Genetic Diversity of the Plasmodium vivax Circumsporozoite Protein (Pvcsp) in Sri Lanka

Abstract

The circumsporozoite protein (CSP), sporozoite’s major surface protein comprises a central repeat (CR) region, flanked with two conserved domains (Coppi et al., 2011). The protein is diverse across all Plasmodium species and consists of tandem arrays of relatively short amino acid motifs (Brito and Ferreira, 2011). P. vivax CSP (PvCSP) displays two major types of peptide repeat motifs (PRMs), each consisting of nine amino acids, GDRA[D/A]GQPA and ANGAGNQPG, defining variants VK210 and VK247, respectively (Rosenberg et al., 1989). Both variants are globally distributed, but geographic biases have been described (Leclerc et al., 2004). We investigated the genetic diversity of Pvcsp in Sri Lanka, where low transmission and unstable malaria prevails. Local and global P. vivax isolates were analyzed for patterns of sequence variation in the csp gene by examining the polymorphism of the PRMs and the evolutionary relationships of the Pvcsp worldwide isolates were traced.

Introduction The circumsporozoite protein (CSP), sporozoite’s major surface protein comprises a central repeat (CR) region, flanked with two conserved domains (Coppi et al., 2011). The protein is diverse across all Plasmodium species and consists of tandem arrays of relatively short amino acid motifs (Brito and Ferreira, 2011). P. vivax CSP (PvCSP) displays two major types of peptide repeat motifs (PRMs), each consisting of nine amino acids, GDRA[D/A]GQPA and ANGAGNQPG, defining variants VK210 and VK247, respectively (Rosenberg et al., 1989). Both variants are globally distributed, but geographic biases have been described (Leclerc et al., 2004). We investigated the genetic diversity of Pvcsp in Sri Lanka, where low transmission and unstable malaria prevails. Local and global P. vivax isolates were analyzed for patterns of sequence variation in the csp gene by examining the polymorphism of the PRMs and the evolutionary relationships of the Pvcsp worldwide isolates were traced.