Plasmodium falciparum circumsporozoite protein (CSP) (PfCSP)

Plasmodium falciparum circumsporozoite protein (CSP) is the most abundant surface protein on the sporozoite stage of the malaria parasite. It is essential for the parasite's motility and its ability to invade human hepatocytes after being transmitted by an Anopheles mosquito (UniProt P06914). CSP consists of a central repeat region, which is highly immunogenic, and a conserved C-terminal domain that facilitates cell binding. In the context of vaccination, CSP serves as the primary target for the RTS,S/AS01 (Mosquirix) and R21/Matrix-M vaccines. These vaccines work by inducing the production of polyclonal antibodies that recognize and bind to CSP on the surface of circulating sporozoites. This binding neutralizes the parasite, preventing it from entering the liver and thus halting the malaria life cycle before the onset of clinical disease (WHO, 2023). Clinical efficacy is closely linked to the concentration of anti-CSP antibodies, making them a key biomarker for vaccine performance (Nature, 2021). Targeting CSP remains a cornerstone of current malaria prevention strategies in endemic regions.

Other names

Circumsporozoite surface proteinCSPPfCSPSporozoite surface antigenP. falciparum CSP

Induction of neutralizing polyclonal antibodies that bind to the sporozoite surface antigens, blocking hepatocyte invasion and preventing the establishment of liver-stage infection.