scholarly journals Diacylglycerol kinase ζ regulates microbial recognition and host resistance to Toxoplasma gondii

2007 ◽  
Vol 204 (4) ◽  
pp. 781-792 ◽  
Author(s):  
Cheng-Hu Liu ◽  
Fabiana S. Machado ◽  
Rishu Guo ◽  
Kim E. Nichols ◽  
A. Wesley Burks ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Toxoplasma Gondii ◽  
Second Messengers ◽  
Endotoxin Shock ◽  
Microbial Infection ◽  
Surface Receptors ◽  
Toxoplasma Gondii Infection ◽  
Factor Α

Mammalian Toll-like receptors (TLRs) recognize microbial pathogen-associated molecular patterns and are critical for innate immunity against microbial infection. Diacylglycerol (DAG) kinases (DGKs) regulate the intracellular levels of two important second messengers involved in signaling from many surface receptors by converting DAG to phosphatidic acid (PA). We demonstrate that the ζ isoform of the DGK family (DGKζ) is expressed in macrophages (Mφ) and dendritic cells. DGKζ deficiency results in impaired interleukin (IL) 12 and tumor necrosis factor α production following TLR stimulation in vitro and in vivo, increased resistance to endotoxin shock, and enhanced susceptibility to Toxoplasma gondii infection. We further show that DGKζ negatively controls the phosphatidylinositol 3–kinase (PI3K)–Akt pathway and that inhibition of PI3K activity or treatment with PA can restore lipopolysaccharide-induced IL-12 production by DGKζ-deficient Mφ. Collectively, our data provide the first genetic evidence that an enzyme involved in DAG/PA metabolism plays an important role in innate immunity and indicate that DGKζ promotes TLR responses via a pathway involving inhibition of PI3K.

Analogs of marinopyrrole A show enhancement to observed in vitro potency against acute Toxoplasma gondii infection

2021 ◽  
Author(s):  
Matthew C. Martens ◽  
Yan Liu ◽  
Austin G. Sanford ◽  
Alexander I. Wallick ◽  
Rosalie C. Warner ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Acute Infection ◽  
Standard Of Care ◽  
Host Cells ◽  
Infection Model ◽  
Current Standard ◽  
Clinical Consequences ◽  
Toxoplasma Gondii Infection

The apicomplexan parasite Toxoplasma gondii is the causative agent of toxoplasmosis, a globally distributed infection with severe clinical consequences for immunocompromised individuals and developing fetuses. There are few available treatments, and these are associated with potentially severe adverse effects. Marinopyrrole A, a compound discovered in a marine Streptomyces species, has previously been found to exhibit potent antimicrobial activity, prompting our interest in exploring efficacy against Toxoplasma gondii . We found that marinopyrrole A was a highly potent anti- Toxoplasma molecule, with an in vitro 50% maximal inhibitory concentration (IC 50 ) of 0.31 μM corresponding to a higher potency than that of the current standard of care (pyrimethamine); however, addition of 20% serum led to abrogation of potency, and toxicity to human cell lines was observed. Yet, application of marinopyrrole A to an in vivo lethal acute infection model facilitated significantly enhanced survival at doses of 5, 10, and 20 mg/kg. We then tested a series of marinopyrrole A analogs—RL002, RL003, and RL125—demonstrating significantly increased potency in vitro , with IC 50 values ranging from 0.09-0.17 μM (3.6-6.8X increase relative to pyrimethamine). No detectable cytotoxicity was observed up to 50 μM in human foreskin fibroblasts, with cytotoxicity in HepG2 cells ranging from ∼28-50 μM, corresponding to >200X selectivity for parasites over host cells. All analogs additionally showed reduced sensitivity to serum. Further, RL003 potently inhibited in vitro -generated bradyzoites at 0.245 μM. Taken together, these data support further development of marinopyrrole A analogs as promising anti- Toxoplasma molecules to further combat this prevalent infection.

Enrofloxacin is able to control Toxoplasma gondii infection in both in vitro and in vivo experimental models

2012 ◽  
Vol 187 (1-2) ◽  
pp. 44-52 ◽  
Author(s):  
Bellisa Freitas Barbosa ◽  
Angelica Oliveira Gomes ◽  
Eloisa Amália Vieira Ferro ◽  
Danielle Reis Napolitano ◽  
José Roberto Mineo ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Experimental Models ◽  
Toxoplasma Gondii Infection

scholarly journals Parasite-induced Lipoxin A4 Is an Endogenous Regulator of IL-12 Production and Immunopathology in Toxoplasma gondii Infection

2002 ◽  
Vol 196 (9) ◽  
pp. 1253-1262 ◽  
Author(s):  
Julio Aliberti ◽  
Charles Serhan ◽  
Alan Sher
Keyword(s):  
Toxoplasma Gondii ◽  
Wild Type ◽  
Microbial Infection ◽  
Lipoxin A4 ◽  
Systemic Control ◽  
Physiological Relevance ◽  
Proinflammatory Responses ◽  
Ifn Γ ◽  
Toxoplasma Gondii Infection

The production of interleukin (IL)-12 is critical for the development of interferon (IFN)-γ–dependent resistance to Toxoplasma gondii. Nevertheless, when this response is dysregulated, such as occurs in the absence of IL-10, the uncontrolled inflammation that results can have lethal consequences for the host. Recently, we demonstrated that lipoxin (LX)A4, an eicosanoid mediator that depends on 5-lipoxygenase (LO) for its biosynthesis, exerts a regulatory role on dendritic cell IL-12 production triggered artificially by a T. gondii extract. We now formally establish the physiological relevance of this pathway in the systemic control of IL-12 production induced by live T. gondii infection and demonstrate its function to be distinct from that of IL-10. Thus, T. gondii–exposed wild-type, but not 5-LO–deficient animals, produced high levels of serum LXA4 beginning at the onset of chronic infection. Moreover, 5-LO−/−, in contrast to wild-type mice, succumbed during the same period displaying a marked encephalitis. The increased mortality of the 5-LO−/− animals was also associated with significant elevations of IL-12 and IFN-γ and was completely prevented by the administration of a stable LXA4 analogue. Together, these findings demonstrate a new pathway involving the induction of host LXs for the in vivo regulation of proinflammatory responses during microbial infection.

scholarly journals Evaluation of the anti-Toxoplasma gondii Activity of Hederagenin in vitro and in vivo

2021 ◽  
Vol 59 (3) ◽  
pp. 297-301
Author(s):  
Run-Hui Zhang ◽  
Runhao Jin ◽  
Hao Deng ◽  
Qing-Kun Shen ◽  
Zhe-Shan Quan ◽  
...  
Keyword(s):  
Food Safety ◽  
Toxoplasma Gondii ◽  
Biochemical Parameters ◽  
Animal Husbandry ◽  
Selectivity Index ◽  
In Vivo Experiments ◽  
Low Cytotoxicity ◽  
Toxoplasma Gondii Infection

Toxoplasma gondii infection is widespread worldwide, not only posing a serious threat to human food safety and animal husbandry, but also endangering human health. The selectivity index was employed to measure anti-T. gondii activity. Hederagenin (HE) exhibited potent anti-T. gondii activity and low cytotoxicity. For this reason, HE was selected for in vivo experiments. HE showed 64.8%±13.1% inhibition for peritoneal tachyzoites in mice, higher than spiramycin 56.8%±6.0%. Biochemical parameters such as alanine aminotransferase, aspartate aminotransferase, glutathione, and malondialdehyde, illustrated that HE was a good inhibitor of T. gondii in vivo. This compound was also effective in relieving T. gondii-induced liver damage. Collectively, it was demonstrated that HE had potential as an anti-T. gondii agent.

scholarly journals In vitro and in vivo evaluation of virus-induced innate immunity in mouse

2021 ◽  
Vol 2 (3) ◽  
pp. 100708
Author(s):  
Long Shen ◽  
Xiao Shan ◽  
Penghui Hu ◽  
Yanan Zhang ◽  
Zemin Ji ◽  
...  
Keyword(s):  
Innate Immunity ◽  
In Vivo Evaluation

Anti-parasitic activity of Annona muricata L. leaf ethanolic extract and its fractions against Toxoplasma gondii in vitro and in vivo

2021 ◽  
pp. 114019
Author(s):  
Natália Carnevalli Miranda ◽  
Ester Cristina Borges Araujo ◽  
Allisson Benatti Justino ◽  
Yusmaris Cariaco ◽  
Caroline Martins Mota ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Ethanolic Extract ◽  
Annona Muricata ◽  
Parasitic Activity

Leishmania infantum and Toxoplasma gondii: Mixed infection of macrophages in vitro and in vivo

2011 ◽  
Vol 128 (3) ◽  
pp. 279-284 ◽  
Author(s):  
Vasiliki Christodoulou ◽  
Ippokratis Messaritakis ◽  
Eleni Svirinaki ◽  
Christos Tsatsanis ◽  
Maria Antoniou
Keyword(s):  
Toxoplasma Gondii ◽  
Mixed Infection ◽  
Leishmania Infantum

scholarly journals Quercetin and Idebenone Ameliorate Oxidative Stress, Inflammation, DNA damage, and Apoptosis Induced by Titanium Dioxide Nanoparticles in Rat Liver

Dose-Response ◽  
2018 ◽  
Vol 16 (4) ◽  
pp. 155932581881218 ◽  
Author(s):  
Laila M. Fadda ◽  
Hanan Hagar ◽  
Azza M. Mohamed ◽  
Hanaa M. Ali
Keyword(s):  
Titanium Dioxide ◽  
Histopathological Examination ◽  
Titanium Dioxide Nanoparticles ◽  
Reactive Protein ◽  
Wide Range ◽  
Factor Α ◽  
Immunoglobin G ◽  
Endothelial Growth Factor

Titanium dioxide nanoparticles (TiO2-NPs) are extensively used in a wide range of applications; however, many reports have investigated their nanotoxicological effect at the molecular level either in vitro or in vivo systems. The defensive roles of quercetin (Qur) or idebenone (Id) against the hepatotoxicity induced by TiO2-NPs were evaluated in the current study. The results showed that the coadministration of Qur or Id to rats intoxicated with TiO2-NPs markedly ameliorated the elevation in hepatic malondialdehyde (MDA), serum alanine amino-transferase (ALT), glucose, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), immunoglobin G (IgG), and C-reactive protein (CRP) levels compared to their levels in TiO2-NPs-treated rats. The aforementioned antioxidants also effectively modulated the changes in the levels of serum vascular endothelial growth factor (VEGF), nitric oxide (NO), hepatic DNA breakage, caspase-3, and inhibition of drug metabolizing enzymes (cytochrome P450s; CYP4502E12E1) in rat livers induced by TiO2-NPs toxicity. The histopathological examination of the liver section showed that TiO2-NPs caused severe degeneration of most hepatocytes with an increase in collagen in the portal region, while treatment with the antioxidants in question improved liver architecture. These outcomes supported the use of Qur and Id as protective agents against the hepatotoxicity induced by TiO2-NPs and other hepatotoxic drugs.

scholarly journals In Vivo and in Vitro Evidence for the Involvement of Tumor Necrosis Factor-α in the Induction of Leptin by Lipopolysaccharide*

Endocrinology ◽  
1998 ◽  
Vol 139 (5) ◽  
pp. 2278-2283 ◽  
Author(s):  
Brian N. Finck ◽  
Keith W. Kelley ◽  
Robert Dantzer ◽  
Rodney W. Johnson
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Factor Α ◽  
Necrosis Factor

scholarly journals Virulent Shigella flexneri subverts the host innate immune response through manipulation of antimicrobial peptide gene expression

2008 ◽  
Vol 205 (5) ◽  
pp. 1121-1132 ◽  
Author(s):  
Brice Sperandio ◽  
Béatrice Regnault ◽  
Jianhua Guo ◽  
Zhi Zhang ◽  
Samuel L. Stanley ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Shigella Flexneri ◽  
Host Cells ◽  
Virulence Plasmid ◽  
Cationic Peptides ◽  
Immunity Genes ◽  
Genes Encoding ◽  
Peptide Gene

Antimicrobial factors are efficient defense components of the innate immunity, playing a crucial role in the intestinal homeostasis and protection against pathogens. In this study, we report that upon infection of polarized human intestinal cells in vitro, virulent Shigella flexneri suppress transcription of several genes encoding antimicrobial cationic peptides, particularly the human β-defensin hBD-3, which we show to be especially active against S. flexneri. This is an example of targeted survival strategy. We also identify the MxiE bacterial regulator, which controls a regulon encompassing a set of virulence plasmid-encoded effectors injected into host cells and regulating innate signaling, as being responsible for this dedicated regulatory process. In vivo, in a model of human intestinal xenotransplant, we confirm at the transcriptional and translational level, the presence of a dedicated MxiE-dependent system allowing S. flexneri to suppress expression of antimicrobial cationic peptides and promoting its deeper progression toward intestinal crypts. We demonstrate that this system is also able to down-regulate additional innate immunity genes, such as the chemokine CCL20 gene, leading to compromised recruitment of dendritic cells to the lamina propria of infected tissues. Thus, S. flexneri has developed a dedicated strategy to weaken the innate immunity to manage its survival and colonization ability in the intestine.

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