Acquisition of Growth-Inhibitory Antibodies against Blood-Stage Plasmodium falciparum

Research output: Contribution to journalArticle

Abstract

Background: Antibodies that inhibit the growth of blood-stage Plasmodium falciparum may play an important role in acquired and vaccine-induced immunity in humans. However, the acquisition and activity of these antibodies is not well understood. Methods: We tested dialysed serum and purified immunoglobulins from Kenyan children and adults for inhibition of P. falciparum blood-stage growth in vitro using different parasite lines. Serum antibodies were measured by ELISA to blood-stage parasite antigens, extracted from P. falciparum schizonts, and to recombinant merozoite surface protein 1 (42 kDa C-terminal fragment, MSP1-42). Results: Antibodies to blood-stage antigens present in schizont protein extract and to recombinant MSP1-42 significantly increased with age and were highly correlated. In contrast, growth-inhibitory activity was not strongly associated with age and tended to decline marginally with increasing age and exposure, with young children demonstrating the highest inhibitory activity. Comparison of growth-inhibitory activity among samples collected from the same population at different time points suggested that malaria transmission intensity influenced the level of growth-inhibitory antibodies. Antibodies to recombinant MSP1-42 were not associated with growth inhibition and high immunoglobulin G levels were poorly predictive of inhibitory activity. The level of inhibitory activity against different isolates varied. Conclusions: Children can acquire growth-inhibitory antibodies at a young age, but once they are acquired they do not appear to be boosted by on-going exposure. Inhibitory antibodies may play a role in protection from early childhood malaria.

Details

Authors
  • F. J. McCallum
  • Kristina Persson
  • C. K. Mugyenyi
  • F. J. I. Fowkes
  • J. A. Simpson
  • J. S. Richards
  • T. N. Williams
  • K. Marsh
  • J. G. Beeson
External organisations
  • Walter and Eliza Hall Institute of Medical Research
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Immunology

Keywords

  • recombinant merozoite surface protein 1, parasite antibody, merozoite surface protein 1, immunoglobulin G, unclassified drug, protozoon antibody
Original languageEnglish
Article numbere3571
JournalPLoS ONE
Volume3
Issue number10
Publication statusPublished - 2008
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes

Bibliographic note

10