title: Truncation of Plasmodium berghei merozoite surface protein 8 does not affect in vivo blood-stage development.
abstract: Merozoite surface protein 8 (MSP8) has shown promise as a vaccine candidate in the Plasmodium yoelii rodent malaria model and has a proposed role in merozoite invasion of erythrocytes. However, the temporal expression and localisation of MSP8 are unusual for a merozoite antigen. Moreover, in Plasmodium falciparum the MSP8 gene could be disrupted with no apparent effect on invitro growth. To address the invivo function of full-length MSP8, we truncated MSP8 in the rodent parasite Plasmodium berghei. PbDeltaMSP8 disruptant parasites displayed a normal blood-stage growth rate but no increase in reticulocyte preference, a phenomenon observed in P. yoelii MSP8 vaccinated mice. Expression levels of erythrocyte surface antigens were similar in P. berghei wild-type and PbDeltaMSP8-infected erythrocytes, suggesting that a parasitophorous vacuole function for MSP8 does not involve global trafficking of such antigens. These data demonstrate that a full-length membrane-associated form of PbMSP8 is not essential for blood-stage growth.
authors: The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3050, Australia. taniad@deakin.edu.au
authors: Tania F
authors: TF
authors: de Koning-Ward
authors: Damien R
authors: DR
authors: Drew
authors: Joanne M
authors: JM
authors: Chesson
authors: James G
authors: JG
authors: Beeson
authors: Brendan S
authors: BS
authors: Crabb
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics* / Q000378:metabolism; D004912:Erythrocytes / Q000469:parasitology*; D017353:Gene Deletion; D008018:Life Cycle Stages; D008288:Malaria / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D010962:Plasmodium berghei / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D052939:Schizonts / Q000254:growth & development / Q000378:metabolism; D053058:Trophozoites / Q000254:growth & development / Q000378:metabolism
chemical_list: D000953:Antigens, Protozoan; D015800:Protozoan Proteins; C431669:merozoite surface protein 8, Plasmodium