title: Complement receptor 1 is the host erythrocyte receptor for Plasmodium falciparum PfRh4 invasion ligand.
abstract: Plasmodium falciparum is responsible for the most severe form of malaria disease in humans, causing more than 1 million deaths each year. As an obligate intracellular parasite, P. falciparum's ability to invade erythrocytes is essential for its survival within the human host. P. falciparum invades erythrocytes using multiple host receptor-parasite ligand interactions known as invasion pathways. Here we show that CR1 is the host erythrocyte receptor for PfRh4, a major P. falciparum ligand essential for sialic acid-independent invasion. PfRh4 and CR1 interact directly, with a K(d) of 2.9 μM. PfRh4 binding is strongly correlated with the CR1 level on the erythrocyte surface. Parasite invasion via sialic acid-independent pathways is reduced in low-CR1 erythrocytes due to limited availability of this receptor on the surface. Furthermore, soluble CR1 can competitively block binding of PfRh4 to the erythrocyte surface and specifically inhibit sialic acid-independent parasite invasion. These results demonstrate that CR1 is an erythrocyte receptor used by the parasite ligand PfRh4 for P. falciparum invasion.
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, Parkville 3052, Australia.
authors.forename: Wai-Hong
authors.initials: WH
authors.lastname: Tham
authors.forename: Danny W
authors.initials: DW
authors.lastname: Wilson
authors.forename: Sash
authors.initials: S
authors.lastname: Lopaticki
authors.forename: Christoph Q
authors.initials: CQ
authors.lastname: Schmidt
authors.forename: Patience B
authors.initials: PB
authors.lastname: Tetteh-Quarcoo
authors.forename: Paul N
authors.initials: PN
authors.lastname: Barlow
authors.forename: Dave
authors.initials: D
authors.lastname: Richard
authors.forename: Jason E
authors.initials: JE
authors.lastname: Corbin
authors.forename: James G
authors.initials: JG
authors.lastname: Beeson
authors.forename: Alan F
authors.initials: AF
authors.lastname: Cowman
mesh_terms: D000818:Animals; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism* / Q000469:parasitology*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D010963:Plasmodium falciparum / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D011485:Protein Binding; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D011951:Receptors, Complement / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D015800:Protozoan Proteins; C464927:RH4 protein, Plasmodium falciparum; D011951:Receptors, Complement; D011994:Recombinant Proteins; D019158:N-Acetylneuraminic Acid