scholarly journals Different Innate Ability of I/St and A/Sn Mice To Combat Virulent Mycobacterium tuberculosis: Phenotypes Expressed in Lung and Extrapulmonary Macrophages

2003 ◽  
Vol 71 (2) ◽  
pp. 697-707 ◽  
Author(s):  
Konstantin B. Majorov ◽  
Irina V. Lyadova ◽  
Tatiana K. Kondratieva ◽  
Eugeny B. Eruslanov ◽  
Elvira I. Rubakova ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Ex Vivo ◽  
Inbred Strains ◽  
Peritoneal Macrophages ◽  
Lung Macrophages ◽  
Isolated Lung ◽  
Mycobacterial Antigens ◽  
Mycobacterial Growth

ABSTRACT Mice of the I/St and A/Sn inbred strains display a severe and moderate course, respectively, of disease caused by Mycobacterium tuberculosis. Earlier, we showed that the response to mycobacterial antigens in I/St mice compared to that in A/Sn mice is shifted toward Th2-like reactivity and a higher proliferative activity and turnover of T cells. However, the physiologic basis for different expressions of tuberculosis severity in these mice remains largely unknown. Here, we extend our previous observations with evidence that I/St interstitial lung macrophages are defective in the ability to inhibit mycobacterial growth and to survive following in vitro infection with M. tuberculosis H37Rv. A unique feature of this phenotype is its exclusive expression in freshly isolated lung macrophages. The defect is not displayed in ex vivo macrophages obtained from the peritoneal cavity nor in macrophages developed in vitro from progenitors extracted from various organs, including the lung itself. In addition, we show that, in sharp contrast to peritoneal macrophages, the mycobactericidal capacity of lung macrophages is not elevated in the presence of exogenous gamma interferon. Our data suggest that the in vivo differentiation in a particular anatomical microenvironment determines the pattern of macrophage-mycobacterium interaction. Thus, caution should be exercised when conclusions based upon the results obtained in a particular in vitro system are generalized to the functions of all phagocytes during M. tuberculosis infection.

scholarly journals Metformin-stimulated AMPK-α1 promotes microvascular repair in acute lung injury

2013 ◽  
Vol 305 (11) ◽  
pp. L844-L855 ◽  
Author(s):  
Ming-Yuan Jian ◽  
Mikhail F. Alexeyev ◽  
Paul E. Wolkowicz ◽  
Jaroslaw W. Zmijewski ◽  
Judy R. Creighton
Keyword(s):  
Endothelial Cells ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Ex Vivo ◽  
Endothelial Permeability ◽  
Beneficial Effects ◽  
Isolated Lung

Acute lung injury secondary to sepsis is a leading cause of mortality in sepsis-related death. Present therapies are not effective in reversing endothelial cell dysfunction, which plays a key role in increased vascular permeability and compromised lung function. AMP-activated protein kinase (AMPK) is a molecular sensor important for detection and mediation of cellular adaptations to vascular disruptive stimuli. In this study, we sought to determine the role of AMPK in resolving increased endothelial permeability in the sepsis-injured lung. AMPK function was determined in vivo using a rat model of endotoxin-induced lung injury, ex vivo using the isolated lung, and in vitro using cultured rat pulmonary microvascular endothelial cells (PMVECs). AMPK stimulation using N1-(α-d-ribofuranosyl)-5-aminoimidizole-4-carboxamide or metformin decreased the LPS-induced increase in permeability, as determined by filtration coefficient ( Kf) measurements, and resolved edema as indicated by decreased wet-to-dry ratios. The role of AMPK in the endothelial response to LPS was determined by shRNA designed to decrease expression of the AMPK-α1 isoform in capillary endothelial cells. Permeability, wounding, and barrier resistance assays using PMVECs identified AMPK-α1 as the molecule responsible for the beneficial effects of AMPK in the lung. Our findings provide novel evidence for AMPK-α1 as a vascular repair mechanism important in the pulmonary response to sepsis and identify a role for metformin treatment in the management of capillary injury.

Aloe Metabolites Prevent LPS-Induced Sepsis and Inflammatory Response by Inhibiting Mitogen-Activated Protein Kinase Activation

2017 ◽  
Vol 45 (04) ◽  
pp. 847-861 ◽  
Author(s):  
Chia-Yang Li ◽  
Katsuhiko Suzuki ◽  
Yung-Li Hung ◽  
Meng-Syuan Yang ◽  
Chung-Ping Yu ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Aloe Vera ◽  
Peritoneal Macrophages ◽  
Mitogen Activated Protein Kinase ◽  
Protective Effects ◽  
Raw264.7 Macrophages ◽  
Mitogen Activated Protein ◽  
Anti Inflammatory

Aloe, a polyphenolic anthranoid-containing Aloe vera leaves, is a Chinese medicine and a popular dietary supplement worldwide. In in vivo situations, polyphenolic anthranoids are extensively broken down into glucuronides and sulfate metabolites by the gut and the liver. The anti-inflammatory potential of aloe metabolites has not been examined. The aim of this study was to investigate the anti-inflammatory effects of aloe metabolites from in vitro (lipopolysaccharides (LPS)-activated RAW264.7 macrophages) and ex vivo (LPS-activated peritoneal macrophages) to in vivo (LPS-induced septic mice). The production of proinflammatory cytokines (TNF-[Formula: see text] and IL-12) and NO was determined by ELISA and Griess reagents, respectively. The expression levels of iNOS and MAPKs were analyzed by Western blot. Our results showed that aloe metabolites inhibited the expression of iNOS, decreased the production of TNF-[Formula: see text], IL-12, and NO, and suppressed the phosphorylation of MAPKs by LPS-activated RAW264.7 macrophages. In addition, aloe metabolites reduced the production of NO, TNF-[Formula: see text] and IL-12 by murine peritoneal macrophages. Furthermore, aloe administration significantly reduced the NO level and exhibited protective effects against sepsis-related death in LPS-induced septic mice. These results suggest that aloe metabolites exerted anti-inflammatory effects in vivo, and that these effects were associated with the inhibition of inflammatory mediators. Therefore, aloe could be considered an effective therapeutic agent for the treatment of sepsis.

scholarly journals Three Mycobacterium tuberculosis Rel Toxin-Antitoxin Modules Inhibit Mycobacterial Growth and Are Expressed in Infected Human Macrophages

2008 ◽  
Vol 191 (5) ◽  
pp. 1618-1630 ◽  
Author(s):  
Shaleen B. Korch ◽  
Heidi Contreras ◽  
Josephine E. Clark-Curtiss
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Smegmatis ◽  
Protein Pair ◽  
Growth Arrest ◽  
Broth Culture ◽  
Human Macrophages ◽  
In Vivo Analysis ◽  
Mycobacterial Growth

ABSTRACT Mycobacterium tuberculosis protein pairs Rv1246c-Rv1247c, Rv2865-Rv2866, and Rv3357-Rv3358, here named RelBE, RelFG, and RelJK, respectively, were identified based on homology to the Escherichia coli RelBE toxin:antitoxin (TA) module. In this study, we have characterized each Rel protein pair and have established that they are functional TA modules. Overexpression of individual M. tuberculosis rel toxin genes relE, relG, and relK induced growth arrest in Mycobacterium smegmatis; a phenotype that was completely reversible by expression of their cognate antitoxin genes, relB, relF, and relJ, respectively. We also provide evidence that RelB and RelE interact directly, both in vitro and in vivo. Analysis of the genetic organization and regulation established that relBE, relFG, and relJK form bicistronic operons that are cotranscribed and autoregulated, in a manner unlike typical TA modules. RelB and RelF act as transcriptional activators, inducing expression of their respective promoters. However, RelBE, RelFG, and RelJK (together) repress expression to basal levels of activity, while RelJ represses promoter activity altogether. Finally, we have determined that all six rel genes are expressed in broth-grown M. tuberculosis, whereas relE, relF, and relK are expressed during infection of human macrophages. This is the first demonstration of M. tuberculosis expressing TA modules in broth culture and during infection of human macrophages.

scholarly journals TLR9 regulates Th1 responses and cooperates with TLR2 in mediating optimal resistance to Mycobacterium tuberculosis

2005 ◽  
Vol 202 (12) ◽  
pp. 1715-1724 ◽  
Author(s):  
Andre Bafica ◽  
Charles A. Scanga ◽  
Carl G. Feng ◽  
Cynthia Leifer ◽  
Allen Cheever ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Ex Vivo ◽  
Double Knockout ◽  
Susceptibility To Infection ◽  
Pathogen Challenge ◽  
In Vitro Response ◽  
Ifn Γ ◽  
Aerosol Infection

To investigate the role of Toll-like receptor (TLR)9 in the immune response to mycobacteria as well as its cooperation with TLR2, a receptor known to be triggered by several major mycobacterial ligands, we analyzed the resistance of TLR9−/− as well as TLR2/9 double knockout mice to aerosol infection with Mycobacterium tuberculosis. Infected TLR9−/− but not TLR2−/− mice displayed defective mycobacteria-induced interleukin (IL)-12p40 and interferon (IFN)-γ responses in vivo, but in common with TLR2−/− animals, the TLR9−/− mice exhibited only minor reductions in acute resistance to low dose pathogen challenge. When compared with either of the single TLR-deficient animals, TLR2/9−/− mice displayed markedly enhanced susceptibility to infection in association with combined defects in proinflammatory cytokine production in vitro, IFN-γ recall responses ex vivo, and altered pulmonary pathology. Cooperation between TLR9 and TLR2 was also evident at the level of the in vitro response to live M. tuberculosis, where dendritic cells and macrophages from TLR2/9−/− mice exhibited a greater defect in IL-12 response than the equivalent cell populations from single TLR9-deficient animals. These findings reveal a previously unappreciated role for TLR9 in the host response to M. tuberculosis and illustrate TLR collaboration in host resistance to a major human pathogen.

scholarly journals Novel Conjugate of Moxifloxacin and Carboxymethylated Glucan with Enhanced Activity against Mycobacterium tuberculosis

2006 ◽  
Vol 50 (6) ◽  
pp. 1982-1988 ◽  
Author(s):  
Y. S. Schwartz ◽  
M. I. Dushkin ◽  
V. A. Vavilin ◽  
E. V. Melnikova ◽  
O. M. Khoschenko ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Targeted Delivery ◽  
Scavenger Receptors ◽  
Intracellular Pathogen ◽  
Macrophage Cell ◽  
Macrophage Receptors ◽  
Mycobacterial Growth ◽  
Dose Dependent

ABSTRACT Mycobacterium tuberculosis is an intracellular pathogen that persists within macrophages of the human host. One approach to improving the treatment of tuberculosis (TB) is the targeted delivery of antibiotics to macrophages using ligands to macrophage receptors. The moxifloxacin-conjugated dansylated carboxymethylglucan (M-DCMG) conjugate was prepared by chemically linking dansylcadaverine (D) and moxifloxacin (M) to carboxymethylglucan (CMG), a known ligand of macrophage scavenger receptors. The targeted delivery to macrophages and the antituberculosis activity of the conjugate M-DCMG were studied in vitro and in vivo. Using fluorescence microscopy, fluorimetry, and the J774 macrophage cell line, M-DCMG was shown to accumulate in macrophages through scavenger receptors in a dose-dependent (1 to 50 μg/ml) manner. After intravenous administration of M-DCMG into C57BL/6 mice, the fluorescent conjugate was concentrated in the macrophages of the lungs and spleen. Analyses of the pharmacokinetics of the conjugate demonstrated that M-DCMG was more rapidly accumulated and more persistent in tissues than free moxifloxacin. Importantly, therapeutic studies of mycobacterial growth in C57BL/6 mice showed that the M-DCMG conjugate was significantly more potent than free moxifloxacin.

scholarly journals Differences betweenMycobacterium-Host Cell Relationships in Latent Tuberculous Infection of MiceEx Vivoand Mycobacterial Infection of Mouse CellsIn Vitro

2016 ◽  
Vol 2016 ◽  
pp. 1-21 ◽  
Author(s):  
Elena Ufimtseva
Keyword(s):  
Bone Marrow ◽  
Ex Vivo ◽  
Mouse Cell ◽  
Peritoneal Macrophages ◽  
Host Cells ◽  
Tuberculous Infection ◽  
Mouse Bone Marrow ◽  
Activation Markers

The search for factors that account for the reproduction and survival of mycobacteria, including vaccine strains, in host cells is the priority for studies on tuberculosis. A comparison of BCG-mycobacterial loads in granuloma cells obtained from bone marrow and spleens of mice with latent tuberculous infection and cells from mouse bone marrow and peritoneal macrophage cultures infected with the BCG vaccinein vitrohas demonstrated that granuloma macrophages each normally contained a single BCG-Mycobacterium, while those acutely infectedin vitrohad increased mycobacterial loads and death rates. Mouse granuloma cells were observed to produce the IFNγ, IL-1α, GM-CSF, CD1d, CD25, CD31, СD35, and S100 proteins. None of these activation markers were found in mouse cell cultures infectedin vitroor in intact macrophages. Lack of colocalization of lipoarabinomannan-labeled BCG-mycobacteria with the lysosomotropic LysoTracker dye in activated granuloma macrophages suggests that these macrophages were unable to destroy BCG-mycobacteria. However, activated mouse granuloma macrophages could control mycobacterial reproduction in cells bothin vivoand inex vivoculture. By contrast, a considerable increase in the number of BCG-mycobacteria was observed in mouse bone marrow and peritoneal macrophages after BCG infectionin vitro, when no expression of the activation-related molecules was detected in these cells.

scholarly journals Characterization of the Leucocyte Immunoglobulin-like Receptor B4 (Lilrb4) Expression in Microglia

Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1300
Author(s):  
Felix Kretzschmar ◽  
Robin Piecha ◽  
Jannik Jahn ◽  
Phani Sankar Potru ◽  
Björn Spittau
Keyword(s):  
Ex Vivo ◽  
Myeloid Cells ◽  
Peritoneal Macrophages ◽  
Primary Microglia ◽  
Tgfβ Signaling ◽  
Bv2 Cells ◽  
Lps Treatment

As resident innate immune cells of the CNS, microglia play important essential roles during physiological and pathological situations. Recent reports have described the expression of Lilrb4 in disease-associated and aged microglia. Here, we characterized the expression of Lilrb4 in microglia in vitro and in vivo in comparison with bone marrow-derived monocytes and peritoneal macrophages in mice. Using BV2 cells, primary microglia cultures as well as ex vivo isolated microglia and myeloid cells in combination with qPCR and flow cytometry, we were able to provide a comprehensive characterization of Lilrb4 expression in distinct mouse myeloid cells. Whereas microglia in vivo display low expression of Lilrb4, primary microglia cultures present high levels of surface LILRB4. Among the analyzed peripheral myeloid cells, peritoneal macrophages showed the highest expression levels of Lilrb4. Moreover, LPS treatment and inhibition of microglial TGFβ signaling resulted in significant increases of LILRB4 cell surface levels. Taken together, our data indicate that LILRB4 is a reliable surface marker for activated microglia and further demonstrate that microglial TGFβ signaling is involved in the regulation of Lilrb4 expression during LPS-induced microglia activation.

scholarly journals Early induction of antibacterial activities distinguishes response of mice to infection with non-permissive from response to permissiveSalmonella

2020 ◽  
Author(s):  
Jitender Yadav ◽  
Ayub Qadri
Keyword(s):  
Ex Vivo ◽  
Serine Protease Inhibitor ◽  
Antibacterial Activities ◽  
Peritoneal Macrophages ◽  
Mrna Levels ◽  
High Homology ◽  
Intraperitoneal Infection ◽  
Very High

Salmonella entericaserovar Typhi (S. Typhi), the causative agent of typhoid in humans, shares very high homology with closely related serovar,S. Typhimurium. Yet, unlikeS. Typhimurium,S. Typhi does not establish infection in mice. We show that intraperitoneal infection of mice withS. Typhi is associated with induction of antibacterial activities. Cell-free peritoneal fluids fromS. Typhi but notS. Typhimurium-infected mice inhibited replication ofSalmonella ex vivo. Administration of serine protease inhibitor, phenylmethylsulfonly fluoride (PMSF), duringS. Typhi infection reduced production of this activity.In vitro, generation of this antibacterial activity from peritoneal macrophages infected withS. Typhi was inhibited with PMSF, and its release was dependent on cell death. Peritoneal cells infected withS. Typhi in vivo or in vitro showed increased mRNA levels of ferroportin and lipocalin. Our findings implicate early induction of antibacterial molecules in the failure ofS. Typhi to establish infection in mice.

scholarly journals Mesenchymal stem cells (MSCs) offer a drug tolerant and immune- privileged niche to Mycobacterium tuberculosis

2019 ◽  
Author(s):  
Neharika Jain ◽  
Haroon Kalam ◽  
Lakshyaveer Singh ◽  
Vartika Sharma ◽  
Saurabh Kedia ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Mycobacterium Tuberculosis ◽  
Prolonged Treatment ◽  
Phagosome Maturation ◽  
Tuberculosis Prevention ◽  
Prevention And Cure ◽  
Mycobacterial Growth

SummaryAnti-tuberculosis (TB) drugs while being highly potent in vitro require prolonged treatment to control Mycobacterium tuberculosis (Mtb) infections in vivo. We report here, mesenchymal stem cells (MSCs) shelter Mtb to help tolerate anti-TB drugs. MSCs uptake Mtb readily and allow them grow unabated despite having functional innate pathway of phagosome maturation. Unlike macrophage-resident ones, MSC-resident Mtb tolerates anti-TB drugs remarkably well, a phenomenon requiring proteins ABCC1, ABCG2 and vacuolar-type H+ATPases. Additionally, contrary to what is classically known, IFNγ and TNFα aid mycobacterial growth within MSCs. Mechanistically, evading drugs and inflammatory cytokines by MSC-resident Mtb is dependent on elevated PGE2 signaling, which we subsequently verified in vivo analyzing sorted CD45-CD73+SCA1+-MSCs from the lungs of infected mice. Moreover granulomas from human pulmonary and extra-pulmonary TB show presence of MSCs co-inhabiting with Mtb. Together the results show targeting the immune-privileged niche, provided by MSCs to Mtb, can revolutionize tuberculosis prevention and cure.

Tuberkulose - Screening

2011 ◽  
Vol 68 (7) ◽  
pp. 381-387
Author(s):  
Otto Schoch
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Interferon Gamma ◽  
Wird Eine ◽  
Interferon Gamma Release Assays

Das primäre Ziel der Aktivitäten zur bevölkerungsbezogenen Tuberkulosekontrolle ist die Identifizierung von Patienten mit sputummikroskopisch positiver Lungentuberkulose. Wenn diese Patienten umgehend therapiert werden, haben sie nicht nur eine optimale Heilungschance, sondern übertragen auch den Krankheitserreger nicht weiter auf andere Personen. Das Screening, die systematische Suche nach Tuberkulose, erfolgt in der Regel radiologisch bei der Suche nach Erkrankten, während immunologische Teste bei der Suche nach einer Infektion mit Mycobacterium tuberculosis zur Anwendung kommen. Diese Infektion, die ein erhöhtes Risiko für die Entwicklung einer Tuberkulose-Erkrankung mit sich bringt, wird im Rahmen der Umgebungsuntersuchungen oder bei Hochrisikogruppen gesucht. Neben dem traditionellen in vivo Mantoux Hauttest stehen heute die neueren in vitro Blutteste, die sogenannten Interferon Gamma Release Assays (IGRA) zur Verfügung, die unter anderem den Vorteil einer höheren Spezifität mit sich bringen, weil die verwendeten Antigene der Mykobakterien-Wand beim Impfstamm Bacille Calmitte Guerin (BCG) und bei den meisten atypischen Mykobakterien nicht vorhanden sind. Zudem kann bei Immunsupprimierten dank einer mitgeführten Positivkontrolle eine Aussage über die Wahrscheinlichkeit eines falsch negativen Testresultates gemacht werden. Bei neu diagnostizierter Infektion mit Mycobacterium tuberculosis wird eine präventive Chemotherapie mit Isoniazid während 9 Monaten durchgeführt.

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