Functional study and immunological analysis of Plasmodium vivax GAMA protein invading Duffy positive/negative erythrocytes

Plasmodium vivax is widely geographical malaria, and threatens almost 40% of the world’s population. P. vivax resists blood-stage infection results from absence of the Duffy (Fy) blood group at the surface of red blood cells (RBCs). Interestingly, resent studies from different malaria-endemic regions showed that P. vivax could infect Duffy-negative blood type people and cause clinical disease, suggesting that P. vivax may be involved into alternative erythrocyte invasion pathway(s). To well understand mechanism of P. vivax invasion, PvGAMA is being targeted which is the homologues of an important RBCs binding protein PfGAMA. Hence, PvGAMA was segmented, and expressed by using wheat germ cell-free expression system. These proteins localization in parasite was clarified by immunofluorescence assay. This project will analyze PvGAMA antigenicity and immunogenicity of these proteins, such as human sera response against antigens, serum titers, the percent of CD4+/ CD8+ positive immune cells, and Th1/ Th2 major cytokines levels of immunized mouse. Furthermore, Duffy +/- erythrocyte binding ability of these proteins will be tested that need to be expressed on the surface of COS-7 cell or HEK 293T cell incubating with erythrocytes. After binding assay, it will turn to screen the receptor(s) of PvGAMA from RBCs membrane using micro-array. Then protein-erythrocyte blocking assay of P. vivax will be processed using protein-specific antibodies. These results may explain the Duffy +/- erythrocyte infection by P. vivax parasite, and advance the development of P. vivax malaria vaccine as well.

Basic Science
P. vivax

Jan 2017 — Dec 2019

$26,626

China