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

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 is still a major concern.Methods: A total of 171 blood samples collected from patients infected with Plasmodium vivax in Myanmar analysed in this study. The gene for PvCSP was amplified by polymerase chain reaction, followed by T&A cloning and sequencing. Polymorphic characteristics and natural selection of Myanmar 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.

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

10.21203/rs.3.rs-18691/v2 ◽

2020 ◽

Author(s):

Tuấn Cường Võ ◽

Hương Giang Lê ◽

Jung-Mi Kang ◽

Mya Moe ◽

Haung Naw ◽

...

Keyword(s):

Genetic Diversity ◽

Natural Selection ◽

Plasmodium Vivax ◽

Surface Protein ◽

Genetic Profile ◽

Repeat Region ◽

Vivax Population ◽

High Level ◽

Global Population ◽

Selection Of

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 is still a major concern. Methods: A total of 171 blood samples collected from patients infected with Plasmodium vivax in Myanmar analysed in this study. The gene for PvCSP was amplified by polymerase chain reaction, followed by T&A cloning and sequencing. Polymorphic characteristics and natural selection of Myanmar 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.

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

Malaria Journal ◽

10.1186/s12936-020-03366-7 ◽

2020 ◽

Vol 19 (1) ◽

Author(s):

Tuấn Cường Võ ◽

Hương Giang Lê ◽

Jung-Mi Kang ◽

Mya Moe ◽

Haung Naw ◽

...

Keyword(s):

Genetic Diversity ◽

Natural Selection ◽

Plasmodium Vivax ◽

Surface Protein ◽

Genetic Profile ◽

Repeat Region ◽

Polymorphic Pattern ◽

High Level ◽

Global Population ◽

Selection Of

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.

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Genetic Diversity and Natural Selection of Plasmodium vivax Duffy Binding Protein-II From China-Myanmar Border of Yunnan Province, China

Frontiers in Microbiology ◽

10.3389/fmicb.2021.758061 ◽

2021 ◽

Vol 12 ◽

Author(s):

Tian-Qi Shi ◽

Hai-Mo Shen ◽

Shen-Bo Chen ◽

Kokouvi Kassegne ◽

Yan-Bing Cui ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Natural Selection ◽

Genetic Differentiation ◽

Positive Selection ◽

Plasmodium Vivax ◽

Yunnan Province ◽

Duffy Binding Protein ◽

Synonymous Mutations ◽

Selection Of

Malaria incidence has declined dramatically over the past decade and China was certified malaria-free in 2021. However, the presence of malaria in border areas and the importation of cases of malaria parasites are major challenges for the consolidation of the achievements made by China. Plasmodium vivax Duffy binding protein (PvDBP) performs a significant role in erythrocyte invasion, and is considered a promising P. vivax vaccine. However, the highly polymorphic region of PvDBP (PvDBP-II) impedes the development of blood-stage vaccine against P. vivax. In this study, we investigated the genetic diversity and natural selection of PvDBP-II among 124 P. vivax isolates collected from the China-Myanmar border (CMB) in Yunnan Province, China, during 2009–2011. To compare genetic diversity, natural selection, and population structure with CMB isolates, 85 pvdbp-II sequences of eastern Myanmar isolates were obtained from GenBank. In addition, global sequences of pvdbp-II were retrieved from GenBank to establish genetic differentiation relationships and networks with the CMB isolates. In total, 22 single nucleotide polymorphisms reflected in 20 non-synonymous and two synonymous mutations were identified. The overall nucleotide diversity of PvDBP-II from the 124 CMB isolates was 0.0059 with 21 haplotypes identified (Hd = 0.91). The high ratio of non-synonymous to synonymous mutations suggests that PvDBP-II had evolved under positive selection. Population structure analysis of the CMB and eastern Myanmar isolates were optimally grouped into five sub-populations (K = 5). Polymorphisms of PvDBP-II display that CMB isolates were genetically diverse. Mutation, recombination, and positive selection promote polymorphism of PvDBP-II of P. vivax population. Although low-level genetic differentiation in eastern Myanmar was identified along with the more effective malaria control measures, the complexity of population structure in malaria parasites has maintained. In conclusion, findings from this study advance knowledge of the understanding of the dynamic of P. vivax population, which will contribute to guiding the rational design of a PvDBP-II based vaccine.

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Genetic Characterization of Plasmodium vivax Isolates from Pakistan Using Circumsporozoite Protein (PvCSP) and Merozoite Surface Protein-1 (PvMSP-1) Genes as Genetic Markers

10.21203/rs.3.rs-32064/v1 ◽

2020 ◽

Author(s):

Zainab Bibi ◽

Anam Fatima ◽

Rehana Rani ◽

Ayesha Maqbool ◽

Samea Khan ◽

...

Keyword(s):

Genetic Diversity ◽

Plasmodium Vivax ◽

Surface Protein ◽

Merozoite Surface Protein ◽

Circumsporozoite Protein ◽

Population Divergence ◽

Large Sample Size ◽

Base Line ◽

Variant Type ◽

High Level

Abstract Background Plasmodium vivax contribute over 70% malaria burden in Pakistan. Limited data exist on various aspects including genetic diversity of the parasite as compared to other parts of the world. The information about extent of genetic diversity assists to understand the transmission patterns of the parasite in human host. The current study was designed to understand population divergence of Plasmodium vivax in Pakistan using circumsporozoite protein and merozoite surface protein-I genes as molecular markers.Methods PvCSP and PvMSP-1 specific PCR and DNA sequencing were carried out for 150 blood samples collected from Islamabad and Rawalpindi, Pakistan. Genetic diversity was analysed using ChromasPro, ClustalW, MEGA7 and DnaSP v.5 programs.Results The PCR for PvCSP and PvMSP-1 genes was carried out for 150 P. vivax isolates resulting the PCR products ranging from 900 to 1100 bp for PvCSP gene and ~ 400 bp for PvMSP-1 gene. Majority (93%; 121/150) of the P. vivax isolates were of VK210 variant type and only 9 isolates were found of VK247 variant type based on PvCSP gene. Out of the numerous peptide repeat motifs (PRMs) detected, GDRADGQPA (PRM1) and GDRAAGQPA (PRM2) were more extensively dispersed among the P. vivax isolates. Partial sequences (~ 400 bp) at the N-terminal of PvMSP-1 gene depicted high level of diversity.Conclusion High-level genetic diversity based on PvCSP and PvMSP-1 genes was observed in clinical isolated in the study area. Parasite typing is essential in predicting pattern of antigenic variations, drug resistance and for effective drug and vaccine designing and development which can further evaluate for malaria control and eradication at individual and community level. The base-line data presented here warrant future studies to investigate more into the genetic diversity of P. vivax with large sample size from across the country for better understanding of the vivax malaria transmission patterns.

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