Dataset Information

Immunogenicity of bacterial-expressed recombinant Plasmodium knowlesi merozoite surface protein-142 (MSP-142).

ABSTRACT:

Background

Plasmodium knowlesi is the fifth Plasmodium species that can infect humans. The Plasmodium merozoite surface protein-1(42) (MSP-1(42)) is a potential candidate for malaria vaccine. However, limited studies have focused on P. knowlesi MSP-1(42).

Methods

A ~42 kDa recombinant P. knowlesi MSP-1(42) (pkMSP-1(42)) was expressed using an Escherichia coli system. The purified pkMSP-1(42) was evaluated with malaria and non-malaria human patient sera (n = 189) using Western blots and ELISA. The immunogenicity of pkMSP-1(42) was evaluated in mouse model.

Results

The purified pkMSP-1(42) had a sensitivity of 91.0% for detection of human malaria in both assays. Specificity was 97.5 and 92.6% in Western blots and ELISA, respectively. Levels of cytokine interferon-gamma, interleukin-2, interleukin-4, and interleukin-10 significantly increased in pkMSP-1(42)-immunized mice as compared to the negative control mice. pkMSP-1(42)-raised antibody had high endpoint titres, and the IgG isotype distribution was IgG1 > IgG2b > IgG3 > IgG2a.

Conclusions

pkMSP-1(42) was highly immunogenic and able to detect human malaria. Hence, pkMSP-1(42) would be a useful candidate for malaria vaccine development and seroprevalence studies.

SUBMITTER: Cheong FW

PROVIDER: S-EPMC3878241 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Immunogenicity of bacterial-expressed recombinant Plasmodium knowlesi merozoite surface protein-142 (MSP-142).

Cheong Fei Wen FW Fong Mun Yik MY Lau Yee Ling YL Mahmud Rohela R

Malaria journal 20131219

<h4>Background</h4>Plasmodium knowlesi is the fifth Plasmodium species that can infect humans. The Plasmodium merozoite surface protein-1(42) (MSP-1(42)) is a potential candidate for malaria vaccine. However, limited studies have focused on P. knowlesi MSP-1(42).<h4>Methods</h4>A ~42 kDa recombinant P. knowlesi MSP-1(42) (pkMSP-1(42)) was expressed using an Escherichia coli system. The purified pkMSP-1(42) was evaluated with malaria and non-malaria human patient sera (n = 189) using Western blot ...[more]

PMID: 24354660

Similar Datasets

Project description:BackgroundThe merozoite surface protein-1 (MSP-1) gene encodes for a leading malaria vaccine candidate antigen. However, its extensive polymorphic nature represents a major obstacle to the development of a protective vaccine. Previously, a pilot study was carried out to explore the sequence variation of the C-terminal 42 kDa fragment within P. knowlesi MSP-1 gene (PkMSP-142) based on 12 clinical samples; however, further study on an adequate sample size is vital in estimating the genetic diversity of the parasite population.MethodsIn the present study, we included a larger sample size of P. knowlesi (83 samples) covering eight states of Malaysia to determine the genetic polymorphism, natural selection and haplotype groups of the gene fragment coding PkMSP-142. The region flanking PkMSP-142 was amplified by PCR and directly sequenced. Genetic diversity, haplotype diversity, population genetic differentiation and natural selection were determined in order to study the polymorphic characteristic of PkMSP-142.ResultsA high level of genetic diversity (Hd = 0.970 ± 0.007; л = 0.01079 ± 0.00033) was observed among the 83 P. knowlesi samples, confirming the extensive genetic polymorphism exhibited among the P. knowlesi population found in Malaysia. A total of 18 distinct haplotypes with 17 amino acid changes were identified, whereby 15 were new haplotypes. High population differentiation values were observed within samples from Peninsular Malaysia and Malaysian Borneo. The 42 kDa fragments of P. knowlesi from Malaysian Borneo were found to be acting on balancing selection whilst purifying selection was suggested to act on isolates from Peninsular Malaysia. The separation of PkMSP-142 haplotypes into two main groups based on geographical separation has further supported the existence of two distinct P. knowlesi lineages.ConclusionsA high level of genetic diversity was observed among PkMSP-142 in Malaysia, whereby most of the polymorphisms were found within the 33 kDa region. Taken together, these data will be useful in order to understand the nature of P. knowlesi population in Malaysia as well as the design and development of a MSP-142 based knowlesi malaria vaccine.

Project description:BACKGROUND:Human infections due to the monkey malaria parasite Plasmodium knowlesi is on the rise in most Southeast Asian countries specifically Malaysia. The C-terminal 19 kDa domain of PvMSP1P is a potential vaccine candidate, however, no study has been conducted in the orthologous gene of P. knowlesi. This study investigates level of polymorphisms, haplotypes and natural selection of full-length pkmsp1p in clinical samples from Malaysia. METHODS:A total of 36 full-length pkmsp1p sequences along with the reference H-strain and 40 C-terminal pkmsp1p sequences from clinical isolates of Malaysia were downloaded from published genomes. Genetic diversity, polymorphism, haplotype and natural selection were determined using DnaSP 5.10 and MEGA 5.0 software. Genealogical relationships were determined using haplotype network tree in NETWORK software v5.0. Population genetic differentiation index (F ST ) and population structure of parasite was determined using Arlequin v3.5 and STRUCTURE v2.3.4 software. RESULTS:Comparison of 36 full-length pkmsp1p sequences along with the H-strain identified 339 SNPs (175 non-synonymous and 164 synonymous substitutions). The nucleotide diversity across the full-length gene was low compared to its ortholog pvmsp1p. The nucleotide diversity was higher toward the N-terminal domains (pkmsp1p-83 and 30) compared to the C-terminal domains (pkmsp1p-38, 33 and 19). Phylogenetic analysis of full-length genes identified 2 distinct clusters of P. knowlesi from Malaysian Borneo. The 40 pkmsp1p-19 sequences showed low polymorphisms with 16 polymorphisms leading to 18 haplotypes. In total there were 10 synonymous and 6 non-synonymous substitutions and 12 cysteine residues were intact within the two EGF domains. Evidence of strong purifying selection was observed within the full-length sequences as well in all the domains. Shared haplotypes of 40 pkmsp1p-19 were identified within Malaysian Borneo haplotypes. CONCLUSIONS:This study is the first to report on the genetic diversity and natural selection of pkmsp1p. A low level of genetic diversity and strong evidence of negative selection was detected and observed in all the domains of pkmsp1p of P. knowlesi indicating functional constrains. Shared haplotypes were identified within pkmsp1p-19 highlighting further evaluation using larger number of clinical samples from Malaysia.

Dataset Information

Immunogenicity of bacterial-expressed recombinant Plasmodium knowlesi merozoite surface protein-142 (MSP-142).

Background

Methods

Results

Conclusions

Publications

Immunogenicity of bacterial-expressed recombinant Plasmodium knowlesi merozoite surface protein-142 (MSP-142).

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets