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

Abstract

Plasmodium vivax Duffy binding protein (DBP) is functionally important in the erythrocyte invasion process and provides a logical target for vaccine-mediated immunity. In the current study, we demonstrated that DBP is naturally immunogenic in different populations of the Brazilian Amazon, and the proportions of DBP IgG positive subjects increased with exposure to malaria, reaching a peak in those subjects with long-term exposure (> 15 years) in the Amazon area. This profile of antibody response was significantly different from the one observed for the P. vivax merozoite surface protein 1 (MSP1(19)), which was relatively uniform in areas with markedly different levels of malaria transmission. In a small sample of adults with symptomless P. vivax infection, we could not detect any significant correlation between antibodies against these P. vivax proteins and asymptomatic infection. Our study provided an additional insight by demonstrating cumulative exposure as a determinant that acts independently of host age in generation of anti-DBP IgG response.

Comparative recognition by human IgG antibodies of recombinant proteins representing three asexual erythrocytic stage vaccine candidates of Plasmodium vivax

“…Our analysis showed that the frequency of responders to PvAMA-1 and PvDBP-RII was higher in the multiple-infected. This data suggests that multiple infections provide a boost to the production of specific antibodies confirming recent observations obtained in other studies in distinct endemic areas of Brazilian Amazon (Ceravolo et al 2005, Tran et al 2005). In the case of PvMSP1 19 , specific IgG responses developed faster after a single exposition to malaria infection, also confirming previous observations of distinct groups that PvMSP1 19 is highly immunogenic during natural human infections (Park et al 2001, Lim et al 2002, Rodrigues et al 2003, Morais et al 2005, Wickramarachchi et al 2007).…”

Antibody Responses and Avidity of Naturally Acquired Anti-Plasmodium vivax Duffy Binding Protein (PvDBP) Antibodies in Individuals from an Area with Unstable Malaria Transmission

“…28,33 However, the serologic responses of residents in vivax malaria-endemic regions did show a positive correlation with exposure and host age, as shown in the previous studies. 23,28,30,44 This result suggests a possible boosting of the PvDBP-II antibody response because of accumulated age-related exposure.…”

“…28,32 As shown by several studies, selection of an antigen for vaccination requires a detailed understanding of natural immune responses elicited by the protein from different malariaendemic regions with various epidemiology, and the result of similar studies from one malaria-endemic region cannot be extrapolated to other areas of malaria-endemic regions in the world. 33 Therefore, the current investigation was designed, Abstract. Plasmodium vivax remains an important cause of morbidity outside Africa, and no effective vaccine is available against this parasite.…”

Evaluation of the Naturally Acquired Antibody Immune Response to the Pv200L N-terminal Fragment of Plasmodium vivax Merozoite Surface Protein-1 in Four Areas of the Amazon Region of Brazil

“…Although two previous Brazilian studies did not show this tendency for the N-terminal of the P. vivax MSP-1, 9, 28 our data are in agreement with another study in which the proportion of responders to PvMSP-1 variants increased during subsequent infections. 38 Moreover, in studies that evaluated the C-terminal of the MSP-1 31 and other parasite proteins, such as DBP-II 39,40 and AMA-1 31,41 a positive correlation was also observed between the increase in the antibody response and the number of past malaria episodes. These data taken together suggest that multiple infections can provide a boost for the production of the specific antibodies.…”