New Insights in Plasmodium vivax biology

Plasmodium vivax is a major species of parasitic protozoa that causes malaria in humans. This pathogen of global health importance has long been known to have a strict preference to invade immature red blood cells named reticulocytes. Our perception of red blood cell invasion by P. vivax has been singularly defined by the demonstration forty years ago of a strict dependence on the presence of a red blood cell surface antigen, the Duffy antigen/receptor for chemokine (DARC). This phenomenon prompted the search for and the eventual discovery of Duffy binding proteins in P. vivax. In the recent years, we have or have participated in the discovery of 2 new reticulocyte receptors, CD71 and CD98 and their cognate receptors PvRBP2b and PvRBP2a. We are now developing identifying B cell epitopes that are the targets of neutralising antibodies. These findings will be important for vaccine development.  Additionally, knowledge on the mechanisms of invasion of merozoite is essential for the development of P. vivax continuous culture. We have also recently developed the continuous culture of P. cynomolgi, a sister species of P. vivax in monkey erythrocytes. This model will help us to uncover the conditions to maintain P. vivax in long-term cultures.