Molecular cloning and expression of the VK247 circumsporozoite protein for serodiagnosis of variant form Plasmodium vivax

Abstract

Plasmodium vivax is classified into two serotypes, VK210 [the dominant form-GDRA(D/A)GQPA repeats] and VK247 [the variant form-ANGA(G/D)(N/D)QPG repeats], based on sequence variation of the repeat region of the circumsporozoite (CS) protein gene. Genomic DNA for the variant CS protein gene was obtained from field isolate strains in Myanmar. The repetitive region has highly 19 immunogenic repeats flanked by non-repeat stretches of amino acids. The sequence including this region (717 bp) was subcloned into the expression vector pQE30 and expressed in Escherichia coli. The expressed recombinant protein has a molecular weight of about 50 kDa as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Anti-VK247 antibodies were found in malaria patients who have been exposed to variant form of P. vivax in western blot analysis. Therefore, this recombinant protein might be a useful tool in serodiagnosis of malaria patients who have been infected with variant form of P. vivax.

Sequence conservation of Plasmodium vivax glutamate dehydrogenase among Korean isolates and its application in seroepidemiology

“…Therefore, a new antigen is needed for serodiagnosis. Several recombinant proteins cloned from Korean isolates of P. vivax have been tested for use as antigens for serodiagnosis, including Circumsporozoite protein (CSP) subtypes Pv210 [18] and Pv247 [33], merozoite surface protein (MSP) [34], CSP and MSP chimeric proteins [35], aldolase [36], and parasite lactate dehydrogenase [37]. None of these antigens has enabled replacement of the IFAT method because of their comparatively low sensitivity.…”

Comparison of the antibody responses to Plasmodium vivax and Plasmodium falciparum antigens in residents of Mandalay, Myanmar

“…To verify that the blood samples had antibodies against the CSP VK210 [24] and VK247 subtypes [25], the Pvs25 [26] and Pvs28 [27] antigens of P. vivax , and the PfLSA-1 [28] and PfLSA-3 [29] antigens of P. falciparum (developed by the authors), an enzyme-linked immunosorbent assays were performed with these antigens. Briefly, 50 μl of capture antigen solution (0.5 μg/ml) was placed in a 96-well plate (Corning, Lowell, MA, USA) and incubated for 12 hrs at room temperature.…”

Polymorphism of the parasite lactate dehydrogenase gene from Plasmodium vivax Korean isolates

“…Therefore, a new antigen is needed for serodiagnosis. Several recombinant proteins cloned from Korean isolates of P. vivax have been tested for use as antigens for serodiagnosis, including circumsporozoite protein (CSP), subtypes Pv210 [32] and Pv247 [33], merozoite surface protein (MSP) [34], and CSP and MSP chimeric proteins [35,36]. None of these antigens were capable of replacing the IFAT method because their sensitivity was less than that of IFAT.…”