Genetic diversity of Duffy binding protein 2 region II of Plasmodium cynomolgi from wild macaques in Peninsular Malaysia

@#Recent reports of natural human infection by Plasmodium cynomolgi indicate the increased risk of zoonotic transmission by this simian parasite. The P. cynomolgi Duffy binding protein 2 (PcDBP2) has a potential role in the invasion pathway of host erythrocytes, and it is a possible vaccine candidate against cynomolgi malaria. This study investigates the genetic diversity, haplotypes, and natural selection of PcDBP2 region II from isolates collected from wild macaques in Peninsular Malaysia. Blood samples from 50 P. cynomolgi-infected wild macaques were used in the study. Genomic DNA extracted from the blood samples was used as template for PCR amplification of the PcDBP2 region II. The amplicons were cloned into a plasmid vector and sequenced. MEGA X and DnaSP ver.6.12.03 programmes were used to analyse the DNA sequences. A genealogical relationship of PcDBP2 region II were determined using haplotype network tree on NETWORK ver.10.2. Result showed high genetic diversity (ð = 0.017 ± 0.002; Hd = 1.000 ± 0.001) of the PcDBP2 region II. The Z-test indicates a purifying selection, with population expansion as shown in Tajima’s D analysis. A total of 146 haplotypes of PcDBP2 region II were observed. Phylogenetic tree analysis showed that these haplotypes were grouped into three allelic types (136 for Strain B type, 9 for Berok type, and 1 recombinant type). In the haplotype network, PcDBP2 region II revealed no geographical groupings but was divided into two distinct clusters.

The Duffy binding protein as a key target for a Plasmodium vivax vaccine: lessons from the Brazilian Amazon

Plasmodium vivax infects human erythrocytes through a major pathway that requires interaction between an apical parasite protein, the Duffy binding protein (PvDBP) and its receptor on reticulocytes, the Duffy antigen/receptor for chemokines (DARC). The importance of the interaction between PvDBP (region II, DBPII) and DARC to P. vivax infection has motivated our malaria research group at Oswaldo Cruz Foundation (state of Minas Gerais, Brazil) to conduct a number of immunoepidemiological studies to characterise the naturally acquired immunity to PvDBP in populations living in the Amazon rainforest. In this review, we provide an update on the immunology and molecular epidemiology of PvDBP in the Brazilian Amazon - an area of markedly unstable malaria transmission - and compare it with data from other parts of Latin America, as well as Asia and Oceania.

Antibody Responses to the Recombinant Circumsporozite Protein, Merozoite Surface Protein, and Duffy Binding Protein Antigens of Plasmodium vivax in Korea / 대한진단검사의학회지

BACKGROUND: Plasmodium vivax circumsporozoite protein (CSP), merozoite surface protein (MSP) and Duffy binding protein (DBP) are functionally important conserved proteins and may have an important role in developing antigens. The aim of this study was to develop recombinant CSP, MSP, and DBP antigens, to evaluate their diagnostic usefulness, and to analyze the prevalence of seroreactivity against P. vivax in five different regions in Korea. METHODS: To construct recombinant CSP, MSP, and DBP antigens from P. vivax, DNA obtained from specimens previously diagnosed as P. vivax was used. To evaluate diagnostic usefulness of recombinant CSP, MSP, and DBP antigens from P. vivax, sera from 45 patients with P. vivax and 48 normal controls including 4 patients with Plasmodium falciparum were used. For the epidemiologic study, a total of 1, 014 serum samples obtained from five different regions in Korea were used. RESULTS: The sensitivity of the IgG antibody against the P. vivax recombinant CSP, MSP, DBP antigens and the antigens mixture of these proteins were 75.6%, 62.2%, 68.9%, and 97.8%, and the specificity were 92.1%, 84.2%, 81.6%, and 97.4%, respectively. The seropositivity against P. vivax recombinant antigens was highest in Cheolwon province. The IgG seropositivity against P. vivax recombinant CSP, MSP and DBP was 2.0%, 1.2%, and 1.5%, respectively. There were no significant differences in seroreactivity against P. vivax between each recombinant protein and each five different regions in Korea. CONCLUSIONS: Newly constructed recombinant CSP, MSP and DBP were useful in the detection of antibodies against the P. vivax antigen.