scholarly journals Mediation of inducible nitric oxide and immune-reactive lysozymes biosynthesis by eicosanoid and biogenic amines in flesh flies

2018 ◽  
Vol 38 (01) ◽  
pp. 93-104 ◽  
Author(s):  
Amr A. Mohamed ◽  
Mona M. Ali ◽  
Moataza A. Dorrah ◽  
Taha T. M. Bassal
Keyword(s):  
Nitric Oxide ◽  
Fat Body ◽  
Micrococcus Luteus ◽  
Insect Immunity ◽  
Immune Functions ◽  
Humoral Immune ◽  
Signalling Molecule ◽  
Flesh Flies ◽  
Biogenic Monoamine ◽  
Inducible Nitric Oxide

AbstractNitric oxide (NO) plays various roles in insect immunity: as a cytotoxic component and as a signalling molecule; and immune-reactive lysozymes (IrLys) provide a first line of humoral immune functions against invading bacteria. Although there is considerable literature on eicosanoid and biogenic monoamine actions on insect immunity, there is no information on the role(s) of these chemicals in inducing NO and IrLys. We addressed this gap by challenging third instarSarcophaga(Liopygia)argyrostoma(Robineau-Desvoidy) with the Gram-positive bacteriumMicrococcus luteus. Here, we report that bacterial challenge induces elevation of NO and IrLys concentrations in haemocytes and in the fat body. The plasma pool content is comparatively low. Eicosanoid biosynthesis inhibitors (EBIs) lead to suppression of both NO and IrLys levels. Control larvae have low constitutive levels of NO and lysozyme concentrations. Octopamine (OA) elicits elevation of NO and IrLys concentrations. A similar effect is obtained by 5-hydroxytryptamine (5-HT) for NO. These data indicate immune-mediating roles of eicosanoids, OA and 5-HT in NO and IrLys activities.

scholarly journals Persistent Cryptococcus neoformansPulmonary Infection in the Rat Is Associated with Intracellular Parasitism, Decreased Inducible Nitric Oxide Synthase Expression, and Altered Antibody Responsiveness to Cryptococcal Polysaccharide

2000 ◽  
Vol 68 (2) ◽  
pp. 832-838 ◽  
Author(s):  
David L. Goldman ◽  
Sunhee C. Lee ◽  
Aron J. Mednick ◽  
Lya Montella ◽  
Arturo Casadevall
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Persistent Infection ◽  
Fungal Pathogens ◽  
Epithelioid Cells ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

ABSTRACT Fungal pathogens are notorious for causing chronic and latent infections, but the mechanism by which they evade the immune response is poorly understood. A major limitation in the study of chronic fungal infection has been the lack of suitable animal models where the infection is controlled and yet persists. Pulmonary Cryptococcus neoformans infection in rats results in a diffuse pneumonitis that resolves without dissemination or scarring except for the persistence of interstitial and subpleural granulomas that harbor viable cryptococci inside macrophages and epithelioid cells. Infected rats are asymptomatic but remain infected for as long as 18 months after inoculation with C. neoformans. Containment of infection is associated with granuloma formation that can be partially abrogated by glucocorticoid administration. Using this model, we identified several features associated with persistent infection in the rat lung, including (i) localization of C. neoformans to discrete, well-organized granulomas; (ii) intracellular persistence ofC. neoformans within macrophages and epithelioid cells; (iii) reduced inducible nitric oxide synthase expression by granulomas harboring C. neoformans; and (iv) reduced antibody responses to cryptococcal polysaccharide. The results show that maintenance of persistent infection is associated with downregulation of both cellular and humoral immune responses.

scholarly journals Inducible Nitric Oxide Synthase-Deficient Mice Develop Enhanced Type 1 Cytokine-Associated Cellular and Humoral Immune Responses after Vaccination with AttenuatedSchistosoma mansoni Cercariae but Display Partially Reduced Resistance

1998 ◽  
Vol 66 (8) ◽  
pp. 3510-3518 ◽  
Author(s):  
Stephanie L. James ◽  
Allen W. Cheever ◽  
Patricia Caspar ◽  
Thomas A. Wynn
Keyword(s):  
Nitric Oxide ◽  
Immune Responses ◽  
Protective Immunity ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Oxide Synthase ◽  
Type 1 Cytokine ◽  
Deficient Mice ◽  
Inducible Nitric Oxide

ABSTRACT High levels of nitric oxide (NO) are produced by inducible nitric oxide synthase (iNOS) in response to activating signals from Th1-associated cytokines and play an important role in cytotoxicity and cytostasis against many pathogenic microorganisms. In addition to its direct effector function, NO serves as a potent immunoregulatory factor. NO produced by gamma interferon-activated macrophages immobilizes and kills Schistosoma mansoni larvae, and several studies have indicated a role for this pathway in protective immunity against this parasite. The potential regulatory influence of NO in immunity to S. mansoni is less well understood. In this study, we have used iNOS-deficient mice to determine the role of NO in mice vaccinated with irradiated cercariae of S. mansoni. We show by enzyme-linked immunosorbent assay and reverse transcriptase PCR analysis that vaccinated iNOS-deficient mice develop exacerbated type 1 cytokine responses in the lungs, the site where resistance to infection is primarily manifested. In addition, parasite-specific immunoglobulin G2a (IgG2a) and IgG2b antibody responses were significantly increased in vaccinated iNOS-deficient animals and total IgE antibody levels in serum were decreased relative to those in wild-type controls. Surprisingly, since resistance in this vaccine model is largely Th1 dependent and since Th1-related cellular and humoral immune responses were found to be exacerbated in vaccinated iNOS-deficient mice, vaccine-elicited protective immunity against challenge infection was found to be reduced. These findings demonstrate that iNOS plays a paradoxical role in immunity to S. mansoni, both in the effector mechanism of resistance and in the down regulation of the type 1 cytokine response, which is ultimately required for NO production.

scholarly journals Nitric Oxide Mediates Insect Cellular Immunity via Phospholipase A2 Activation

2017 ◽  
Vol 10 (1) ◽  
pp. 70-81 ◽  
Author(s):  
Md Sadekuzzaman ◽  
David Stanley ◽  
Yonggyun Kim
Keyword(s):  
Nitric Oxide ◽  
Biogenic Amines ◽  
Cross Talk ◽  
Fat Body ◽  
Dependent Manner ◽  
Immune Functions ◽  
Pla2 Activity ◽  
No Donor ◽  
Signaling Systems ◽  
Rnai Treatment

After infection or invasion is recognized, biochemical mediators act in signaling insect immune functions. These include biogenic amines, insect cytokines, eicosanoids, and nitric oxide (NO). Treating insects or isolated hemocyte populations with different mediators often leads to similar results. Separate treatments with an insect cytokine, 2 biogenic amines, and an eicosanoid lead to a single result, hemocyte spreading, understood in terms of intracellular cross-talk among these signaling systems. This study focuses on the cross-talk between NO and eicosanoid signaling in our model insect, Spodoptera exigua. Bacterial injection increased NO concentrations in the larval hemocytes and fat body, and RNA interference (RNAi) of the S. exigua NO synthase (NOS) gene suppressed NO concentrations. RNAi treatment also led to a significant reduction in hemocyte nodulation following bacterial injection. Similar RNAi treatments led to significantly reduced PLA2 activities in the hemocytes and fat body compared to control larvae. Injection of L-NAME also prevented the induction of PLA2 activity following bacterial challenge. An injected NO donor, S-nitroso-N-acetyl-DL-penicillamine, increased PLA2 activity in a dose-dependent manner. However, eicosanoids did not influence NO concentrations in immune-challenged larvae. We infer that NO and eicosanoid signaling operate via cross-talk mechanisms in which the elevated NO concentrations activate PLA2 and eicosanoid biosynthesis, which finally mediates various immune responses.

289: Roles of Inducible Nitric Oxide Synthase in Voiding Function and Bladder Pain During Experimental Cystitis

2006 ◽  
Vol 175 (4S) ◽  
pp. 96-96
Author(s):  
Masayoshi Nomura ◽  
Hisae Nishii ◽  
Masato Tsutsui ◽  
Naohiro Fujimoto ◽  
Tetsuro Matsumoto
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Voiding Function ◽  
Bladder Pain ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Thrombin Prevents the Expression of Inducible Nitric Oxide Synthase in Vascular Smooth Muscle Cells by a Proteolytically-Activated Thrombin Receptor

1995 ◽  
Vol 74 (03) ◽  
pp. 980-986 ◽  
Author(s):  
Valérie B Schini-Kerth ◽  
Beate Fißithaler ◽  
Thomas T Andersen ◽  
John W Fenton ◽  
Paul M Vanhoutte ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Inducible Nitric Oxide Synthase ◽  
Muscle Cells ◽  
Thrombin Receptor ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

SummaryProteolytically active forms of thrombin (α- and γ-thrombin) and thrombin receptor peptides inhibited the release of nitrite, a stable endproduct of nitric oxide, evoked by interleukin-1 β(IL-1 β) in cultured vascular smooth muscle cells while proteolytically inactive forms [D-Phe-Pro-Arg chloromethyl ketone-α-thrombin (PPACK-α- thrombin) and diisopropylphosphoryl-α-thrombin (DIP-α-thrombin)] had either no or only minimal inhibitory effects. Under bioassay conditions, perfusates from columns containing IL-1 β-activated vascular smooth muscle cells or cells treated with IL-1βplus PPACK-α-thrombin relaxed detector blood vessels. These relaxations were abolished by the inhibitor of nitric oxide synthesis, NG-nitro-L arginine. No relaxations were obtained with untreated cells or IL-1 β-treated cells in the presence of α-thrombin. The expression of inducible nitric oxide synthase mRNA and protein in vascular smooth muscle cells by IL-1 β was impaired by α-thrombin. These results demonstrate that thrombin regulates the expression of the inducible nitric oxide synthase at a transcriptional level via the proteolytic activation of the thrombin receptor in vascular smooth muscle cells

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