The Plasmodium sporozoite is an important target for chemoprevention and vaccine intervention. After inoculation through a mosquito bite, the sporozoites travel to the liver, cross the liver sinusoid epithelium, traverse several hepatocytes, and eventually infect a final host cell. The molecular mechanism of hepatocyte infection by the sporozoite is not fully understood. Recently, human EphA2, a membrane-bound receptor tyrosine kinase, was identified as a receptor for hepatocyte infection by Plasmodium falciparum and Plasmodium yoelii. In this study, the role of EphA2 in Plasmodium vivax infection was investigated. We found that transient overexpression of recombinant extracellular EphA2 fragments can increase the parasite infection rate, suggesting a role of EphA2. Furthermore, a new stable cell line overexpressing the whole extracellular domain of EphA2 was found to be more susceptible to P. vivax infection. These findings together support the notion that EphA2 was a hepatocytic receptor for P. vivax, paving the way for exploring the biology of exoerythrocytic P. vivax-host interaction.
Keywords: Plasmodium vivax, malaria, sporozoite, hepatocyte, exoerythrocytic, pre-erythrocytic