Induced Macrophage Activation Research Articles

M2 macrophages contribute to osteogenesis and angiogenesis on nanotubular TiO2 surfaces.

The monocyte/macrophage system plays an essential role in the host response and the fate of endosseous implanted materials. Macrophage behavior was thought to be regulated by nanostructured titanium which has been considered as a very promising candidate for dental implants. However, there is little known for subsequent effects of these activated macrophages on osteogenesis and angiogenesis which were essential for bone integration. Here we presented two different dimensions of titanium nanotubes generated by anodic oxidation at 10 V (NT 10) and 20 V (NT 20), respectively. The behavior of macrophages on the surfaces was evaluated, and their conditioned medium (CM) was collected to stimulate MC3T3 and HUVECs, with commercially pure titanium (cp Ti) as control. We found that NT 20 induced macrophage activation similar to the anti-inflammatory M2 macrophage state with the enhanced expression of IL-10 and ARG, while NT 10 was associated with M1 macrophage phenotype characterized by high levels of IL-1β, iNOS and TNF-α. Furthermore, the osteogenic capacity of MC3T3 in CM from NT 20 was enhanced (NT 20 > NT 10 ≈ cp Ti) and the tube formation capacity of HUVECs was promoted in CM from nanotubular surfaces with increasing tube dimensions (NT 20 > NT 10 > cp Ti). Our data suggest that dental implants with the large nanotube dimension surface could result in a favorable osteoimmunomodulatory microenvironment for the establishment of osseointegration.

P-Cresyl sulfate affects the oxidative burst, phagocytosis process, and antigen presentation of monocyte-derived macrophages

Immune system dysfunction is a common condition in chronic kidney disease (CKD). The present study investigated the effect of p-Cresyl sulfate (pCS) on human cell line U937 monocyte-derived macrophages (MDM) activity. MDM (1×106 cells/mL) were incubated with pCS (10, 25, or 50μg/mL), with or without lipopolysaccharide (LPS; 25ng/mL) and then evaluated NO production, phagocytosis and antigen-presenting molecules expression (HLA-ABC, HLA-DR, CD80 and CD86). All analyses were performed by flow cytometry. All pCS concentrations were able to increase NO production (49±12.1%, 39.8±7.75%, 43.7±11.9%, respectively) compared to untreated cells (4.35±3.34%) after 6h incubation but only the lowest concentration increased this production after 12h (82.9±8.6%, 61±7.2%, 40.8±11.7%). Combined with LPS, the same results were observed. Regarding to phagocytosis, all concentrations were able to induce bead engulfment (35.4±2.71%, 30±3.04%, 23.28±4.58%). In addition, pCS (50μg/mL) was able to increase HLA-ABC and CD80 expression, showed a slight effect on HLA-DR expression and, no difference in basal CD86 levels. pCS can induce an increased oxidative burst and phagocytosis by human macrophages while no modulation of HLA-DR or CD86 expression was induced. Together, these results suggest that pCS induces macrophage activation but interfere in antigen processing, leading to a failure in adaptive immune response in CKD.

Cry1Ac toxin induces macrophage activation via ERK1/2, JNK and p38 mitogen-activated protein kinases

The Cry1Ac toxin from Bacillus thuringiensis is used commercially as a bio-insecticide and is expressed in transgenic plants that are used for human and animal consumption. Although it was originally considered innocuous for mammals, the Cry1Ac toxin is not inert and has the ability to induce mucosal and systemic immunogenicity. Herein, we examined whether the Cry1Ac toxin promotes macrophage activation and explored the signalling pathways that may mediate this effect. Treatment of primary and RAW264.7 macrophages with the Cry1Ac toxin resulted in upregulation of the costimulatory molecules CD80, CD86 and ICOS-L and enhanced production of nitric oxide, the chemokine MCP-1 and the proinflammatory cytokines TNF-α and IL-6. Remarkably, the Cry1Ac toxin induced phosphorylation of the mitogen-activated protein kinases (MAPKs) ERK1/2, JNK and p38 and promoted nuclear translocation of nuclear factor-kappa B (NF-κB) p50 and p65. p38 and ERK1/2 MAPKs were involved in this effect, as indicated by the Cry1Ac-induced upregulation of CD80 and IL-6 and TNF-α abrogation by the p38 MAPK inhibitor SB203580. Furthermore, treatment the MEK1/2 kinase inhibitor PD98059 blocked increases in MCP-1 secretion and augmented Cry1Ac-induced ICOS-L upregulation. These data demonstrate the capacity of the Cry1Ac toxin to induce macrophage activation via the MAPK and NF-κB pathways.

Modulation of Macrophage Inflammatory Nuclear Factor κB (NF-κB) Signaling by Intracellular Cryptococcus neoformans

Cryptococcus neoformans (Cn) is a common facultative intracellular pathogen that can cause life-threatening fungal meningitis in immunocompromised individuals. Shortly after infection, Cn is detectable as both extra- and intracellular yeast particles, with Cn being capable of establishing long-lasting latent infections within host macrophages. Although recent studies have shown that shed capsular polysaccharides and intact extracellular Cn can compromise macrophage function through modulation of NF-κB signaling, it is currently unclear whether intracellular Cn also affects NF-κB signaling. Utilizing live cell imaging and computational modeling, we find that extra- and intracellular Cn support distinct modes of NF-κB signaling in cultured murine macrophages. Specifically, in RAW 264.7 murine macrophages treated with extracellular glucuronoxylomannan (GXM), the major Cn capsular polysaccharide, LPS-induced nuclear translocation of p65 is inhibited, whereas in cells with intracellular Cn, LPS-induced nuclear translocation of p65 is both amplified and sustained. Mathematical simulations and quantification of nascent protein expression indicate that this is a possible consequence of Cn-induced "translational interference," impeding IκBα resynthesis. We also show that long term Cn infection induces stable nuclear localization of p65 and IκBα proteins in the absence of additional pro-inflammatory stimuli. In this case, nuclear localization of p65 is not accompanied by TNFα or inducible NOS (iNOS) expression. These results demonstrate that capsular polysaccharides and intact intracellular yeast manipulate NF-κB via multiple distinct mechanisms and provide new insights into how Cn might modulate cellular signaling at different stages of an infection.

Immune Enhancing Activity of β-(1,3)-Glucan Isolated from Genus Agrobacterium in Bone-Marrow Derived Macrophages and Mice Splenocytes.

An effective method for activating macrophages and deriving a Th1 immune response could be used to improve the defenses of hosts. In this study, we investigated the immunomodulation effect and the related signaling mechanism of [Formula: see text]-(1,3)-glucan, isolated from the Agrobacterium species. Here, we found that [Formula: see text]-(1,3)-glucan predominantly induced the tumor necrosis factor (TNF)-[Formula: see text], interleukin (IL)-1[Formula: see text], IL-6, IL-12p70, and nitric oxide, which was dependent on mitogen-activated protein kinases (MAPK) and nuclear factor (NF)-[Formula: see text]B signaling. Additionally, [Formula: see text]-(1,3)-glucan treatment significantly up-regulated the expression of the co-stimulatory molecules CD80 and CD86, and also significantly increased the expression of iNOS and Dectin-1, which is a transmembrane protein that binds [Formula: see text]-glucan and associates with macrophage activation. Importantly, the splenic T cells co-cultured with [Formula: see text]-(1,3)-glucan-treated macrophages produced the a Th1 cytokine profile that includes high levels of IFN-[Formula: see text], but not IL-4 (Th2 cytokine), indicating that [Formula: see text]-(1,3)-glucan contributes to Th1 polarization of the immune response. Taken together, our results suggest that [Formula: see text]-(1,3)-glucan isolated from Agrobacterium species can induce macrophage activation through the MAPK and NF-[Formula: see text]B signaling pathway, as well as Th1 polarization.

Toxoplasma gondii Chitinase Induces Macrophage Activation.

Toxoplasma gondii is an obligate intracellular protozoan parasite found worldwide that is able to chronically infect almost all vertebrate species, especially birds and mammalians. Chitinases are essential to various biological processes, and some pathogens rely on chitinases for successful parasitization. Here, we purified and characterized a chitinase from T. gondii. The enzyme, provisionally named Tg_chitinase, has a molecular mass of 13.7 kDa and exhibits a Km of 0.34 mM and a Vmax of 2.64. The optimal environmental conditions for enzymatic function were at pH 4.0 and 50°C. Tg_chitinase was immunolocalized in the cytoplasm of highly virulent T. gondii RH strain tachyzoites, mainly at the apical extremity. Tg_chitinase induced macrophage activation as manifested by the production of high levels of pro-inflammatory cytokines, a pathogenic hallmark of T. gondii infection. In conclusion, to our knowledge, we describe for the first time a chitinase of T. gondii tachyzoites and provide evidence that this enzyme might influence the pathogenesis of T. gondii infection.

Titanium surface characteristics, including topography and wettability, alter macrophage activation

Biomaterial surface properties including chemistry, topography, and wettability regulate cell response. Previous studies have shown that increasing surface roughness of metallic orthopaedic and dental implants improved bone formation around the implant. Little is known about how implant surface properties can affect immune cells that generate a wound healing microenvironment. The aim of our study was to examine the effect of surface modifications on macrophage activation and cytokine production. Macrophages were cultured on seven surfaces: tissue culture polystyrene (TCPS) control; hydrophobic and hydrophilic smooth Ti (PT and oxygen-plasma-treated (plasma) PT); hydrophobic and hydrophilic microrough Ti (SLA and plasma SLA), and hydrophobic and hydrophilic nano-and micro-rough Ti (aged modSLA and modSLA). Smooth Ti induced inflammatory macrophage (M1-like) activation, as indicated by increased levels of interleukins IL-1β, IL-6, and TNFα. In contrast, hydrophilic rough titanium induced macrophage activation similar to the anti-inflammatory M2-like state, increasing levels of interleukins IL-4 and IL-10. These results demonstrate that macrophages cultured on high surface wettability materials produce an anti-inflammatory microenvironment, and this property may be used to improve the healing response to biomaterials. Statement of significanceMetals like titanium (Ti) are common in orthopaedics and dentistry due to their ability to integrate with surrounding tissue and good biocompatibility. Roughness- and wettability-increasing surface modifications promote osteogenic differentiation of stem cells on Ti. While these modifications increase production of osteoblastic factors and bone formation, little is known about their effect on immune cells. The initial host response to a biomaterial is controlled primarily by macrophages and the factors they secrete in response to the injury caused by surgery and the material cues. Here we demonstrate the effect of surface roughness and wettability on the activation and production of inflammatory factors by macrophages. Control of inflammation will inform the design of surface modification procedures to direct the immune response and enhance the success of implanted materials.

Abstract 13240: Soluble Flt-1 Deficiency is One of the Mechanisms of Cardiac Hypertrophy and Heart Failure in CKD Through Up-regulation of MCP-1

Background: Uremic cardiomyopathy is responsible for high morbidity and mortality in patients with chronic kidney disease (CKD), which is characterized by cardiac hypertrophy and heart failure. But precise mechanisms are still unknown. In our previous data, soluble Flt-1 (sFlt-1), which is an endogenous inhibitor of PLGF (placental growth factor), is a key molecule of cardiovascular disease in CKD. Soluble Flt-1 production was decreased with the progression of renal diseases, and sFlt-1 deficiency resulted in progression of cardiac hypertrophy and heart failure, which was revealed by using sFlt-1 KO mice (sFlt-1 -/- ). In this study, we examined the novel mechanisms of heart failure and cardiac hypertrophy using sFlt-1 -/- mice which mimic the CKD condition. Methods and Results: We performed transverse aortic constriction (TAC) in sFlt-1 -/- and WT, and evaluated after 7 days. LV wall thickening was significantly increased and ejection fraction was decreased in sFlt-1 -/- compared to WT by echocardiography. Histological analysis showed that myocardial fibrosis and macrophage infiltration were significantly increased in sFlt-1 KO compared to WT. Anti-PLGF neutralizing antibody (αPLGF: ThromboGenics, Heverlee, Belgium) prevented pressure-overloaded cardiac hypertrophy and cardiac dysfunction after TAC in sFlt-1 -/- . In addition, MCP-1 expression was increased in the hearts of sFlt-1 -/- compared to WT after TAC. Echocardiographic analysis showed that inhibition of MCP-1 with neutralizing antibody prevented cardiac hypertrophy and systolic dysfunction in sFlt-1 -/- , which implied that MCP-1 was one of the key chemokines for the progression of heart failure in sFlt-1 deficiency. Human cardiac biopsy samples revealed that macrophage mobilization, fibrosis, and MCP-1 expression were increased in uremic cardiomyopathy, which was quite similar to sFlt-1 -/- . Conclusions: The present study demonstrated that PLGF activation in CKD by decrement of sFlt-1 induced macrophage activation and MCP-1 up-regulation which led to cardiac hypertrophy and heart failure. PLGF and MCP-1 are novel mechanisms and therapeutic target of cardiac hypertrophy and heart failure in CKD.

Opposing Effects of NGF and proNGF on HIV Induced Macrophage Activation.

Macrophage and microglial activation by HIV in the central nervous system (CNS) triggers the secretion of soluble factors which damage neurons. Therapeutic approaches designed to restore cognitive function by suppressing this inflammatory activity have not yet been successful. Recent studies have indicated that the phenotype of macrophages is differentially controlled by the mature and pro form of nerve growth factor. These cells therefore may be highly responsive to the imbalance in pro versus mature neurotrophins often associated with neurodegenerative diseases. In this study we evaluated the interactions between neurotrophins and HIV induced macrophage activation. HIV stimulation of macrophages induced a neurotoxic phenotype characterized by the expression of podosomes, suppression of calcium spiking and increased neurotoxin production. The secretome of the activated macrophages revealed a bias toward anti-angiogenic like activity and increased secretion of MMP-9. Co-stimulation with NGF and HIV suppressed neurotoxin secretion, increased calcium spiking, suppressed podosome expression and reversed 86% of the proteins secreted in response to HIV, including MMP-9 and many growth factors. In contrast, co-stimulation of macrophages with proNGF not only failed to reverse the effects of HIV but increased the neurotoxic phenotype. These differential effects of proNGF and NGF on HIV activation provide a potential novel therapeutic avenue for controlling macrophage activation in response to HIV.

주박(酒粕)에서 분리된 다당류의 대식세포 면역조절 활성

Activating macrophage cells play an important role in the host immune defense system. In this paper, immuno-modulatory activities of polysaccharides separated from Jubak (JPS) in macrophage cells were investigated. Immuno-modulatory activities were estimated based on cell proliferation, nitric oxide (NO) and cytokine production, degree of mitogen-activated protein kinases (MAPKs), and nuclear factor (NF)-κB phosphorylation in RAW264.7 macrophage cells. JPS (62.5 to 250 μg/mL) did not induce a cytotoxic event. Additionally, NO and proinflammatory cytokines (tumor necrosis factor-α and interleukin-6) production significantly increased in a dose-dependent manner. Similarly, phosphorylation of MAPKs and NF-κB increased upon JPS treatment. Therefore, our results suggest that polysaccharides separated from Jubak can induce macrophage activation through MAPK and NF-κB signaling and induction of Th1 polarization.

Canine mammary cancer cells direct macrophages toward an intermediate activation state between M1/M2.

BackgroundCanine mammary carcinoma is the most common cancer in female dogs and is often fatal due to the development of distance metastasis. The microenvironment of a tumour often contains abundant infiltrates of macrophages called tumour-associated macrophages (TAMs). TAMs express an activated phenotype, termed M2, which sustains proliferation of cancer cells, and has been correlated with poor clinical outcomes in human cancer patients. Cancer cells themselves have been implicated in stimulating the conversion of macrophages to a TAM with an M2 phenotype. This process has yet to be fully elucidated. Here we investigate the interplay between cancer cells and macrophages in the context of canine mammary carcinoma.ResultsWe show that cancer cells inhibit lipopolysaccharide (LPS)-induced macrophage activation. Further, we show that macrophage associated proteins, colony-stimulating factor (CSF)-1 and C-C motif ligand (CCL)-2, stimulate macrophages and are responsible for the effects of cancer cells on macrophages. We suggest the existence of a feedback loop between macrophages and cancer cells; while cancer cells influence the phenotype of the TAMs through CSF-1 and CCL2, the macrophages induce canine mammary cancer cells to upregulate their own expression of the receptors for CSF-1 and CCL2 and increase the cancer cellular metabolic activity. However, these cytokines in isolation induce a phenotypic state in macrophages that is between M1 and M2 phenotypes.ConclusionsOverall, our results demonstrate the extent to which canine mammary carcinoma cells influence the macrophage phenotype and the relevance of a feedback loop between these cells, involving CSF-1 and CCL2 as important mediators.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-015-0473-y) contains supplementary material, which is available to authorized users.

Health benefits of lactic acid bacteria isolated from kimchi, with respect to immunomodulatory effects

Kimchi is a traditional Korean fermented vegetable product, which is fermented by various lactic acid bacteria (LAB), including the genera Lactobacillus, Leuconostoc, Pediococcus, and Weissella. While the immunomodulatory effects of LAB isolated from dairy products are relatively well established, little is known about whether kimchi LAB are capable of modulating a variety of host immune responses. Recent studies have shown that several kimchi LAB that show probiotic properties regulate the balance of T-helper cell response by inducing macrophage activation and enhance the differentiation and activation of regulatory T cells, resulting in the alleviation of allergies and atopic dermatitis in animal models. In this review, current knowledge will be discussed about the beneficial effects of kimchi LAB, including the effects of different strains on immunological functions, and the potential use of kimchi LAB strains as immunomodulators in various immunological settings for therapeutic purposes.

CTLA4-Ig treatment improves RBP4-induced adipose tissue inflammation and insulin resistance triggered by MyD88, JNK, ERK and p38 pathways (IRC8P.443)

Abstract Adipose tissue (AT) inflammation and impaired insulin action is a major cause of type 2 diabetes. RBP4 is an adipocyte- and liver-derived protein that has an important role in insulin resistance, metabolic syndrome and AT inflammation. RBP4 elevation causes AT inflammation by activating innate immunity that elicits an adaptive immune response. Our aims are to determine the signaling pathways involved in RBP4-induced macrophage activation and the resulting antigen presentation and Th1 polarization and whether the blockade of antigen presentation improves AT inflammation and insulin resistance. RBP4-overexpressing mice (RBP4-Ox) are insulin resistant and glucose intolerant and have increased AT macrophage and Th1 cell infiltration. In RBP4-Ox, AT macrophages display enhanced JNK, ERK and p38 phosphorylation, and in vitro inhibition of these pathways reduces macrophage activation and macrophage-induced CD4 T cell proliferation and Th1 polarization. Moreover, macrophages obtained from MyD88 knockout mice and activated with RBP4 do not secrete TNF, IL12 and IL-1b and fail to induce CD4 T cell proliferation and Th1 polarization. Treatment of RBP4-Ox mice with CLTA4-Ig reduces AT inflammation and improves insulin resistance. Thus, RBP4 causes insulin resistance, at least partly, through MyD88 pathway and downstream by activating JNK, ERK and p38 pathways. These pathways induce macrophage activation and Th1 polarization, which can be blocked by inhibiting antigen presentation.

232 Mixed Lineage Kinase 3 Mediates the Release of Proinflammatory Extracellular Vesicles in Nonalcoholic Steatohepatitis

Backgrounds and aims: We have recently demonstrated that genetic deletion of mixed lineage kinase 3 (MLK3) reduces inflammation in a murine model of NASH. However, the mechanistic links between MLK3 activation in hepatocytes and macrophage-driven inflammation in NASH are not fully elucidated. Our hypothesis is that MLK3 mediates the release of chemokine rich extracellular vehicles (EVs), which induce macrophage activation & trafficking to the liver in NASH. Methods: Two MLK3 inhibitors CLFB-1134 and URMC099 were kindly provided by Califia Bio, Inc. Primary mouse hepatocytes (PMH) and Huh7 cells were treated with lysophosphatidylcholine (LPC), a toxic metabolite of saturated fatty acid with and without one of the MlK3 inhibitors. Released EVs were isolated by differential ultracentrifugation, quantified by nanoparticle tracking analysis, and employed for macrophage treatment. EVs protein contents were profiled by mass spectrometry (MSP). Results: LPC treatment of PMH & Huh7 cells induced a 3.6-fold and 140-fold increase in release of EVs, respectively, which was prevented by either genetic knock down or pharmacological inhibition of MLK3. Mass spectrometry identified the potent chemokine CXCL10 in the EVs. CXCL10 was markedly enriched in EVs isolated from LPC treated PMH versus untreated cells, as assessed by immuno-gold electron microscopy and immunoblot analysis. Unexpectedly, either genetic deletion or pharmacological inhibition of MLK3 prevented CXCL10 enrichment in EV (corrected for the number of EV secreted). Treatment of mouse bone marrow-derived macrophages with physiologically relevant concentrations of lipotoxic hepatocyte-derived EVs induced macrophage activation and chemotaxis, an effect blocked by incubation with CXCL10 neutralizing antiserum. Finally, activating phospho-MLK3 expression was increased in liver biopsies of patients with fatty liver compared to the normal control. In Conclusion: during hepatocyte lipotoxicity, activated MLK3 induces the release of CXCL10-bearing vesicles from hepatocytes which are proinflammatory for macrophages. We speculate that these EVs mediate hepatic inflammation in vivo by inducing macrophages trafficking to the liver and that inhibition of MLK3-dependent EV release from hepatocytes could be salutary in human NASH.

233 Hepatic Overexpression of SIRT3 in Mice Heterozygous for Mitochondrial Trifunctional Protein Rescues Hepatic Steatosis and Improves Insulin Sensitivity

Backgrounds and aims: We have recently demonstrated that genetic deletion of mixed lineage kinase 3 (MLK3) reduces inflammation in a murine model of NASH. However, the mechanistic links between MLK3 activation in hepatocytes and macrophage-driven inflammation in NASH are not fully elucidated. Our hypothesis is that MLK3 mediates the release of chemokine rich extracellular vehicles (EVs), which induce macrophage activation & trafficking to the liver in NASH. Methods: Two MLK3 inhibitors CLFB-1134 and URMC099 were kindly provided by Califia Bio, Inc. Primary mouse hepatocytes (PMH) and Huh7 cells were treated with lysophosphatidylcholine (LPC), a toxic metabolite of saturated fatty acid with and without one of the MlK3 inhibitors. Released EVs were isolated by differential ultracentrifugation, quantified by nanoparticle tracking analysis, and employed for macrophage treatment. EVs protein contents were profiled by mass spectrometry (MSP). Results: LPC treatment of PMH & Huh7 cells induced a 3.6-fold and 140-fold increase in release of EVs, respectively, which was prevented by either genetic knock down or pharmacological inhibition of MLK3. Mass spectrometry identified the potent chemokine CXCL10 in the EVs. CXCL10 was markedly enriched in EVs isolated from LPC treated PMH versus untreated cells, as assessed by immuno-gold electron microscopy and immunoblot analysis. Unexpectedly, either genetic deletion or pharmacological inhibition of MLK3 prevented CXCL10 enrichment in EV (corrected for the number of EV secreted). Treatment of mouse bone marrow-derived macrophages with physiologically relevant concentrations of lipotoxic hepatocyte-derived EVs induced macrophage activation and chemotaxis, an effect blocked by incubation with CXCL10 neutralizing antiserum. Finally, activating phospho-MLK3 expression was increased in liver biopsies of patients with fatty liver compared to the normal control. In Conclusion: during hepatocyte lipotoxicity, activated MLK3 induces the release of CXCL10-bearing vesicles from hepatocytes which are proinflammatory for macrophages. We speculate that these EVs mediate hepatic inflammation in vivo by inducing macrophages trafficking to the liver and that inhibition of MLK3-dependent EV release from hepatocytes could be salutary in human NASH.

Combination of low dose major n3 PUFAs in fresh water mussel lipid is an alternative of EPA–DHA supplementation in inflammatory conditions of arthritis and LPS stimulated macrophages

This article deals with the nutritional aspect of fresh water mussel Lamellidens marginalis and its pharmacological potential in inflammatory disorders. Fresh water mussel extract shows anti-inflammatory activity after oral supplementation. Therefore, the present work was aimed to elucidate anti-inflammatory activity of Lamellidens lipid in in vivo adjuvant induced arthritis and in vitro LPS induced macrophage activation model, where its activity was compared with pharmaceutical grade EPA–DHA supplement. Parameters that showed better response to mussel lipid, than to EPA–DHA supplement, were paw and ankle diameters, paw weight, urinary hydroxyproline, glucosamine, serum phosphatases, macrophage lipid peroxidation level and pro-inflammatory interleukin level in adjuvant induced arthritis and TNFα, NO level, intracellular ROS generation as well as nuclear translocation of NFκB p65 in LPS activated in vitro primary macrophage culture. Fresh water mussel lipid was found to have lower n3:n6 ratio than that in marine species but contain all the major n3 fatty acids. This study, for the first time, showed anti-inflammatory potential of lipid from a fresh water species. It has also raised the possibility of the presence of balanced fatty acid combination in a dietary dose, rather than the established EPA–DHA supplement, to be more effective against inflammatory conditions of arthritis and LPS stimulated macrophages.

Inhibitory effects of Leishmanial sphingolipid on Endotoxin induced macrophage activation and sepsis associated inflammatory injury

Sepsis is the reflection of systemic immune response that manifests in the sequential inflammatory process in presence of infection with excessive production of inflammatory mediators and causes severe tissue injuries. Total lipid of attenuated Leishmania donovani establish as a bioactive. Moreover, sphingolipids moderate various cellular processes. So, this finding encourages us to evaluate inflammatory response in system using the microbial sphingolipid.In this study, we have used bacterial endotoxin stimulated macrophages to evaluate the efficacy of leishmanial sphingolipid (LSPL) towards the amelioration of inflammatory mediators (TNF‐α, IL‐1β, IL‐6, IL‐17, IL‐10) and transcriptional factors with associated TLR4‐CD14 expression. In vivo system, endotoxin induced murine sepsis model was used in focusing on multiple organ injury (Lungs, Liver, and Kidney) and status of different cytokine‐chemokine(s) storm. Due to the effect of LSPL, endotoxin induced inflammatory cytokine‐chemokine(s) levels were significantly reduced in serum and other major organs with the reduction of vascular permeability factors and suppressed the expression of cell adhesion molecule in septic mice evident by immunochemical approaches.These findings indicate that LSPL may prove to be a potential anti‐inflammatory agent as protection against bacterial sepsis with associated organ injury.

Extracellular, but not intracellular HMGB1, facilitates self-DNA induced macrophage activation via promoting DNA accumulation in endosomes and contributes to the pathogenesis of lupus nephritis

Systemic lupus erythematosus (SLE) is a typical autoimmune disease with unclear etiology. Aberrant self-DNA recognition has been proven critical for the initiation of excessive immune responses in lupus. Consistently, we previously reported that a sort of self-DNA, activated lymphocyte-derived DNA (ALD-DNA) could potentially induce macrophage activation, which contributes to the pathogenesis of murine lupus nephritis. However, the mechanism underlying the self-DNA recognition needs to be further elucidated. Serum level of high mobility group box 1 (HMGB1) has been reported significantly increased both in SLE patients and in lupus mice. Considering its DNA-binding and pro-inflammatory properties, we assumed that HMGB1 might play a role in the processes of ALD-DNA recognition and subsequent activation of macrophages. Here, we found that HMGB1 level was robustly elevated in macrophages following ALD-DNA stimulation via a TLR9 dependent manner. More interestingly, only extracellular but not intracellular HMGB1 could significantly facilitate the ALD-DNA induced macrophage activation, as functional blockade of extracellular HMGB1 efficiently abolished the inflammatory cytokines including IL-6, IL-10, TNF-α, and MCP-1 in ALD-DNA induced macrophages. This effect of extracellular HMGB1 to promote inflammatory cytokine production was associated with its property of accelerating and increasing the accumulation of ALD-DNA in endosomes, which might benefit the DNA recognition by endosome related DNA sensors and promote the subsequent macrophage activation. The pathological role of released HMGB1 was also verified in ALD-DNA induced lupus mice by blocking the serum HMGB1 with glycyrrhizin, which led to the significantly alleviated lupus nephritis as shown decreased inflammatory cytokines, anti-double-stranded DNA (anti-dsDNA) antibodies, urine protein, glomerular IgG and C3 deposition as well as relieved renal histopathology. Taken together, our findings not only better understand in the role of extracellular HMGB1 facilitating ALD-DNA recognition and the subsequent macrophages activation, but also suggest that HMGB1 might serve as an attractive emerging target for SLE treatment.

PPE57 induces activation of macrophages and drives Th1-type immune responses through TLR2

Proline-glutamic acid (PE) and proline-proline-glutamic acid (PPE) are related proteins exclusive to Mycobacteria that play diverse roles in modulating critical innate immune pathways. In this study, we observed that the PPE57 protein is associated with the cell wall and is exposed on the cell surface. PPE57 enhances Mycobacterium spp. entering into macrophages and plays a role in macrophage phagocytosis. To explore the underlying mechanism, we demonstrated that PPE57 is able to recognise Toll-like receptor 2 (TLR2) and further induce macrophage activation by augmenting the expression of several cell surface molecules (CD40, CD80, CD86 and MHC class II) and pro-inflammatory cytokines (TNF-α, IL-6 and IL-12p40) within macrophages. These molecules are involved in the mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) signalling pathways. We demonstrated that PPE57 effectively polarises T cells to secrete interferon (IFN)-γ and IL-2 and to up-regulate CXCR3 expression in vivo and in vitro, suggesting that this protein may contribute to Th1 polarisation during the immune response. Moreover, recombinant Bacillus Calmette-Guérin (BCG) over-expressing PPE57 could provide better protective efficacy against Mycobacterium tuberculosis challenge compared with BCG. Taken together, our data provides several pieces of evidence that PPE57 may regulate innate and adaptive immunity by interacting with TLR2. These findings indicate that PPE57 protein is a potential antigen for the rational design of an efficient vaccine against M. tuberculosis. PPE57 is located on the cell surface and enhances mycobacterium entry into macrophage. PPE57 interacts directly with TLR2 on macrophages. PPE57 plays a key role in the activation of macrophages in a TLR2-dependent manner. PPE57 induces a Th1 immune response via TLR2-mediated macrophage functions. Recombinant BCG over-expressing PPE57 could improve protective efficacy against M. tuberculosis.

EFFECT OF SUPERNATANT OF CERVICAL CANCER CELLS IN THE PHENOTYPIC SWITCH FROM M1 ACTIVATED MACROPHAGE TO M2 SUPRESSOR MACROPHAGE AND ITS IMPACT ON THE PROFILE EXPRESSION OF TOLL LIKE RECEPTORS AND TRANSCRIPTION FACTORS

EFFECT OF SUPERNATANT OF CERVICAL CANCER CELLS IN THE PHENOTYPIC SWITCH FROM M1 ACTIVATED MACROPHAGE TO M2 SUPRESSOR MACROPHAGE AND ITS IMPACT ON THE PROFILE EXPRESSION OF TOLL LIKE RECEPTORS AND TRANSCRIPTION FACTORS