According to Science Daily, the parasitic organism Toxoplasmosis is caused by the parasite Toxoplasma gondii. That’s because it’s one of the most common zoonoses on the planet. Although cats are the parasite’s preferred host, any warm-blooded mammal, including humans, is fair game.
A team of LMU researchers led by Professor Markus Meissner, who holds the Chair of Experimental Parasitology at LMU, discovered a crucial protein complex while examining how the virus infects such a diverse range of hosts.
“We hypothesized that this invasion complex is significantly conserved and exists both in Toxoplasma and in Plasmodium,” says senior author Dr. Mirko Singer. “We investigated and contrasted the invasion processes and components employed by Toxoplasma and Plasmodium to better understand how and why these two parasites have such diverse host specificities.”
Apicomplexa are parasitic single-celled organisms. Unlike Toxoplasma, most species in this category are host-specific and can only infect a restricted number of cell types. The Plasmodium parasite, which causes malaria, cannot infect any other type of cell except those in the liver and red blood cells. This does not affect the other cellular kinds.
Toxoplasma’s capacity to infect such a diverse spectrum of host animals lends credence to the theory that this parasite can identify a number of host cell structures, activating a critical invasion complex.
“We hypothesized that this invasion complex is significantly conserved and occurs both in Toxoplasma and in Plasmodium,” stated principal scientist and author Dr. Mirko Singer. To better understand the invasion processes and probable reasons for the varying host specificity, they evaluated the parameters involved in Toxoplasma and Plasmodium host invasion.
To understand more about invasion mechanisms and what could explain the observed host specificity. Scientists investigated a large family of Cysteine Repeat Modular Proteins (CRMPs) thought to have a role in invasion. Toxoplasma, but just two in Plasmodium. Through a series of studies, the researchers discovered two CRMP variations that interact in pairs, with Variant A interacting with Variant B in each pair.
Toxoplasma puts everything together before moving to the parasite’s surface and invading the host cell. Because parasites rely on the complex as a “master key” to access host cells, the parasite cannot establish a foothold if one component is lacking.
Furthermore, the researchers discovered two new Toxoplasma small helper proteins that bind to one of the variations. These proteins are unique to a particular variant. As per Meissner,” Toxoplasma has a tougher time penetrating cells without their help.” It is critical to use this sentence. They are notable in Plasmodium and may give information on the broad host range infected by Toxoplasma.
