Most humans have long-lived infections in various tissues — including in the nervous system — that typically do not result in disease. The microbes associated with these infections enter a latent stage during which they quietly hide in cells, playing the long game to evade capture and ensure their own survival. But a lack of natural models to study these quiescent stages has led to gaps in scientists’ understanding of how latency contributes to pathogen persistence and whether these stages can be targeted by the immune system.
Now, a team led by University of Pennsylvania School of Veterinary Medicine researchers shows that the immune system indeed recognizes the latent stage of the parasite Toxoplasma gondii, which causes toxoplasmosis — challenging some common assumptions about how the immune system deals with…