Expression of Plasmodium falciparum 3D7 STEVOR proteins for evaluation of antibody responses following malaria infections in naïve infants

Parasitology. 2008 Feb;135(2):155-67. doi: 10.1017/S0031182007003794. Epub 2007 Oct 12.

Abstract

Clinical immunity to Plasmodium falciparum malaria develops after repeated exposure to the parasite. At least 2 P. falciparum variant antigens encoded by multicopy gene families (var and rif) are targets of this adaptive antibody-mediated immunity. A third multigene family of variant antigens comprises the stevor genes. Here, 4 different stevor sequences were selected for cloning and expression in Escherichia coli and His6-tagged fusion proteins were used for assessing the development of immunity. In a cross-sectional analysis of clinically immune adults living in a malaria endemic area in Ghana, high levels of anti-STEVOR IgG antibody titres were determined in ELISA. A cross-sectional study of 90 nine-month-old Ghanaian infants using 1 recombinant STEVOR showed that the antibody responses correlated positively with the number of parasitaemia episodes. In a longitudinal investigation of 17 immunologically naïve 9-month-old infants, 3 different patterns of anti-STEVOR antibody responses could be distinguished (high, transient and low). Children with high anti-STEVOR-antibody levels exhibited an elevated risk for developing parasitaemia episodes. Overall, a protective effect could not be attributed to antibodies against the STEVOR proteins chosen for the study presented here.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amino Acid Sequence
  • Animals
  • Antibodies, Protozoan / blood*
  • Antigens, Protozoan / genetics
  • Antigens, Protozoan / immunology*
  • Antigens, Protozoan / metabolism
  • Cross-Sectional Studies
  • Escherichia coli / genetics
  • Ghana
  • Humans
  • Immunoglobulin G / blood*
  • Infant
  • Longitudinal Studies
  • Mice
  • Molecular Sequence Data
  • Phylogeny
  • Plasmodium falciparum / genetics
  • Plasmodium falciparum / immunology*
  • Recombinant Fusion Proteins / immunology*
  • Sequence Alignment
  • Time Factors

Substances

  • Antibodies, Protozoan
  • Antigens, Protozoan
  • Immunoglobulin G
  • Recombinant Fusion Proteins
  • STEVOR antigen, Plasmodium falciparum