High-level expression of the malaria blood-stage vaccine candidate Plasmodium falciparum apical membrane antigen 1 and induction of antibodies that inhibit erythrocyte invasion

Infect Immun. 2002 Aug;70(8):4471-6. doi: 10.1128/IAI.70.8.4471-4476.2002.

Abstract

Apical membrane antigen 1 (AMA-1) is a highly promising malaria blood-stage vaccine candidate that has induced protection in rodent and nonhuman primate models of malaria. Authentic conformation of the protein appears to be essential for the induction of parasite-inhibitory antibody responses. Here we have developed a synthetic gene with adapted codon usage to allow expression of Plasmodium falciparum FVO strain AMA-1 (PfAMA-1) in Pichia pastoris. In addition, potential N-glycosylation sites were changed, exploiting the lack of conservation of these sites in Plasmodium, to obtain high-level secretion of a homogeneous product, suitable for scale-up according to current good manufacturing procedures. Purified PfAMA-1 displayed authentic antigenic properties, indicating that the amino acid changes had no deleterious effect on the conformation of the protein. High-titer antibodies, raised in rabbits, reacted strongly with homologous and heterologous P. falciparum by immunofluorescence. In addition, purified immunoglobulin G from immunized animals strongly inhibited invasion of red blood cells by homologous and, to a somewhat lesser extent, heterologous P. falciparum.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Protozoan / immunology
  • Antigens, Protozoan / genetics
  • Antigens, Protozoan / immunology*
  • Base Sequence
  • DNA, Protozoan
  • Erythrocytes / immunology
  • Erythrocytes / parasitology
  • Gene Expression
  • Malaria Vaccines / genetics
  • Malaria Vaccines / immunology*
  • Malaria, Falciparum / prevention & control*
  • Membrane Proteins / genetics
  • Membrane Proteins / immunology*
  • Molecular Sequence Data
  • Plasmodium falciparum / genetics
  • Plasmodium falciparum / immunology*
  • Protozoan Proteins / genetics
  • Protozoan Proteins / immunology*
  • Rabbits
  • Vaccines, Synthetic / genetics
  • Vaccines, Synthetic / immunology*

Substances

  • Antibodies, Protozoan
  • Antigens, Protozoan
  • DNA, Protozoan
  • Malaria Vaccines
  • Membrane Proteins
  • Protozoan Proteins
  • Vaccines, Synthetic
  • apical membrane antigen I, Plasmodium

Associated data

  • GENBANK/AJ277646