Red-cell invasion is essential to malaria. P. falciparum uses a PCRCR complex, but Rh5 is species restricted. Orthologs of PTRAMP, CSS and Ripr from P. falciparum, P. vivax and P. knowlesi formed disulfide-linked PTRAMP-CSS heterodimers and bound the Ripr C terminus as a conserved PCR complex. Cross-reactive antibodies differentially inhibited invasion, crystallography revealed an inhibitory PvRipr epitope, and P. knowlesi cryo-EM confirmed a conserved invasion scaffold.
Key findings
- The PTRAMP-CSS heterodimer and Ripr C-terminal interaction were conserved; antibodies cross-reacted with differential inhibition; a PvRipr inhibitory epitope was resolved; cryo-EM confirmed the core scaffold.
Why this matters globally
A conserved target may support vaccines spanning falciparum and vivax malaria, while structural information enables rational immunogen and antibody design.
Thai researcher contribution
Jetsumon Sattabongkot and Rhea J. Longley of Mahidol University connect Thailand's P. vivax expertise with international structural immunology.
Limitations to consider
Inhibition is in vitro and varies by species and antibody. Animal protection, durability, immune focusing and safety are not shown. Structural conservation does not ensure equal epitope accessibility, and field polymorphism may reduce coverage.