High polymorphism in Plasmodium vivax merozoite surface protein-5 (MSP5)

Abstract

A key issue relating to developing multi-component anti-malarial vaccines, lies in studying Plasmodium vivax surface proteins' genetic variation. The present work was aimed at amplifying, cloning and sequencing the gene encoding P. vivax merozoite surface protein 5 (PvMSP5) in samples obtained from infected patients from Colombian areas having varying malaria transmission rates. Nucleotide sequence data reported in this paper are available in the GenBank, EMBL and DDBJ databases under Accessions numbers DQ341586 to DQ341601. Our results have revealed that PvMSP5 is one of the P. vivax surface proteins having greater polymorphism, this being restricted to specific protein regions. The intron and exon II (which includes the GPI anchor and EGF-like domain) were both highly conserved when compared to exon I; exon I displayed the greatest variation and most of the recombination events occurred within it. No geographical grouping was observed. The Nei-Gojobori test revealed significant positive selection in the samples analysed here, whereas Tajima and Fu and Li tests presented a neutral selection pattern. The results reflected a localized variation pattern, recombination between PvMSP5 alleles and also functional and immune pressures, where stronger selective forces might be acting on exon I than on exon II, suggesting that the latter could be an important region to be included in an anti-malarial vaccine.

Plasmodium vivax: comparison of immunogenicity among proteins expressed in the cell-free systems of Escherichia coli and wheat germ by suspension array assays

“…As expected, results demonstrated that MSP proteins are immunogenic in natural infections. Moreover, results confirmed that MSP1-19 is more immunogenic than MSP1-N [20] and that in spite of MSP5 being highly polymorphic [34], it is also highly immunogenic. Furthermore, in line with being a multigene family differentially expressed during blood stages [35], reactivity against MSP7 was lower than MSP1 or MSP5.…”

Immunological markers of Plasmodium vivaxexposure and immunity: a systematic review and meta-analysis

“…The highly polymorphic Pv MSP-5 contains potential signal and glycosylphosphatidyl inositol (GPI) anchor sequences and a single EGF-like domain near the carboxyl-terminus [55]. Pv MSP-5 has been localized to the apical end of merozoites [56].…”

Evaluation ofPlasmodium vivaxGenotyping Markers for Molecular Monitoring in Clinical Trials

“…19) of the Ministry of Health in Papua New Guinea, and consent was obtained from parents or legal guardians before recruitment of each patient. Blood samples, obtained via finger prick, were collected into EDTA microtainer tubes, and DNA was extracted using a QIAamp DNA blood kit (Qiagen) according to the manufacturer's instructions.…”

“…Sequencing revealed msp1 as highly polymorphic, with 31 alleles among 40 isolates analyzed [17]. High diversity was also detected in msp3␤ [18], msp5 [18,19], and dpb [20 -22].…”