Soluble and glyco-lipid modified baculovirus Plasmodium falciparum C-terminal merozoite surface protein 1, two forms of a leading malaria vaccine candidate

Vaccine. 2006 Aug 14;24(33-34):5997-6008. doi: 10.1016/j.vaccine.2006.04.069. Epub 2006 Jun 5.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Baculoviridae / genetics
  • Cell Line
  • Chromatography, Gel
  • Cloning, Molecular
  • Electrophoresis, Polyacrylamide Gel
  • Gene Expression
  • Genetic Vectors
  • Malaria Vaccines / chemistry*
  • Malaria Vaccines / genetics*
  • Malaria Vaccines / isolation & purification
  • Malaria Vaccines / metabolism
  • Mass Spectrometry
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / isolation & purification
  • Merozoite Surface Protein 1 / chemistry*
  • Merozoite Surface Protein 1 / genetics*
  • Merozoite Surface Protein 1 / isolation & purification
  • Merozoite Surface Protein 1 / metabolism
  • Molecular Sequence Data
  • Plasmodium falciparum / genetics
  • Plasmodium falciparum / immunology*
  • Polysaccharides / analysis
  • Protein Processing, Post-Translational
  • Protein Transport
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Sequence Analysis, Protein
  • Solubility
  • Spodoptera

Substances

  • Malaria Vaccines
  • Membrane Proteins
  • Merozoite Surface Protein 1
  • Polysaccharides
  • Recombinant Proteins