scholarly journals Nano DNA Vaccine Encoding Toxoplasma gondii Histone Deacetylase SIR2 Enhanced Protective Immunity in Mice

Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1582
Author(s):  
Zhengqing Yu ◽  
Yujia Lu ◽  
Wandi Cao ◽  
Muhammad Tahir Aleem ◽  
Junlong Liu ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Histone Deacetylase ◽  
Dna Vaccine ◽  
Laser Scanning ◽  
Lethal Dose ◽  
Parasite Burden ◽  
Effective Vaccine ◽  
Th2 Immune Response ◽  
Plga Nanospheres

The pathogen of toxoplasmosis, Toxoplasma gondii (T. gondii), is a zoonotic protozoon that can affect the health of warm-blooded animals including humans. Up to now, an effective vaccine with completely protection is still inaccessible. In this study, the DNA vaccine encoding T. gondii histone deacetylase SIR2 (pVAX1-SIR2) was constructed. To enhance the efficacy, chitosan and poly (d, l-lactic-co-glycolic)-acid (PLGA) were employed to design nanospheres loaded with the DNA vaccine, denoted as pVAX1-SIR2/CS and pVAX1-SIR2/PLGA nanospheres. The pVAX1-SIR2 plasmids were transfected into HEK 293-T cells, and the expression was evaluated by a laser scanning confocal microscopy. Then, the immune protections of pVAX1-SIR2 plasmid, pVAX1-SIR2/CS nanospheres, and pVAX1-SIR2/PLGA nanospheres were evaluated in a laboratory animal model. The in vivo findings indicated that pVAX1-SIR2/CS and pVAX1-SIR2/PLGA nanospheres could generate a mixed Th1/Th2 immune response, as indicated by the regulated production of antibodies and cytokines, the enhanced maturation and major histocompatibility complex (MHC) expression of dendritic cells (DCs), the induced splenocyte proliferation, and the increased percentages of CD4+ and CD8+ T lymphocytes. Furthermore, this enhanced immunity could obviously reduce the parasite burden in immunized animals through a lethal dose of T. gondii RH strain challenge. All these results propose that pVAX1-SIR2 plasmids entrapped in chitosan or PLGA nanospheres could be the promising vaccines against acute T. gondii infections and deserve further investigations.

scholarly journals With Chitosan and PLGA as the Delivery Vehicle, Toxoplasma gondii Oxidoreductase-Based DNA Vaccines Decrease Parasite Burdens in Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhengqing Yu ◽  
Wandi Cao ◽  
Xuchen Gao ◽  
Muhammad Tahir Aleem ◽  
Junlong Liu ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Dna Vaccine ◽  
Parasite Burden ◽  
Mice Model ◽  
Delivery Vehicle ◽  
Hek 293 ◽  
Cellular And Humoral Immunity ◽  
Acute Toxoplasmosis ◽  
Promising Vaccine Candidate ◽  
Plga Nanospheres

Toxoplasma gondii (T. gondii) is an intracellular parasitic protozoan that can cause serious public health problems. However, there is no effectively preventive or therapeutic strategy available for human and animals. In the present study, we developed a DNA vaccine encoding T. gondii oxidoreductase from short-chain dehydrogenase/reductase family (TgSDRO-pVAX1) and then entrapped in chitosan and poly lactic-co-glycolic acid (PLGA) to improve the efficacy. When encapsulated in chitosan (TgSDRO-pVAX1/CS nanospheres) and PLGA (TgSDRO-pVAX1/PLGA nanospheres), adequate plasmids were loaded and released stably. Before animal immunizations, the DNA vaccine was transfected into HEK 293-T cells and examined by western blotting and laser confocal microscopy. Th1/Th2 cellular and humoral immunity was induced in immunized mice, accompanied by modulated secretion of antibodies and cytokines, promoted the maturation and MHC expression of dendritic cells, and enhanced the percentages of CD4+ and CD8+ T lymphocytes. Immunization with TgSDRO-pVAX1/CS and TgSDRO-pVAX1/PLGA nanospheres conferred significant immunity with lower parasite burden in the mice model of acute toxoplasmosis. Furthermore, our results also lent credit to the idea that TgSDRO-pVAX1/CS and TgSDRO-pVAX1/PLGA nanospheres are substitutes for each other. In general, the current study proposed that TgSDRO-pVAX1 with chitosan or PLGA as the delivery vehicle is a promising vaccine candidate against acute toxoplasmosis.

scholarly journals Toxoplasma gondii Proteasome Subunit Alpha Type 1 with Chitosan: A Promising Alternative to Traditional Adjuvant

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 752
Author(s):  
Zhengqing Yu ◽  
Wenxi Ding ◽  
Muhammad Tahir Aleem ◽  
Junzhi Su ◽  
Junlong Liu ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Parasite Burden ◽  
Effective Vaccine ◽  
Promising Alternative ◽  
Proteasome Subunit ◽  
Humoral Immune ◽  
Alpha Type

As an important zoonotic protozoan, Toxoplasma gondii (T. gondii) has spread around the world, leading to infections in one-third of the population. There is still no effective vaccine or medicine against T. gondii, and recombinant antigens entrapped within nanospheres have benefits over traditional vaccines. In the present study, we first expressed and purified T. gondii proteasome subunit alpha type 1 (TgPSA1), then encapsulated the recombinant TgPSA1 (rTgPSA1) in chitosan nanospheres (CS nanospheres, rTgPSA1/CS nanospheres) and incomplete Freund’s adjuvant (IFA, rTgPSA1/IFA emulsion). Antigens entrapped in CS nanospheres reached an encapsulation efficiency of 67.39%, and rTgPSA1/CS nanospheres showed a more stable release profile compared to rTgPSA1/IFA emulsion in vitro. In vivo, Th1-biased cellular and humoral immune responses were induced in mice and chickens immunized with rTgPSA1/CS nanospheres and rTgPSA1/IFA emulsion, accompanied by promoted production of antibodies, IFN-γ, IL-4, and IL-17, and modulated production of IL-10. Immunization with rTgPSA1/CS nanospheres and rTgPSA1/IFA emulsion conferred significant protection, with prolonged survival time in mice and significantly decreased parasite burden in chickens. Furthermore, our results also indicate that rTgPSA1/CS nanospheres could be used as a substitute for rTgPSA1/IFA emulsion, with the optimal administration route being intramuscular in mass vaccination. Collectively, the results of this study indicate that rTgPSA1/CS nanospheres represent a promising vaccine to protect animals against acute toxoplasmosis.

scholarly journals In Silico Prediction of T and B Cell Epitopes of SAG1-Related Sequence 3 (SRS3) Gene for Developing Toxoplasma gondii Vaccine

2020 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Abolfazl Mirzadeh ◽  
Geita Saadatnia ◽  
Majid Golkar ◽  
Jalal Babaie ◽  
Samira Amiri ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Dna Vaccine ◽  
In Silico ◽  
Effective Vaccine ◽  
T Cell Epitopes ◽  
In Silico Prediction ◽  
Vaccine Strategy ◽  
Related Sequence ◽  
Ideal Tool ◽  
Major Surface

: Toxoplasmosis is a worldwide infection that can lead to serious problems in immune-compromised individuals and fetuses. A DNA vaccine strategy would be an ideal tool against Toxoplasma gondii. One of the necessary measures to provide an effective vaccine is the selection of proteins with high antigenicity. The SAG1-related sequence 3 (SRS3) protein is a major surface antigen in T. gondii that can be used as a vaccine candidate. In the present study, bioinformatics and computational methods were utilized to predict protein characteristics, as well as secondary and tertiary structures. The in silico approach is highly suited to analyze, design, and evaluate DNA vaccine strategies. Hence, in silico prediction was used to identify B and T cell epitopes and compare the antigenicity of SRS3 and other candidate genes of Toxoplasma previously applied in the production of vaccines. The results of the analysis theoretically showed that SRS3 has multiple epitopes with high antigenicity, proposing that SRS3 is a promising immunogenic candidate for the development of DNA vaccines against toxoplasmosis.

scholarly journals Antitumor Effect of a Novel Spiro-Acridine Compound is Associated with Up-Regulation of Th1-Type Responses and Antiangiogenic Action

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 29 ◽  
Author(s):  
Daiana K. Frade Silva ◽  
Sâmia S. Duarte ◽  
Thaís M. H. Lisboa ◽  
Rafael C. Ferreira ◽  
Ana Luíza de O. Lopes ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Antitumor Activity ◽  
Tumor Cells ◽  
Antitumor Effect ◽  
Inflammatory Responses ◽  
Lethal Dose ◽  
Ehrlich Ascites Carcinoma ◽  
Antitumor Effects ◽  
Th2 Immune Response

Tumor cells have specific features, including angiogenesis induction, cell cycle dysregulation, and immune destruction evasion. By inducing a T helper type 2 (Th2) immune response, tumor cells may favor immune tolerance within the tumor, which allows progression of cancer growth. Drugs with potential antitumor activity are the spiro-acridines, which is a promising new class of acridine compounds. Herein, the novel spiro-acridine (E)-5′-oxo-1′-((3,4,5-trimethoxybenzylidene)amino)-1′,5′-dihydro-10H-spiro[acridine-9,2′-pyrrole]-4′-carbonitrile (AMTAC-17) was synthesized and tested for antitumor effects. Toxicity evaluation was performed in mice after acute treatment (2000 mg/kg, intraperitoneally, i.p.). The Ehrlich ascites carcinoma model was used to investigate the antitumor activity of AMTAC-17 (12.5, 25, or 50 mg/kg, i.p.) after seven days of treatment. Effects on the cell cycle, angiogenesis, and inflammatory responses were investigated. LD50 (lethal dose 50%) was estimated to be higher than 5000 mg/kg. AMTAC-17 reduced the Ehrlich tumor’s total viable cancer cells count and peritumoral micro-vessels density, and induced an increase in the sub-G1 peak. Additionally, there was an increase of Th1 cytokine profile levels (IL-1β, TNF-α, and IL-12). In conclusion, the spiro-acridine compound AMTAC-17 presents low toxicity, and its in vivo antitumor effect involves modulation of the immune system to a cytotoxic Th1 profile and a reduction of tumor angiogenesis.

Generation of Toxoplasma gondii GRA1 protein and DNA vaccine loaded chitosan particles: preparation, characterization, and preliminary in vivo studies

2003 ◽  
Vol 266 (1-2) ◽  
pp. 17-27 ◽  
Author(s):  
Maytal Bivas-Benita ◽  
Marleen Laloup ◽  
Soetkin Versteyhe ◽  
Joelle Dewit ◽  
Jos De Braekeleer ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Dna Vaccine ◽  
In Vivo Studies

scholarly journals Licarin-B Exhibits Activity Against the Toxoplasma gondii RH Strain by Damaging Mitochondria and Activating Autophagy

2021 ◽  
Vol 9 ◽  
Author(s):  
Jili Zhang ◽  
Hongfei Si ◽  
Kun Lv ◽  
Yanhua Qiu ◽  
Jichao Sun ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
High Efficiency ◽  
Quantitative Polymerase Chain Reaction ◽  
Parasite Burden ◽  
New Drugs ◽  
Ultrastructural Changes ◽  
Dependent Manner ◽  
Dapi Staining

Toxoplasma gondii is an obligate intracellular pathogen that infects warm-blooded animals and humans. However, side effects limit toxoplasmosis treatment, and new drugs with high efficiency and low toxicity need to be developed. Natural products found in plants have become a useful source of drugs for toxoplasmosis. In this study, twenty natural compounds were screened for anti-T. gondii activity by Giemsa staining or real-time fluorescence quantitative polymerase chain reaction (qPCR) in vitro. Among these, licarin-B from nutmeg exhibited excellent anti-T. gondii activity, inhibiting T. gondii invasion and proliferation in a dose-dependent manner, with an EC50 of 14.05 ± 3.96 μg/mL. In the in vivo, licarin-B treatment significantly reduced the parasite burden in tissues compared to no treatment, protected the 90% infected mice from to death at 50 mg/kg.bw. Flow cytometry analysis suggested a significant reduction in T. gondii survival after licarin-B treatment. Ultrastructural changes in T. gondii were observed by transmission electron microscopy (TEM), as licarin-B induced mitochondrial swelling and formation of cytoplasmic vacuoles, an autophagosome-like double-membrane structure and extensive clefts around the T. gondii nucleus. Furthermore, MitoTracker Red CMXRos, MDC, and DAPI staining showed that licarin-B promoted mitochondrial damage, autophagosome formation, and nuclear disintegration, which were consistent with the TEM observations. Together, these findings indicate that licarin-B is a promising anti-T. gondii agent that potentially functions by damaging mitochondria and activating autophagy, leading to T. gondii death.

scholarly journals Transcriptomic Analysis of the Effects of Chemokine Receptor CXCR3 Deficiency on Immune Responses in the Mouse Brain during Toxoplasma gondii Infection

2021 ◽  
Vol 9 (11) ◽  
pp. 2340
Author(s):  
Kousuke Umeda ◽  
Youta Goto ◽  
Kenichi Watanabe ◽  
Nanako Ushio ◽  
Ragab M. Fereig ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Mouse Brain ◽  
Chemokine Receptor ◽  
Chemokine Receptors ◽  
Expression Patterns ◽  
Parasite Burden ◽  
Cxc Chemokine ◽  
Immune Related Genes ◽  
The Brain

The obligate intracellular parasite Toxoplasma gondii infects warm-blooded animals, including humans. We previously revealed through a whole-brain transcriptome analysis that infection with T. gondii in mice causes immune response-associated genes to be upregulated, for instance, chemokines and chemokine receptors such as CXC chemokine receptor 3 (CXCR3) and its ligand CXC chemokine ligand 10 (CXCL10). Here, we describe the effect of CXCR3 on responses against T. gondii infection in the mouse brain. In vivo assays using CXCR3-deficient mice showed that the absence of CXCR3 delayed the normal recovery of body weight and increased the brain parasite burden, suggesting that CXCR3 plays a role in the control of pathology in the brain, the site where chronic infection occurs. Therefore, to further analyze the function of CXCR3 in the brain, we profiled the gene expression patterns of primary astrocytes and microglia by RNA sequencing and subsequent analyses. CXCR3 deficiency impaired the normal upregulation of immune-related genes during T. gondii infection, in astrocytes and microglia alike. Collectively, our results suggest that the immune-related genes upregulated by CXCR3 perform a particular role in controlling pathology when the host is chronically infected with T. gondii in the brain.

scholarly journals Determination of lumefantrine as an effective drug against Toxoplasma gondii infection – in vitro and in vivo study

Parasitology ◽  
2020 ◽  
pp. 1-7
Author(s):  
Dawei Wang ◽  
Mengen Xing ◽  
Saeed El-Ashram ◽  
Yingying Ding ◽  
Xiao Zhang ◽  
...  
Keyword(s):  
Side Effects ◽  
Toxoplasma Gondii ◽  
Parasite Burden ◽  
Vero Cells ◽  
Negative Control ◽  
Protective Mechanism ◽  
High Dose ◽  
Mouse Tissues

Abstract Toxoplasma gondii is an obligate intracellular protozoan parasite, which can infect almost all warm-blooded animals, including humans, leading to toxoplasmosis. Currently, the effective treatment for human toxoplasmosis is the combination of sulphadiazine and pyrimethamine. However, both drugs have serious side-effects and toxicity in the host. Therefore, there is an urgent need for the discovery of new anti-T. gondii drugs with high potency and less or no side-effects. Our findings suggest that lumefantrine exerts activity against T. gondii by inhibiting its proliferation in Vero cells in vitro without being toxic to Vero cells (P ≤ 0.01). Lumefantrine prolonged mice infected with T. gondii from death for 3 days at the concentration of 50 μg L−1 than negative control (phosphate-buffered saline treated only), and reduced the parasite burden in mouse tissues in vivo (P ≤ 0.01; P ≤ 0.05). In addition, a significant increase in interferon gamma (IFN-γ) production was observed in high-dose lumefantrine-treated mice (P ≤ 0.01), whereas interleukin 10 (IL-10) and IL-4 levels increased in low-dose lumefantrine-treated mice (P ≤ 0.01). The results demonstrated that lumefantrine may be a promising agent to treat toxoplasmosis, and more experiments on the protective mechanism of lumefantrine should be undertaken in further studies.

scholarly journals Spiroindolone That Inhibits PfATPase4 Is a Potent, Cidal Inhibitor of Toxoplasma gondii TachyzoitesIn VitroandIn Vivo

2013 ◽  
Vol 58 (3) ◽  
pp. 1789-1792 ◽  
Author(s):  
Ying Zhou ◽  
Alina Fomovska ◽  
Stephen Muench ◽  
Bo-Shiun Lai ◽  
Ernest Mui ◽  
...  
Keyword(s):  
Body Weight ◽  
Toxoplasma Gondii ◽  
Inhibitory Concentration ◽  
Parasite Burden ◽  
Content Type ◽  
Medicine Development ◽  
Lead Candidate ◽  
Oral Doses

ABSTRACTHere, we show that spiroindolone, an effective treatment for plasmodia, is also active againstToxoplasma gondiitachyzoites.In vitro, spiroindolone NITD609 is cidal for tachyzoites (50% inhibitory concentration [IC50], 1μM) and not toxic to human cells at ≥10μM. Two daily oral doses of 100 mg/kg of body weight reduced the parasite burden in mice by 90% (P= 0.002), measured 3 days after the last dose. This inhibition ofT. gondiitachyzoitesin vitroandin vivoindicates that spiroindolone is a promising lead candidate for further medicine development.

scholarly journals LmjF.22.0810 from Leishmania major Modulates the Th2-Type Immune Response and Is Involved in Leishmaniasis Outcome

Biomedicines ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 452
Author(s):  
Andrés Vacas ◽  
Celia Fernández-Rubio ◽  
Esther Larrea ◽  
José Peña-Guerrero ◽  
Paul A. Nguewa
Keyword(s):  
Immune Response ◽  
Protein Kinase ◽  
Leishmania Major ◽  
Parasite Burden ◽  
Mrna Levels ◽  
Expression Change ◽  
Arginase 1 ◽  
Th2 Immune Response

A novel serine/threonine protein kinase, LmjF.22.0810, was recently described in Leishmania major. After generating an L. major cell line overexpressing LmjF.22.0810 (named LmJ3OE), the ability of this novel protein to modulate the Th2-type immune response was analyzed. Our results suggest that the protein kinase LmjF.22.0810 might be involved in leishmaniasis outcomes. Indeed, our study outlined the LmJ3OE parasites infectivity in vitro and in vivo. Transgenic parasites displayed lower phagocytosis rates in vitro, and their promastigote forms exhibited lower expression levels of virulence factors compared to their counterparts in control parasites. In addition, LmJ3OE parasites developed significantly smaller footpad swelling in susceptible BALB/c mice. Hematoxylin–eosin staining allowed the observation of a lower inflammatory infiltrate in the footpad from LmJ3OE-infected mice compared to animals inoculated with control parasites. Gene expression of Th2-associated cytokines and effectors revealed a dramatically lower induction in interleukin (IL)-4, IL-10, and arginase 1 (ARG1) mRNA levels at the beginning of the swelling; no expression change was found in Th1-associated cytokines except for IL-12. Accordingly, such results were validated by immunohistochemistry studies, illustrating a weaker expression of ARG1 and a similar induction for inducible NO synthase (iNOS) in footpads from LmJ3OE-infected mice compared to control L. major infected animals. Furthermore, the parasite burden was lower in footpads from LmJ3OE-infected mice. Our analysis indicated that such significant smaller footpad swellings might be due to an impairment of the Th2 immune response that subsequently benefits Th1 prevalence. Altogether, these studies depict LmjF.22.0810 as a potential modulator of host immune responses to Leishmania. Finally, this promising target might be involved in the modulation of infection outcome.

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