Expansion of host cellular niche can drive adaptation of a zoonotic malaria parasite to humans

摘要: The macaque malaria parasite Plasmodium knowlesi has recently emerged as an important zoonosis in Southeast Asia. Infections are typically mild but can cause severe disease, achieving densities similar to fatal falciparum infections. Here we show that a primate-adapted P. proliferates poorly human blood due strong preference for young red cells (RBCs). We establish continuous vitro culture system by using enriched cells. Mathematical modelling predicts adaptation invasion of older RBCs is likely mechanism leading high clinical Consistent with this model, find adapt invade wider age range RBCs, resulting proliferation normal blood. Such cellular niche expansion may increase pathogenesis humans and will be key feature monitor emerges populations.