A handful of genes were affected by all three strains, notably a gene called VIPR2 that regulates neurotransmitters and nerve signaling and may play a role in schizophrenia, the researchers say.
If these findings are confirmed in clinical studies with people, they could help physicians predict the severity of an infection by strain type and tailor treatments accordingly, the researchers say.
"While disease course in humans is often more unpredictable than what we see in the controlled setting of a lab, these results give us a fascinating first look into the distinct genetic cascade of reactions that each strain can unlock and may one day serve as the basis for individualized treatment of symptomatic infections," says lead investigator Jianchun Xiao, Ph.D., a neurovirologist at the Stanley Division of Developmental Neurovirology at Johns Hopkins.
A 2008 study by Yolken and colleagues revealed that toxoplasma infection increases the risk for schizophrenia and could precipitate the disease in genetically predisposed people, a classic example of how genes and environment come together in the development of disease.
Most infections with toxoplasma occur early in life following exposure to the parasite from cat feces or undercooked beef or pork.
Farm animals and rodents also get infected, but the parasite reaches full sexual reproduction only in cats. Infections rarely cause symptoms, but the parasite remains in the body and can reactivate after lying dormant for years.
|Contact: Ekaterina Pesheva|
Johns Hopkins Medical Institutions