Immunogenicity and antigenicity of Plasmodium vivax merozoite surface protein 10

Abstract

Among the proteins involved in the invasion by merozoite, the glycosylphosphatidylinositol-anchored proteins (GPI-APs) are suggested as potential vaccine candidates because of their localization to apical organelles and the surface; these candidates are predicted to play essential roles during invasion. As a GPI-AP, Plasmodium vivax merozoite surface protein 10 (PvMSP-10) induces high antibody titers. However, such high antibody titers have shown no protective efficacy for animals challenged with P. vivax parasites in a previous study. To adequately evaluate the immunogenicity and further characterize PvMSP-10 in order to understand its vaccine potential, we assessed its immunogenicity by immunizing BALB/c mice with cell-free expressed recombinant PvMSP-10 protein. The antigenicity of MSP-10 was analyzed, and we found 42% sensitivity and 95% specificity using serum samples from P. vivax-infected Korean patients. The IgG1 and IgG3 were the predominant immunoreactive antibodies against PvMSP-10 in vivax patient sera, and IgG1 and IgG3 and Th1-type cytokines were predominantly secreted in PvMSP-10-immunized mice. We conclude that the immunogenicity and antigenicity of MSP-10 may serve as a potential vaccine against vivax malaria.

Genome-Scale Protein Microarray Comparison of Human Antibody Responses in Plasmodium vivax Relapse and Reinfection

“…42 Studies with P. falciparum MSP10 demonstrated a lack of cross-reactivity with other MSPs (PfMSP-1, -4, -5 and -8), consistent with the 95% specificity for P. vivax infection found for antibodies detected against wheat germ-expressed PvMSP10. 42 No experimental evidence has emerged to date regarding the viability of any Plasmodium spp. MSP10 as a candidate for an asexual blood-stage-based vaccine.…”

“…Antibodies to PvMSP10 have previously been readily detected in humans with P. vivax malaria 41,42 using E. coli-expressed 41 and wheat germ in vitro expression system-expressed protein. 42 Studies with P. falciparum MSP10 demonstrated a lack of cross-reactivity with other MSPs (PfMSP-1, -4, -5 and -8), consistent with the 95% specificity for P. vivax infection found for antibodies detected against wheat germ-expressed PvMSP10. 42 No experimental evidence has emerged to date regarding the viability of any Plasmodium spp.…”

Immunoprofiling of the Tryptophan-Rich Antigen Family in Plasmodium vivax

“…The GST protein was expressed and used as a control. The purity of each recombinant protein was confirmed by SDS-PAGE and Western blot analysis according to protocols described previously (21). We also expressed the helical N terminus of P. vivax, interspersed with the subtelomeric/caveola-vesicle complexes-81 95 (PHIST/ CVC-81 95 ) protein (PVX_093680), which was used as a control caveolavesicle complex (CVC) marker (22), using a pGEX-4T-2 (GE Healthcare) expression vector with a GST tag (data not shown).…”

Anti–MSP-10 IgG indicates recent exposure to Plasmodium vivax infection in the Peruvian Amazon

“…Thus, the significant differences in seropositivity levels between individuals who presented with P. vivax infections and those who did not confirm the excellent antigenicity of the PvMSP10 proteins expressed in mammalian cell expression systems. Modest sensitivity (around 45%) and high specificity (95%) of IgG responses against PvMSP10 on serum samples for the diagnosis of malaria in symptomatic infected P. vivax patients have been reported in a Korean study that assessed the role of this protein as a vaccine candidate for P. vivax (35). However, the performance of serological tests for malaria diagnosis is always affected by the antibody kinetics, and this can have wide variability among individuals and fluctuate in levels over time (36,37), affecting the sensitivity of antigen-antibody responses.…”