Regulation Of Macrophage Function Research Articles

Targeting macrophage autophagy for inflammation resolution and tissue repair in inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a chronic, non-specific, recurrent inflammatory disease, majorly affecting the gastrointestinal tract. Due to its unclear pathogenesis, the current therapeutic strategy for IBD is focused on symptoms alleviation. Autophagy is a lysosome-mediated catabolic process for maintaining cellular homeostasis. Genome-wide association studies and subsequent functional studies have highlighted the critical role of autophagy in IBD via a number of mechanisms, including modulating macrophage function. Macrophages are the gatekeepers of intestinal immune homeostasis, especially involved in regulating inflammation remission and tissue repair. Interestingly, many autophagic proteins and IBD-related genes have been revealed to regulate macrophage function, suggesting that macrophage autophagy is a potentially important process implicated in IBD regulation. Here, we have summarized current understanding of macrophage autophagy function in pathogen and apoptotic cell clearance, inflammation remission and tissue repair regulation in IBD, and discuss how this knowledge can be used as a strategy for IBD treatment.

Matrix Stiffness Regulation of Macrophage Function

Macrophages are found throughout the body, engulfing microorganisms and cell debris, while coordinating inflammatory responses to maintain tissue homeostasis. As macrophages patrol within different organs and tissues, they are exposed not only to a variety of biochemical cues, but also to mechanical cues, such as tissue stiffness. More and more studies have shown that macrophages can sense changes in microenvironment stiffness, but little is known about the molecular mechanism of how stiffness regulates macrophage function. The 2020 Nobel Prize-winning mechanically-sensitive ion channels the transient receptor potential channel subfamily V member 4 (TRPV4) and Piezo1 are of widespread interest. Research suggests that Piezo1 and TRPV4 on macrophages can sense matrix stiffness in the microenvironment and convert it into biochemical signals to activate specific cellular effector functions. These findings help us better understand how microenvironment stiffness affects macrophage behavior, which may be associated with diseases in which tissue stiffness is altered, and may enhance our understanding of disease mechanisms.

Activin A and CCR2 regulate macrophage function in testicular fibrosis caused by experimental autoimmune orchitis

Experimental autoimmune-orchitis (EAO), a rodent model of chronic testicular inflammation and fibrosis, replicates pathogenic changes seen in some cases of human spermatogenic disturbances. During EAO, increased levels of pro-inflammatory and pro-fibrotic mediators such as TNF, CCL2, and activin A are accompanied by infiltration of leukocytes into the testicular parenchyma. Activin A levels correlate with EAO severity, while elevated CCL2 acting through its receptor CCR2 mediates leukocyte trafficking and recruits macrophages. CCR2 + CXCR4 + macrophages producing extracellular matrix proteins contribute widely to fibrogenesis. Furthermore, testicular macrophages (TMs) play a critical role in organ homeostasis. Therefore, we aimed to investigate the role of the activin A/CCL2-CCR2/macrophage axis in the development of testicular fibrosis. Following EAO induction, we observed lower levels of organ damage, collagen deposition, and leukocyte infiltration (including fibronectin+, collagen I+ and CXCR4+ TMs) in Ccr2−/− mice than in WT mice. Furthermore, levels of Il-10, Ccl2, and the activin A subunit Inhba mRNAs were lower in Ccr2−/− EAO testes. Notably, fibronectin+ TMs were also present in biopsies from patients with impaired spermatogenesis and fibrotic alterations. Overexpression of the activin A antagonist follistatin reduced tissue damage and collagen I+ TM accumulation in WT EAO testes, while treating macrophages with activin A in vitro increased the expression of Ccr2, Fn1, Cxcr4, and Mmp2 and enhanced migration along a CCL2 gradient; these effects were abolished by follistatin. Taken together, our data indicate that CCR2 and activin A promote fibrosis during testicular inflammation by regulating macrophage function. Inhibition of CCR2 or activin A protects against damage progression, offering a promising avenue for therapeutic intervention.

Tumor cell-derived asymmetric dimethylarginine regulates macrophage functions and polarization

BackgroundAsymmetric dimethylarginine (ADMA), which is significantly elevated in the plasma of cancer patients, is formed via intracellular recycling of methylated proteins and serves as a precursor for resynthesis of arginine. However, the cause of ADMA elevation in cancers and its impact on the regulation of tumor immunity is not known.MethodsThree mouse breast cell lines (normal breast epithelial HC11, breast cancer EMT6 and triple negative breast cancer 4T1) and their equivalent 3D stem cell culture were used to analyze the secretion of ADMA using ELISA and their responses to ADMA. Bone marrow-derived macrophages and/or RAW264.7 cells were used to determine the impact of increased extracellular ADMA on macrophage-tumor interactions. Gene/protein expression was analyzed through RNAseq, qPCR and flow cytometry. Protein functional analyses were conducted via fluorescent imaging (arginine uptake, tumor phagocytosis) and enzymatic assay (arginase activity). Cell viability was measured via MTS assay and/or direct cell counting using Countess III FL system.ResultsFor macrophages, ADMA impaired proliferation and phagocytosis of tumor cells, and even caused death in cultures incubated without arginine. ADMA also led to an unusual macrophage phenotype, with increased expression of arginase, cd163 and cd206 but decreased expression of il10 and dectin-1. In contrast to the severely negative impacts on macrophages, ADMA had relatively minor effects on proliferation and survival of mouse normal epithelial HC11 cells, mouse breast cancer EMT6 and 4T1 cells, but there was increased expression of the mesenchymal markers, vimentin and snail2, and decreased expression of the epithelial marker, mucin-1 in EMT6 cells. When tumor cells were co-cultured ex vivo with tumor antigen in vivo-primed splenocytes, the tumor cells secreted more ADMA and there were alterations in the tumor cell arginine metabolic landscape, including increased expression of genes involved in arginine uptake, metabolism and methylation, and decreased expression of a gene that is responsible for arginine demethylation. Additionally, interferon-gamma, a cytokine involved in immune challenge, increased secretion of ADMA in tumor cells, a process attenuated by an autophagy inhibitor.ConclusionOur results suggest initial immune attack promotes autophagy in tumor cells, which then secrete ADMA to manipulate macrophage polarization favoring tumor tolerance.

Characterization of exosomes derived from IPEC-J2 treated with probiotic Bacillus amyloliquefaciens SC06 and its regulation of macrophage functions.

Probiotics can maintain or improve health by modulating the response of immune cells in the gastrointestinal tract. However, the mechanisms by which probiotics promote macrophage (Mφ) activity are poorly understood. Here, we evaluated exosomes derived from intestinal epithelial cells treated with Bacillus amyloliquefaciens SC06 (Ba) and investigated the regulation of Mφ phagocytosis, apoptosis, and polarization. We isolated two exosomes from intestinal porcine epithelial cell lines (IPEC-J2) with or without Ba-treatment, named Ba-Exo and Exo, respectively. They had typical sizes and a cup-shaped morphology, and their surfaces presented typical exosomes-associated proteins, including CD63, ALIX, and TSG101. Ba-Exo and Exo could entrer Mφ (3D4/21 cells) effectively. Moreover, an in vitro phagocytosis assay demonstrated that Ba-Exo can promote phagocytosis of Mφ. Similar to Exo, Ba-Exo had no effect on Mφ apoptosis. Furthermore, Ba-Exo significantly increased inducible nitric oxide synthase (iNOS), declined the expression of arginase 1 (Arg1) in Mφ, and stimulated Mφ polarization to M1. To explore the differences in the regulation of Mφ polarization between Ba-Exo and Exo, we performed reverse transcription quantitative polymerase chain reaction analysis of the small RNAs and found that miR-222 increased in the Ba-Exo group compared to that in the Exo group. These results provide a new perspective on the relationship between probiotics and intestinal immunity.

DOT1L regulates lipid biosynthesis and inflammatory responses in macrophages and promotes atherosclerotic plaque stability.

Macrophages are critical immune cells in inflammatory diseases, and their differentiation and function are tightly regulated by histone modifications. H3K79 methylation is a histone modification associated with active gene expression, and DOT1L is the only histone methyltransferase for H3K79. Here we determine the role of DOT1L in macrophages by applying a selective DOT1L inhibitor in mouse and human macrophages and using myeloid-specific Dot1l-deficient mice. We found that DOT1L directly regulates macrophage function by controlling lipid biosynthesis gene programs including central lipid regulators like sterol regulatory element-binding proteins SREBP1 and SREBP2. DOT1L inhibition also leads to macrophage hyperactivation, which is associated with disrupted SREBP pathways. Invivo, myeloid Dot1l deficiency reduces atherosclerotic plaque stability and increases the activation of inflammatory plaque macrophages. Our data show that DOT1L is a crucial regulator of macrophage inflammatory responses and lipid regulatory pathways and suggest a high relevance of H3K79 methylation in inflammatory disease.

Photoactivated adenylyl cyclases attenuate sepsis-induced cardiomyopathy by suppressing macrophage-mediated inflammation.

Sepsis-induced myocardiopathy, characterized by innate immune cells infiltration and proinflammatory cytokines release, may lead to perfusion failure or even life-threatening cardiogenic shock. Macrophages-mediated inflammation has been shown to contribute to sepsis-induced myocardiopathy. In the current study, we introduced two photoactivated adenylyl cyclases (PACs), Beggiatoa sp. PAC (bPAC) and Beggiatoa sp. IS2 PAC (biPAC) into macrophages by transfection to detect the effects of light-induced regulation of macrophage pro-inflammatory response and LPS-induced sepsis-induced myocardiopathy. By this method, we uncovered that blue light-induced bPAC or biPAC activation considerably inhibited the production of pro-inflammatory cytokines IL-1 and TNF-α, both at mRNA and protein levels. Further, we assembled a GelMA-Macrophages-LED system, which consists of GelMA-a type of light crosslink hydrogel, gene modulated macrophages and wireless LED device, to allow light to regulate cardiac inflammation in situ with murine models of LPS-induced sepsis. Our results showed significant inhibition of leukocytes infiltration, especially macrophages and neutrophils, suppression of pro-inflammatory cytokines release, and alleviation of sepsis-induced cardiac dysfunction. Thus, our study may represent an emerging means to treat sepsis-induced myocardiopathy and other cardiovascular diseases by photo-activated regulating macrophage function.

Hydrogen Sulfide Regulates Macrophage Function in Cardiovascular Diseases.

Significance: Hydrogen sulfide (H2S) is an endogenous gasotransmitter that plays a vital role in immune system regulation. Recently, the regulation of macrophage function by H2S has been extensively and actively recognized. Recent Advances: The mechanisms by which endogenous H2S controls macrophage function have attracted increasing attention. The generation of endogenous H2S from macrophages is mainly catalyzed by cystathionine-γ-lyase. H2S is involved in the macrophage activation and inflammasome formation, which contributes to macrophage apoptosis, adhesion, chemotaxis, and polarization. In addition, H2S has redox ability and interacts with reactive oxygen species to prevent oxidative stress. Moreover, H2S epigenetically regulates gene expression. Critical Issues: In this article, the generation of endogenous H2S in macrophages and its regulatory effect on macrophage function are reviewed. In addition, the signal transduction targeting macrophages by H2S is also addressed. Finally, the potential therapeutic effect of H2S on macrophages is discussed. Future Directions: Further experiments are required to explore the involvement of endogenous H2S in the regulation of macrophage function in various physiological and pathophysiological processes and elucidate the mechanisms involved. Regarding the clinical translation of H2S, further exploration of the application of H2S in inflammation-related diseases is needed. Antioxid. Redox Signal. 38, 45-56.

Human MIKO-1, a Hybrid Protein That Regulates Macrophage Function, Suppresses Lung Fibrosis in a Mouse Model of Bleomycin-Induced Interstitial Lung Disease.

Although interstitial lung disease (ILD) is a life-threatening pathological condition that causes respiratory failure, the efficiency of current therapies is limited. This study aimed to investigate the effects of human MIKO-1 (hMIKO-1), a hybrid protein that suppresses the abnormal activation of macrophages, on murine macrophage function and its therapeutic effect in a mouse model of bleomycin-induced ILD (BLM-ILD). To this end, the phenotype of thioglycolate-induced murine peritoneal macrophages co-cultured with hMIKO-1 was examined. The mice were assigned to normal, BLM-alone, or BLM + hMIKO-1 groups, and hMIKO-1 (0.1 mg/mouse) was administered intraperitoneally from day 0 to 14. The mice were sacrificed on day 28, and their lungs were evaluated by histological examination, collagen content, and gene expression levels. hMIKO-1 suppressed the polarization of murine macrophages to M2 predominance in vitro. The fibrosis score of lung pathology and lung collagen content of the BLM + hMIKO-1 group were significantly lower than those in the BLM-alone group. The expression levels of TNF-α, IL-6, IL-1β, F4/80, and TIMP-1 in the lungs of the BLM + hMIKO-1 group were significantly lower than those in the BLM-alone group. These findings indicate that hMIKO-1 reduces lung fibrosis and may be a future therapeutic candidate for ILD treatment.

Progress in preclinical studies of macrophage autophagy in the regulation of ALI/ARDS.

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a critical clinical syndrome with high morbidity and mortality that poses a major challenge in critical care medicine. The development of ALI/ARDS involves excessive inflammatory response, and macrophage autophagy plays an important role in regulating the inflammatory response in ALI/ARDS. In this paper, we review the effects of autophagy in regulating macrophage function, discuss the roles of macrophage autophagy in ALI/ARDS, and highlight drugs and other interventions that can modulate macrophage autophagy in ALI/ARDS to improve the understanding of the mechanism of macrophage autophagy in ALI/ARDS and provide new ideas and further research directions for the treatment of ALI/ARDS.

The Essential Role of FoxO1 in the Regulation of Macrophage Function.

Macrophages are widely distributed in various tissues and organs. They not only participate in the regulation of innate and adaptive immune response, but also play an important role in tissue homeostasis. Dysregulation of macrophage function is closely related to the initiation, development and prognosis of multiple diseases, including infection and tumorigenesis. Forkhead box transcription factor O1 (FoxO1) is an important member among the forkhead box transcription factor family. Through directly binding to the promoter regions of downstream target genes, FoxO1 is implicated in cell proliferation, apoptosis, metabolic activities and other biological processes. In this review, we summarized the regulatory role of FoxO1 in macrophage phagocytosis, migration, differentiation and inflammatory activation. We also emphasized that macrophage reciprocally modulated FoxO1 activity via a post-translational modification (PTM) dominant manner.

Ectodysplasin-A mRNA in exosomes released from activated hepatic stellate cells stimulates macrophage response

IntroductionThe interaction between activated hepatic stellate cells (aHSCs) and macrophages is central to liver fibrosis development. The cargo contained within aHSC exosomes (aHSC-EXOs) and how aHSC-EXOs affect macrophage function is poorly understood. MethodsRNA from aHSC-EXOs was separated into small (<200-basepairs) and large (≥200-basepairs) RNA species, transfected into macrophages, and macrophage IL-6 and TNFα mRNA expression and protein secretion measured. Next generation sequencing was performed on EXOs from rat quiescent and aHSCs and human aHSCs. aHSCs were transfected with siRNA against ectodysplasin-A (EDA), EXOs collected, and their effect on macrophage function analyzed. Human cirrhotic liver was analyzed for EDA mRNA expression and compared to non-tumor liver (NTL). ResultsTransfection with large RNA from aHSC-EXOs stimulated macrophage IL-6 and TNFα mRNA expression and protein secretion. EDA mRNA was highly expressed in aHSCs and transfection of aHSCs with EDA-siRNA decreased aHSC-EXO EDA mRNA and blunted the effect of aHSC-EXOs on macrophage function (IL-6/TNFα expression and macrophage migration). Human cirrhotic liver exhibited high EDA mRNA compared to NTL. ConclusionsHSC activation leads to altered EXO mRNA/miRNA profiles with aHSC-EXOs mRNAs exerting a dominant role in altering macrophage function. Ectodysplasin-A mRNA is an important component in aHSC-EXOs in regulating macrophage function.

Abstract 3847: Tumor stem cell derived asymmetric dimethylarginine drives immune evasion via functional modulation of macrophages

Abstract Macrophages are the most abundant tumor infiltrating immune cells and perform diverse immune functions including phagocytosis and incitation of T cells to mount an immune attack against tumors. However, the macrophage plasticity can lead to different outcomes of tumor progression and the amino acid, arginine, plays a central role in macrophage dichotomy. The exact role of arginine on the management of macrophage polarization is not completely understood. We have discovered that a methylated arginine metabolite, asymmetric dimethylarginine (ADMA), serves as an important regulator of macrophage functions. Upon stimulation by ADMA, macrophages have reduced survival and show a delayed tumor-phagocytic capacity. Additionally, ADMA blocks the Nitric Oxide Synthase (NOS) but not the Arginase activity in macrophages leading to a tendency of M2-like phenotype polarization. ADMA has minor effect on tumor cell proliferation but significantly drives the epithelial to mesenchymal transition. Tumor cells, particularly the tumor stem cells, are the major sources of ADMA. Production and secretion of ADMA by tumor (stem) cells profoundly increase when co-cultured with activated T cells or treated with T cell associated inflammatory cytokine, interferon-gamma (IFN-r). IFN-r initiates autophagy of tumor (stem) cells and inhibition of autophagy reduces the output of ADMA by tumor (stem) cells. Similarly, IFN-r enhances the proteasomal degradation and inhibition of the proteasomal pathway also reduces the ADMA production induced by IFN-r. In summary, our work shows that tumor (stem) cells may escape from immune surveillance (such as their exposure to activated T lymphocytes or to cytotoxic cytokine, IFN-r) through the secretion of ADMA generated via both autophagic and proteasomal pathways. Citation Format: Yiling Chen, AKaychia T. Lowery, Andres Becerril, Zaida T. Laventure, Shareda Ferguson, Kuan-Hui Ethan Chen. Tumor stem cell derived asymmetric dimethylarginine drives immune evasion via functional modulation of macrophages [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3847.

SHED-derived exosomes promote LPS-induced wound healing with less itching by stimulating macrophage autophagy

High-quality cutaneous wound healing is associated with rapid wound closure and a comfortable healing process. Currently, exosomes derived from mesenchymal stem cells displayed a prominent therapeutic effect on skin wound closure. But the therapeutic approaches for wound itching are very limited in clinical. Stem cells from human exfoliated deciduous teeth (SHED) may offer a unique exosome resource for cell-free therapeutics in potential clinical applications. Here, we investigated the common mechanisms underlying wound closure and unpleasant sensation of itching, focusing on the contribution of the SHED-derived exosome to immune response and wound itching during healing. The effects of SHED-derived exosomes on inflammatory wound healing were examined using lipopolysaccharide (LPS)-induced wounds in a mouse model. We found prolonged inflammation and distinct itch responses in skin wound tissue during LPS-induced wound healing. SHED-derived exosomes facilitated LPS-induced wound closure and relieved wound itching. Therefore, they are ideal for the treatment of wound healing. Macrophages in skin wound tissues are responsible for autophagy during wound healing. Macrophage autophagy also regulates cell proliferation, migration, and neuronal signal transduction in vitro. SHED-derived exosomes containing miR-1246 enhanced autophagy by regulating macrophage function through the AKT, ERK1/2, and STAT3 signaling pathways. Thus, SHED-derived exosomes promote wound healing with less itching in an LPS-induced wound model by stimulating macrophage autophagy, which has implications for the treatment of inflammatory wound healing.Graphical

Abstract 151: Macrophage Specific Ablation Of Bmal1 Regulate Cholesterol Metabolism And Atherosclerosis

Macrophages play a critical role in atherosclerosis. We have previously shown that Clock mutant and global or liver-specific Bmal1 deficient mice show enhanced atherosclerosis. Yet, the role of macrophage Bmal1 in cholesterol transport and atherosclerosis remains unknown. Here, we used global and macrophage-specific ablation of Bmal1 to clarify the role of Bmal1 in macrophage function in atherosclerosis. We found that macrophage-specific Bmal1 deficient mice show increased atherosclerosis. Biochemical studies showed that Bmal1 deficient macrophages exhibit increased expression of Lox-1 and Cd36 and take up more oxLDL. Furthermore, they show decreased expression of Abca1 and Abcg1 and reduced cholesterol efflux as well as in vivo reverse cholesterol transport. Thus, Bmal1 regulates macrophage cholesterol metabolism by regulating uptake of oxidized lipoproteins and cholesterol efflux pathways. Molecular studies showed that Bmal1 indirectly regulates Cd36 and Abca1/Abcg1 by modulating Nr1d1 and Znf202, respectively. We provide evidence that Bmal1 collaborates with Clock and interacts with Nr1d1 promoter. Furthermore, our studies show that Bmal1 interacts with both Clock and Npas2 to regulate Znf202. Thus, Bmal1 regulates two different transcription factors to regulate uptake of oxidized lipoproteins and cholesterol efflux. In summary, our data show that Bmal1 is a key regulator of cholesterol metabolism in macrophages and atherosclerosis. It regulates macrophage function by modulating the expression of different transcription factors. It is likely that augmentation of Bmal1 may prevent atherosclerosis.

Immunomodulatory effect of Ganoderma lucidum polysaccharide extract on peritoneal macrophage function of BALB/c mice

Ganoderma lucidum has been suggested as a natural immunomodulator. It is not yet clear exactly which combination of this extract is responsible for its immunomodulatory effects. Still, it appears that the 3-complement (CR3) receptor on the surface of immune cells acts as a receptor for beta-glucans (glucan-8), which is the main component of this extract. Since glucose-6-phosphate dehydrogenase (G6PD) plays a vital role in regulating macrophage functions, including nitric oxide production, we considered the effect of this extract on viability, G6PD enzyme activity, and nitric oxide (NO) production in peritoneal BALB/c macrophages. First, peritoneal macrophages of BALB/c mice were isolated and treated with concentrations (0.001, 0.01, 0.1, 1, 10, and 100 g/ml) of Ganoderma lucidum polysaccharide extract (GL-PS). After 24 hours of incubation by MTT test, we evaluated the viability of macrophages, and the effective dose was determined to be 0.1g/ml. To determine the specific activity of glucose-6-phosphates, they were incubated with GI-PS for 24 hours at a 0.1 mg/ml dose. Determination of protein concentration was obtained by the Bradford method in cell supernatant extract. Also, after 18 hours of incubation, the amount of nitric oxide (NO) production was measured using Grace colorimetric method. According to the results, a dose of 0.1μg/ml of Ganoderma lucidum polysaccharide extract had the most significant effect on the viability (stimulation coefficient) of peritoneal macrophages compared to other amounts (p Ganoderma lucidum, a medicinal fungus, is widely used in East Asian countries, especially in China, to increase the quality of life and longevity. After this study, we concluded that GL-PS extract has an immunomodulatory effect on macrophage activity. Therefore, the polysaccharide extract of this fungus can be used as a strengthening agent of the phagocytic system against infectious agents and pathogens such as the Leishmania parasite because of the production of nitric oxide by macrophages plays an essential role in defense against them.

Functional characterization of the biogenic amine transporters on human macrophages.

Monocyte-derived macrophages (MDMs) are key players in tissue homeostasis and diseases regulated by a variety of signaling molecules. Recent literature has highlighted the ability for biogenic amines to regulate macrophage functions, but the mechanisms governing biogenic amine signaling in and around immune cells remain nebulous. In the CNS, biogenic amine transporters are regarded as the master regulators of neurotransmitter signaling. While we and others have shown that macrophages express these transporters, relatively little is known of their function in these cells. To address these knowledge gaps, we investigated the function of norepinephrine transporter (NET) and dopamine transporter (DAT) on human MDMs. We found that both NET and DAT are present and can uptake substrate from the extracellular space at baseline. Not only was DAT expressed in cultured MDMs, but it was also detected in a subset of intestinal macrophages in situ. Surprisingly, we discovered a NET-independent, DAT-mediated immunomodulatory mechanism in response to LPS. LPS induced reverse transport of dopamine through DAT, engaging an autocrine/paracrine signaling loop that regulated the macrophage response. Removing this signaling loop enhanced the proinflammatory response to LPS. Our data introduce a potential role for DAT in the regulation of innate immunity.

Exosomes from HPV-16 E7-pulsed dendritic cells prevent the migration, M1 polarization, and inflammation of macrophages in cervical cancer by regulating catalase 2 (CAT2).

BackgroundCervical cancer is mainly caused by persistent infection with human papillomavirus (HPV), especially HPV-16. Recently, HPV-16 E7-modified dendritic cells (DCs) have been reported to play a blocking role in the progression of cervical cancer. Conversely, the effect and mechanism of HPV-16 E7-pulsed DCs in cervical cancer are not entirely clear.MethodsDCs from the peripheral blood of patients with cervical cancer were induced with lipopolysaccharide and identified through the detection of cluster of differentiation (CD)11c, major histocompatibility complex (MHC)-II, CD83, and CD40 levels, and exosomes from HPV-16 E7-pulsed and catalase 2 (CAT2)-silenced DCs were extracted and identified through transmission electron microscopy and the detection of markers. Additionally, the migration, inflammatory factors, and polarization of macrophages were confirmed using Transwell, enzyme-linked immunoassay, and Western blot of arginase-1 (Arg-1) and inducible nitric oxide synthase (iNOS). In vivo, we also built a mice xenograft model of HPV cervical cancer.ResultsWe first successfully induced and identified DCs from cervical cancer patients, and successfully extracted and confirmed the exosomes from the constructed HPV-16 E7-pulsed and CAT2-silenced DCs. Subsequently, we proved that exosomes from HPV-16 E7-pulsed DCs restrained migration and inflammation and induced M2 polarization in macrophages, while the effect of exosomes from CAT2-silenced DCs on macrophage migration, polarization, and inflammation was opposite to that of exosomes from HPV-16 E7-pulsed DCs, and the 2 affected each other. Additionally, we found that exosomes from CAT2-silenced DCs also prevented growth and M2 polarization in a mice xenograft model of HPV cervical cancer.ConclusionsExosomes from HPV-16 E7-pulsed DCs blocked cervical cancer progression by regulating macrophage function, and its mechanism was relevant to CAT2.

Fibrinogen-like protein 2 deficiency inhibits virus-induced fulminant hepatitis through abrogating inflammatory macrophage activation.

BACKGROUNDHeterogeneous macrophages play an important role in multiple liver diseases, including viral fulminant hepatitis (VFH). Fibrinogen-like protein 2 (FGL2) is expressed on macrophages and regulates VFH pathogenesis; however, the underlying mechanism remains unclear. AIMTo explore how FGL2 regulates macrophage function and subsequent liver injury during VFH. METHODSMurine hepatitis virus strain 3 (MHV-3) was used to induce VFH in FGL2-deficient (Fgl2-/-) and wild-type (WT) mice. The dynamic constitution of hepatic macrophages was examined. Adoptive transfer of Fgl2-/- or WT bone marrow-derived macrophages (BMDMs) into WT recipients with macrophages depleted prior to infection was carried out and the consequent degree of liver damage was compared. The signaling cascades that may be regulated by FGL2 were detected in macrophages.RESULTSFollowing MHV-3 infection, hepatic macrophages were largely replenished by proinflammatory monocyte-derived macrophages (MoMFs), which expressed high levels of FGL2. In Fgl2-/- mice, the number of infiltrating inflammatory MoMFs was reduced compared with that in WT mice after viral infection. Macrophage depletion ameliorated liver damage in WT mice and further alleviated liver damage in Fgl2-/- mice. Adoptive transfer of Fgl2-/- BMDMs into macrophage-removed recipients significantly reduced the degree of liver damage. Inhibition of monocyte infiltration also significantly ameliorated liver damage. Functionally, Fgl2 deletion impaired macrophage phagocytosis and the antigen presentation potential and attenuated the proinflammatory phenotype. At the molecular level, FGL2 deficiency impaired IRF3, IRF7, and p38 phosphorylation, along with NF-κB activation in BMDMs in response to viral infection. CONCLUSIONInfiltrated MoMFs represent a major source of hepatic inflammation during VFH progression, and FGL2 expression on MoMFs maintains the proinflammatory phenotype via p38-dependent positive feedback, contributing to VFH pathogenesis.

Irgm1 regulates metabolism and function in T cell subsets

Immunity Related GTPases (IRG) are a family of proteins produced during infection that regulate membrane remodeling events in cells, particularly autophagy and mitophagy. The human IRGM gene has been strongly associated with Crohn’s disease and other inflammatory diseases through Genome-Wide Association studies. Absence of Irgm1 in mice prompts intestinal inflammation, autoimmunity, and impaired immune control of pathogenic bacteria and protozoa. Although prior work has focused on a prominent role for IRGM/Irgm1 in regulating macrophage function, the work described here addresses a potential role of Irgm1 in regulating the function of mature T cells. Irgm1 was found to be highly expressed in T cells in a manner that varied with the particular T cell subset and increased with activation. Mice with a complete lack of Irgm1, or a conditional lack of Irgm1 specifically in T cells, displayed numerous changes in T cell numbers and function in all subsets examined, including CD4+ (Th1 and Treg) and CD8+ T cells. Related to changes in T cell number, apoptosis was found to be increased in Irgm1-deficient CD4+ and CD8+ T cells. Altered T cell metabolism appeared to be a key driver of the phenotypes: Glucose metabolism and glycolysis were increased in Irgm1-deficient CD4+ and CD8+ T cells, and muting these effects with glycolytic inhibitors partially restored T cell function and viability.