A human monoclonal antibody blocks malaria transmission and defines a highly conserved neutralizing epitope on gametes
Camila H. Coelho, Wai Kwan Tang, Martin Burkhardt, Jacob D. Galson, Olga Muratova, Nichole D. Salinas, Thiago Luiz Alves e Silva, Karine Reiter, Nicholas J. MacDonald, Vu Nguyen, Raúl Herrera, Richard L. Shimp, David L. Narum, Miranda Byrne‐Steele, Wenjing Pan, Xiaohong Hou, Brittany Brown, Mary Eisenhower, Jian Han, Bethany J. Jenkins, Justin Doritchamou, Margery Smelkinson, Joel Vega-Rodríguez, Johannes Trück, Justin J. Taylor, Issaka Sagara, Sara A. Healy, Jonathan P. Renn, Niraj H. Tolia, Patrick E. Duffy
Abstract
Malaria elimination requires tools that interrupt parasite transmission. Here, we characterize B cell receptor responses among Malian adults vaccinated against the first domain of the cysteine-rich 230 kDa gamete surface protein Pfs230, a key protein in sexual stage development of P. falciparum parasites. Among nine Pfs230 human monoclonal antibodies (mAbs) that we generated, one potently blocks transmission to mosquitoes in a complement-dependent manner and reacts to the gamete surface; the other eight show only low or no blocking activity. The structure of the transmission-blocking mAb in complex with vaccine antigen reveals a large discontinuous conformational epitope, specific to domain 1 of Pfs230 and comprising six structural elements in the protein. The epitope is conserved, suggesting the transmission-blocking mAb is broadly functional. This study provides a rational basis to improve malaria vaccines and develop therapeutic antibodies for malaria elimination.