Plasmodium falciparum sexual stage surface antigen Pfs25 (Pfs25)

Plasmodium falciparum sexual stage surface antigen Pfs25 is a 25 kDa cysteine-rich, glycosylphosphatidylinositol (GPI)-anchored protein expressed on the surface of zygotes and ookinetes during the sexual stages of P. falciparum development in the mosquito vector[1][2][5][9]. It contains four tandem epidermal growth factor (EGF)-like domains stabilized by eleven disulfide bonds and plays a key role in parasite development within the mosquito, interacting as a ligand with laminin in the mosquito midgut basal lamina[1][8]. Pfs25 is the principal target of multiple malaria transmission-blocking vaccine (TBV) candidates, where antibodies induced by vaccination bind the protein and prevent the parasite from maturing further in the mosquito, thus blocking transmission from human to mosquito[2][8][10]. There are no small-molecule drugs targeting Pfs25, but it is the focus of vaccine and antibody biologic research. Homologs exist in other Plasmodium species (Pvs25, Pbs25), and genetic ablation studies strongly support its essential function in transmission. The main therapeutic and research value of Pfs25 is as a vaccine antigen for interrupting the transmission phase of malaria rather than treating established infection[1][2][8].

Other names

Pfs25ookinete surface antigen Pfs25

Transmission-blocking via eliciting antibodies that inhibit parasite development in the mosquito midgut by binding Pfs25 and preventing ookinete maturation or midgut invasion[2][3][8]