scholarly journals Complete Protection against Lethal Toxoplasma gondii Infection in Mice Immunized with a Plasmid Encoding theSAG1 Gene

1999 ◽  
Vol 67 (12) ◽  
pp. 6358-6363 ◽  
Author(s):  
Henrik Vedel Nielsen ◽  
Sanne Lise Lauemøller ◽  
Lone Christiansen ◽  
Søren Buus ◽  
Anders Fomsgaard ◽  
...  
Keyword(s):  
T Cells ◽  
Toxoplasma Gondii ◽  
Cytotoxic T Lymphocyte ◽  
Protozoan Parasite ◽  
Complete Protection ◽  
Effective Protection ◽  
Partial Protection ◽  
Empty Plasmid ◽  
Toxoplasma Gondii Infection ◽  
Best Fit

ABSTRACT Infection with the protozoan parasite Toxoplasma gondiiis transmitted to humans from infected animals by tissue cysts and oocysts excreted by cats. Immunization with inactivated parasites or recombinant proteins has at best shown partial protection. We constructed a plasmid expressing the SAG1 surface antigen of T. gondii, p1tPASAG1, and showed that animals immunized with the plasmid produce anti-SAG1 antibodies which recognize the native SAG1. Mice immunized with p1tPASAG1 showed 80 to 100% protection against challenge with the non-cyst-producing, virulent RH isolate, compared to an 80% mortality in mice immunized with empty plasmid, which is the greatest efficacy of any vaccine against T. gondii produced so far. The SAG1 molecule was analyzed for potential cytotoxic T-lymphocyte (CTL) epitopes, and four peptides with the best fit were synthesized. The ability of the peptides to stimulate gamma interferon production by CD8+ T cells from p1tPASAG1-immunized mice was tested in an ELISPOT assay, and one new CTL epitope was identified. Adoptive transfer of CD8+ T cells from p1tPASAG1-immunized to naı̈ve mice showed partial protection. In conclusion, DNA vaccination with p1tPASAG1 gave effective protection in mice againstT. gondii infection and the protection could be adoptively transferred by purified CD8+ T cells.

scholarly journals Potential linkage between Toxoplasma gondii Infection and physical education scores of College Students

2020 ◽  
Author(s):  
Zhijin Sheng ◽  
Yu Jin ◽  
Yinan Du ◽  
Xinlei Yan ◽  
Yong Yao
Keyword(s):  
College Students ◽  
Physical Education ◽  
Toxoplasma Gondii ◽  
Protozoan Parasite ◽  
Anhui Province ◽  
Behavioral Changes ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
School Students ◽  
Toxoplasma Gondii Infection

ABSTRACTObjectiveToxoplasma gondii is a worldwide protozoan parasite that could infect virtually all warm-blooded animals, including humans. Our study aimed to investigate the prevalence of T. gondii infection in college students at Anhui province, China. Moreover, growing studies demonstrated the association between T. gondii infection and host behavioral changes. We also studied the linkage between T. gondii and scores of college students.Methods2704 serum samples of medical school students attending physical education lessons were collected from September 2017 to September 2019 and evaluated for T. gondii IgG antibodies using an enzyme-linked immunosorbent assay (ELISA). We also analysed PE scores of T. gondii infected students and T. gondii uninfected students.ResultsThe overall seroprevalence of T. gondii was 11.5%. The main risk factors related to T. gondii infections were cat in the household and gardening or agriculture activity. Furthermore, in basketball group and football group, scores of T. gondii seropositive students were significantly higher than that of seronegative students, while in other sports there is no difference between scores of T. gondii infected students and T. gondii uninfected students.ConclusionThis is the first report of T. gondii seroprevalence in college students in Anhui province, China.

scholarly journals Differential Regulation of Effector- and Central-Memory Responses to Toxoplasma gondii Infection by IL-12 Revealed by Tracking of Tgd057-Specific CD8+ T Cells

2010 ◽  
Vol 6 (3) ◽  
pp. e1000815 ◽  
Author(s):  
Douglas C. Wilson ◽  
Gijsbert M. Grotenbreg ◽  
Kenian Liu ◽  
Yanlin Zhao ◽  
Eva-Maria Frickel ◽  
...  
Keyword(s):  
T Cells ◽  
Toxoplasma Gondii ◽  
Cd8 T Cells ◽  
Differential Regulation ◽  
Central Memory ◽  
Toxoplasma Gondii Infection

scholarly journals Seroprevalence and associated risk factors of Toxoplasma gondii infection among pregnant mother in Makassar, Indonesia

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0245572
Author(s):  
Nurul Fadilah Ali Polanunu ◽  
Sitti Wahyuni ◽  
Firdaus Hamid
Keyword(s):  
Toxoplasma Gondii ◽  
Pregnant Women ◽  
Protozoan Parasite ◽  
Cross Sectional Study ◽  
Igg Antibody ◽  
Cross Sectional ◽  
Antibody Positivity ◽  
Toxoplasma Gondii Infection ◽  
Associated Risk Factors ◽  
Pregnant Mothers

The protozoan parasite, Toxoplasma gondii is estimated to infect one-third of the world’s population. Infection in pregnant women can cause severe conditions for their babies. Until now, there is no data regarding Toxoplasma infection from Makassar pregnant mothers. This study aims to obtain information on Toxoplasma specific antibodies and to measure the risk factor associate with parasite infection. This cross-sectional study conducted in 9 of 47 primary health centres (Puskesmas) in Makassar. Blood samples and questionnaires were collected from 184 pregnant women aged 15–42 years old from September to October 2020. ELISA technique was used to examine the IgG and IgM antibodies. Univariable and multivariable analyses were carried out to measure factors that independently associate with Toxoplasma antibody positivity. Our result showed the range of Toxoplasma IgM and IgG are 0.06–1.01 and 0.09–3.01, respectively. While no one of our participants has an acute Toxoplasma gondii infection (IgM positive), we found 32,6% pregnant mothers are exposed to parasite (positive IgG). Contact with cats [OR(95%CI): 10.45(3.77–28.99)], consume chicken satay [OR(95%CI): 9.72(3.71–25.48)] and consume un-boiled water/ filtered water [OR(95%CI): 5.98(1.77–20.23)] are independently associate with positive Toxoplasma IgG antibody. Based on the result, we conclude that pregnant women in Makassar are exposed to T. gondii and the oocyst and tissue cyst of parasite contaminates food and water in Makassar.

scholarly journals Early Th2 cytokine production in Heligmosomoides polygyrus and Toxoplasma gondii co-infected mice is associated with reduced IFNγ production, increased parasite loads and increased mortality

2021 ◽  
Author(s):  
Edina K. Szabo ◽  
Christina Bowhay ◽  
Namratha Badawadagi ◽  
Beatrice Fung ◽  
Camila Gaio ◽  
...  
Keyword(s):  
T Cells ◽  
Toxoplasma Gondii ◽  
Cd8 T Cells ◽  
Γδ T Cells ◽  
Protozoan Parasite ◽  
Careful Consideration ◽  
Single Infection ◽  
Mesenteric Lymph Nodes ◽  
Heligmosomoides Polygyrus ◽  
Infection Dynamics

Co-infections are a common reality but understanding how the immune system responds in this context is complex and can be unpredictable. Despite this, it is key to develop models that will provide better translatability to real world situations. Heligmosomoides polygyrus (parasitic roundworm) and Toxoplasma gondii (protozoan parasite) are well studied organisms that stimulate a characteristic Th2 and Th1 response respectively. IFNγ-producing T cells, NK and γδ T cells contribute to early protective immunity during T. gondii infection. To minimise immunopathology, IL-10 is also key to a successful response. Previous research has found H. polygyrus to improve survival during co-infection with both parasites. IFNγ-producing CD4+ and CD8+ T cells were implicated in this protection. Using a similar approach, we have found the opposite. Our co-infected animals displayed greater mortality and intestinal pathology than either single infection. This was associated with an early increase in Th2 cytokines in the Peyers patches, mesenteric lymph nodes and spleen. Co-infected animals also had reduced IFNγ producing cells at day 5 post T. gondii infection in the Peyers patches (CD8 T cells only) and in the MLN (NK, NKT, γδ T, CD4+ T and CD8+ T cells). This correlated with increased parasite loads in the MLN at 10 days post T. gondii infection. Our results demonstrate that co-infection dynamics can vary dramatically and that careful consideration needs to be taken when interpreting data in each situation.

scholarly journals Presence of Toxoplasma gondii tissue cysts in human semen

2021 ◽  
Author(s):  
Wen Han Tong ◽  
Jana Hlaváčová ◽  
Samira Abdulai-Saiku ◽  
Šárka Kaňková ◽  
Jaroslav Flegr ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Sexual Transmission ◽  
Congenital Toxoplasmosis ◽  
Protozoan Parasite ◽  
Specific Gene ◽  
Human Populations ◽  
Human Semen ◽  
Latently Infected ◽  
Clinically Significant ◽  
Toxoplasma Gondii Infection

Toxoplasma gondii is a widely prevalent protozoan parasite in human populations. This parasite is thought to be primarily transmitted through undercooked meat and contamination by cat feces. Here, we demonstrate that Toxoplasma gondii cysts can be found within human semen, thus suggesting a potential for sexual transmission. We visualized Toxoplasma gondii cysts in ejaculates of immune-competent and latently infected human volunteers. We confirmed the encystment by probing transcription of a bradyzoite-specific gene in these structures. These observations extend previous observations of the parasite in semen of several non-human host species, including rats, dogs, and sheep. Toxoplasma gondii infection is a clinically significant infection, in view of its high prevalence, its purported role in neuropsychiatric disorders such as schizophrenia, as well as in the more serious form of congenital toxoplasmosis. Our demonstration of intact Toxoplasma gondii cysts in the ejaculate supports the possibility of sexual transmission of the parasite and provides an impetus for further investigations.

scholarly journals Investigation of Toxoplasma gondii Infection in Aborted Fetuses of Sheep Using PCR: A Study in North Khorasan Province, Iran

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Mitra Salehi ◽  
Hosein Nezami ◽  
Hamid Reza Niazkar
Keyword(s):  
Toxoplasma Gondii ◽  
Gestational Age ◽  
Protozoan Parasite ◽  
Abortion Rate ◽  
Obligate Intracellular ◽  
Significant Difference ◽  
Pcr Method ◽  
Toxoplasma Gondii Infection ◽  
Intracellular Protozoan Parasite

Toxoplasma gondii is a zoonotic obligate intracellular protozoan parasite that infects warm-blooded animals as well as humans worldwide. The purpose of this study was to delineate the prevalence of Toxoplasma infection in aborted fetuses of sheep in North Khorasan province, Iran. Three hundred and ninety-nine samples of the liver (133 samples), placenta (133 samples), and brain (133 samples) from 133 aborted fetuses of sheep were collected from 2015 to 2017. The ages of aborted fetuses were higher than 120 days’ gestational age in this study. According to the samples, sixteen out of 133 aborted fetuses of sheep were infected with T. gondii. Toxoplasma DNA was found in the placenta (68.75%) and liver (31.25%) samples of infected fetuses using the PCR method. The highest and lowest rates of Toxoplasma infection were observed during 2016 and 2017, respectively. Shirvan and Faruj provinces were recognized as the two most infected districts among others. There was a significant difference between the year and abortion rate in sheep due to infection by the Toxoplasma parasite (P<0.05). Furthermore, no significant difference between the prevalence of T. gondii infection and aborted fetuses was seen (P>0.05) in different areas. According to the present study, T. gondii infection can be one of the causes of fetus abortion of sheep in North Khorasan province, Iran.

IL-6 is required for the generation of T follicular helper CD4 T cells during Toxoplasma gondii infection

Cytokine ◽  
2009 ◽  
Vol 48 (1-2) ◽  
pp. 71
Author(s):  
Jonathan S. Silver ◽  
Jason S. Stumhofer ◽  
Christopher A. Hunter
Keyword(s):  
T Cells ◽  
Toxoplasma Gondii ◽  
Cd4 T Cells ◽  
Follicular Helper ◽  
Toxoplasma Gondii Infection

scholarly journals Evasion of Human Neutrophil-Mediated Host Defense during Toxoplasma gondii Infection

mBio ◽  
2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Tatiane S. Lima ◽  
Lanny Gov ◽  
Melissa B. Lodoen
Keyword(s):  
Toxoplasma Gondii ◽  
Host Defense ◽  
Human Neutrophil ◽  
Human Peripheral Blood ◽  
Acute Infection ◽  
Protozoan Parasite ◽  
Human Neutrophils ◽  
Protein Levels ◽  
Major Player ◽  
Toxoplasma Gondii Infection

ABSTRACT Neutrophils are a major player in host immunity to infection; however, the mechanisms by which human neutrophils respond to the intracellular protozoan parasite Toxoplasma gondii are still poorly understood. In the current study, we found that, whereas primary human monocytes produced interleukin-1beta (IL-1β) in response to T. gondii infection, human neutrophils from the same blood donors did not. Moreover, T. gondii inhibited lipopolysaccharide (LPS)-induced IL-1β synthesis in human peripheral blood neutrophils. IL-1β suppression required active parasite invasion, since heat-killed or mycalolide B-treated parasites did not inhibit IL-1β release. By investigating the mechanisms involved in this process, we found that T. gondii infection of neutrophils treated with LPS resulted in reduced transcript levels of IL-1β and NLRP3 and reduced protein levels of pro-IL-1β, mature IL-1β, and the inflammasome sensor NLRP3. In T. gondii-infected neutrophils stimulated with LPS, the levels of MyD88, TRAF6, IKKα, IKKβ, and phosphorylated IKKα/β were not affected. However, LPS-induced IκBα degradation and p65 phosphorylation were reduced in T. gondii-infected neutrophils, and degradation of IκBα was reversed by treatment with the proteasome inhibitor MG-132. Finally, we observed that T. gondii inhibited the cleavage and activity of caspase-1 in human neutrophils. These results indicate that T. gondii suppression of IL-1β involves a two-pronged strategy whereby T. gondii inhibits both NF-κB signaling and activation of the NLRP3 inflammasome. These findings represent a novel mechanism of T. gondii evasion of human neutrophil-mediated host defense by targeting the production of IL-1β. IMPORTANCE Toxoplasma gondii is an obligate intracellular parasite that infects approximately one-third of humans worldwide and can invade virtually any nucleated cell in the human body. Although it is well documented that neutrophils infiltrate the site of acute T. gondii infection, there is limited understanding of how human neutrophils respond to T. gondii. Neutrophils control infectious pathogens by a variety of mechanisms, including the release of the cytokine IL-1β, a major driver of inflammation during infection. This study reveals that T. gondii is able to inhibit IL-1β production in human neutrophils by impairing the activation of the NF-κB signaling pathway and by inhibiting the inflammasome, the protein complex responsible for IL-1β maturation. This two-pronged strategy of targeting the IL-1β pathway may facilitate the survival and spread of T. gondii during acute infection.

scholarly journals Seroepidemiology of Toxoplasma gondii infection in patients with liver disease in eastern China

2017 ◽  
Vol 145 (11) ◽  
pp. 2296-2302 ◽  
Author(s):  
A. L. TIAN ◽  
G. X. LI ◽  
H. M. ELSHEIKHA ◽  
D. S. GARDNER ◽  
X. Y. ZHANG ◽  
...  
Keyword(s):  
Risk Factors ◽  
Liver Disease ◽  
Toxoplasma Gondii ◽  
Eastern China ◽  
Multivariate Logistic Regression Analysis ◽  
Protozoan Parasite ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Toxoplasma Gondii Infection

SUMMARYThe role of the protozoan parasite Toxoplasma gondii in the pathogenesis of liver disease has recently gained much interest. The aim of this study was to determine the prevalence and risk factors associated with T. gondii infection in patients with liver disease from three cities in Shandong and Henan provinces, China. A case–control study was conducted from December 2014 to November 2015 and included 1142 patients with liver disease and 1142 healthy controls. Serum samples were collected from all individuals and were examined with enzyme-linked immunosorbent assay for the presence of anti-T. gondii IgG and IgM antibodies. Information on the demographics, clinical, and lifestyle characteristics of the participants was collected from the medical records and by the use of a questionnaire. The prevalence of anti-T. gondii IgG was 19·7% in patients with liver disease compared with 12·17% in the controls. Only 13 patients had anti-T. gondii IgM antibodies compared with 12 control individuals (1·14% vs. 1·05%, respectively). The highest seroprevalence was detected in patients with liver cancer (22·13%), followed by hepatitis patients (20·86%), liver cirrhosis patients (20·42%), and steatosis patients (20%). Multivariate logistic regression analysis indicated that consumption of raw meat (odds ratio (OR) = 1·32; 95% confidence interval (CI) 1·01–1·71; P = 0·03) and source of drinking water from wells (OR = 1·56; 95% CI 1·08–2·27; P = 0·01) were independent risk factors for T. gondii infection in liver disease patients. These findings indicate that T. gondii infection is more likely to be present in patients with liver disease. Therefore, efforts should be directed toward health education of populations at high risk of T. gondii infection and measures should be taken to protect vulnerable patients with liver disease.

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