scholarly journals Inhibition of Different Lassa Virus Strains by Alpha and Gamma Interferons and Comparison with a Less Pathogenic Arenavirus

2004 ◽  
Vol 78 (6) ◽  
pp. 3162-3169 ◽  
Author(s):  
Marcel Asper ◽  
Thomas Sternsdorf ◽  
Meike Hass ◽  
Christian Drosten ◽  
Antje Rhode ◽  
...  
Keyword(s):  
Vero Cells ◽  
Lassa Fever ◽  
Lassa Virus ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
High Pathogenicity ◽  
Ifn Γ ◽  
Virus Strains

ABSTRACT The high pathogenicity of Lassa virus is assumed to involve resistance to the effects of interferon (IFN). We have analyzed the effects of alpha IFN (IFN-α), IFN-γ, and tumor necrosis factor alpha (TNF-α) on replication of Lassa virus compared to the related, but less pathogenic, lymphocytic choriomeningitis virus (LCMV). Three low-passage Lassa virus strains (AV, NL, and CSF), isolated from humans with mild to fulminant Lassa fever, were tested. Lassa virus replication was inhibited by IFN-α and IFN-γ, but not TNF-α, in Huh7 and Vero cells. The degree of IFN sensitivity of a Lassa virus isolate did not correlate with disease severity in human patients. Furthermore, cytokine effects observed for Lassa virus and LCMV (strains CH-5692, Armstrong, and WE) were similar. To address the mechanisms involved in the IFN effect, we used cell lines in which overexpression of IFN-stimulated proteins promyelocytic leukemia protein (PML) and Sp100 could be induced. Both proteins reside in PML bodies, a cellular target of the LCMV and Lassa virus Z proteins. Overexpression of PML or Sp100 did not affect replication of either virus. This, together with the previous finding that PML knockout facilitates LCMV replication in vitro and in vivo (M. Djavani, J. Rodas, I. S. Lukashevich, D. Horejsh, P. P. Pandolfi, K. L. Borden, and M. S. Salvato, J. Virol. 75:6204-6208, 2001; W. V. Bonilla, D. D. Pinschewer, P. Klenerman, V. Rousson, M. Gaboli, P. P. Pandolfi, R. M. Zinkernagel, M. S. Salvato, and H. Hengartner, J. Virol. 76:3810-3818, 2002), describes PML as a mediator within the antiviral pathway rather than as a direct effector protein. In conclusion, the high pathogenicity of Lassa virus compared to LCMV is probably not due to increased resistance to the effects of IFN-α or IFN-γ. Both cytokines inhibit replication which is relevant for the design of antiviral strategies against Lassa fever with the aim of enhancing the IFN response.

scholarly journals Differential Regulation of DAP12 and Molecules Associated with DAP12 during Host Responses to Mycobacterial Infection

2004 ◽  
Vol 72 (5) ◽  
pp. 2477-2483 ◽  
Author(s):  
Naoko Aoki ◽  
Anna Zganiacz ◽  
Peter Margetts ◽  
Zhou Xing
Keyword(s):  
Mycobacterial Infection ◽  
Host Responses ◽  
Necrosis Factor Alpha ◽  
Lung Macrophage ◽  
Tnf Α ◽  
Kinetic Expression ◽  
Ifn Γ

ABSTRACT DAP12 and its associating molecules MDL-1, TREM-1, and TREM-2 are the recently identified immune regulatory molecules, expressed primarily on myeloid cells including monocytes/macrophages, dendritic cells, NK cells, and neutrophils. However, little is known about the regulation of their expression during host antimicrobial responses. We have investigated the effect of pulmonary mycobacterial infection and type 1 cytokines on the expression of these molecules both in vivo and in vitro. While DAP12 was constitutively expressed at high levels in the lungs, the MDL-1, TREM-1, and TREM-2 molecules were inducible during mycobacterial infection. Their kinetic expression was correlated with that of the type 1 cytokines tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ). In primary lung macrophage cultures, high constitutive levels of DAP12 and TREM-2 were not modulated by mycobacterial or type 1 cytokine exposure. In contrast, expression of both MDL-1 and TREM-1 was markedly induced by mycobacterial infection and such induction was inhibited by concurrent exposure to IFN-γ. On mycobacterial infection of TNF-α−/− and IFN-γ−/− mice in vivo or their lung macrophages in vitro, TNF-α was found to be critical for mycobacterially induced MDL-1, but not TREM-1, expression whereas IFN-γ negatively regulated mycobacterially induced MDL-1 and TREM-1 expression. Our findings thus suggest that DAP12 and its associating molecules are differentially regulated by mycobacterial infection and type 1 cytokines and that MDL-1- and TREM-1-triggered DAP12 signaling may play an important role in antimicrobial type 1 immunity.

scholarly journals Pentoxifylline Inhibits Superantigen-Induced Toxic Shock and Cytokine Release

1999 ◽  
Vol 6 (4) ◽  
pp. 594-598 ◽  
Author(s):  
Teresa Krakauer ◽  
Bradley G. Stiles
Keyword(s):  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Toxic Shock ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Ifn Γ ◽  
Toxic Shock Syndrome Toxin

ABSTRACT Tumor necrosis factor alpha (TNF-α) is a critical cytokine that mediates the toxic effects of bacterial superantigens like staphylococcal enterotoxin B (SEB) and toxic shock syndrome toxin 1 (TSST-1). Pentoxifylline, an anti-inflammatory agent that inhibits endotoxemia and lipopolysaccharide (LPS)-induced release of TNF-α, was tested for its ability to inhibit SEB- and TSST-1-induced activation of human peripheral blood mononuclear cells (PBMCs) in vitro and toxin-mediated shock in mice. Stimulation of PBMCs by SEB or TSST-1 was effectively blocked by pentoxifylline (10 mM), as evidenced by the inhibition of TNF-α, interleukin 1β (IL-1β), gamma interferon (IFN-γ), and T-cell proliferation. The levels of TNF-α, IL-1α, and IFN-γ in serum after an SEB or TSST-1 injection were significantly lower in mice given pentoxifylline (5.5 mg/animal) versus control mice. Additionally, pentoxifylline diminished the lethal effects and temperature fluctuations elicited by SEB and TSST-1. Thus, in addition to treating endotoxemias, the cumulative in vitro and in vivo data suggest that pentoxifylline may also be useful in abrogating the ill effects of staphylococcal enterotoxins and TSST-1.

scholarly journals Nramp1 Is Not a Major Determinant in the Control of Brucella melitensis Infection in Mice

2003 ◽  
Vol 71 (2) ◽  
pp. 621-628 ◽  
Author(s):  
Laurence A. Guilloteau ◽  
Jacques Dornand ◽  
Antoine Gross ◽  
Michel Olivier ◽  
Fabienne Cortade ◽  
...  
Keyword(s):  
Brucella Melitensis ◽  
Natural Resistance ◽  
Interleukin 12 ◽  
Necrosis Factor Alpha ◽  
Reverse Transcription Pcr ◽  
Tnf Α ◽  
Ifn Γ ◽  
Oxide Synthase

ABSTRACT Brucella, the causative agent of brucellosis in animals and humans, can survive and proliferate within macrophages. Macrophages mediate mouse resistance to various pathogens through the expression of the Nramp1 gene. The role of this gene in the control of Brucella infection was investigated. When BALB/c mice (Nramp1s ) and C.CB congenic mice (Nramp1r ) were infected with Brucella melitensis, the number of Brucella organisms per spleen was significantly larger in the C.CB mice than in the BALB/c mice during the first week postinfection (p.i.). This Nramp1-linked susceptibility to Brucella was temporary, since similar numbers of Brucella were recovered from the two strains of mice 2 weeks p.i. The effect of Nramp1 expression occurred within splenocytes intracellularly infected by Brucella. However, there was no difference between in vitro replication rates of Brucella in macrophages isolated from the two strains of mice infected in vivo or in Nramp1 RAW264 transfectants. In mice, infection with Brucella induced an inflammatory response, resulting in splenomegaly and recruitment of phagocytes in the spleen, which was amplified in C.CB mice. Reverse transcription-PCR (RT-PCR), performed 5 days p.i., showed that inducible nitric oxide synthase, tumor necrosis factor alpha (TNF-α), interleukin-12 p40 (IL-12p40), gamma interferon (IFN-γ), and IL-10 mRNAs were similarly induced in spleens of the two strains. In contrast, the mRNA of KC, a C-X-C chemokine, was induced only in infected C.CB mice at this time. This pattern of mRNA expression was maintained at 14 days p.i., with IFN-γ and IL-12p40 mRNAs being more intensively induced in the infected C.CB mice, but TNF-α mRNA was no longer induced. The higher recruitment of neutrophils observed in the spleens of infected C.CB mice could explain the temporary susceptibility of C.CB mice to B. melitensis infection. In contrast to infections with Salmonella, Leishmania, and Mycobacterium, the expression of the Nramp1 gene appears to be of limited importance for the natural resistance of mice to Brucella.

scholarly journals Leukotriene B4 Induces Nitric Oxide Synthesis in Trypanosoma cruzi-Infected Murine Macrophages and Mediates Resistance to Infection

2002 ◽  
Vol 70 (8) ◽  
pp. 4247-4253 ◽  
Author(s):  
A. Talvani ◽  
F. S. Machado ◽  
G. C. Santana ◽  
A. Klein ◽  
L. Barcelos ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Trypanosoma Cruzi ◽  
Leukotriene B4 ◽  
No Production ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACT The production of nitric oxide (NO) by gamma interferon (IFN-γ)-activated macrophages is a major effector mechanism during experimental Trypanosoma cruzi infection. In addition to IFN-γ, chemoattractant molecules, such as platelet-activating factor (PAF) and CC chemokines, may also activate macrophages to induce NO and mediate the killing of T. cruzi in an NO-dependent manner. Here we investigated the ability of leukotriene B4 (LTB4) to induce the production of NO by macrophages infected with T. cruzi in vitro and whether NO mediated LTB4-induced parasite killing. The activation of T. cruzi-infected but not naive murine peritoneal macrophages with LTB4 induced the time- and concentration-dependent production of NO. In addition, low concentrations of LTB4 acted in synergy with IFN-γ to induce NO production. The NO produced mediated LTB4-induced microbicidal activity in macrophages, as demonstrated by the inhibitory effects of an inducible NO synthase inhibitor. LTB4-induced NO production and parasite killing were LTB4 receptor dependent and were partially blocked by a PAF receptor antagonist. LTB4 also induced significant tumor necrosis factor alpha (TNF-α) production, and blockade of TNF-α suppressed LTB4-induced NO release and parasite killing. A blockade of LTB4 or PAF receptors partially inhibited IFN-γ-induced NO and TNF-α production but not parasite killing. Finally, daily treatment of infected mice with CP-105,696 was accompanied by a significantly higher level of blood parasitemia, but not lethality, than that seen in vehicle-treated animals. In conclusion, our results suggest a role for LTB4 during experimental T. cruzi infection. Chemoattractant molecules such as LTB4 not only may play a major role in leukocyte migration into sites of inflammation in vivo but also, in the event of an infection, may play a relevant role in the activation of recruited leukocytes to kill the invading microorganism in an NO-dependent manner.

scholarly journals CD40 Ligation Prevents Trypanosoma cruziInfection through Interleukin-12 Upregulation

1999 ◽  
Vol 67 (4) ◽  
pp. 1929-1934 ◽  
Author(s):  
Damien Chaussabel ◽  
Frédérique Jacobs ◽  
Jan de Jonge ◽  
Marijke de Veerman ◽  
Yves Carlier ◽  
...  
Keyword(s):  
De Novo ◽  
Critical Role ◽  
Interleukin 12 ◽  
No Production ◽  
Cd40 Ligation ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Ifn Γ

ABSTRACT Because of the critical role of the CD40-CD40 ligand (CD40L) pathway in the induction and effector phases of immune responses, we investigated the effects of CD40 ligation on the control ofTrypanosoma cruzi infection. First, we observed that supernatants of murine spleen cells stimulated by CD40L-transfected 3T3 fibroblasts (3T3-CD40L transfectants) prevent the infection of mouse peritoneal macrophages (MPM) by T. cruzi. This phenomenon depends on de novo production of nitric oxide (NO) as it is prevented by the addition of N-nitro-l-arginine methyl ester, a NO synthase inhibitor. NO production requires interleukin (IL)-12-mediated gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) synthesis as demonstrated by inhibition experiments using neutralizing anti-IL-12, anti-IFN-γ, and anti-TNF-α monoclonal antibodies (MAb). We found that an activating anti-CD40 MAb also directly stimulates IFN-γ-activated MPM to produce NO and thereby to control T. cruzi infection. To determine the in vivo relevance of these in vitro findings, mice were injected with 3T3-CD40L transfectants or 3T3 control fibroblasts at the time ofT. cruzi inoculation. We observed that in vivo CD40 ligation dramatically reduced both parasitemia and the mortality rate of T. cruzi-infected mice. A reduced parasitemia was still observed when the injection of 3T3-CD40L transfectants was delayed 8 days postinfection. It was abolished by injection of anti-IL-12 MAb. Taken together, these data establish that CD40 ligation facilitates the control of T. cruzi infection through a cascade involving IL-12, IFN-γ, and NO.

scholarly journals A 70-Kilodalton Recombinant Heat Shock Protein ofCandida albicans Is Highly Immunogenic and Enhances Systemic Murine Candidiasis

1998 ◽  
Vol 66 (5) ◽  
pp. 2154-2162 ◽  
Author(s):  
Carla Bromuro ◽  
Roberto La Valle ◽  
Silvia Sandini ◽  
Francesca Urbani ◽  
Clara M. Ausiello ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Mononuclear Cells ◽  
Cell Mediated Immunity ◽  
Healthy Human ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Ifn Γ

ABSTRACT The 70-kDa recombinant Candida albicans heat shock protein (CaHsp70) and its 21-kDa C-terminal and 28-kDa N-terminal fragments (CaHsp70-Cter and CaHsp70-Nter, respectively) were studied for their immunogenicity, including proinflammatory cytokine induction in vitro and in vivo, and protection in a murine model of hematogenous candidiasis. The whole protein and its two fragments were strong inducers of both antibody (Ab; immunoglobulin G1 [IgG1] and IgG2b were the prevalent isotypes) and cell-mediated immunity (CMI) responses in mice. CaHsp70 preparations were also recognized as CMI targets by peripheral blood mononuclear cells of healthy human subjects. Inoculation of CaHsp70 preparations into immunized mice induced rapid production of interleukin-6 (IL-6) and tumor necrosis factor alpha, peaking at 2 to 5 h and declining within 24 h. CaHsp70 and CaHsp70-Cter also induced gamma interferon (IFN-γ), IL-12, and IL-10 but not IL-4 production by CD4+ lymphocytes cocultured with splenic accessory cells from nonimmunized mice. In particular, the production of IFN-γ was equal if not superior to that induced in the same cells by whole, heat-inactivated fungal cells or the mitogenic lectin concanavalin A. In immunized mice, however, IL-4 but not IL-12 was produced in addition to IFN-γ upon in vitro stimulation of CD4+ cells with CaHsp70 and CaHsp70-Cter. These animals showed a decreased median survival time compared to nonimmunized mice, and their mortality was strictly associated with organ invasion by fungal hyphae. Their enhanced susceptibility was attributable to the immunization state, as it did not occur in congenitally athymic nude mice, which were unable to raise either Ab or CMI responses to CaHsp70 preparations. Together, our data demonstrate the elevated immunogenicity of CaHsp70, with which, however, no protection against but rather some enhancement of Candida infection seemed to occur in the mouse model used.

Προβιοτικές και τεχνολογικές ιδιότητες οξυγαλακτικών βακτηρίων. In vitro και in vivo επίδραση στο ελικοβακτήριο του πυλωρού

2004 ◽  
Author(s):  
Πέτρος-Αχιλλέας Μαραγκουδάκης
Keyword(s):  
E Coli ◽  
Tnf Α ◽  
Ifn Γ

Σκοπός: Ο σκοπός της παρούσας διατριβής ήταν η εξέταση του προβιοτικού δυναμικού στελεχών οξυγαλακτικών βακτηρίων μέσω μίας σειράς in vitro δοκιμών, και της μετέπειτα εφαρμογής επιλεγμένων στελεχών σε in vivo μοντέλα ποντικών έναντι της λοίμωξης του Η. pylori και της ελκώδους κολίτιδας, αλλά και σε τεχνολογικό επίπεδο στην παρασκευή γιαουρτιού.Υλικά και μέθοδοι: Στη διατριβή αυτή μελετήθηκαν 51 στελέχη Lactobacillus του Εργαστηρίου Γαλακτοκομίας του Γεωπονικού Πανεπιστημίου Αθηνών, απομονωμένα κυρίως από γαλακτοκομικά προϊόντα και κόπρανα προβάτων, καθώς και 22 στελέχη Enterococcus και Streptococcus, απομονωμένα από κόπρανα προβάτων. Τα στελέχη αυτά εξετάστηκαν σε μία σειρά in vitro δοκιμών που αφορούν την επιβίωσή τους σε συνθήκες εξομοίωσης του ανθρώπινου γαστρεντερικού συστήματος, οι οποίες περιελάμβαναν επιβίωση σε χαμηλό pH, επιβίωση παρουσία των πρωτεολυτικών ενζύμων πεψίνη και παγκρεατίνη, και επιβίωση παρουσία χολικών αλάτων.Στην συνέχεια τα στελέχη εξετάστηκαν σε δοκιμές βασικές για την ασφάλεια χρήσης τους στον ανθρώπινο οργανισμό. "Ολα τα στελέχη δοκιμάστηκαν ως προς την αιμολυτική τους δραστικότητα, και τα στελέχη γαλακτοβακίλλων συγκεκριμένα για την ανθεκτικότητά τους έναντι επιλεγμένων αντιβιοτικών.Παράλληλα, εξετάστηκαν in vitro βασικές ιδιότητες που θεωρούνται επιθυμητές για τα προβιοτικά στελέχη, όπως υδρόλυση των χολικών αλάτων, μελέτη της υδροφοβίας και της ικανότητας πρόσδεσης των γαλακτοβακίλλων σε κύτταρα Caco-2, ικανότητά διέγερσης κυττάρων του ανθρώπινου οργανισμού (PBMCs), καθώς και μελέτη της αντιμικροβιακής δράσης έναντι παθογόνων βακτηρίων και της δυνατότητάς αναστολής της πρόσδεσης παθογόνων σε κύτταρα Caco-2.Στην συνέχεια πραγματοποιήθηκαν in vivo μελέτες σε ποντίκια, για την εξακρίβωση του προβιοτικού χαρακτήρα επιλεγμένων στελεχών. Τα στελέχη L. casei Shirota ACA-DC 6002 και L. paracasei subsp. tolerans ACA-DC 4037 χορηγήθηκαν σε ποντίκια επιμολυσμένα με Η. pylori και αξιολογήθηκε η επίδραση των γαλακτοβακίλλων αυτών στον αποικισμό του παθογόνου και στην αξιολόγηση του βαθμού και της δραστικότητας στο στομάχι. Επίσης, τα στελέχη αυτά χρησιμοποιήθηκαν και για την πρόληψη TNBS- κολίτιδας σε ποντίκια.Τέλος, επιλεγμένα στελέχη γαλακτοβακίλλων αξιολογήθηκαν για την τεχνολογική τους εφαρμογή, μελετώντας την ικανότητά οξίνϊσης του γάλακτος και τη χρήση τους ως καλλιέργειες για την παρασκευή γιαούρτηςΑποτελέσματα: Ορισμένα στελέχη βρέθηκαν να έχουν ικανοποιητική επιβίωση σε συνθήκες εξομοίωσης του ανθρώπινου πεπτικού συστήματος. Κανένα στέλεχος δεν βρέθηκε να έχει ισχυρή (β-) αιμολυτική δράση, ενώ η αντοχή των γαλακτοβακίλλων έναντι επιλεγμένων αντιβιοτικών δεν παρουσιάστηκε διαφορετική από την έμφυτη και αναμενόμενη, ανάλογα το είδος των εξεταζόμενων γαλακτοβακίλλων, ενώ αρκετά στελέχη παρουσίασαν ικανότητα υδρόλυσης χολικών αλάτων. Τα στελέχη παρουσίασαν ποικιλόμορφη πρόσδεση στους οργανικούς διαλύτες, αλλά γενικά τα περισσότερα στελέχη δεν παρουσίασαν μεγάλη υδροφοβία, ενώ αρκετά στελέχη γαλακτοβακίλλων παρουσίασαν ικανοποιητική πρόσδεση σε κύτταρα Caco-2 (>5%), με το στέλεχος L. plantarum ACA-DC 146 (25% πρόσδεση) να ξεχωρίζει. Το ίδιο στέλεχος, μαζί με το L. paracasei subsp. tolerans ACA-DC 4037 βρέθηκαν να προκαλούν την έκκριση υψηλών επιπέδων φλεγμονωδών κυτταροκινών (IL-12, TNF-α και IFN-γ) από PBMCs, ενώ αντίθετα το στέλεχος L. casei Shirota ACA-DC 6002 προκάλεσε την έκκριση της αντιφλεγμονώδους κυτταροκίνης IL-10. Παρόλο που κανένα από τα υπερκείμενα των στελεχών δεν παρεμπόδισε τα στελέχη E. coli, S. typhimurium και Η. pylori, ορισμένα στελέχη, όπως τα L. casei Shirota, L. plantarum ACA-DC 146 και L. paracasei subsp. tolerans ACA-DC 4037 προκάλεσαν την αναστολή της πρόσδεσης εντερικών παθογόνων (E. coli και S. typhimurium) σε κύτταρα Caco-2 σε επίπεδα μέχρι και 50%.In vivo, η χορήγηση του L. casei Shirota ACA-DC 6002 σε ποντίκια οδήγησε στην μείωση του βαθμού και της δραστικότητας της γαστρίτιδας αλλά και στον αποικισμό του Η. pylori. Παρόμοια αποτελέσματα, αλλά σε μικρότερη έκταση, παρατηρήθηκαν με την χορήγηση του στελέχους L. paracasei subsp. tolerans ACA-DC 4037. Παράλληλα, το στέλεχος L. casei Shirota ACA-DC 6002 δείχνει να παρέχει προστασία σε ποντίκια κατά την πρόκληση ελκώδους κολίτιδας με την χορήγηση TNBS.Σε τεχνολογικό επίπεδο, κανένα από τα εξεταζόμενα στελέχη δεν παρουσίασε υψηλή ικανότητα οξύνισης στο γάλα και κατά συνέπεια δεν ήταν δυνατόν να χρησιμοποιηθούν ως εναρκτήριες καλλιέργειες για την παρασκευή γιαούρτης. Από την άλλη, καθώς κανένα στέλεχος δεν παρεμποδίζει αλλά και δεν παρεμποδίζεται από τις παραδοσιακές εναρκτήριες καλλιέργειες γιαούρτης, ήταν δυνατή η χρήση τους ως συμπληρωματικές καλλιέργειας για την παρασκευή γιαούρτης. Στην συνέχεια επιλεγμένα στελέχη χρησιμοποιήθηκαν για το σκοπό αυτό και το στέλεχος L. paracasei subsp. tolerans ACA- DC 4037 ξεχώρισε όταν χρησιμοποιήθηκε ως συμπληρωματική καλλιέργεια για την παρασκευή γιαούρτης με εμβόλιο πηγμένου γάλακτος (1% ν/ν) στους 42°C, λόγω της υψηλής μικροβιακής, φυσικοχημικής και οργανοληπτικής ποιότητας του προϊόντος. Συμπεράσματα: Τα στελέχη L. casei Shirota ACA-DC 6002, L. plantarum ACA-DC 146 και L. paracasei subsp. tolerans ACA-DC 4037, επέδειξαν υποσχόμενο προβιοτικό δυναμικό κατά την διάρκεια εκτεταμένων in vitro και in vivo δοκιμών. Η μελέτη αυτή επιβεβαιώνει τις προβιοτικές ιδιότητες του L. casei Shirota και επιδεικνύει την πιθανή εφαρμογής του στη λοίμωξη του Η. pylori και στην ελκώδη κολίτιδα στον άνθρωπο. Επιπλέον, το στέλεχος L paracasei subsp. tolerans ACA-DC 4037 διαθέτει επίσης δυναμικό χρήσης έναντι του Η. pylori αλλά και στην παρασκευή ενός επιτυχημένου προβιοτικού γιαουρτιού. Τέλος, το στέλεχος L. plantarum ACA-DC 146 μπορεί να εξεταστεί in vivo σε μοντέλα αλλεργικών αντιδράσεων, λόγω της υψηλής αντιφλεγμονώδους επίδρασής τους σε ανθρώπινα περιφερειακά μονοπύρηνα (PBMCs.)

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 Diagnostic Implications of Antigen-Induced Gamma Interferon, Nitric Oxide, and Tumor Necrosis Factor Alpha Production by Peripheral Blood Mononuclear Cells from Mycobacterium bovis-Infected Cattle

2003 ◽  
Vol 10 (5) ◽  
pp. 960-966 ◽  
Author(s):  
W. R. Waters ◽  
M. V. Palmer ◽  
D. L. Whipple ◽  
M. P. Carlson ◽  
B. J. Nonnecke
Keyword(s):  
Bovine Tuberculosis ◽  
Tumor Necrosis ◽  
Mononuclear Cells ◽  
Infected Cattle ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Factor Alpha ◽  
Ifn Γ ◽  
Necrosis Factor

ABSTRACT Bovine tuberculosis in the United States has proven costly to cattle producers as well as to government regulatory agencies. While in vivo responsiveness to mycobacterial antigens is the current standard for the diagnosis of tuberculosis, in vitro assays are gaining acceptance, especially as ancillary or complementary tests. To evaluate in vitro indices of cellular sensitization, antigen-induced gamma interferon (IFN-γ), nitric oxide (NO), and tumor necrosis factor alpha (TNF-α) responses by blood mononuclear cells from Mycobacterium bovis-infected cattle were quantified and compared. Using an aerosol model of infection, two doses of each of two strains of M. bovis (95-1315 and HC-2045T) were used to induce a range of IFN-γ, NO, and TNF-α responses. Infection-specific increases in NO, but not in IFN-γ or TNF-α, were detected in nonstimulated cultures at 48 h, a finding that is indicative of nonspecific activation and spontaneous release of NO. The infective dose of M. bovis organisms also influenced responses. At 34 days postinfection, IFN-γ, NO, and TNF-α responses in antigen-stimulated cells from cattle receiving 105 CFU of M. bovis organisms were greater than responses of cells from cattle infected with 103 CFU of M. bovis organisms. The NO response, but not the IFN-γ and TNF-α responses, was influenced by infective strains of M. bovis. The TNF-α, NO, and IFN-γ responses followed similar kinetics, with strong positive associations among the three readouts. Overall, these findings indicate that NO and TNF-α, like IFN-γ, may prove useful as indices for the diagnosis of bovine tuberculosis.

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