scholarly journals Host-Pathogen Interaction and Signaling Molecule Secretion Are Modified in thedpp3Knockout Mutant of Candida lusitaniae

2013 ◽  
Vol 82 (1) ◽  
pp. 413-422 ◽  
Author(s):  
Ayman Sabra ◽  
Jean-Jacques Bessoule ◽  
Vessela Atanasova-Penichon ◽  
Thierry Noël ◽  
Karine Dementhon
Keyword(s):  
Interleukin 10 ◽  
Gene Inactivation ◽  
Physical Contact ◽  
Knockout Mutant ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Tnf Α ◽  
Candida Lusitaniae

ABSTRACTCandida lusitaniaeis an emerging opportunistic yeast and an attractive model to discover new virulence factors inCandidaspecies by reverse genetics. Our goal was to create adpp3Δ knockout mutant and to characterize the effects of this gene inactivation on yeastin vitroandin vivointeraction with the host. The secretion of two signaling molecules inCandidaspecies, phenethyl alcohol (PEA) and tyrosol, but not of farnesol was surprisingly altered in thedpp3Δ knockout mutant. NO and reactive oxygen species (ROS) production as well as tumor necrosis factor alpha (TNF-α) and interleukin 10 (IL-10) secretion were also modified in macrophages infected with this mutant. Interestingly, we found that the wild-type (WT) strain induced an increase in IL-10 secretion by zymosan-activated macrophages without the need for physical contact, whereas thedpp3Δ knockout mutant lost this ability. We further showed a striking role of PEA and tyrosol in this modulation. Last, theDPP3gene was found to be an essential contributor to virulence in mice models, leading to an increase in TNF-α secretion and brain colonization. Although reinsertion of a WTDPP3copy in thedpp3Δ knockout mutant was not sufficient to restore the WT phenotypesin vitro, it allowed a restoration of those observedin vivo. These data support the hypothesis that some of the phenotypes observed followingDPP3gene inactivation may be directly dependent onDPP3, while others may be the indirect consequence of another genetic modification that systematically arises when theDPP3gene is inactivated.

scholarly journals Cellular Microbiology of Mycoplasma canis

2016 ◽  
Vol 84 (6) ◽  
pp. 1785-1795 ◽  
Author(s):  
Dina L. Michaels ◽  
Jeffrey A. Leibowitz ◽  
Mohammed T. Azaiza ◽  
Pollob K. Shil ◽  
Suzanne M. Shama ◽  
...  
Keyword(s):  
Antigen Expression ◽  
Interleukin 10 ◽  
Factor H ◽  
Basic Knowledge ◽  
Complement Factor ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Dh82 Cells

Mycoplasma caniscan infect many mammalian hosts but is best known as a commensal or opportunistic pathogen of dogs. The unexpected presence ofM. canisin brains of dogs with idiopathic meningoencephalitis prompted newin vitrostudies to help fill the void of basic knowledge about the organism's candidate virulence factors, the host responses that it elicits, and its potential roles in pathogenesis. Secretion of reactive oxygen species and sialidase varied quantitatively (P< 0.01) among strains ofM. canisisolated from canine brain tissue or mucosal surfaces. All strains colonized the surface of canine MDCK epithelial and DH82 histiocyte cells and murine C8-D1A astrocytes. Transit through MDCK and DH82 cells was demonstrated by gentamicin protection assays and three-dimensional immunofluorescence imaging. Strains further varied (P< 0.01) in the extents to which they influenced the secretion of tumor necrosis factor alpha (TNF-α) and the neuroendocrine regulatory peptide endothelin-1 by DH82 cells. Inoculation withM. canisalso decreased major histocompatibility complex class II (MHC-II) antigen expression by DH82 cells (P< 0.01), while secretion of gamma interferon (IFN-γ), interleukin-6 (IL-6), interleukin-10 (IL-10), and complement factor H was unaffected. The basis for differences in the responses elicited by these strains was not obvious in their genome sequences. No acute cytopathic effects on any homogeneous cell line, or consistent patterns ofM. canispolyvalent antigen distribution in canine meningoencephalitis case brain tissues, were apparent. Thus, while it is not likely a primary neuropathogen,M. canishas the capacity to influence meningoencephalitis through complex interactions within the multicellular and neurochemicalin vivomilieu.

scholarly journals SpyAD, a Moonlighting Protein of Group A Streptococcus Contributing to Bacterial Division and Host Cell Adhesion

2014 ◽  
Vol 82 (7) ◽  
pp. 2890-2901 ◽  
Author(s):  
Marilena Gallotta ◽  
Giovanni Gancitano ◽  
Giampiero Pietrocola ◽  
Marirosa Mora ◽  
Alfredo Pezzicoli ◽  
...  
Keyword(s):  
Cell Division ◽  
Mammalian Cells ◽  
Group A Streptococcus ◽  
Host Cells ◽  
Knockout Mutant ◽  
Content Type ◽  
Moonlighting Protein ◽  
Group A

ABSTRACTGroup A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of thespy0269gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interactin vitrowith the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cellsin vitroand thatLactococcus lactisexpressing Spy0269 on its cell surface could adhere to mammalian cellsin vitroand to mice nasal mucosain vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (StreptococcuspyogenesAdhesion andDivision protein).

scholarly journals Micrococcus luteus Teichuronic Acids Activate Human and Murine Monocytic Cells in a CD14- and Toll-Like Receptor 4-Dependent Manner

2001 ◽  
Vol 69 (4) ◽  
pp. 2025-2030 ◽  
Author(s):  
Shuhua Yang ◽  
Shunji Sugawara ◽  
Toshihiko Monodane ◽  
Masahiro Nishijima ◽  
Yoshiyuki Adachi ◽  
...  
Keyword(s):  
Lipid A ◽  
Micrococcus Luteus ◽  
Dependent Manner ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Necrosis Factor Alpha ◽  
Monocytic Cells ◽  
Tnf Α

ABSTRACT Teichuronic acid (TUA), a component of the cell walls of the gram-positive organism Micrococcus luteus (formerlyMicrococcus lysodeikticus), induced inflammatory cytokines in C3H/HeN mice but not in lipopolysaccharide (LPS)-resistant C3H/HeJ mice that have a defect in the Toll-like receptor 4 (TLR4) gene, both in vivo and in vitro, similarly to LPS (T. Monodane, Y. Kawabata, S. Yang, S. Hase, and H. Takada, J. Med. Microbiol. 50:4–12, 2001). In this study, we found that purified TUA (p-TUA) induced tumor necrosis factor alpha (TNF-α) in murine monocytic J774.1 cells but not in mutant LR-9 cells expressing membrane CD14 at a lower level than the parent J774.1 cells. The TNF-α-inducing activity of p-TUA in J774.1 cells was completely inhibited by anti-mouse CD14 monoclonal antibody (MAb). p-TUA also induced interleukin-8 (IL-8) in human monocytic THP-1 cells differentiated to macrophage-like cells expressing CD14. Anti-human CD14 MAb, anti-human TLR4 MAb, and synthetic lipid A precursor IVA, an LPS antagonist, almost completely inhibited the IL-8-inducing ability of p-TUA, as well as LPS, in the differentiated THP-1 cells. Reduced p-TUA did not exhibit any activities in J774.1 or THP-1 cells. These findings strongly suggested that M. luteus TUA activates murine and human monocytic cells in a CD14- and TLR4-dependent manner, similar to LPS.

scholarly journals Metabolic Profiling of Buddleia indica Leaves using LC/MS and Evidence of their Antioxidant and Hepatoprotective Activity Using Different In Vitro and In Vivo Experimental Models

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 412
Author(s):  
Fadia S. Youssef ◽  
Mohamed L. Ashour ◽  
Hesham A. El-Beshbishy ◽  
Abdel Nasser B. Singab ◽  
Michael Wink
Keyword(s):  
Antioxidant Properties ◽  
Lipid Peroxide ◽  
Hepatoprotective Activity ◽  
Experimental Models ◽  
Ionization Mass ◽  
Necrosis Factor Alpha ◽  
Stress Markers ◽  
Tnf Α

LC-ESI-MS (Liquid Chromatography coupled with Electrospray Ionization Mass Spectrometry profiling of a methanol extract from Buddleia indica (BIM) leaves revealed 12 main peaks in which verbascoside and buddlenoid B represent the major compounds. The antioxidant and hepatoprotective activities of BIM were investigated using different in vitro and in vivo experimental models. BIM exhibited substantial in vitro antioxidant properties in DPPH· and HepG2 assays. Regarding CCl4 (carbon tetrachloride) induced hepatotoxicity in a rat model, oxidative stress markers became significantly ameliorated after oral administration of BIM. Lipid peroxide levels showed a 51.85% decline relative to CCl4-treated rats. Super oxide dismutase (SOD), total antioxidant status (TAS), and catalase (CAT) revealed a marked increase by 132.48%, 187.18%, and 114.94% relative to the CCl4 group. In a tamoxifen-induced hepatotoxicity model, BIM showed a considerable alleviation in liver stress markers manifested by a 46.06% and 40% decline in ALT (Alanine Transaminase) and AST (Aspartate Transaminase) respectively. Thiobarbituric acid reactive substances (TBARS) were reduced by 28.57% and the tumor necrosis factor alpha (TNF-α) level by 50%. A virtual screening of major secondary metabolites of BIM to TNF-alpha employing the C-docker protocol showed that gmelinoside H caused the most potent TNF- α inhibition as indicated from their high fitting scores. Thus, BIM exhibited a potent hepatoprotective activity owing to its richness in antioxidant metabolites.

scholarly journals Mycobacterium avium Biofilm Attenuates Mononuclear Phagocyte Function by Triggering Hyperstimulation and Apoptosis during Early Infection

2013 ◽  
Vol 82 (1) ◽  
pp. 405-412 ◽  
Author(s):  
Sasha J. Rose ◽  
Luiz E. Bermudez
Keyword(s):  
Immune System ◽  
Mycobacterium Avium ◽  
Innate Immune System ◽  
Innate Immune ◽  
Mononuclear Phagocytes ◽  
Bacterial Killing ◽  
Content Type ◽  
Tnf Α

ABSTRACTMycobacterium aviumsubsp.hominissuisis an opportunistic human pathogen that has been shown to form biofilmin vitroandin vivo. Biofilm formationin vivoappears to be associated with infections in the respiratory tract of the host. The reasoning behind howM. aviumsubsp.hominissuisbiofilm is allowed to establish and persist without being cleared by the innate immune system is currently unknown. To identify the mechanism responsible for this, we developed anin vitromodel using THP-1 human mononuclear phagocytes cocultured with establishedM. aviumsubsp.hominissuisbiofilm and surveyed various aspects of the interaction, including phagocyte stimulation and response, bacterial killing, and apoptosis.M. aviumsubsp.hominissuisbiofilm triggered robust tumor necrosis factor alpha (TNF-α) release from THP-1 cells as well as superoxide and nitric oxide production. Surprisingly, the hyperstimulated phagocytes did not effectively eliminate the cells of the biofilm, even when prestimulated with gamma interferon (IFN-γ) or TNF-α or cocultured with natural killer cells (which have been shown to induce anti-M. aviumsubsp.hominissuisactivity when added to THP-1 cells infected with planktonicM. aviumsubsp.hominissuis). Time-lapse microscopy and the TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) assay determined that contact with theM. aviumsubsp.hominissuisbiofilm led to early, widespread onset of apoptosis, which is not seen until much later in planktonicM. aviumsubsp.hominissuisinfection. Blocking TNF-α or TNF-R1 during interaction with the biofilm significantly reduced THP-1 apoptosis but did not lead to elimination ofM. aviumsubsp.hominissuis. Our data collectively indicate thatM. aviumsubsp.hominissuisbiofilm induces TNF-α-driven hyperstimulation and apoptosis of surveilling phagocytes, which prevents clearance of the biofilm by cells of the innate immune system and allows the biofilm-associated infection to persist.

scholarly journals Interleukin-10 inhibits the in vivo and in vitro adverse effects of TNF-α on the endothelium of murine aorta

2010 ◽  
Vol 299 (4) ◽  
pp. H1160-H1167 ◽  
Author(s):  
Saiprasad M. Zemse ◽  
Chin Wei Chiao ◽  
Rob H. P. Hilgers ◽  
R. Clinton Webb
Keyword(s):  
Endothelial Dysfunction ◽  
Interleukin 10 ◽  
Enos Expression ◽  
Response Curves ◽  
Female Mice ◽  
In Vivo Experiments ◽  
Tnf Α ◽  
Significant Impairment

TNF-α is a proinflammatory cytokine and is an important mediator of maternal endothelial dysfunction leading to preeclampsia. In this study, we tested whether IL-10 protects against TNF-α-induced endothelial dysfunction in murine aorta. In in vitro experiments, aortic rings of C57BL/6 female mice were incubated in Dulbecco's modified Eagle's medium in the presence of either vehicle (distilled H2O), TNF-α (4 nmol/l), or recombinant mouse IL-10 (300 ng/ml) or in the presence of both TNF-α and IL-10 for 22 h at 37°C. In in vivo experiments C57BL6/IL-10 knockout female mice were treated with saline or TNF-α (220 ng·kg−1·day−1) for 14 days. Aortic rings were isolated from in vitro and in vivo experiments and mounted in a wire myograph (Danish Myotech) and stretched to a tension of 5 mN. Endothelium-dependent relaxation was assessed by constructing cumulative concentration-response curves to acetylcholine (ACh, 0.001–10 μmol/l) during phenylephrine (10 μmol/l)-induced contraction. As a result, overnight exposure of aortic rings to TNF-α resulted in significant blunted maximal relaxing responses ( Emax) to ACh compared with untreated rings (22 ± 4 vs. 82 ± 3%, respectively). IL-10 knockout mice treated with TNF-α showed significant impairment in ACh responses ( Emax) compared with C57BL/6 mice treated with TNF-α (51 ± 3 vs. 72 ± 3%, respectively). Western blot analysis showed that endothelial nitric oxide synthase (eNOS) expression was reduced by TNF-α in in vitro and in vivo experiments, whereas IL-10 restored the eNOS expression. In conclusion, the anti-inflammatory cytokine IL-10 prevents impairment in endothelium-dependent vasorelaxation caused by TNF-α by protecting eNOS expression.

scholarly journals Modulation of Endotoxin- and Enterotoxin-Induced Cytokine Release by In Vivo Treatment with β-(1,6)-Branched β-(1,3)-Glucan

1999 ◽  
Vol 67 (1) ◽  
pp. 244-252 ◽  
Author(s):  
Jindrich Soltys ◽  
Mark T. Quinn
Keyword(s):  
Proinflammatory Cytokines ◽  
Necrosis Factor Alpha ◽  
Enhanced Production ◽  
Tnf Α ◽  
Host Mortality ◽  
Toxic Shock Syndrome Toxin ◽  
Stimulation Of ◽  
In Cells

ABSTRACT Leukocytes activated by endotoxin or enterotoxins release proinflammatory cytokines, thereby contributing to the cascade of events leading to septic shock. In the present studies, we analyzed the effects of in vivo administration of a soluble immunomodulator, β-(1,6)-branched β-(1,3)-glucan (soluble β-glucan), on toxin-stimulated cytokine production in monocytes and lymphocytes isolated from treated mice. In vitro stimulation of lymphocytes isolated from soluble β-glucan-treated mice with lipopolysaccharide (LPS) resulted in enhanced production of interleukin-6 (IL-6) and suppressed production of tumor necrosis factor alpha (TNF-α), while stimulation of these cells with staphylococcal enterotoxin B (SEB) or toxic shock syndrome toxin 1 (TSST-1) resulted in enhanced production of gamma interferon (IFN-γ) and suppressed production of IL-2 and TNF-α compared to that in cells isolated from untreated mice. In vitro stimulation of monocytes isolated from soluble β-glucan-treated mice with LPS also resulted in suppressed TNF-α production, while stimulation of these cells with SEB or TSST-1 resulted in suppressed IL-6 and TNF-α production compared to that in cells isolated from untreated mice. Thus, the overall cytokine pattern of leukocytes from soluble β-glucan-treated mice reflects suppressed production of proinflammatory cytokines, especially TNF-α. Taken together, our results suggest that treatment with soluble β-glucan can modulate the induction cytokines during sepsis, resulting in an overall decrease in host mortality.

scholarly journals Mechanisms Involved in the Pathogenesis of Sepsis Are Not Necessarily Reflected by In Vitro Cell Activation Studies

1998 ◽  
Vol 66 (11) ◽  
pp. 5372-5378 ◽  
Author(s):  
Claudia R. Amura ◽  
R. Silverstein ◽  
D. C. Morrison
Keyword(s):  
Cell Activation ◽  
Endotoxic Shock ◽  
Peritoneal Macrophages ◽  
In Vitro Studies ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
In Vitro Systems ◽  
A Cell

ABSTRACT It is thought that lipopolysaccharide (LPS) from gram-negative bacteria contributes significantly to the pathogenesis of septic shock. In vitro studies to address the mechanisms involved in this process have often investigated human monocytes or mouse macrophages, since these cells produce many of the mediators found in septic patients. Targeting of these mediators, especially tumor necrosis factor alpha (TNF-α), has been pursued as a means of reducing mortality in sepsis. Two experimental approaches were designed to test the assumption that in vitro studies with macrophages accurately predict in vivo mechanisms of LPS pathogenesis. In the first approach, advantage was taken of the fact that on consecutive days after injection of thioglycolate into mice, increased numbers of macrophages could be harvested from the peritoneum. These cells manifested markedly enhanced levels of in vitro TNF-α, interleukin 6 (IL-6), and nitric oxide production in response to LPS. In d-galactosamine-sensitized mice, however, thioglycolate treatment significantly decreased mortality due to LPS, as well as levels of circulating TNF-α and IL-6. Anti-TNF-α treatment confirmed this cytokine’s role in the observed lethality. In a second experimental approach, we compared the mouse macrophage-stimulating potencies of different LPS preparations with their lethalities to mice. In these studies, the in vitro macrophage-stimulating profiles presented by rough-LPS and smooth-LPS preparations were the reverse of their relative lethal potencies in vivo. In conclusion, peritoneal macrophages appear not to be the major cells responsible for the overall host response during endotoxic shock. These findings underscore the importance of verifying the correlation of in vivo systems with in vitro systems when attributing specific functions to a cell type.

scholarly journals Characterization of the Plasmacytoid Dendritic Cell Response to Transmitted/Founder and Nontransmitted Variants of HIV-1

2018 ◽  
Vol 92 (19) ◽  
Author(s):  
Jordan Ari Schwartz ◽  
Hongliang Zhang ◽  
Zachary Ende ◽  
Martin J. Deymier ◽  
Terry Lee ◽  
...  
Keyword(s):  
Dendritic Cell ◽  
Plasmacytoid Dendritic Cell ◽  
Female Genital Tract ◽  
Enzyme Linked Immunosorbent Assay ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
The Impact ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection often arises from a single transmitted/founder (TF) viral variant among a large pool of viruses in the quasispecies in the transmitting partner. TF variants are typically nondominant in blood and genital secretions, indicating that they have unique traits. The plasmacytoid dendritic cell (pDC) is the primary alpha interferon (IFN-α)-producing cell in response to viral infections and is rapidly recruited to the female genital tract upon exposure to HIV-1. The impact of pDCs on transmission is unknown. We investigated whether evasion of pDC responses is a trait of TF viruses. pDCs from healthy donors were stimulated in vitro with a panel of 20 HIV-1 variants, consisting of one TF variant and three nontransmitted (NT) variants each from five transmission-linked donor pairs, and secretion of IFN-α and tumor necrosis factor alpha (TNF-α) was measured by enzyme-linked immunosorbent assay (ELISA). No significant differences in cytokine secretion in response to TF and NT viruses were observed, despite a trend toward enhanced IFN-α and TNF-α production in response to TF viruses. NT viruses demonstrated polarization toward production of either IFN-α or TNF-α, indicating possible dysregulation. Also, for NT viruses, IFN-α secretion was associated with increased resistance of the virus to inactivation by IFN-α in vitro, suggesting in vivo evolution. Thus, TF viruses do not appear to preferentially subvert pDC activation compared to that with nontransmitted HIV-1 variants. pDCs may, however, contribute to the in vivo evolution of HIV-1. IMPORTANCE The plasmacytoid dendritic cell (pDC) is the first cell type recruited to the site of HIV-1 exposure; however, its contribution to the viral bottleneck in HIV-1 transmission has not been explored previously. We hypothesized that transmitted/founder viruses are able to avoid the pDC response. In this study, we used previously established donor pair-linked transmitted/founder and nontransmitted (or chronic) variants of HIV-1 to stimulate pDCs. Transmitted/founder HIV-1, instead of suppressing pDC responses, induced IFN-α and TNF-α secretion to levels comparable to those induced by viruses from the transmitting partner. We noted several unique traits of chronic viruses, including polarization between IFN-α and TNF-α production as well as a strong relationship between IFN-α secretion and the resistance of the virus to neutralization. These data rule out the possibility that TF viruses preferentially suppress pDCs in comparison to the pDC response to nontransmitted HIV variants. pDCs may, however, be important drivers of viral evolution in vivo.

scholarly journals Cinnamon and Eucalyptus Oils Suppress the Inflammation Induced by Lipopolysaccharide In Vivo

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7410
Author(s):  
Chen Zhao ◽  
Yuwei Cao ◽  
Zhuo Zhang ◽  
Dechao Nie ◽  
Yanling Li
Keyword(s):  
Tissue Injury ◽  
Body Weight Gain ◽  
Animal Health ◽  
Interleukin 10 ◽  
Necrosis Factor Alpha ◽  
Cinnamon Oil ◽  
Eucalyptus Oil ◽  
Tnf Α ◽  
Anti Inflammatory

Inflammation caused by bacterial lipopolysaccharide (LPS) disrupts epithelial homeostasis and threatens both human and animal health. Therefore, the discovery and development of new anti-inflammatory drugs is urgently required. Plant-derived essential oils (EOs) have good antioxidant and anti-inflammatory activities. Thus, this study aims to screen and evaluate the effects of cinnamon oil and eucalyptus oil on anti-inflammatory activities. The associated evaluation indicators include body weight gain, visceral edema coefficient, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), nitrogen monoxide (NO), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor alpha (TNF-α), Urea, Crea, ALT, TLR4, MyD88, NF-κB, IκB-α, iNOS, and Mn-SOD. In addition, tissue injury was determined by H&E staining. The results revealed that cinnamon oil and eucalyptus oil suppressed inflammation by decreasing SOD, TNF-α, and NF-κB levels. We also found that cinnamon oil increased the level of GSH-Px, MDA, and Mn-SOD, as well as the visceral edema coefficient of the kidney and liver. Altogether, these findings illustrated that cinnamon oil and eucalyptus oil exhibited wide antioxidant and anti-inflammatory activities against LPS-induced inflammation.

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