Toxoplasma gondii, the Immune System, and Suicidal Behavior

2012 ◽  
pp. 408-433
Keyword(s):  
Immune System ◽  
Toxoplasma Gondii ◽  
Suicidal Behavior

scholarly journals Experimental toxoplasmosis in hypoiodemic mice

2012 ◽  
Vol 47 (No. 2 - 3) ◽  
pp. 67-74
Author(s):  
S. Šlosárková ◽  
V. Híbalová ◽  
I. Literák ◽  
I. Herzig ◽  
E. Bártová ◽  
...  
Keyword(s):  
Immune System ◽  
Toxoplasma Gondii ◽  
Mortality Rate ◽  
Immune Function ◽  
Iodine Deficiency ◽  
Laboratory Mouse ◽  
Lymphocyte Transformation ◽  
Lymphocyte Transformation Test ◽  
Spleen Lymphocyte ◽  
Spleen Cells

The hypothesis, that hypoiodemia of goats causes such a compromise of the immune system, which during subsequent Toxoplasma gondii infections results in clinically more pronounced signs of toxoplasmosis, was verifying in laboratory mouse. Hypoiodemic mice (fed by wheat and supplied by water), normoiodemic mice (fed by wheat and supplied by water containing 1.25 mg KI/l) and the majority of standard mice (fed by commercial grain mixture containing 0.83 mg I/kg) were experimentally infected with T. gondii oocysts or tachyzoites. The susceptibility to acute T. gondii infection was evaluated according to mortality rate. As a criterion of cell-mediated immune function has been chosen the spleen-lymphocyte transformation test (LTT). We observed no difference in LTT between hypoiodemic and normoiodemic mice infected with T. gondii oocysts or tachyzoites and no difference in mortality of both infected groups. Four days after the exposure to 100 tachyzoites of T. gondii (K24 strain), all experimentally infected groups of mice showed statistically significant decrease (P = 0.004) in spleen cells responsiveness to stimulation by all mitogens used – as compared to non-infected standard mice group. Reduced responsiveness of cells was probably caused by T. gondii infection itself – the relation to iodine deficiency has not been found.

scholarly journals Effect of Toxoplasma gondii on colon cancer growth in mouse model

2021 ◽  
Vol 9 (2) ◽  
pp. 168-176
Author(s):  
Farideh Zavareh ◽  
◽  
Mahboubeh Hadiipour ◽  
Reza Kalantari ◽  
Somayeh Mousavi ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Immune System ◽  
Toxoplasma Gondii ◽  
Tumor Growth ◽  
Cancer Immunotherapy ◽  
Target Therapy ◽  
Control Group ◽  
Neoplastic Cells ◽  
Tumor Environment ◽  
The Difference

Despite all advances in cancer treatment methods, failure of treatment is a major concern. This failure can be caused by tumor environment made by tumor cells and prevents immune system to reach neoplastic cells. So, cancer immunotherapy and target therapy are in the focus of scientists. Due to the inverse relationship shown between parasites and cancer, parasites are a candidate for use in cancer immunotherapy. Toxoplasma gondii is an intracellular parasite invades many cells of vertebrae spices but make symptoms only in fetus and immuno-deficient person. Studies have shown T. gondii can stimulate immune system against neoplastic cells and break fort of tumor environment. In this experimental work, Colon cancer bearing mice randomly divided into three groups. Groups 1 and 2 were injected with either lysate or irradiated tachyzoite of T. gondii respectively. The third group were left intact as control group. Our resulted data showed that in irradiated tachyzoite or lysate treated groups there was a significant reduction in tumor growth in comparison with control group. However, the difference in survival time was not statistically significant. In conclusion, treatment with T. gondii antigens resulted in suppression of tumor growth.

scholarly journals Both Expansion of Regulatory GR1+ CD11b+ Myeloid Cells and Anergy of T Lymphocytes Participate in Hyporesponsiveness of the Lung-Associated Immune System during Acute Toxoplasmosis

2004 ◽  
Vol 72 (9) ◽  
pp. 5487-5492 ◽  
Author(s):  
Mathieu-Benoît Voisin ◽  
Dominique Buzoni-Gatel ◽  
Daniel Bout ◽  
Florence Velge-Roussel
Keyword(s):  
Nitric Oxide ◽  
Immune System ◽  
Toxoplasma Gondii ◽  
T Lymphocytes ◽  
Interleukin 2 ◽  
Myeloid Cells ◽  
Oral Infection ◽  
Activated T Lymphocytes ◽  
Acute Toxoplasmosis

ABSTRACT Oral infection with Toxoplasma gondii leads to transient systemic hyporesponsiveness. In this report, we characterized the presence in the lungs of GR1+ CD11b+ myeloid cells that have potent nitric oxide-dependent immunoregulatory properties. We also demonstrated the interleukin 2-reversible anergy of both pulmonary CD8+ and CD4+ activated T lymphocytes with infection.

scholarly journals Toxoplasma gondii Infection and Suicidal Behavior in People with Alcohol Consumption

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 734
Author(s):  
Cosme Alvarado-Esquivel ◽  
Sergio Estrada-Martínez ◽  
Alma Rosa Pérez-Álamos ◽  
Isabel Beristain-García ◽  
Ángel Osvaldo Alvarado-Félix ◽  
...  
Keyword(s):  
Suicidal Ideation ◽  
Toxoplasma Gondii ◽  
Alcohol Consumption ◽  
Suicidal Behavior ◽  
Suicide Attempts ◽  
Igg Antibodies ◽  
Igm Antibodies ◽  
Immunosorbent Assays ◽  
Toxoplasma Gondii Infection

We determined the association between T. gondii infection and suicidal behavior in people with alcohol consumption. One-thousand four-hundred and twenty-three people with alcohol consumption were screened for suicidal behavior and tested for anti-T. gondii IgG and IgM antibodies using commercially available enzyme-linked immunosorbent assays. Anti-T. gondii IgG antibodies were found in 34 of 224 (15.2%) individuals with suicidal ideation and in 118 (9.8%) of 1199 individuals without suicidal ideation (OR: 1.63; 95% CI: 1.08–2.47; p = 0.01). Seropositivity to T. gondii was associated with suicidal ideation in women (OR: 2.24; 95% CI: 1.33–3.78; p = 0.001) and in individuals aged ≤30 years (OR: 2.68; 95% CI: 1.22–5.87; p = 0.01) and >50 years (OR: 2.85; 95% CI: 1.19–6.77; p = 0.01). Anti-T. gondii IgG antibodies were found in 17 of 136 (12.5%) individuals with suicide attempts and in 135 (10.5%) of 1287 individuals without suicide attempts (OR: 1.21; 95% CI: 0.71–2.08; p = 0.47). Seroprevalence of T. gondii infection was associated with suicide attempts in women (OR: 1.88; 95% CI: 0.99–3.55; p = 0.04). No association between anti-T. gondii IgM and suicidal ideation or suicide attempts was found. Results suggest that T. gondii infection is associated with suicidal behavior in people with alcohol consumption.

Toxoplasma gondii and subversion of the immune system

2006 ◽  
Vol 22 (10) ◽  
pp. 448-452 ◽  
Author(s):  
Dominique Buzoni-Gatel ◽  
Catherine Werts
Keyword(s):  
Immune System ◽  
Toxoplasma Gondii

scholarly journals Lessons from Toxoplasma: Host responses that mediate parasite control and the microbial effectors that subvert them

2021 ◽  
Vol 218 (11) ◽  
Author(s):  
Eva-Maria Frickel ◽  
Christopher A. Hunter
Keyword(s):  
Immune System ◽  
Toxoplasma Gondii ◽  
Experimental System ◽  
Host Responses ◽  
Host Immune System ◽  
Intracellular Parasite ◽  
Parasite Control ◽  
Host Pathogen ◽  
Ifn Γ ◽  
Intracellular Infections

The intracellular parasite Toxoplasma gondii has long provided a tractable experimental system to investigate how the immune system deals with intracellular infections. This review highlights the advances in defining how this organism was first detected and the studies with T. gondii that contribute to our understanding of how the cytokine IFN-γ promotes control of vacuolar pathogens. In addition, the genetic tractability of this eukaryote organism has provided the foundation for studies into the diverse strategies that pathogens use to evade antimicrobial responses and now provides the opportunity to study the basis for latency. Thus, T. gondii remains a clinically relevant organism whose evolving interactions with the host immune system continue to teach lessons broadly relevant to host–pathogen interactions.

scholarly journals Transformed Toxoplasma gondiiTachyzoites Expressing the Circumsporozoite Protein ofPlasmodium knowlesi Elicit a Specific Immune Response in Rhesus Monkeys

1999 ◽  
Vol 67 (4) ◽  
pp. 1677-1682 ◽  
Author(s):  
Manlio di Cristina ◽  
Firman Ghouze ◽  
Clemens H. M. Kocken ◽  
Silvia Naitza ◽  
Pamela Cellini ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Toxoplasma Gondii ◽  
Antibody Response ◽  
Rhesus Monkeys ◽  
Malaria Parasite ◽  
Plasmodium Knowlesi ◽  
Immunodominant Antigen ◽  
Positive Serum ◽  
Immunoglobulin Class Switching

ABSTRACT Toxoplasma gondii tachyzoites were transformed with the coding sequence of the circumsporozoite (CS) protein of the primate malaria parasite Plasmodium knowlesi. A single inoculation of live transformed tachyzoites elicited an antibody response directed against the immunodominant repeat epitope (EQPAAGAGG)2 of the P. knowlesi CS protein in rhesus monkeys. Notably, these animals failed to show a positive serum conversion against T. gondii. Antibodies againstToxoplasma antigens were detected only after a second inoculation with a higher number of transformed tachyzoites. This boost induced an increased antibody response against the P. knowlesi CS protein associated with immunoglobulin class switching, thus demonstrating the establishment of immunological memory. These results indicate that theToxoplasma-derived CS protein is efficiently recognized by the monkey immune system and represents an immunodominant antigen in transformed parasites.

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