Bacterially expressed full-length recombinant Plasmodium falciparum RH5 protein binds erythrocytes and elicits potent strain-transcending parasite-neutralizing antibodies.

Plasmodium falciparum reticulocyte binding like homolog protein 5 (PfRH5) is important merozoites receptor ligand binding to erythrocytes, basigin. PfRH5 is an attractive candidate malaria vaccine, as expressed by a number of strains Hamster Recombinant Proteins of P. falciparum, can not be genetically altered, and exhibit limited sequence polymorphism. 

Viral vector-induced potent antibody PfRH5 erythrocyte invasion is inhibited. However, it has been a challenge to produce a full-length recombinant expression systems based PfRH5 in bacterial cells. In this study, we have produced full-length recombinant PfRH5 in Escherichia coli that specifically bind erythrocytes exhibit similar to the original PfRH5 parasite protein and also, importantly, elicits potent inhibitory antibodies invasion against a number of strains of P. falciparum. Antibasigin antibodies block the erythrocyte binding both native and recombinant PfRH5, further asserted that they bind with basigin. 

We have thus succeeded in producing a full-length functional PfRH5 as erythrocyte binding active recombinant protein with conformational integrity that mimics that of native parasite protein and elicits potent antibody-neutralizing parasite strain-exceeded. P. falciparum has the ability to develop immune escape mechanism, and thus, the blood-stage malaria vaccines that target multiple antigens or pathways may prove efficacious. 

In this case, the combination of antibodies targeting antigens PfRH5 and other key merozoites produced an additive inhibitory effective against strains of P. falciparum worldwide a few. PfRH5 are immunogenic when immunized with other Mouse Recombinant Proteins antigens, allowing a strong antibody response inhibition invasion with no immune disorders. Our results strongly support the development of a vaccine PfRH5 as a component of a combination of blood-stage malaria.