gms | German Medical Science

11th Malaria Meeting

Malaria Group / Section Antiparasitic Chemotherapy of the Paul-Ehrlich-Society (PEG e. V.) in cooperation with the German Society for Tropical Medicine and International Health (DTG e. V.) and the German Society for Parasitology (DGP e. V.)

08.11. - 09.11.2013, Aachen

Combined var gene and microsatellite genotyping of Plasmodium falciparum strains to study the inheritance of variant surface antigens

Meeting Abstract

Suche in Medline nach

  • Ellen Bruske - Institute of Tropical Medicine, University of Tuebingen, Tuebingen, Germany
  • Joana Volk - Institute of Tropical Medicine, University of Tuebingen, Tuebingen, Germany
  • Matthias Frank - Institute of Tropical Medicine, University of Tuebingen, Tuebingen, Germany

11th Malaria Meeting. Aachen, 08.-09.11.2013. Düsseldorf: German Medical Science GMS Publishing House; 2014. Doc13mal17

doi: 10.3205/13mal17, urn:nbn:de:0183-13mal170

Veröffentlicht: 29. Januar 2014

© 2014 Bruske et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielfältigt, verbreitet und öffentlich zugänglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

In Plasmodium falciparum malaria, cytoadherence of infected red blood cells to host endothelial receptors is mediated by a polymorphic family of surface proteins collectively referred to as Plasmodium falciparum membrane protein 1 (PfEMP1). This protein family is considered the primary target of the humoral immune response. Each parasite harbours approximately 60 different variants of the protein, encoded by 60 different members of the var multigene family. Antigenic variation – a mechanism to avoid the host’s immune response – is the result of mutually exclusive expression of one of the 60 var gene loci and switching of the active var gene. The var gene repertoire of individual Plasmodium strains is almost completely different between individual isolates. However, it is not clear if this antigenic diversity is constantly expanded by recombination events or if it simply reflects a very large pool of individual variants. Recombination events have been found in subtelomeric regions of heterologous chromosomes, which harbour the majority of gene families encoding variant surface proteins such as PfEMP1. In these regions, single nucleotide polymorphisms (snps) are prevalent. It remains an open question if these snps represent recombination events of erroneous assembly due to repetitive regions and homopolymer runs. Here we aim to use microsatellite typing and locus specific var gene PCR as a tool to investigate the inheritance of var genes and other multicopy gene families in P. falciparum. On this account, we characterized the 3D7 strain and its sibling parasite E5. In a first step, we tested 70 microsatellite primers across the genome in silico using bioinformatical tools and single nucleotide polymorphism maps for E5 and 3D7. In a second step, these primers were evaluated by PCR on genomic DNA and all fragments were characterized by Sanger sequencing. Together with a PCR analysis of the entire var gene family this allowed us to assess if var gene inheritance follows a Mendelian pattern. In a third step, microsatellite analysis based on fragment length polymorphism will be established in order to enable high throughput analysis of field isolates.