B. Representative images indicate the positivity of merozoites to EBA175 surface expression upon incubation with PfRH2b A7 or without A7 (Control). Merozoites nuclei shown in blue (DAPI) and EBA175 surface staining indicated in green color. Scale bar indicates 2 mm.
C. Schematic of the effect of PfRH2b A7 on merozoite Ca2+ signalling and invasion. After the merozoite initially attaches to the RBC and reorient itself, PfRH2b is released from rhoptry neck aiding in the sensing of the RBC by engaging in apical end interaction with the surface of the RBC (a). The interaction between PfRH2b and its receptor triggers the increase of intracellular Ca2+ of the merozoite (b). The increase in cytosolic Ca2+ levels lead to
a release of microneme proteins such as EBA175 to bind to its receptor glycophorin A (GPA). This therefore triggers the recruitment of other members leading to moving/tight junction formation (c). In the presence of PfRH2b A7 mAb, interactions between PfRH2b and its receptor is abrogated thereby affecting the intracellular Ca2+ increase (d) necessary for the release of EBA175. This, therefore, hinders recruitment of other proteins, such as AMA1,
needed for merozoite tight junction formation. Hence no tight or moving junction is formed leading to invasion blocking.
Aniweh Y, Gao X, Gunalan K, Preiser PR. PfRH2b Specific Monoclonal Antibodies Inhibit Merozoite Invasion. Mol Microbiol. 2016 Jul 20.
Other associated proteins
|PF3D7_0731500||erythrocyte binding antigen-175|