What could possibly draw a direct line between a group of international researchers, disgraced "pharma bro" Martin Shkreli and cat intestines? The answer: toxoplasmosis.
Scientists at Stockholm University have found that the parasite Toxoplasma gondii, which is estimated by the WHO to be carried by about a third of the world's human population, is so successful at infecting mammals because it tricks the immune system into doing its bidding. The researchers discovered that the parasite injects a protein into immune cells of humans and animals that turns those cells into "zombies" that spread the parasite further.
This type of targeted infection is more precise than experts had ever thought, according to a release from Stockholm University, and the discovery could lead to better understanding of the infection and new treatments. The scientists, led by professor Antonio Barragan, published their findings in the scientific journal Cell Host & Microbe.
"It is astonishing that the parasite succeeds in hijacking the identity of the immune cells in such a clever way," Barragan said in a statement. "We believe that the findings can explain why Toxoplasma spreads so efficiently in the body when it infects humans and animals."
If you give a cat a parasite
What makes toxoplasmosis arguably the most common parasitic infection in humans globally can also affect their pets. In people, the disease first presents with mild flu-like symptoms and then lies dormant for what could be the person's entire life, according to Stockholm University. In healthy people, the infection isn't often a big problem outside of possible eye infections, but people with immunodeficiencies could develop encephalitis, a potentially fatal brain infection, and pregnant people can pass the parasite to a fetus.
But cats play a unique role in the “zombie” parasite's life cycle. Only in a cat's digestive system can Toxoplasma sexually reproduce and spread — the parasite travels from a cat's feces to rodents who consume it, and then back to cats in the natural progression.
Where humans become infected is through eating tainted meat — or through contact with cats.
How does the convicted securities fraudster Shkreli fit into all this? The drug Daraprim that his then-company Turing Pharmaceuticals bought in 2015 is a treatment for people with toxoplasmosis. And after the company fought off generic competition, it was able to almost immediately raise the price of Daraprim from $13.50 a tablet to $750 — about a 5,000% increase. This jacked-up price for an old and life-saving treatment was what led a federal jury in 2017 to find Shkreli guilty of securities fraud. He has since been released.
The price gouging illustrates the importance of bringing new treatments to the market to fight off toxoplasmosis, and finding ways that the parasite interacts with its hosts is a stepping stone to discovering a better medicine.