Plasmodium falciparum Pf11.1 antigen (Pf11.1)

Plasmodium falciparum Pf11.1 is a megadalton-sized, highly repetitive protein expressed during the sporozoite, liver, and asexual blood stages of the malaria parasite's life cycle (Scherf et al., 1992, EMBO J). It is characterized by extensive tandem repeats of glutamic acid-rich motifs, specifically the Glu-Glu-Val-Val sequence, which are strongly immunogenic and recognized by the sera of individuals living in malaria-endemic areas (Mercereau-Puijalon et al., 1991). Biologically, the protein is localized to the parasitophorous vacuole and is implicated in the process of parasite egress from host cells, potentially facilitating the rupture of the erythrocyte membrane (Blisnick et al., 2000, Mol Biochem Parasitol). As a therapeutic target, Pf11.1 has been explored as a candidate for multi-stage vaccines designed to elicit antibodies that neutralize the parasite across different phases of infection (PlasmoDB: PF3D7_1038400). However, its massive size and repetitive nature present significant challenges for vaccine development, including difficulties in recombinant protein expression and the potential for the protein to act as an immunological decoy that distracts the host immune system from more vulnerable targets (Scherf et al., 1992). Despite these challenges, specific regions of the Pf11.1 antigen remain of interest for developing targeted immunotherapies and diagnostic biomarkers for malaria exposure.

Other names

Pf11.1 proteinPf11-1Glutamic acid-rich protein Pf11.1PF3D7_1038400

Induction of humoral immune responses (antibodies) that target the repetitive motifs of the protein to inhibit parasite development, invasion, or egress across sporozoite, liver, and blood stages.