Toxoplasma inside host cell png‌Toxoplasmosis

The Toxoplasma gondii parasite is found all over the world, and in other animal species.  Infection can occur through eating undercooked meat or from accidently ingesting cat faeces (e.g. if you change a cat’s litter tray and don’t wash your hands afterwards).   There is also maternal transmission if a woman becomes infected with T. gondii during, or shortly before her pregnancy.  Many infected individuals do not display any symptoms, although some can experience mild flu-like symptoms (e.g. high temperature and aching muscles).  However, if a person has a weakened immune system (e.g. due to HIV/AIDS or treatment for cancer), toxoplasmosis can be dangerous and lead to inflammation in the brain, heart and lungs, which can be fatal.  Congenital toxoplasmosis can cause miscarriage or still birth, blindness, deafness, hydrocephalus (water on the brain) and brain damage.  Some babies may appear fine at birth but develop visual or hearing problems later in life or have learning difficulties.

About 80% people infected with Toxoplasma fight the infection naturally – they get no ill effects, and the parasite lies dormant in their bodies for life and normally no treatment is required.  However, if they then become immunosuppressed, the parasite can reactivate and cause disease.  Similarly, if an immunosuppressed person encounters Toxoplasma for the first time, they may also get disease symptoms.  Then a patient will be treated with one or more antibiotics for several weeks. It has also been suggested that Toxoplasmosis can alter a person’s behaviour, although this remains controversial.

To prevent infection, wear gloves and wash your hands after handling soil, changing cat litter trays etc.  Wash fruit and veg before eating, and don’t eat raw or undercooked meat.  There is no vaccine available against Toxoplasma.

WCIP research focus

At the Centre we are investigating the following:

  • Toxoplasma as model system for apicomplexan parasites: Tool development for reverse genetics
  • Elucidation of invasion mechanisms involved in host cell invasion by apicomplexan parasites
  • Characterisation of biogenesis, regulation and secretion of the unique secretory organelles (micronemes and rhoptries)
  • Characterisation of host-parasite interactions using forward genetic screens   
  • Understanding the mechanisms controlling the biogenesis of endosymbiotic organelles in Toxoplasma                                                                                                                                                                                 
  • Characterisation of protein and RNA transport machineries

Key WCIP publications

Complexome profile of Toxoplasma gondii mitochondria identifies a divergent cytochrome bc1 complex (2020), BioRxiv, https://www.biorxiv.org/content/10.1101/2020.08.17.252163v2

 

Supply and demand—heme synthesis, salvage and utilization by apicomplexa, 2020, febs j. https://doi.org/10.1111/febs.15445

Identification of the toxoplasma gondii mitochondrial ribosome, and characterisation of a protein essential for mitochondrial translation (2019) Mol Microbiol, https://pubmed.ncbi.nlm.nih.gov/31339607/ 

Genetic screens reveal a central role for heme biosynthesis in artemisinin, 2019, susceptibility biorxiv doi: https://doi.org/10.1101/746974 

Alveolar proteins stabilize cortical microtubules in toxoplasma gondii.nat commun. 2019 jan 23;10(1):401. doi: 10.1038/s41467-019-08318-7. https://www.ncbi.nlm.nih.gov/pubmed/30674885  

identification of the toxoplasma gondii mitochondrial ribosome, and characterization of a protein essential for mitochondrial translation. mol microbiol. 2019 jul 24. doi: 10.1111/mmi.14357. https://www.ncbi.nlm.nih.gov/pubmed/31339607 

a unique dynamin-related protein is essential for mitochondrial fission in toxoplasma gondii. plos pathog. 2019 apr 4;15(4):e1007512. doi: 10.1371/journal.ppat.1007512. ecollection 2019 apr. https://www.ncbi.nlm.nih.gov/pubmed/30947298 

two essential thioredoxins mediate apicoplast biogenesis, protein import, and gene expression in toxoplasma gondii. plos pathog. 2018 feb 22;14(2):e1006836. doi: 10.1371/journal.ppat.1006836 https://www.ncbi.nlm.nih.gov/pubmed/29470517 

mitochondrial behaviour throughout the lytic cycle of toxoplasma gondii.sci rep. 2017 feb 16;7:42746. doi: 10.1038/srep42746. https://www.ncbi.nlm.nih.gov/pubmed/28202940 

gliding associated proteins play essential roles during the formation of the inner membrane complex of toxoplasma gondii. plos pathog. 2016 feb 4;12(2):e1005403. doi: 10.1371/journal.ppat.1005403. https://www.ncbi.nlm.nih.gov/pubmed/26845335