Azithromycin Alters Macrophage Phenotype and Pulmonary Compartmentalization during Lung Infection with Pseudomonas

ABSTRACT Infection with mucoid strains of Pseudomonas aeruginosa in chronic inflammatory diseases of the airway is difficult to eradicate and can cause excessive inflammation. The roles of alternatively activated and regulatory subsets of macrophages in this pathophysiological process are not well characterized. We previously demonstrated that azithromycin induces an alternatively activated macrophage-like phenotype in vitro. In the present study, we tested whether azithromycin affects the macrophage activation status and migration in the lungs of P. aeruginosa-infected mice. C57BL/6 mice received daily doses of oral azithromycin and were infected intratracheally with a mucoid strain of P. aeruginosa. The properties of macrophage activation, immune cell infiltration, and markers of pulmonary inflammation in the lung interstitial and alveolar compartments were evaluated postinfection. Markers of alternative macrophage activation were induced by azithromycin treatment, including the surface expression of the mannose receptor, the upregulation of arginase 1, and a decrease in the production of proinflammatory cytokines. Additionally, azithromycin increased the number of CD11b+ monocytes and CD4+ T cells that infiltrated the alveolar compartment. A predominant subset of CD11b+ cells was Gr-1 positive (Gr-1+), indicative of a subset of cells that has been shown to be immunoregulatory. These differences corresponded to decreases in neutrophil influx into the lung parenchyma and alteration of the characteristics of peribronchiolar inflammation without any change in the clearance of the organism. These results suggest that the immunomodulatory effects of azithromycin are associated with the induction of alternative and regulatory macrophage activation characteristics and alteration of cellular compartmentalization during infection.

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Oxidized LDL Induces Alternative Macrophage Phenotype through Activation of CD36 and PAFR

Mediators of Inflammation ◽

10.1155/2013/198193 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 34

Author(s):

Francisco J. Rios ◽

Marianna M. Koga ◽

Mateus Pecenin ◽

Matheus Ferracini ◽

Magnus Gidlund ◽

...

Keyword(s):

Mrna Expression ◽

Macrophage Activation ◽

Oxidized Ldl ◽

Platelet Activating Factor ◽

Mannose Receptor ◽

Mrna Levels ◽

Macrophage Phenotype ◽

Macrophage Differentiation ◽

Arginase 1 ◽

Pre Treatment

OxLDL is recognized by macrophage scavenger receptors, including CD36; we have recently found that Platelet-Activating Factor Receptor (PAFR) is also involved. Since PAFR in macrophages is associated with suppressor function, we examined the effect of oxLDL on macrophage phenotype. It was found that the presence of oxLDL during macrophage differentiation induced high mRNA levels to IL-10, mannose receptor, PPARγand arginase-1 and low levels of IL-12 and iNOS. When human THP-1 macrophages were pre-treated with oxLDL then stimulated with LPS, the production of IL-10 and TGF-βsignificantly increased, whereas that of IL-6 and IL-8 decreased. In murine TG-elicited macrophages, this protocol significantly reduced NO, iNOS and COX2 expression. Thus, oxLDL induced macrophage differentiation and activation towards the alternatively activated M2-phenotype. In murine macrophages, oxLDL induced TGF-β, arginase-1 and IL-10 mRNA expression, which were significantly reduced by pre-treatment with PAFR antagonists (WEB and CV) or with antibodies to CD36. The mRNA expression of IL-12, RANTES and CXCL2 were not affected. We showed that this profile of macrophage activation is dependent on the engagement of both CD36 and PAFR. We conclude that oxLDL induces alternative macrophage activation by mechanisms involving CD36 and PAFR.

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Knockdown of Leptin Receptor Affects Macrophage Phenotype in the Tumor Microenvironment Inhibiting Breast Cancer Growth and Progression

Cancers ◽

10.3390/cancers12082078 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2078

Author(s):

Luca Gelsomino ◽

Giuseppina Daniela Naimo ◽

Rocco Malivindi ◽

Giuseppina Augimeri ◽

Salvatore Panza ◽

...

Keyword(s):

Breast Cancer ◽

Tumor Microenvironment ◽

Leptin Receptor ◽

Macrophage Phenotype ◽

In Vivo Models ◽

Monocyte Chemoattractant Protein 1 ◽

Arginase 1 ◽

The Impact

Aberrant leptin (Ob) signaling, a hallmark of obesity, has been recognized to influence breast cancer (BC) biology within the tumor microenvironment (TME). Here, we evaluated the impact of leptin receptor (ObR) knockdown in affecting BC phenotype and in mediating the interaction between tumor cells and macrophages, the most abundant immune cells within the TME. The stable knockdown of ObR (ObR sh) in ERα-positive and ERα-negative BC cells turned the tumor phenotype into a less aggressive one, as evidenced by in vitro and in vivo models. In xenograft tumors and in co-culture experiments between circulating monocytes and BC cells, the absence of ObR reduced the recruitment of macrophages, and also affected their cytokine mRNA expression profile. This was associated with a decreased expression and secretion of monocyte chemoattractant protein-1 in ObR sh clones. The loss of Ob/ObR signaling modulated the immunosuppressive TME, as shown by a reduced expression of programmed death ligand 1/programmed cell death protein 1/arginase 1. In addition, we observed increased phagocytic activity of macrophages compared to control Sh clones in the presence of ObR sh-derived conditioned medium. Our findings, addressing an innovative role of ObR in modulating immune TME, may open new avenues to improve BC patient health care.

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Similarity and Diversity in Macrophage Activation by Nematodes, Trematodes, and Cestodes

Journal of Biomedicine and Biotechnology ◽

10.1155/2010/262609 ◽

2010 ◽

Vol 2010 ◽

pp. 1-14 ◽

Cited By ~ 55

Author(s):

Stephen J. Jenkins ◽

Judith E. Allen

Keyword(s):

Macrophage Activation ◽

Helminth Infection ◽

Current Knowledge ◽

Host Tissue ◽

Macrophage Phenotype ◽

Activated Macrophages ◽

Alternatively Activated Macrophages ◽

Helminth Infections ◽

Host Metabolism ◽

Alternatively Activated

This review summarizes current knowledge of macrophages in helminth infections, with a focus not only on delineating the striking similarities in macrophage phenotype between diverse infections but also on highlighting the differences. Findings from many different labs illustrate that macrophages in helminth infection can act as anti-parasite effectors but can also act as powerful immune suppressors. The specific role for their alternative (Th2-mediated) activation in helminth killing or expulsion versus immune regulation remains to be determined. Meanwhile, the rapid growth in knowledge of alternatively activated macrophages will require an even more expansive view of their potential functions to include repair of host tissue and regulation of host metabolism.

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Identification of a new C-type lectin, TES-70, secreted by infective larvae of Toxocara canis, which binds to host ligands

Parasitology ◽

10.1017/s0031182099006721 ◽

2000 ◽

Vol 121 (5) ◽

pp. 545-554 ◽

Cited By ~ 57

Author(s):

A. LOUKAS ◽

A. DOEDENS ◽

M. HINTZ ◽

R. M. MAIZELS

Keyword(s):

Immune Cell ◽

Sequence Similarity ◽

Mannose Receptor ◽

Toxocara Canis ◽

Dependent Manner ◽

Expression Screening ◽

Lectin Domain ◽

Calcium Dependent ◽

Infective Larvae

Infective larvae of the dog roundworm Toxocara canis survive in the tissues of their hosts for extended periods in a state of developmental arrest, successfully evading immune destruction. This survival strategy is thought to be mediated by T. canis excretory/secretory (TES) products which downregulate or divert the immune response. We purified one of the major TES products, TES-70 and gained amino acid sequence from 4 tryptic peptides. These peptides were matched to a predicted protein from a cDNA that was isolated by expression screening a T. canis cDNA library with mouse anti-TES serum. The predicted protein (Tc-CTL-4) is similar to, but larger than, Tc-CTL-1, a 32-kDa C-type lectin secreted by T. canis larvae. Tc-CTL-4 has a signal peptide, 2 Cys-rich domains and a C-terminal calcium-dependent C-type lectin domain that shares sequence similarity with host immune cell receptors such as macrophage mannose receptor and CD23. The lectin domain was expressed in bacteria and antiserum to the purified recombinant protein was used to confirm that Tc-ctl-4 did encode the native TES-70 glycoprotein. TES-70 selectively bound to ligands on the surface of Madin–Darby Canine Kidney cells in vitro in a calcium-dependent manner, inhibitable by mammalian serum, indicating that a host glycan is the native ligand for this new parasite lectin.

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Effects of surfactant protein A and surfactant lipids on lymphocyte proliferation in vitro

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1994.267.4.l357 ◽

1994 ◽

Vol 267 (4) ◽

pp. L357-L364 ◽

Cited By ~ 21

Author(s):

S. G. Kremlev ◽

T. M. Umstead ◽

D. S. Phelps

Keyword(s):

Lymphocyte Proliferation ◽

Cell Function ◽

Immune Cell ◽

Pulmonary Inflammation ◽

Protein A ◽

Surfactant Protein ◽

Surfactant Protein A ◽

Inhibitory Influence ◽

Surfactant Replacement Therapy

We studied the effects of dipalmitoyl L-alpha-phosphatidylcholine (DPPC), Survanta, surfactant protein A (SP-A), and mixtures of these substances on mitogen-induced lymphocyte proliferation using concanavalin A as a mitogen. A concentration-dependent suppression of proliferation was observed with 50-250 micrograms/ml of DPPC or Survanta. However, when SP-A was added to cultures, proliferation was stimulated. The inhibitory effects of DPPC and Survanta were altered in mixtures that contained SP-A. When added to 50 micrograms/ml of Survanta, SP-A reversed the inhibitory influence of Survanta and caused increased proliferation. These findings suggest that surfactant phospholipids cause a suppression of mitogen-induced lymphocyte proliferation, which is reversed somewhat by addition of SP-A. We hypothesize that immune cell function in the lung varies with changes in the relative amounts of surfactant components. Changes in surfactant composition may occur during pulmonary inflammation or infection or with surfactant replacement therapy and may influence immune and inflammatory processes in the lung.

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Schistosoma mansoni Hemozoin Modulates Alternative Activation of Macrophages via Specific Suppression of Retnla Expression and Secretion

Infection and Immunity ◽

10.1128/iai.00701-12 ◽

2012 ◽

Vol 81 (1) ◽

pp. 133-142 ◽

Cited By ~ 17

Author(s):

Martha Truscott ◽

D. Andrew Evans ◽

Matt Gunn ◽

Karl F. Hoffmann

Keyword(s):

Schistosoma Mansoni ◽

Macrophage Activation ◽

Inflammatory Responses ◽

Interleukin 4 ◽

Alternative Activation ◽

Content Type ◽

Hepatic Expression ◽

Life Years ◽

Alternatively Activated

The trematodeSchistosoma mansoniis one of the etiological agents of schistosomiasis, a key neglected tropical disease responsible for an estimated annual loss of 70 million disability-adjusted life years. Hematophagy represents the primary nutrient acquisition pathway of this parasite, but digestion of hemoglobin also liberates toxic heme. Schistosomes detoxify heme via crystallization into hemozoin, which is subsequently regurgitated into the host's circulation. Here we demonstrate that during experimental schistosomiasis, hemozoin accumulating in the mouse liver is taken up by phagocytes at a time coincident with the development of the egg-induced T-helper 2 (Th2) granulomatous immune response. Furthermore, the uptake of hemozoin also coincides with the hepatic expression of markers of alternative macrophage activation. Alternatively activated macrophages are a key effector cell population associated with protection against schistosomiasis, making hemozoin well placed to play an important immunomodulatory role in this disease. To systematically explore this hypothesis,S. mansonihemozoin was purified and added toin vitrobone marrow-derived macrophage cultures concurrently exposed to cytokines chosen to reflect the shifting state of macrophage activationin vivo. Macrophages undergoing interleukin-4 (IL-4)-induced alternative activation in the presence of hemozoin developed a phenotype specifically lacking inRetnla, a characteristic alternatively activated macrophage product associated with regulation of Th2 inflammatory responses. As such, in addition to its important detoxification role during hematophagy, we propose that schistosome hemozoin also provides a potent immunomodulatory function in the coevolved network of host-parasite relationships during schistosomiasis.

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Netrin-1-treated macrophages protect the kidney against ischemia-reperfusion injury and suppress inflammation by inducing M2 polarization

AJP Renal Physiology ◽

10.1152/ajprenal.00580.2012 ◽

2013 ◽

Vol 304 (7) ◽

pp. F948-F957 ◽

Cited By ~ 50

Author(s):

Punithavathi Vilapakkam Ranganathan ◽

Calpurnia Jayakumar ◽

Ganesan Ramesh

Keyword(s):

Reperfusion Injury ◽

Macrophage Activation ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Macrophage Polarization ◽

Kidney Injury ◽

In Vitro Studies ◽

Arginase 1 ◽

M2 Polarization

Improper macrophage activation is pathogenically linked to various metabolic, inflammatory, and immune disorders. Therefore, regulatory proteins controlling macrophage activation have emerged as important new therapeutic targets. We recently demonstrated that netrin-1 regulates inflammation and infiltration of monocytes and ameliorates ischemia-reperfusion-induced kidney injury. However, it was not known whether netrin-1 regulates the phenotype of macrophages and the signaling mechanism through which it might do this. In this study, we report novel mechanisms underlying netrin-1's effects on macrophages using in vivo and in vitro studies. Overexpression of netrin-1 in spleen and kidney of transgenic mice increased expression of arginase-1, IL-4, and IL-13 and decreased expression of COX-2, indicating a phenotypic switch in macrophage polarization toward an M2-like phenotype. Moreover, flow cytometry analysis showed a significant increase in mannose receptor-positive macrophages in spleen compared with wild type. In vitro, netrin-1 induced the expression of M2 marker expression in bone marrow-derived macrophages, peritoneal macrophages, and RAW264.7 cells, and suppressed IFNγ-induced M1 polarization and production of inflammatory mediators. Adoptive transfer of netrin-1-treated macrophages suppressed inflammation and kidney injury against ischemia-reperfusion. Netrin-1 activated PPAR pathways and inhibition of PPAR activation abolished netrin-1-induced M2 polarization and suppression of cytokine production. Consistent with in vitro studies, administration of PPAR antagonist to mice abolished the netrin-1 protective effects against ischemia-reperfusion injury of the kidney. These findings illustrate that netrin-1 regulates macrophage polarization through PPAR pathways and confers anti-inflammatory actions in inflammed kidney tissue.

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Inhibition of atherogenesis by the COP9 signalosome subunit 5 in vivo

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1618411114 ◽

2017 ◽

Vol 114 (13) ◽

pp. E2766-E2775 ◽

Cited By ~ 14

Author(s):

Yaw Asare ◽

Miriam Ommer ◽

Florence. A. Azombo ◽

Setareh Alampour-Rajabi ◽

Marieke Sternkopf ◽

...

Keyword(s):

Atherosclerotic Lesion ◽

Cop9 Signalosome ◽

Macrophage Phenotype ◽

Ring E3 Ligase ◽

Atherosclerotic Lesions ◽

Arginase 1 ◽

Proinflammatory Gene ◽

A Subunit

Constitutive photomorphogenesis 9 (COP9) signalosome 5 (CSN5), an isopeptidase that removes neural precursor cell-expressed, developmentally down-regulated 8 (NEDD8) moieties from cullins (thus termed “deNEDDylase”) and a subunit of the cullin-RING E3 ligase-regulating COP9 signalosome complex, attenuates proinflammatory NF-κB signaling. We previously showed that CSN5 is up-regulated in human atherosclerotic arteries. Here, we investigated the role of CSN5 in atherogenesis in vivo by using mice with myeloid-specific Csn5 deletion. Genetic deletion of Csn5 in Apoe−/− mice markedly exacerbated atherosclerotic lesion formation. This was broadly observed in aortic root, arch, and total aorta of male mice, whereas the effect was less pronounced and site-specific in females. Mechanistically, Csn5 KO potentiated NF-κB signaling and proinflammatory cytokine expression in macrophages, whereas HIF-1α levels were reduced. Inversely, inhibition of NEDDylation by MLN4924 blocked proinflammatory gene expression and NF-κB activation while enhancing HIF-1α levels and the expression of M2 marker Arginase 1 in inflammatory-elicited macrophages. MLN4924 further attenuated the expression of chemokines and adhesion molecules in endothelial cells and reduced NF-κB activation and monocyte arrest on activated endothelium in vitro. In vivo, MLN4924 reduced LPS-induced inflammation, favored an antiinflammatory macrophage phenotype, and decreased the progression of early atherosclerotic lesions in mice. On the contrary, MLN4924 treatment increased neutrophil and monocyte counts in blood and had no net effect on the progression of more advanced lesions. Our data show that CSN5 is atheroprotective. We conclude that MLN4924 may be useful in preventing early atherogenesis, whereas selectively promoting CSN5-mediated deNEDDylation may be beneficial in all stages of atherosclerosis.

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Extraintestinal Helminth Infection Limits Pathology and Proinflammatory Cytokine Expression during DSS-Induced Ulcerative Colitis: A Role for Alternatively Activated Macrophages and Prostaglandins

BioMed Research International ◽

10.1155/2015/563425 ◽

2015 ◽

Vol 2015 ◽

pp. 1-17 ◽

Cited By ~ 20

Author(s):

Yadira Ledesma-Soto ◽

Blanca E. Callejas ◽

César A. Terrazas ◽

Jose L. Reyes ◽

Arlett Espinoza-Jiménez ◽

...

Keyword(s):

Ulcerative Colitis ◽

Inflammatory Responses ◽

Inflammatory Diseases ◽

Activity Index ◽

Disease Activity Index ◽

Helminth Parasites ◽

Activated Macrophages ◽

Alternatively Activated Macrophages ◽

Arginase 1 ◽

Alternatively Activated

Chronic inflammation of the intestinal mucosa is characteristic of inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease. Helminth parasites have developed immunomodulatory strategies that may impact the outcome of several inflammatory diseases. Therefore, we investigated whetherTaenia crassicepsinfection is able to decrease the inflammatory effects of dextran sulfate sodium- (DSS-) induced ulcerative colitis in BALB/c and C57BL/6 mice. Preinfection significantly reduced the manifestations of DSS-induced colitis, as weight loss and shortened colon length, and decreased the disease activity index independently of the genetic background of the mice.Taeniainfection decreased systemic levels of proinflammatory cytokines while increasing levels of IL-4 and IL-10, and the inflammatory infiltrate into the colon was also markedly reduced. RT-PCR assays from colon showed thatT. crassiceps-infected mice displayed increased expression of Arginase-1 but decreased expression of iNOS compared to DSS-treated uninfected mice. The percentages of T regulatory cells were not increased. The adoptive transfer of alternatively activated macrophages (AAMФs) from infected mice into mice with DSS-induced colitis reduced the severity of colon inflammation. Administration of indomethacin abrogated the anticolitic effect ofTaenia. Thus,T. crassicepsinfection limits the pathology of ulcerative colitis by suppressing inflammatory responses mechanistically associated with AAMФs and prostaglandins.

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Single-Domain Antibodies for Targeting, Detection, and In Vivo Imaging of Human CD4+ Cells

Frontiers in Immunology ◽

10.3389/fimmu.2021.799910 ◽

2021 ◽

Vol 12 ◽

Author(s):

Bjoern Traenkle ◽

Philipp D. Kaiser ◽

Stefania Pezzana ◽

Jennifer Richardson ◽

Marius Gramlich ◽

...

Keyword(s):

T Cell ◽

Immune Cell ◽

Inflammatory Diseases ◽

Xenograft Model ◽

Single Domain ◽

Positron Emission ◽

Depth Analysis ◽

Single Domain Antibodies

The advancement of new immunotherapies necessitates appropriate probes to monitor the presence and distribution of distinct immune cell populations. Considering the key role of CD4+ cells in regulating immunological processes, we generated novel single-domain antibodies [nanobodies (Nbs)] that specifically recognize human CD4. After in-depth analysis of their binding properties, recognized epitopes, and effects on T-cell proliferation, activation, and cytokine release, we selected CD4-specific Nbs that did not interfere with crucial T-cell processes in vitro and converted them into immune tracers for noninvasive molecular imaging. By optical imaging, we demonstrated the ability of a high-affinity CD4-Nb to specifically visualize CD4+ cells in vivo using a xenograft model. Furthermore, quantitative high-resolution immune positron emission tomography (immunoPET)/MR of a human CD4 knock-in mouse model showed rapid accumulation of 64Cu-radiolabeled CD4-Nb1 in CD4+ T cell-rich tissues. We propose that the CD4-Nbs presented here could serve as versatile probes for stratifying patients and monitoring individual immune responses during personalized immunotherapy in both cancer and inflammatory diseases.

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