Genetic polymorphism and natural selection of circumsporozoite protein in Myanmar Plasmodium vivax

Malaria Journal

Moe Kyaw Myint¹  Mya Moe¹  Haung Naw²  Woon-Mok Sohn²  Jung-Mi Kang²  Byoung-Kuk Na²  Tuấn Cường Võ²  Hương Giang Lê²  Tong-Soo Kim³  Jinyoung Lee³ 

[1] Department of Medical Research Pyin Oo Lwin Branch;Department of Parasitology and Tropical Medicine, Gyeongsang National University College of Medicine;Department of Tropical Medicine, Inha University College of Medicine;

关键词: Plasmodium vivax;    Circumsporozoite protein;    Genetic polymorphism;    Natural selection;    Myanmar;   

DOI  :  10.1186/s12936-020-03366-7

来源: DOAJ

【 摘 要 】

Abstract Background Circumsporozoite surface protein (CSP) of malaria parasites has been recognized as one of the leading vaccine candidates. Clinical trials of vaccines for vivax malaria incorporating Plasmodium vivax CSP (PvCSP) have demonstrated their effectiveness in preventing malaria, at least in part. However, genetic diversity of pvcsp in the natural population remains a major concern. Methods A total of 171 blood samples collected from patients infected with Plasmodium vivax in Myanmar were analysed in this study. The pvcsp was amplified by polymerase chain reaction, followed by cloning and sequencing. Polymorphic characteristics and natural selection of pvcsp population in Myanmar were analysed using DNASTAR, MEGA6 and DnaSP programs. The polymorphic pattern and natural selection of publicly accessible global pvcsp sequences were also comparatively analysed. Results Myanmar pvcsp sequences were divided into two subtypes VK210 and VK247 comprising 143 and 28 sequences, respectively. The VK210 subtypes showed higher levels of genetic diversity and polymorphism than the VK247 subtypes. The N-terminal non-repeat region of pvcsp displayed limited genetic variations in the global population. Different patterns of octapeptide insertion (ANKKAEDA in VK210 and ANKKAGDA in VK247) and tetrapeptide repeat motif (GGNA) were identified in the C-terminal region of global pvcsp population. Meanwhile, the central repeat region (CRR) of Myanmar and global pvcsp, both in VK210 and VK247 variants, was highly polymorphic. The high level of genetic diversity in the CRR has been attributed to the different numbers, types and combinations of peptide repeat motifs (PRMs). Interestingly, 27 and 5 novel PRMs were found in Myanmar VK210 and VK247 variants, respectively. Conclusion Comparative analysis of the global pvcsp population suggests a complex genetic profile of pvcsp in the global population. These results widen understanding of the genetic make-up of pvcsp in the global P. vivax population and provide valuable information for the development of a vaccine based on PvCSP.

【 授权许可】

Unknown