Gondii Parasites Research Articles

PLGA Nanoparticles as an Efficient Platform in Protein Vaccines Against Toxoplasma gondii.

Toxoplasma gondii (T. gondii) as an obligatory intracellular is widespread all over the world and causes considerable concerns in immunocompromised patients by developing toxoplasmic encephalitis and in pregnancy because of serious consequences in the fetus. Although vaccination is the only approach to overcome toxoplasmosis, there is no commercially available human vaccine against T. gondii. The remarkable features of poly (lactic-co-glycolic acid) (PLGA) particles have brought up the application of PLGA as a promising vaccine delivery vehicle against T. gondii and other intracellular parasites. This review focuses on the application of the PLGA delivery system in the development of preventive vaccines against T. gondii. In this study, all required data were collected from articles indexed in English databases, including Scopus, PubMed, Web of Science, Science Direct, and Google Scholar. Immunity against T. gondii, characteristics of PLGA particles as a delivery vehicle, and all researches on particulate PLGA vaccines with different T. gondii antigens and DNA against were discussed and their efficacies in conferring protection against a lethal challenge based on increased survival or reduced brain cyst loads have been shown. Although various levels of protection against lethal challenge have been achieved through PLGA-based vaccinations, there is still no complete protection against T. gondii infection. Surprisingly, the application of surface modifications of PLGA particles by mucoadhesive polymers, cationic agents, DCs (dendritic cells) targeting receptors, specialized membranous epithelial cells (M-cells), and co-delivery of the desired antigen along with toll-like receptor ligands would be a revolutionized vaccine strategy against T. gondii.

Real-Time Analysis of Mitochondrial Electron Transport Chain Function in Toxoplasma gondii Parasites Using a Seahorse XFe96 Extracellular Flux Analyzer.

The mitochondrial electron transport chain (ETC) performs several critical biological functions, including maintaining mitochondrial membrane potential, serving as an electron sink for important metabolic pathways, and contributing to the generation of ATP via oxidative phosphorylation. The ETC is important for the survival of many eukaryotic organisms, including intracellular parasites such as the apicomplexan Toxoplasma gondii. The ETC of T. gondii and related parasites differs in several ways from the ETC of the mammalian host cells they infect, and can be targeted by anti-parasitic drugs, including the clinically used compound atovaquone. To characterize the function of novel ETC proteins found in the parasite and to identify new ETC inhibitors, a scalable assay that assesses both ETC function and non-mitochondrial parasite metabolism (e.g., glycolysis) is desirable. Here, we describe methods to measure the oxygen consumption rate (OCR) of intact T. gondii parasites and thereby assess ETC function, while simultaneously measuring the extracellular acidification rate (ECAR) as a measure of general parasite metabolism, using a Seahorse XFe96 extracellular flux analyzer. We also describe a method to pinpoint the location of ETC defects and/or the targets of inhibitors, using permeabilized T. gondii parasites. We have successfully used these methods to investigate the function of T. gondii proteins, including the apicomplexan parasite-specific protein subunit TgQCR11 of the coenzyme Q:cytochrome c oxidoreductase complex (ETC Complex III). We note that these methods are also amenable to screening compound libraries to identify candidate ETC inhibitors.

Dynamics of toxoplasmosis in the cat's population with an exposed stage and a time delay.

We propose a new mathematical model to investigate the effect of the introduction of an exposed stage for the cats who become infected with the T. gondii parasite, but that are not still able to produce oocysts in the environment. The model considers a time delay in order to represent the duration of the exposed stage. Besides the cat population the model also includes the oocysts related to the T. gondii in the environment. The model includes the cats since they are the only definitive host and the oocysts, since they are relevant to the dynamics of toxoplasmosis. The model considers lifelong immunity for the recovered cats and vaccinated cats. In addition, the model considers that cats can get infected through an effective contact with the oocysts in the environment. We find conditions such that the toxoplasmosis disease becomes extinct. We analyze the consequences of considering the exposed stage and the time delay on the stability of the equilibrium points. We numerically solve the constructed model and corroborated the theoretical results.

Considering opportunistic parasitic infections in COVID-19 policies and recommendations.

The COVID-19 pandemic has led to a significant increase in the immunosuppressed population worldwide due to the disease pathology and extensive use of corticosteroids. This has subsequently increased the risk of opportunistic parasitic infections such as Toxoplasma gondii, Strongyloides stercoralis and other parasites in these patients. The reactivation of such parasites may remain unnoticed due to overlapping symptoms, the difficulty of diagnosis and lack of guidelines for opportunistic parasitic infections in COVID-19 management. Therefore, recommendations for systematic screening of high-risk patients in endemic regions and active research and surveillance to estimate the impact of these infections are required in COVID-19 policy guidelines.

Activity of Fluorinated Curcuminoids against Leishmania major and Toxoplasma gondii Parasites.

A new 3,4-difluorobenzylidene analog of curcumin, CDF, was recently reported, which demonstrated significantly enhanced bioavailability and in vivo anticancer activity compared with curcumin. For highlighting the antiparasitic behavior of CDF, we tested this compound together with its new O-methylated analog MeCDF against Leishmania major and Toxoplasma gondii parasites. Both CDF and MeCDF were tested in vitro against L. major and T. gondii. In addition, the in vitro cytotoxicity against Vero cells and macrophages was determined and selectivity indices were calculated. The DPPH radical scavenging activity assay was carried out in order to determine the antioxidant activity of the test compounds. Both compounds showed high activities against both parasite forms with EC50 values in the (sub-)micromolar range (0.35 to 0.8 μM for CDF, 0.31 to 1.2 μM for MeCDF). The higher activity of CDF against L. major amastigotes when compared with MeCDF can in parts be attributed to the antioxidant activity of CDF while MeCDF lacking any antioxidant activity was more active than CDF against T. gondii parasites. In conclusion, CDF and MeCDF are promising antiparasitic drug candidates due to their high activities against L. major and T. gondii parasites.

P-Trifluoromethyl- and p-pentafluorothio-substituted curcuminoids of the 2,6-di[(E)-benzylidene)]cycloalkanone type: Syntheses and activities against Leishmania major and Toxoplasma gondii parasites

A series of the title curcuminoids with structural variance in the heteroatom of the cycloalkanone and the p-substituents of the phenyl rings were tested for their activities against Leishmania major and Toxoplasma gondii parasites. The majority of them showed high activities against both parasite forms with EC50 values in the sub-micromolar concentration range. Bis(p-pentafluorothio)-substituted 3,5-di[(E)-benzylidene]piperidin-4-one 1b was not just noticeable antiparasitic, but also exhibited a considerable selectivity for L. major promastigotes over normal Vero cells. While derivatives differing only in the p-phenyl substituents being CF3 or SF5 showed similar antiparasitic activities, the cyclic ketone hub was more decisive both for the anti-parasitic activities and the selectivities for the parasites vs. normal cells. QSAR calculations confirmed the observed structure–activity relations and suggested structural variations for a further improvement of the antiparasitic activity. Docking studies based on DFT calculations revealed L. major pteridine reductase 1 as a likely molecular target protein of the title compounds.

Detection and genetic characterisation of Toxoplasma gondii circulating in free-range chickens, pigs and seropositive pregnant women in Benue state, Nigeria.

Toxoplasma gondii parasites present strong but geographically varied signatures of population structure. Populations sampled from Europe and North America have commonly been defined by over-representation of a small number of clonal types, in contrast to greater diversity in South America. The occurrence and extent of genetic diversity in African T. gondii populations remains understudied, undermining assessments of risk and transmission. The present study was designed to establish the occurrence, genotype and phylogeny of T. gondii in meat samples collected from livestock produced for human consumption (free-range chickens, n = 173; pigs, n = 211), comparing with T. gondii detected in blood samples collected from seropositive pregnant women (n = 91) in Benue state, Nigeria. The presence of T. gondii DNA was determined using a published nested polymerase chain reaction, targeting the 529 bp multicopy gene element. Samples with the highest parasite load (assessed using quantitative PCR) were selected for PCR-restriction fragment length polymorphism (PCR-RFLP) targeting the surface antigen 3 (SAG3), SAG2 (5' and 3'), beta-tubulin (BTUB) and dense granule protein 6 (GRA6) loci, and the apicoplast genome (Apico). Toxoplasma gondii DNA was detected in all three of the populations sampled, presenting 30.6, 31.3 and 25.3% occurrence in free-range chickens, pigs and seropositive pregnant women, respectively. Quantitative-PCR indicated low parasite occurrence in most positive samples, limiting some further molecular analyses. PCR-RFLP results suggested that T. gondii circulating in the sampled populations presented with a type II genetic background, although all included a hybrid type I/II or II/III haplotype. Concatenation of aligned RFLP amplicon sequences revealed limited diversity with nine haplotypes and little indication of host species-specific or spatially distributed sub-populations. Samples collected from humans shared haplotypes with free-range chickens and/or pigs. Africa remains under-explored for T. gondii genetic diversity and this study provides the first detailed definition of haplotypes circulating in human and animal populations in Nigeria.

Identifying the major lactate transporter of Toxoplasma gondii tachyzoites

Toxoplasma gondii and Plasmodium falciparum parasites both extrude l-lactate, a byproduct of glycolysis. The P. falciparum Formate Nitrite Transporter, PfFNT, mediates l-lactate transport across the plasma membrane of P. falciparum parasites and has been validated as a drug target. The T. gondii genome encodes three FNTs that have been shown to transport l-lactate, and which are proposed to be the targets of several inhibitors of T. gondii proliferation. Here, we show that each of the TgFNTs localize to the T. gondii plasma membrane and are capable of transporting l-lactate across it, with TgFNT1 making the primary contribution to l-lactate transport during the disease-causing lytic cycle of the parasite. We use the Xenopus oocyte expression system to provide direct measurements of l-lactate transport via TgFNT1. We undertake a genetic analysis of the importance of the tgfnt genes for parasite proliferation, and demonstrate that all three tgfnt genes can be disrupted individually and together without affecting the lytic cycle under in vitro culture conditions. Together, our experiments identify the major lactate transporter in the disease causing stage of T. gondii, and reveal that this transporter is not required for parasite proliferation, indicating that TgFNTs are unlikely to be targets for anti-Toxoplasma drugs.

Divergent features of the coenzyme Q:cytochrome c oxidoreductase complex in Toxoplasma gondii parasites.

The mitochondrion is critical for the survival of apicomplexan parasites. Several major anti-parasitic drugs, such as atovaquone and endochin-like quinolones, act through inhibition of the mitochondrial electron transport chain at the coenzyme Q:cytochrome c oxidoreductase complex (Complex III). Despite being an important drug target, the protein composition of Complex III of apicomplexan parasites has not been elucidated. Here, we undertake a mass spectrometry-based proteomic analysis of Complex III in the apicomplexan Toxoplasma gondii. Along with canonical subunits that are conserved across eukaryotic evolution, we identify several novel or highly divergent Complex III components that are conserved within the apicomplexan lineage. We demonstrate that one such subunit, which we term TgQCR11, is critical for parasite proliferation, mitochondrial oxygen consumption and Complex III activity, and establish that loss of this protein leads to defects in Complex III integrity. We conclude that the protein composition of Complex III in apicomplexans differs from that of the mammalian hosts that these parasites infect.

Antiparasitary Activity Of The Juglone Compound: A Narrative Review

Objective: To report, based on the literature, the action of the compound 5-hydroxy-1,4-naphthoquinone against parasites (protozoa and helminths) that affect humans. Methods: This is a narrative review that used Pubmed and Google Scholar as a data tool. This work included articles published until September 2020 that were directly related to the use of the compound juglone in antiparasitic trials. Results: The compound juglone demonstrated promising effects as a human and animal antiparasitic substance. In protozoa, the Apicomplexo Toxoplasma gondii parasite showed a high mortality rate in concentrations of juglone in the nanomolar range. The juglone showed an average inhibitory concentration (IC50) of 1.62 µM, >100 µM, and 2.02 µM µM for Trypanosoma cruzi, T. brucei rhodesiense, and Leishmania donovani, respectively. Also, the juglone showed antihelmintic activity on Hymenolepis nana in mice, and on adult worms of Schistosoma mansoni (LE strain) with IC50 34.16 µM, 32.14 µM, and 25 µM in the 24h, 48h, and 72 h, respectively. Conclusion: The results published so far show the in vitro antiparasitic potential of juglone, and the need for further studies on the specific mode of action that interacts with parasites. Besides, the literature is still limited to studies that evaluate in vivo the compound juglone, requiring better information on its interaction with living organisms.

New Pyrano-4H-benzo[g]chromene-5,10-diones with Antiparasitic and Antioxidant Activities.

New pyranonaphthoquinone derivatives were synthesized and investigated for their activity against Trypanosoma brucei, Leishmania major, and Toxoplasma gondii parasites. The pentafluorophenyl derivative was efficacious against T. brucei with single digit micromolar EC50 values and against T. gondii with even sub-micromolar values. The 3-chloro-4,5-dimethoxyphenyl derivative showed an activity against amastigotes of Leishmania major parasites comparable to that of amphotericin B. In addition, antioxidant activities were observed for the bromophenyl derivatives, and their redox behavior was studied by cyclovoltammetry. Anti-parasitic and antioxidative activities of the new naphthoquinone derivatives appear uncorrelated.

Key Limitations and New Insights Into the Toxoplasma gondii Parasite Stage Switching for Future Vaccine Development in Human, Livestock, and Cats.

Toxoplasmosis is a parasitic disease affecting human, livestock and cat. Prophylactic strategies would be ideal to prevent infection. In a One Health vaccination approach, the objectives would be the prevention of congenital disease in both women and livestock, prevention/reduction of T. gondii tissue cysts in food-producing animals; and oocyst shedding in cats. Over the last few years, an explosion of strategies for vaccine development, especially due to the development of genetic-engineering technologies has emerged. The field of vaccinology has been exploring safer vaccines by the generation of recombinant immunogenic proteins, naked DNA vaccines, and viral/bacterial recombinants vectors. These strategies based on single- or few antigens, are less efficacious than recombinant live-attenuated, mostly tachyzoite T. gondii vaccine candidates. Reflections on the development of an anti-Toxoplasma vaccine must focus not only on the appropriate route of administration, capable of inducing efficient immune response, but also on the choice of the antigen (s) of interest and the associated delivery systems. To answer these questions, the choice of the animal model is essential. If mice helped in understanding the protection mechanisms, the data obtained cannot be directly transposed to humans, livestock and cats. Moreover, effectiveness vaccines should elicit strong and protective humoral and cellular immune responses at both local and systemic levels against the different stages of the parasite. Finally, challenge protocols should use the oral route, major natural route of infection, either by feeding tissue cysts or oocysts from different T. gondii strains. Effective Toxoplasma vaccines depend on our understanding of the (1) protective host immune response during T. gondii invasion and infection in the different hosts, (2) manipulation and modulation of host immune response to ensure survival of the parasites able to evade and subvert host immunity, (3) molecular mechanisms that define specific stage development. This review presents an overview of the key limitations for the development of an effective vaccine and highlights the contributions made by recent studies on the mechanisms behind stage switching to offer interesting perspectives for vaccine development.

In Consideration of Our Mutual Relationship with Cats

[ ]attached and loyal to humans, Maeo Boran are easy to keep in the home and to train to walk on a leash;they often have a beautiful, chatty voice and behave as if they were engaging in lively conversations Cats are the only animal in which the Toxoplasma gondii parasite completes its life cycle, and humans in close contact with cat litter, for example, are at risk of developing toxoplasmosis, which pregnant women can potentially transmit to a fetus Paper folding book [cited 2020 Oct 1] https://www bl uk/manuscripts/Viewer aspx?ref=OR_16797_f001r Centers for Disease Control and Prevention

Anticancer, antimicrobial and antiparasitical activities of copper(I) complexes based on N-heterocyclic carbene (NHC) ligands bearing aryl substituents

New benzimidazolium salts were synthesized as N-heterocyclic carbene precursors. These NHC precursors were metallated with Cu2O and CuI in acetone and water under reflux to give novel copper(I) complexes. The structures of these benzimidazolium salts and copper(I) complexes were characterized on the basis of elemental analysis, 1H NMR, 13C NMR, IR and LC–MS spectroscopic techniques. The (NHC)Cu(I) complexes 3–4 were tested against MCF7 and MDA-MB-231 cancer cells, Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans microorganisms, Leishmania major promastigotes and amastigotes, Toxoplasma gondii parasites and against Vero cell line in vitro. The synthesized copper NHC carbene complex 4b (1,3-bis(2,3,4,5,6-pentamdthylbenzyl)-2,3-dihydro-1H-benzo[d]imidazol-2-yl)copper(I) chloride) was the most active against MCF7 cancer cells (half growth Inhibition Concentrations (IC50) = 0.3 µg mL−1), as well as the most potent antimicrobial against E. coli (inhibition zone (IZ) = 23.3 mm), MRSA (IZ = 25.5 mm) and C. albicans (IZ = 28.5 mm) besides its antileishmanial activities against L. major promastigotes and amastigotes (IC50 < 0.04 µg mL−1). Compound 4c (1,3-bis(4-(tert-butyl)benzyl)-2,3-dihydro-1H-benzo[d]imida-zol-2-yl)copper(II) bromide) is the most potent anticancer against MDA-MB-231 cancer cells IC50 = 0.4 µg mL−1). Compound 4e (5,6-dimethyl-1,3-bis(2,4,6-trimethylbenzyl)-2,3-dihydro-1H-benzo[d]imidazol-2-yl)copper(I) chloride) is the best suitable antitoxoplasmal drug candidate due to its SI of 16.5. These candidates need further study to identify mode of action and drug standardization.

Biological Activities of NHC–Pd(II) Complexes Based on Benzimidazolylidene N-heterocyclic Carbene (NHC) Ligands Bearing Aryl Substituents

N-heterocyclic carbene (NHC) precursors (2a–i), their pyridine-enhanced precatalyst preparation stabilization and initiation (PEPPSI)-themed palladium N-heterocyclic carbene complexes (3a–i) and palladium N-heterocyclic triphenylphosphines complexes (4a–i) were synthesized and characterized by elemental analysis and 1H NMR, 13C NMR, IR, and LC–MS spectroscopic techniques. The (NHC)Pd(II) complexes 3–4 were tested against MCF7 and MDA-MB-231 cancer cells, Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), Candida albicans microorganisms, Leishmania major promastigotes and amastigotes, Toxoplasma gondii parasites, and Vero cells in vitro. The biological assays indicated that all compounds are highly active against cancer cells, with an IC50 &lt; 1.5 µg mL−1. Eight compounds proved antibacterial and antileishmanial activities, while only three compounds had strong antifungal activities against C. albicans. In our conclusion, compounds 3 (b, f, g, and h) and 4b are the most suitable drug candidates for anticancer, antimicrobial, and antiparasitical.

Seroprevalence of Toxoplasma gondii infection in sows and finishers from conventional and organic herds in Denmark: Implications for potential future serological surveillance

Pigs are one of several host species for Toxoplasma gondii parasites, and consumption of infected pork may lead to toxoplasmosis in humans. We estimated seroprevalence in sows and finishers from conventional and organic herds in Denmark and discussed the strategies for reducing the risk from pork. We collected 447 blood samples from 59 herds, and additional meat-juice samples from 212 of the same pigs. Using a T. gondii IgG commercial ELISA test, we found 2% (95% CI = 0.4%–5%) apparent seroprevalence of T. gondii in conventional finishers, 11% (95% CI = 6%–17%) in organic finishers, 19% (95% CI = 11%–30%) in conventional sows and 60% (95% CI = 47%–72%) in organic sows. The odds of an animal testing positive for T. gondii was 16 times higher (95% CI = 4.6–74.3) in organic compared to conventional herds. The odds were 22 times higher (95% CI = 6.5–88.3) if the animal was a sow compared to a finisher. Meat-juice ELISA values were significantly correlated with plasma results (P < 0.001), but on average 64% of the blood-plasma ELISA values. Lowering the recommended cut-off from 20 to 13 percent positive values of the positive control for meat-juice ELISA, resulted in the meat-juice ELISA identifying 93% of the plasma positives as positive and 99% of the plasma negatives as negative. The time taken to detect one or more infected pigs from a T. gondii positive herd at slaughter was estimated using abattoir data on pigs (17,195,996) and batches (165,569) delivered to Danish abattoirs in 2018. The time to detection was affected by the seroprevalence, frequency at which the pigs were delivered, the number of samples tested per batch delivery and the batch sizes. Time to detection was long in conventional finisher herds due to low prevalence, and in sow herds because of intermittent delivery of a low number of sows. In organic finisher herds, time to detection was short due to medium prevalence and frequent delivery of a high number of finishers. Conventional finisher herds may be classified as low-risk, organic finisher herds as medium-risk, and conventional and organic sow herds as high-risk herds. Risk-mitigation strategies at processing plants (freezing or curing) or at the consumer level (heat treatment) for meat originating from high-risk herds, surveillance of medium-risk herds, and auditing for controlled housing (high biosecurity) in low-risk herds may be cost-effective alternatives to serological surveillance of all Danish pig herds.

Molecular Investigation of the Toxoplasma gondii Parasite with the Study of Pathological Changes in Pregnant Women in Najaf Governorate

Molecular Investigation of the Toxoplasma gondii Parasite with the Study of Pathological Changes in Pregnant Women in Najaf Governorate

A Toxoplasma gondii patatin-like phospholipase contributes to host cell invasion.

Toxoplasma gondii is an obligate intracellular parasite that can invade any nucleated cell of any warm-blooded animal. In a previous screen to identify virulence determinants, disruption of gene TgME49_305140 generated a T. gondii mutant that could not establish a chronic infection in mice. The protein product of TgME49_305140, here named TgPL3, is a 277 kDa protein with a patatin-like phospholipase (PLP) domain and a microtubule binding domain. Antibodies generated against TgPL3 show that it is localized to the apical cap. Using a rapid selection FACS-based CRISPR/Cas-9 method, a TgPL3 deletion strain (ΔTgPL3) was generated. ΔTgPL3 parasites have defects in host cell invasion, which may be caused by reduced rhoptry secretion. We generated complementation clones with either wild type TgPL3 or an active site mutation in the PLP domain by converting the catalytic serine to an alanine, ΔTgPL3::TgPL3S1409A (S1409A). Complementation of ΔTgPL3 with wild type TgPL3 restored all phenotypes, while S1409A did not, suggesting that phospholipase activity is necessary for these phenotypes. ΔTgPL3 and S1409A parasites are also virtually avirulent in vivo but induce a robust antibody response. Vaccination with ΔTgPL3 and S1409A parasites protected mice against subsequent challenge with a lethal dose of Type I T. gondii parasites, making ΔTgPL3 a compelling vaccine candidate. These results demonstrate that TgPL3 has a role in rhoptry secretion, host cell invasion and survival of T. gondii during acute mouse infection.

Coinfection of Toxoplasma Gondii and Intestinal Parasites among Elderly Immunocompromised Patients

Introduction: Patients with cancer and hemodialysis are prone to opportunistic infections. The present research aims to examine the frequency of Toxoplasmosis and intestinal parasites in these patients. Methods: In the present cross-sectional study, seventy stool and blood samples from immunocompromised patients (46 hemodialysis and 24 cancer patients) from Guilan Province were collected in 2017-2018. Different tests including direct smear examination and formalin-ether was conducted for the intestinal protozoan parasites. To detect coccidian parasites (e.g. Cryptosporidium spp.) Ziehl Neelsen staining was applied. The anti T.gondii antibodies were detected via ELISA method. Results: Totally 6.52% and 4.16% cases of hemodialysis and cancer patients were positive for intestinal parasite infection respectively. Blastocystis hominis was only intestinal parasite that were detected in these patients. IgG anti-Toxoplasma antibody detected in 35 (76.8%) hemodialysis and 15 (62.5%) cancer patients. IgM antibody were found in 1 elderly hemodialysis patient. Mix infection (Toxoplasmosis and Blastocystis) was observed in 6.52% and 4.16% in hemodialysis and cancer patients respectively. Conclusion: It is recommended to evaluate these patients for intestinal parasitic infections during hemodialysis or chemotherapy sessions. Data showed the high percentage of elderly patients were susceptible to reactivation of chronic Toxoplasmosis. Therefore, in order to refer them for early therapy or other interventions, it is important that elderly hemodialysis and cancer patients with toxoplasma infection be diagnosed and identified.

Immunomodulatory activity of gamma radiation-attenuated Toxoplasma gondii in adjuvant arthritic mice

There is growing evidence that some parasitic infections can impact a variety of autoimmune diseases by disease-inducing or protecting capacities. Anti-inflammatory molecules secreted by Toxoplasma gondii and other parasites are capable of preventing some autoimmune disease like arthritis, lupus nephritis and systemic lupus erythematosus by acting on the immune system. Here we aimed to evaluate the protective efficacy of vaccination with Toxoplasma gondii (T. gondii), either gamma radiation-attenuated or not, on an adjuvant arthritis mouse model. Forty female Swiss albino mice were conducted in experiment divided into normal control; mice were injected with Complete Freund's adjuvant (CFA) into the right hind paws; mice vaccinated with irradiated T. gondii in the 3rd group and un-irradiated T. gondii in the 4th group then were injected two weeks later with CFA. Histopathological changes and IL-17, STAT6 and ROR-γ levels in the joints, as well as serum survivin and Anti-CCP, were evaluated. Also, the splenic production of TGF-β1, TGF-βR, IL-23, IL-1β, IFN-γ, TFN-∞, NFKβ, MMP1 and MMP3 were assessed. Results exhibited an enhancement of the histopathological changes with diminished the rise of IL-17, STAT 6 and ROR- γ within the joints of both vaccinated groups. Also, serum survivin and Anti-CCP, as well as splenic inflammatory cytokines were reduced. It can be concluded that vaccination with un-irradiated or radiation-attenuated T. gondii exerted a protective effect against adjuvant arthritis with better pathological achievement in the radiation-attenuated vaccinated group. Using gamma radiation-attenuated parasite to exclude the delirious effects of imposing infection of live one may pave the way to new preventative modality against rheumatoid arthritis.