• About
  • Keywords

Toxoplasma gondii & Human Phenotype

Compendium of Known Effects and Ongoing Research

ifn-gamma

Disease tolerance in Toxoplasma infection

January 31, 2020
Melchor, S. J., Ewald, S. E.
Frontiers in Cellular and Infection Microbiology 2019, 9
Click for abstract
Toxoplasma gondii is a successful protozoan parasite that cycles between definitive fetid hosts and a broad range of intermediate hosts, including rodents and humans. Within intermediate hosts, this obligate intracellular parasite invades the small intestine, inducing an inflammatory response. Toxoplasma infects infiltrating immune cells, using them to spread systemically and reach tissues amenable to chronic infection. An intact immune system is necessary to control life-long chronic infection. Chronic infection is characterized by formation of parasite cysts, which are necessary for survival through the gastrointestinal tract of the next host. Thus, Toxoplasma must evade sterilizing immunity, but still rely on the host's immune response for survival and transmission. To do this, Toxoplasma exploits a central cost-benefit tradeoff in immunity: the need to escalate inflammation for pathogen clearance vs. the need to limit inflammation-induced bystander damage. What are the consequences of sustained inflammation on host biology? Many studies have focused on aspects of the immune response that directly target Toxoplasma growth and survival, commonly referred to as "resistance mechanisms." However, it is becoming clear that a parallel arm of the immune response has evolved to mitigate damage caused by the parasite directly (for example, egress-induced cell death) or bystander damage due to the inflammatory response (for example, reactive nitrogen species, degranulation). These so-called "disease tolerance" mechanisms promote tissue function and host survival without directly targeting the pathogen. Here we review changes to host metabolism, tissue structure, and immune function that point to disease tolerance mechanisms during Toxoplasma infection. We explore the impact tolerance programs have on the health of the host and parasite biolog

Tagged: chronic infection, gondii tachyzoites, ifn-gamma, immune-response, immunity, inferon gamma, innate, intracellural pathogen, natural-killer-cellsregulatory t- cells, oral infection, Parasite, resistancecachexia, small. intestine, tolerance, Toxoplasma gondii

Uncategorized

Is toxoplasmosis a potential risk factor for liver cirrhosis?

October 9, 2015 Leave a Comment
El-Henawy, A. A., Razik, A. A., Zakaria, S., Elhammady, D., Saudy, N., Azab, M. S.
Asian Pacific Journal of Tropical Medicine 2015; 8: 768-775
Click for abstract
Objective: To document Toxoplasma gondii (T. gondii) antibody status in patients with liver disease, blood samples were taken from 180 hepatic patients and 180 healthy controls. Methods: Toxoplasma IgG antibody was detected using enzyme-linked immunosorbent assay and histopathological assessment of liver biopsy METAVIR score was applied. Results: Anti-T. gondii IgG antibodies were found in 32.8% of patients and in 22.2% of controls (P=0.02). Toxoplasma scropositivity was significantly associated with lymphadenopathy, history of blood transfusion and reflex impairment in patients. Chronic hepatitis C virus (HCV) and chronic HCV-related cirrhosis groups compared to chronic HBV and chronic HBV-related cirrhosis groups expressed significantly higher prevalence of T. gondii seropositivity (odds ratio (OR) =4; 95% confidence interval (CI): 1.3-12.6; P=0.013, OR=4.8; 95% CI: 1.5-14.9; P=0.006, respectively). Within the chronic HCV group, T. gondii seropositivity significantly associated disease evolution as regards to METAVIR histopathological system for fibrosis and inflammation (OR=19.4; 95% Cl: 2.3-165.2; P=0.0008, OR=0.29; 95% Cl: 0.1-0.8; P=0.01, respectively). Albumin, international normalized ratio (INR) and platelets count were the laboratory parameters significantly altered in Toxoplasma-positive chronic HCV patients (P=0.001, 0.03, 0.04, respectively). Child-Pugh scoring for cirrhosis in chronic HCV group placed the majority of seropositive patient in class C with significant statistical difference compared to Child A reference group (OR=0.08; 95% Cl 0.01-0.5; P=0.003). Conclusions: Toxoplasma seropositivity was high in patients with cirrhosis and associated higher grades of inflammation and necrosis signifying disease evolution, suggesting that cirrhotic patients may thus form a risk group for toxoplasmosis

Tagged: blood-donors, c virus-infection, child-pugh score, chronic viral-hepatitis, congenital toxoplasmosis, diagnosis, disease, gondii infection, hbv, hcv, hepatic stellate cells, ifn-gamma, liver cirrhosis, metavir score, needle-aspiration-cytology, Toxoplasma gondii

Physical health

Neuropsychiatric disease and Toxoplasma gondii infection

October 26, 2009
Henriquez, S. A., Brett, R., Alexander, J., Pratt, J., Roberts, C. W.
Neuroimmunomodulation 2009; 16: 122-133.
Click for abstract
Toxoplasma gondii infects approximately 30% of the world's population, but causes overt clinical symptoms in only a small proportion of people. In recent years, the ability of the parasite to manipulate the behaviour of infected mice and rats and alter personality attributes of humans has been reported. Furthermore, a number of studies have now suggested T. gondii infection as a risk factor for the development of schizophrenia and depression in humans. As T. gondii forms cysts that are located in various anatomical sites including the brain during a chronic infection, it is well placed anatomically to mediate these effects directly. The T. gondii genome is known to contain 2 aromatic amino acid hydroxylases that potentially could directly affect dopamine and/or serotonin biosynthesis. However, stimulation of the immune response has also recently been associated with mood and behavioural alterations in humans, and compounds designed to alter mood, such as fluoxetine, have been demonstrated to alter aspects of immune function. Herein, the evidence for T.-gondii-induced behavioural changes relevant to schizophrenia and depression is reviewed. Potential mechanisms responsible for these changes in behaviour including the role of tryptophan metabolism and the hypothalamic-pituitary-adrenal axis are discussed. Copyright (C) 2009 S. Karger AG, Basel

Tagged: anterior cingulate cortex, cd4(+) t-cells, central-nervous-system, cytokine messenger-rna, hippocampal volume, ifn-gamma, immune-response, major depressive disorder, pituitary-adrenal axis, rattus-norvegicus

Mental health

Topics

  • Behavior 105
  • Cognitive functions 64
  • Mental health 439
  • Morphology 6
  • Motor functions 10
  • Personality 36
  • Physical health 134
  • Reproduction 36
  • Reviews 40
  • Sensory functions 3
  • Uncategorized 2

Archives

Recent articles

  • Mortality Patterns of Toxoplasmosis and Its Comorbidities in Tanzania: A 10-Year Retrospective Hospital-Based Survey February 6, 2020
  • The role of latent toxoplasmosis in the aetiopathogenesis of schizophrenia–the risk factor or an indication of a contact with cat? February 6, 2020
  • The Association between Toxoplasma gondii Infection and Risk of Parkinson’s Disease: A Systematic Review and Meta-Analysis February 6, 2020

Recent Comments

  • plaquenil grid on Autism spectrum disorders may be due to cerebral toxoplasmosis associated with chronic neuroinflammation causing persistent hypercytokinemia that resulted in an increased lipid peroxidation, oxidative stress, and depressed metabolism of endogenous and exogenous substances
  • paxil medication on Autism spectrum disorders may be due to cerebral toxoplasmosis associated with chronic neuroinflammation causing persistent hypercytokinemia that resulted in an increased lipid peroxidation, oxidative stress, and depressed metabolism of endogenous and exogenous substances
  • metformin xr dosage on Autism spectrum disorders may be due to cerebral toxoplasmosis associated with chronic neuroinflammation causing persistent hypercytokinemia that resulted in an increased lipid peroxidation, oxidative stress, and depressed metabolism of endogenous and exogenous substances
  • medications neurontin on Autism spectrum disorders may be due to cerebral toxoplasmosis associated with chronic neuroinflammation causing persistent hypercytokinemia that resulted in an increased lipid peroxidation, oxidative stress, and depressed metabolism of endogenous and exogenous substances
  • comprar propecia on Autism spectrum disorders may be due to cerebral toxoplasmosis associated with chronic neuroinflammation causing persistent hypercytokinemia that resulted in an increased lipid peroxidation, oxidative stress, and depressed metabolism of endogenous and exogenous substances

Meta

  • Log in
  • Entries feed
  • Comments feed
  • WordPress.org

Copyright © 2021 Toxoplasma gondii & Human Phenotype.

ToxoBehavior WordPress Theme by Jelena Braum