Expression and serologic activity of a soluble recombinant Plasmodium vivax Duffy binding protein

Abstract

Plasmodium vivax Duffy binding protein (DBP) is a conserved functionally important protein. P. vivax DBP is an asexual blood-stage malaria vaccine candidate because adhesion of P. vivax DBP to its erythrocyte receptor is essential for the parasite to continue development in human blood. We developed a soluble recombinant protein of P. vivax DBP (rDBP) and examined serologic activity to it in residents of a region of high endemicity. This soluble rDBP product contained the cysteine-rich ligand domain and most of the contiguous proline-rich hydrophilic region. rDBP was expressed as a glutathione S-transferase (GST) fusion protein and was isolated from GST by thrombin treatment of the purified fusion protein bound on glutathione agarose beads. P. vivax rDBP was immunogenic in rabbits and induced antibodies that reacted with P. vivax and Plasmodium knowlesi merozoites. Human sera from adult residents of a region of Papua New Guinea where malaria is highly endemic or P. vivax-infected North American residents reacted with rDBP in an immunoblot and an enzyme-linked immunosorbent assay. The reactivity to reduced, denatured P. vivax rDBP and the cross-reactivity with P. knowlesi indicated the presence of immunogenic conserved linear B-cell epitopes. A more extensive serologic survey of Papua New Guinea residents showed that antibody response to P. vivax DBP is common and increases with age, suggesting a possible boosting of the antibody response in some by repeated exposure to P. vivax. A positive humoral response to P. vivax DBP correlated with a significantly higher response to P. vivax MSP-1 19. The natural immunogenicity of this DBP should strengthen its usefulness as a vaccine.

Plasmodium vivax Duffy binding protein: baseline antibody responses and parasite polymorphisms in a well‐consolidated settlement of the Amazon Region

“…This profile of antibody response was quite different to that obtained to another vaccine candidate, the 19‐kDa C‐terminal region of the merozoite surface protein 1 (PvMSP1 19 ), in which subject’s age was not related with positivity or intensity of antibody response. Consistent with these observations, previous studies were unable to demonstrate an association between anti‐PvMSP1 19 antibodies and cumulative exposure to malaria (Fraser et al. 1997; Ceravolo et al.…”

“…The recombinant PvDBP, which includes amino acids 132–771 (regions II–IV, DBP II–IV ), was expressed as a 140 kDa soluble glutathione S‐transferase (GST) fusion protein. A detailed description of this GST fusion protein has been reported elsewhere (Fraser et al. 1997; Ceravolo et al.…”

Anti–plasmodium Vivax Duffy Binding Protein Antibodies Measure Exposure to Malaria in the Brazilian Amazon

“…Recombinant DBP (rDBP) was expressed in prokaryotic system and purified using only minor modifications of the protocol described previously. 11 Briefly, a portion of DBP from amino acids 177 to 815 that includes regions II to IV (DBP II-IV ) was inserted in frame with glutathione S-transferase (GST) in the expression vector pGEX-2T. 11 The GST fusion protein was purified directly from bacterial lysates through affinity chromatography using matrix glutathione sepharose 4B, according to the manufacturer's instructions (Amersham Biosciences, Piscataway, NJ).…”

“…11 Briefly, a portion of DBP from amino acids 177 to 815 that includes regions II to IV (DBP II-IV ) was inserted in frame with glutathione S-transferase (GST) in the expression vector pGEX-2T. 11 The GST fusion protein was purified directly from bacterial lysates through affinity chromatography using matrix glutathione sepharose 4B, according to the manufacturer's instructions (Amersham Biosciences, Piscataway, NJ). Even though the fusion protein was cleaved by thrombin treatment, one contaminant of 70 kDa, probably one bacterial chapero-nin, was frequently co-purified with the rDBP (data not shown).…”

“…Because DBP is a molecule of very low abundance in the parasite, and because of limitations in culturing P. vivax parasites, the available data on immune responses to DBP in human population are still limited. [11][12][13][14] In Latin America, a single study on the prevalence of anti-DBP antibodies has been carried out so far. 12 However, this study cannot be extrapolated to other areas of Latin America because it was performed in an area on the Pacific coast of Colombia where most people are probably resistant to P. vivax infection; that is, 93% of them were black of African origin (Duffy negative trait).…”