Structural elucidation of full-length Pfs48/45 in complex with potent monoclonal antibodies isolated from a naturally exposed individual

This is the authors' abstract. We don't add key points for this paper.

Biomedical interventions that block the transmission of Plasmodium falciparum (Pf) from humans to mosquitoes may be critical for malaria elimination. Pfs48/45, a gamete-surface protein essential for Pf development in the mosquito midgut, is a target of clinical-stage transmission-blocking vaccines and monoclonal antibodies (mAbs) that disrupt Pf transmission to mosquitoes. Antibodies directed to domain 3 of Pfs48/45 have been structurally and functionally described; however, in-depth information about other inhibitory epitopes on Pfs48/45 is currently limited. Here, we present a cryo-electron microscopy structure of full-length Pfs48/45 in complex with potent human mAbs targeting all three domains. Our data indicate that although Pfs48/45 domains 1 and 2 are rigidly coupled, there is substantial conformational flexibility between domains 2 and 3. Characterization of mAbs against domain 1 revealed the presence of a conformational epitope class that is largely conserved across Pf field isolates and is associated with recognition by potent antibodies. Our study provides insights into epitopes across full-length Pfs48/45 and has implications for the design of next-generation malaria interventions. Kucharska, Ivanochko and Hailemariam and colleagues solved cryo-EM structures of Pfs48/45, needed for Plasmodium falciparum development, with potent antibodies. The work revealed conformational epitopes, with implications for design of therapies against malaria.