Immunization with Transgenic Rodent Malaria Parasites Expressing Pfs25 Induces Potent Transmission-Blocking Activity

Sci Rep. 2018 Jan 25;8(1):1573. doi: 10.1038/s41598-017-18831-8.

Abstract

An anti-malarial transmission blocking vaccine (TBV) would be an important tool for disease control or elimination, though current candidates have failed to induce high efficacy in clinical studies. The ookinete surface protein P25 is a primary target for TBV development, but heterologous expression of P25 with appropriate conformation is problematic and a pre-requisite for achieving functional titers. A potential alternative to recombinant/sub-unit vaccine is immunization with a non-pathogenic, whole-parasite vaccine. This study examines the ability of a purified transgenic rodent-malaria parasite (PbPfs25DR3), expressing Plasmodium falciparum P25 in native conformation on the P. berghei ookinete surface, to act as a TBV. Vaccination with purified PbPfs25DR3 ookinetes produces a potent anti-Pfs25 response and high transmission-blocking efficacy in the laboratory, findings that are then translated to experimentation on natural field isolates of P. falciparum from infected individuals in Burkina Faso. Efficacy is demonstrated in the lab and the field (up to 93.3%/97.1% reductions in transmission intensity respectively), with both a homologous strategy with one and two boosts, and as part of a prime-boost regime, providing support for the future development of a whole-parasite TBV.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Burkina Faso
  • Chromobox Protein Homolog 5
  • Disease Transmission, Infectious / prevention & control*
  • Female
  • Humans
  • Immunization Schedule
  • Malaria Vaccines / administration & dosage
  • Malaria Vaccines / genetics
  • Malaria Vaccines / immunology*
  • Malaria, Falciparum / prevention & control*
  • Mice, Inbred BALB C
  • Plasmodium berghei / genetics
  • Plasmodium berghei / immunology*
  • Protozoan Proteins / genetics
  • Protozoan Proteins / immunology*
  • Treatment Outcome
  • Vaccines, Synthetic / administration & dosage
  • Vaccines, Synthetic / genetics
  • Vaccines, Synthetic / immunology

Substances

  • CBX5 protein, human
  • Malaria Vaccines
  • Pfs25 protein, Plasmodium falciparum
  • Protozoan Proteins
  • Vaccines, Synthetic
  • Chromobox Protein Homolog 5