Theft of host transferrin receptor-1 by Toxoplasma gondii is required for infection.

Tachyzoites of Toxoplasma gondii robustly take up host transferrin receptor 1 and other iron homeostasis proteins, enabling increased trafficking to endolysosomes that boosts growth rate.

• Why it matters: Apicomplexan parasites need host nutrients for infection, but the specific mechanisms for iron acquisition and storage protein theft remain unclear.
• What they did: The study identified that T. gondii lacks conserved iron transport/storage genes and showed tachyzoites robustly acquire host transferrin receptor 1, transferrin, ferritin chains, and clathrin light chain across host species and virulence types.
• The result: Enhanced trafficking of host transferrin receptor 1 to endolysosomes increased tachyzoite acquisition of host proteins and growth rate, while bradyzoites showed little capacity, consistent with the cyst wall barrier.