Researchers at the Walter and Eliza Hall Institute have discovered how the common Toxoplasma parasite can hijack its host cells and stockpile food, allowing it to lie dormant for decades at a time and even possibly change the behavior and personality of its host over time. The study revealed that the parasite requires a human host cell, such as a neuron, in order ensure its own growth and survival.
"Toxoplasma infection leads to massive changes in the host cell to prevent immune attack and enable it to acquire a steady nutrient supply," Chris Tonkin, co-author of the study, said in a press release. "The parasite achieves this by sending proteins into the host cell that manipulate the host's own cellular pathways, enabling it to grow and reproduce."
These changes are large enough that Tonkin and his team, which includes Justin Boddey, believe that the proteins used for cellular pathway manipulation could alter the personality of its host.
"There is a fascinating association between Toxoplasma infection and psychiatric diseases including schizophrenia and bipolar disorder," said Boddey. "It is now possible to test whether proteins sent from the hibernating parasite into a host neuron disrupt normal brain function and contribute to development of these diseases."
The Toxoplasma parasite is known to pose risks to pregnant women, including an increased chance of birth defects and miscarriage, and is commonly transmitted through cats. The findings could help scientists develop a vaccine to protect pregnant women as well as drugs that can help cancer patients and others with compromised immune systems fight off the infection.
"Cats are one of the primary transmitters of Toxoplasma parasites," Tonkin said. "If the parasites are transmitted to pregnant women, for example through contact with kitty litter, there is a substantial risk of miscarriage or birth defects.
"We hope to use our discoveries to develop a vaccine that stops cats transmitting the parasite, to prevent these potentially catastrophic consequences."
The study was published in the Nov. 18 issue of the journal eLife.
