recent clinical trials using regulatory T cells (Treg) support the therapeutic potential of Treg-based therapy in transplantation and autoinflammatory diseases. Despite these clinical successes, the effect of Treg on inflamed tissues, as well as their impact on immune effector function in vivo, is poorly understood. Therefore, we here evaluated the effect of human Treg injection on cutaneous inflammatory processes in vivo using a humanized mouse model of human skin inflammation (huPBL-SCID-huSkin). Methods SCID beige mice were transplanted with human skin followed by intraperitoneal (IP) injection of 20‐40 × 106 allogeneic human PBMCs. This typically results in human skin inflammation as indicated by epidermal thickening (hyperkeratosis) and changes in dermal inflammatory markers such as the antimicrobial peptide hBD2 and epidermal barrier cytokeratins K10 and K16, as well as T cell infiltration in the dermis. Ex vivo-expanded human Treg were infused intraperitoneally. Human cutaneous inflammation and systemic immune responses were analysed by immunohistochemistry and flow cytometry. Results We confirmed that human Treg injection inhibits skin inflammation and the influx of effector T cells. As a novel finding, we demonstrate that human Treg injection led to a reduction of IL-17-secreting cells while promoting a relative increase in immunosuppressive FOXP3+ Treg in the human skin, indicating active immune regulation in controlling the local proinflammatory response. Consistent with the local control (skin), systemically (splenocytes), we observed that Treg injection led to lower frequencies of IFNγ and IL-17A-expressing human T cells, while a trend towards enrichment of FOXP3+ Treg was observed. Conclusion Taken together, we demonstrate that inhibition of skin inflammation by Treg infusion, next to a reduction of infiltrating effector T cells, is mediated by restoring both the local and systemic balance between cytokine-producing effector T cells and immunoregulatory T cells. This work furthers our understanding of Treg-based immunotherapy.

Type I Interferons Ameliorate Zinc Intoxication of Candida glabrata by Macrophages and Promote Fungal Immune Evasion.

SummaryHost and fungal pathogens compete for metal ion acquisition during infectious processes, but molecular mechanisms remain largely unknown. Here, we show that type I interferons (IFNs-I) dysregulate zinc homeostasis in macrophages, which employ metallothionein-mediated zinc intoxication of pathogens as fungicidal response. However, Candida glabrata can escape immune surveillance by sequestering zinc into vacuoles. Interestingly, zinc-loading is inhibited by IFNs-I, because a Janus kinase 1 (JAK1)-dependent suppression of zinc homeostasis affects zinc distribution in macrophages as well as generation of reactive oxygen species (ROS). In addition, systemic fungal infections elicit IFN-I responses that suppress splenic zinc homeostasis, thereby altering macrophage zinc pools that otherwise exert fungicidal actions. Thus, IFN-I signaling inadvertently increases fungal fitness both in vitro and in vivo during fungal infections. Our data reveal an as yet unrecognized role for zinc intoxication in antifungal immunity and suggest that interfering with host zinc homeostasis may offer therapeutic options to treat invasive fungal infections.

Target the Host, Kill the Bug; Targeting Host Respiratory Immunosuppressive Responses as a Novel Strategy to Improve Bacterial Clearance During Lung Infection.

The lung is under constant pressure to protect the body from invading bacteria. An effective inflammatory immune response must be tightly orchestrated to ensure complete clearance of any invading bacteria, while simultaneously ensuring that inflammation is kept under strict control to preserve lung viability. Chronic bacterial lung infections are seen as a major threat to human life with the treatment of these infections becoming more arduous as the prevalence of antibiotic resistance becomes increasingly commonplace. In order to survive within the lung bacteria target the host immune system to prevent eradication. Many bacteria directly target inflammatory cells and cytokines to impair inflammatory responses. However, bacteria also have the capacity to take advantage of and strongly promote anti-inflammatory immune responses in the host lung to inhibit local pro-inflammatory responses that are critical to bacterial elimination. Host cells such as T regulatory cells and myeloid-derived suppressor cells are often enhanced in number and activity during chronic pulmonary infection. By increasing suppressive cell populations and cytokines, bacteria promote a permissive environment suitable for their prolonged survival. This review will explore the anti-inflammatory aspects of the lung immune system that are targeted by bacteria and how bacterial-induced immunosuppression could be inhibited through the use of host-directed therapies to improve treatment options for chronic lung infections.

Anisakis pegreffii

Anisakis pegreffii belongs to the Anisakis simplex species complex that causes anisakiasis, an important fish-borne zoonosis worldwide. The parasite typically reproduces in the gastric chambers of toothed whales (final hosts). Larvae hatch from the eggs that are expelled in seawater; the larvae are ingested by crustaceans and small fish (intermediate hosts). Many fish and cephalopod species (paratenic hosts) that prey upon them transport infective third-stage larvae (L3) to the final host. Humans are accidentally infected by L3 through consumption of uncooked seafood. Anisakiasis is characterised by four main types: gastric, intestinal, ectopic, and gastroallergic that elicit mostly mild, only occasionally severe symptoms. Recently, a fifth type has been proposed based on many asymptomatic Anisakis-IgE seropositive subjects, predominately in countries with high per capita fish consumption. In humans, L3 fails to develop into the adult stage, dies, and decomposes in infected tissues, evoking a local proinflammatory response characterized by eosinophilic granulomatosis.

Advanced Glycation End Products As Biomarkers in Systemic Diseases: Premises and Perspectives of Salivary Advanced Glycation End Products

Advanced glycation end products (AGEs) are glycated proteins associated with high dry temperature food processing, coloring and flavor modification of food products. Previous studies on diet-related disease support the role of the glycation products as biomarkers in local and general proinflammatory response. Exogenous and endogenous AGEs are involved in chronic low-level inflammation, which underlies the onset of metabolic syndrome influenced by food intake, there by demonstrating their implication in diet-related pathologies. Although studies have revealed a strong association between the accumulation of AGEs and the occurrence/worsening of metabolic diseases, their routine use for the diagnosis or monitoring of local and general disease has not yet been reported.

Pharmacokinetic and pharmacodynamic evaluation of ingenol mebutate for the treatment of actinic keratosis

ABSTRACTIntroduction: Actinic keratosis (AK) is a common skin condition that results from exposure to chronic ultraviolet (UV) radiation. AK is characterized by visible, scaly lesions; sub-clinical lesions may also be present within a field of UV-exposed skin. These lesions exist on a disease continuum with squamous cell carcinoma. Field therapies, such as ingenol mebutate, aim to treat the visible and sub-clinical lesions within an area of sun-damaged skin.Areas covered: According to the SmPC, ingenol mebutate has a proposed dual mechanism of action that induces cell death necrosis with the production of a local pro-inflammatory response and stimulation of apoptosis. In clinical trials, efficacy of ingenol mebutate has been shown through clearance of AK lesions. Adverse events and local skin responses generally resolved within 2–4 weeks from the end of treatment, depending on body location.Expert opinion: AK can be treated using lesion-directed or topical therapies. Topical treatment with ingenol mebutate has been shown to have superior efficacy compared with diclofenac/sodium hyaluronate. The short and simple treatment regimen may improve patient adherence to ingenol mebutate and satisfaction with treatment. It might be worth evaluating further indications for ingenol mebutate including treatment of basal cell carcinoma.

Ethyl pyruvate ameliorates hepatic injury following blunt chest trauma and hemorrhagic shock by reducing local inflammation, NF-kappaB activation and HMGB1 release.

BackgroundThe treatment of patients with multiple trauma including blunt chest/thoracic trauma (TxT) and hemorrhagic shock (H) is still challenging. Numerous studies show detrimental consequences of TxT and HS resulting in strong inflammatory changes, organ injury and mortality. Additionally, the reperfusion (R) phase plays a key role in triggering inflammation and worsening outcome. Ethyl pyruvate (EP), a stable lipophilic ester, has anti-inflammatory properties. Here, the influence of EP on the inflammatory reaction and liver injury in a double hit model of TxT and H/R in rats was explored.MethodsFemale Lewis rats were subjected to TxT followed by hemorrhage/H (60 min, 35±3 mm Hg) and resuscitation/R (TxT+H/R). Reperfusion was performed by either Ringer`s lactated solution (RL) alone or RL supplemented with EP (50 mg/kg). Sham animals underwent all surgical procedures without TxT+H/R. After 2h, blood and liver tissue were collected for analyses, and survival was assessed after 24h.ResultsResuscitation with EP significantly improved haemoglobin levels and base excess recovery compared with controls after TxT+H/R, respectively (p<0.05). TxT+H/R-induced significant increase in alanine aminotransferase levels and liver injury were attenuated by EP compared with controls (p<0.05). Local inflammation as shown by increased gene expression of IL-6 and ICAM-1, enhanced ICAM-1 and HMGB1 protein expression and infiltration of the liver with neutrophils were also significantly attenuated by EP compared with controls after TxT+H/R (p<0.05). EP significantly reduced TxT+H/R-induced p65 activation in liver tissue. Survival rates improved by EP from 50% to 70% after TxT+H/R.ConclusionsThese data support the concept that the pronounced local pro-inflammatory response in the liver after blunt chest trauma and hemorrhagic shock is associated with NF-κB. In particular, the beneficial anti-inflammatory effects of ethyl pyruvate seem to be regulated by the HMGB1/NF-κB axis in the liver, thereby, restraining inflammatory responses and liver injury after double hit trauma in the rat.

Induction of Pro-Inflammatory Response via Activated Macrophage-Mediated NF-κB and STAT3 Pathways in Gastric Cancer Cells

Background/Aims: Chronic inflammation plays an important role in the initiation and progression of gastric cancer (GC). However, the role and relationship of activated macrophages with gastric mucous epithelium cells in initiating and maintaining the inflammatory process during gastric carcinogenesis remains unclear. Methods: The tumour associated macrophages (TAMs) density of gastric cancer was characterized by immunohistochemistry, and the relationship between macrophages and gastric epithelium cells was analysed using an in vitro culture system that imitates the inflammatory microenvironment. The production of pro-inflammatory cytokines was detected by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR (qRT-PCR). MTT assays, Western blotting, qRT-PCR, and luciferase reporter assays were used to detect the effects of cell proliferation, as well as the NF-κB and STAT3 signalling pathways. Results: TAMs infiltrated with a high intensity in GC and were significantly correlated with histology grade (P = 0.012), metastasis (P = 0.001), TNM stage (P = 0.002), and poor prognosis in patients (PFS, P = 0.005; OS, P = 0.028). In addition, IL-6 and IL-8 were elevated in the serum of GC patients and significantly promoted the growth of GC. The exposure of BGC823 gastric cancer cells to a conditioned medium from LPS-treated D-THP-1 cells significantly induced the production of TNF-α, IL-6, IL-1β and IL-8 (P< 0.01). LPS and LPS-treated D-THP-1-conditioned media promoted gastric cancer cell proliferation and triggered the significant activation of NF-κB and STAT3 with a concomitant degradation of IκBα and an increase in JAK2 phosphorylation (P < 0.05). Moreover, gastric cancer cells markedly expressed cell membrane LPS receptors, such as TLR1, TLR4, TLR6, CD14 and MD2. Conclusions: TAMs are closely associated with the growth of GC and prognosis in GC patients. GC cells may directly sustain and amplify the local pro-inflammatory response upon encountering activated macrophages and LPS via NF-κB and STAT3 signalling pathways, thereby promoting tumour progression.

Interferon Regulatory Factor 1 Protects against Chikungunya Virus-Induced Immunopathology by Restricting Infection in Muscle Cells.

The innate immune system protects cells against viral pathogens in part through the autocrine and paracrine actions of alpha/beta interferon (IFN-α/β) (type I), IFN-γ (type II), and IFN-λ (type III). The transcription factor interferon regulatory factor 1 (IRF-1) has a demonstrated role in shaping innate and adaptive antiviral immunity by inducing the expression of IFN-stimulated genes (ISGs) and mediating signals downstream of IFN-γ. Although ectopic expression experiments have suggested an inhibitory function of IRF-1 against infection of alphaviruses in cell culture, its role in vivo remains unknown. Here, we infected Irf1 -/- mice with two distantly related arthritogenic alphaviruses, chikungunya virus (CHIKV) and Ross River virus (RRV), and assessed the early antiviral functions of IRF-1 prior to induction of adaptive B and T cell responses. IRF-1 expression limited CHIKV-induced foot swelling in joint-associated tissues and prevented dissemination of CHIKV and RRV at early time points. Virological and histological analyses revealed greater infection of muscle tissues in Irf1 -/- mice than in wild-type mice. The antiviral actions of IRF-1 appeared to be independent of the induction of type I IFN or the effects of type II and III IFNs but were associated with altered local proinflammatory cytokine and chemokine responses and differential infiltration of myeloid cell subsets. Collectively, our in vivo experiments suggest that IRF-1 restricts CHIKV and RRV infection in stromal cells, especially muscle cells, and that this controls local inflammation and joint-associated swelling.IMPORTANCE Interferon regulatory factor 1 (IRF-1) is a transcription factor that regulates the expression of a broad range of antiviral host defense genes. In this study, using Irf1 -/- mice, we investigated the role of IRF-1 in modulating pathogenesis of two related arthritogenic alphaviruses, chikungunya virus and Ross River virus. Our studies show that IRF-1 controlled alphavirus replication and swelling in joint-associated tissues within days of infection. Detailed histopathological and virological analyses revealed that IRF-1 preferentially restricted CHIKV infection in cells of nonhematopoietic lineage, including muscle cells. The antiviral actions of IRF-1 resulted in decreased local inflammatory responses in joint-associated tissues, which prevented immunopathology.

PF4-HIT antibody (KKO) complexes activate broad innate immune and inflammatory responses

IntroductionHeparin-induced thrombocytopenia (HIT) is an immune-mediated complication of heparin anticoagulation therapy resulting in thrombocytopenia frequently accompanied by thrombosis. Current evidence suggests that HIT is associated with antibodies developed in response to multi-molecular complexes formed by platelet factor 4 (PF4) bound to heparin or cell surface glycosaminoglycans. These antibody complexes activate platelets and monocytes typically through FcγRIIA receptors increasing the production of PF4, inflammatory mediators, tissue factor and thrombin. The influence of underlying events in HIT including complex-induced pro-inflammatory cell activation and structural determinants leading to local inflammatory responses are not fully understood. MethodsThe stoichiometry and complex component requirements were determined by incubating fresh peripheral blood mononuclear cells (PBMC) with different concentrations of unfractionated heparin (H), low molecular weight heparin (LMWH), PF4- and anti-PF4-H complex antibodies (KKO). Cytokine mRNA or protein were measured by qRT-PCR or Meso Scale Discovery technology, respectively. Gene expression profile analysis for 594 genes was performed using Nanostring technology and analyzed using Ingenuity Pathway Analysis software. Results and conclusionsThe data show that antibodies magnify immune responses induced in PBMCs by PF4 alone or in complex with heparin or LMWH. We propose that following induction of HIT antibodies by heparin-PF4 complexes, binding of the antibodies to PF4 is sufficient to induce a local pro-inflammatory response which may play a role in the progression of HIT. In vitro assays using PBMCs may be useful in characterizing local inflammatory and innate immune responses induced by HIT antibodies in the presence of PF4 and different sources of heparins. FDA disclaimerThe findings and conclusions in this article are solely the responsibility of the authors and are not being formally disseminated by the Food and Drug Administration. Thus, they should not be construed to represent any Agency determination or policy.