Pfs230 Domain 7 is targeted by a potent malaria transmission-blocking monoclonal antibody

Malaria transmission-blocking vaccines (TBVs) aim to induce antibodies that block Plasmodium parasite development in the mosquito midgut, thus preventing mosquitoes from becoming infectious. While the Pro-domain and first of fourteen 6-Cysteine domains (Pro-D1) of the Plasmodium gamete surface protein Pfs230 are known targets of transmission-blocking antibodies, no studies to date have discovered other Pfs230 domains that are functional targets. Here, we show that a murine monoclonal antibody (mAb), 18F25.1, targets Pfs230 Domain 7. We generated a subclass-switched complement-fixing variant, mAb 18F25.2a, using a CRISPR/Cas9-based hybridoma engineering method. This subclass-switched mAb 18F25.2a induced lysis of female gametes in vitro. Importantly, mAb 18F25.2a potently reduced P. falciparum infection of Anopheles stephensi mosquitoes in a complement-dependent manner, as assessed by standard membrane feeding assays. Together, our data identify Pfs230 Domain 7 as target for transmission-blocking antibodies and provide a strong incentive to study domains outside Pfs230Pro-D1 as TBV candidates.