title: Soluble and glyco-lipid modified baculovirus Plasmodium falciparum C-terminal merozoite surface protein 1, two forms of a leading malaria vaccine candidate.
abstract: Recombinant homologues of the Plasmodium merozoite surface protein 1 C-terminus are leading blood stage malaria vaccine candidates. MSP1 is anchored to the merozoite plasma membrane in vivo by a glycosyl-phosphatidyl-inositol (GPI) moiety, implicated in malaria pathology. Two types of recombinant Plasmodium falciparum MSP1p19 (PfMSP1p19) expressed in baculovirus/insect cells are described here: (1) a soluble, secreted form (PfMSP1p19S) and (2) detergent soluble cellular form(s) (PfMSP1p19+A), released from the infected cell surface by treatment with GPI specific phosphatidyl-inositol phospholipase C (PI-PLC). Soluble and cellular PfMSP1p19 were purified and characterized using SDS-PAGE, mass spectrometry (MS), N-terminal amino acid sequencing, gel filtration and glycan analyses. Quantitative inositol dosage suggested that surface GPI processed entities constituted only 14% of the purified cellular PfMSP1p19+A, with GPI unprocessed forms likely recovered in the endoplasmic reticulum. Nevertheless, this preparation has dramatic immuno-stimulatory activity to be described elsewhere. The interest of these results for both malaria specific and generic vaccine development are discussed.
authors.affiliation: Laboratoire de Vaccinologie Parasitaire, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris Cedex 15, France.
authors.forename: Sarah
authors.initials: S
authors.lastname: Bonnet
authors.forename: Stéphane
authors.initials: S
authors.lastname: Pêtres
authors.forename: Inge
authors.initials: I
authors.lastname: Holm
authors.forename: Thierry
authors.initials: T
authors.lastname: Fontaine
authors.forename: Sandrine
authors.initials: S
authors.lastname: Rosario
authors.forename: Charles
authors.initials: C
authors.lastname: Roth
authors.forename: Shirley
authors.initials: S
authors.lastname: Longacre
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D002460:Cell Line; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D015870:Gene Expression; D005822:Genetic Vectors; D017780:Malaria Vaccines / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D020066:Merozoite Surface Protein 1 / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000235:genetics / Q000276:immunology*; D011134:Polysaccharides / Q000032:analysis; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D020539:Sequence Analysis, Protein; D012995:Solubility; D018411:Spodoptera
chemical_list: D017780:Malaria Vaccines; D008565:Membrane Proteins; D020066:Merozoite Surface Protein 1; D011134:Polysaccharides; D011994:Recombinant Proteins