Abstract
BackgroundDifferent antigens are needed to characterize Plasmodium falciparum infection in terms of seroreactivity and targets for invasion inhibition, in order to guide and identify the proper use of such proteins as tools for the development of serological markers and/or as vaccine candidates.MethodsIgG responses in 84 serum samples from individuals with P. falciparum infection [classified as symptomatic (Sym) or asymptomatic (Asym)], or acute Plasmodium vivax infection, from the Peruvian Amazon region, were evaluated by enzyme-linked immunosorbent assays specific for a baculovirus-produced recombinant protein P. falciparum Merozoite Surface Protein 10 (rMSP10) and for non-EGF region selected peptides of PfMSP10 selected by a bioinformatics tool (PfMSP10-1, PfMSP10-2 and PfMSP10-3). Monoclonal antibodies against the selected peptides were evaluated by western blotting, confocal microscopy and inhibition invasion assays.ResultsSeroreactivity analysis of the P. falciparum Sym- and Asym-infected individuals against rMSP10 showed a higher response as compared to the individuals with P. vivax acute infection. IgG responses against peptide PfMSP10-1 were weak. Interestingly high IgG response was found against peptide PfMSP10-2 and the combination of peptides PfMSP10-1 + PfMSP10-2. Monoclonal antibodies were capable of detecting native PfMSP10 on purified schizonts by western blot and confocal microscopy. A low percentage of inhibition of merozoite invasion of erythrocytes in vitro was observed when the monoclonal antibodies were compared with the control antibody against AMA-1 antigen. Further studies are needed to evaluate the role of PfMSP10 in the merozoite invasion.ConclusionsThe rMSP10 and the PfMSP10-2 peptide synthesized for this study may be useful antigens for evaluation of P. falciparum malaria exposure in Sym and Asym individuals from the Peruvian Amazon region. Moreover, these antigens can be used for further investigation of the role of this protein in other malaria-endemic areas.
Highlights
Different antigens are needed to characterize Plasmodium falciparum infection in terms of seroreactiv‐ ity and targets for invasion inhibition, in order to guide and identify the proper use of such proteins as tools for the development of serological markers and/or as vaccine candidates
Peptides The three peptides selected by the bioinformatics tool (PfMSP10-1, PfMSP10-2, PfMSP10-3) corresponded to non-Epidermal Growth Factor (EGF) domains of PfMSP10
86.7% of the individuals infected with P. vivax showed high seroreactivity to rMSP10 (Fig. 3a and Table 2), this result may be explained by the high identity reported between proteins PfMSP10 and PvMSP10 in the C-terminal region where two EGF domains are found (Additional file 1: Figure S4)
Summary
Different antigens are needed to characterize Plasmodium falciparum infection in terms of seroreactiv‐ ity and targets for invasion inhibition, in order to guide and identify the proper use of such proteins as tools for the development of serological markers and/or as vaccine candidates. Studies in the Peruvian Amazon region have revealed the presence of a large number of non-febrile or asymptomatic infections that can occur over short time periods. Individuals with asymptomatic infections are able to develop and maintain IgG responses against the P. falciparum merozoite for up to a 6-month period, in contrast to the response seen in high transmission areas such as Africa [5,6,7]. P. falciparum Merozoite Surface Protein 10 (PfMSP10) was demonstrated to have high reactivity to the serum samples from symptomatic (Sym) and asymptomatic (Asym) P. falciparum-infected individuals from the Peruvian Amazon region, on platforms as the protein-array and enzyme-linked immunosorbent assay (ELISA) [6, 8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
