scholarly journals The Plasmodium vivax Merozoite Surface Protein 1 Paralog Is a Novel Erythrocyte-Binding Ligand of P. vivax

2013 ◽  
Vol 81 (5) ◽  
pp. 1585-1595 ◽  
Author(s):  
Yang Cheng ◽  
Yue Wang ◽  
Daisuke Ito ◽  
Deok-Hoon Kong ◽  
Kwon-Soo Ha ◽  
...  

ABSTRACTMerozoite surface protein 1 ofPlasmodium vivax(PvMSP1), a glycosylphosphatidylinositol-anchored protein (GPI-AP), is a malaria vaccine candidate forP. vivax. The paralog of PvMSP1, namedP. vivaxmerozoite surface protein 1 paralog (PvMSP1P; PlasmoDB PVX_099975), was recently identified and predicted as a GPI-AP. The similarities in genetic structural characteristics between PvMSP1 and PvMSP1P (e.g., size of open reading frames, two epidermal growth factor-like domains, and GPI anchor motif in the C terminus) led us to study this protein. In the present study, different regions of the PvMSP1P protein, demarcated based on the processed forms of PvMSP1, were expressed successfully as recombinant proteins [i.e., 83 (A, B, and C), 30, 38, 42, 33, and 19 fragments]. We studied the naturally acquired immune response against each fragment of recombinant PvMSP1P and the potential ability of each fragment to bind erythrocytes. The N-terminal fragment (83A) and two C-terminal fragments (33 and 19) reacted strongly with sera fromP. vivax-infected patients, with 50 to 68% sensitivity and 95 to 96% specificity, respectively. Due to colocalization of PvMSP1P with PvMSP1, we supposed that PvMSP1P plays a similar role as PvMSP1 during erythrocyte invasion. Anin vitrocytoadherence assay showed that PvMSP1P, especially the 19-kDa C-terminal region, could bind to erythrocytes. We also found that human sera from populations naturally exposed to vivax malaria and antisera obtained by immunization using the recombinant molecule PvMSP1P-19 inhibitedin vitrobinding of human erythrocytes to PvMSP1P-19. These results provide further evidence that the PvMSP1P might be an essential parasite adhesion molecule in theP. vivaxmerozoite and is a potential vaccine candidate againstP. vivax.

2005 ◽  
Vol 73 (9) ◽  
pp. 5936-5944 ◽  
Author(s):  
Sheetij Dutta ◽  
Deep C. Kaushal ◽  
Lisa A. Ware ◽  
Sunil K. Puri ◽  
Nuzhat A. Kaushal ◽  
...  

ABSTRACT The 42-kDa fragment of the merozoite surface protein 1 (MSP-142) is a leading candidate for the development of a vaccine to control malaria. We previously reported a method for the production of Plasmodium vivax MSP-142 (PvMSP-142) as a soluble protein (S. Dutta, L. W. Ware, A. Barbosa, C. F. Ockenhouse, and D. E. Lanar, Infect. Immun. 69:5464-5470, 2001). We report here a process to manufacture the same PvMSP-142 protein but as an insoluble inclusion body-derived protein which was then refolded in vitro. We compared the immunogenicity and protective efficacy of the soluble and refolded forms of PvMSP-142 protein by using a heterologous but closely related P. cynomolgi-rhesus monkey challenge model. As comparative controls we also expressed, purified, and immunized rhesus with the soluble and refolded forms of the P. cynomolgi MSP-142 (PcMSP-142) proteins. All proteins induced equally high-titer, cross-reacting antibodies. Upon challenge with P. cynomolgi, none of the MSP-142-vaccinated groups demonstrated sterile protection or a delay in the prepatent period. However, following an initial rise in parasitemia, all MSP-1-vaccinated animals had significantly lower parasite burdens as indicated by lower cumulative parasitemia, lower peak parasitemia, lower secondary peak parasitemia, and lower average daily parasitemia compared to the adjuvant control group (P < 0.05). Except the soluble PcMSP-142 group, monkeys in all other groups had fewer numbers of days with parasitemia of >10,000 parasites mm−3. Interestingly, there was no significant difference in the level of partial protection observed in the homologous and heterologous groups in this challenge model. The soluble and refolded forms of PcMSP-142 and PvMSP-142 proteins also appeared to have a similar partially protective effect.


2001 ◽  
Vol 69 (9) ◽  
pp. 5464-5470 ◽  
Author(s):  
Sheetij Dutta ◽  
Lisa A. Ware ◽  
Arnoldo Barbosa ◽  
Christian F. Ockenhouse ◽  
David E. Lanar

ABSTRACT The Plasmodium vivax merozoite surface protein 1 (MSP-1) 42-kDa fragment (PvMSP-1 p42) is a promising vaccine candidate antigen against the blood stage of the malarial parasite. We have developed a process for the production of this vaccine target, keeping in mind its use in human volunteers. A novel strain, Origami(DE3), of Escherichia coli with mutations in the glutathione and thioredoxin reductase genes yielded 60% more soluble PvMSP-1 p42 than the conventional E. coliBL21(DE3) strain. Recombinant PvMSP-1 p42 was purified to ≥99% purity with a rapid two-step protocol designed for easy scaling up. The final product had a low endotoxin content and was stable in its lyophilized form. PvMSP-1 p42 was found to have the predicted primary and tertiary structures and consisted of a single conformer containing one free cysteine, as predicted. The product was recognized by conformational monoclonal antibodies against P. vivax MSP-1. Immunogenicity studies of PvMSP-1 p42 were carried out with two strains of mice and the adjuvants Montanide ISA51 and Montanide ISA720. Both formulations were found to induce high levels of immunoglobulin G1 (IgG1), IgG2b, and IgG2a antibodies along with low levels of IgG3. Lymphocytes from animals in all the PvMSP-1 p42-immunized groups showed proliferative responses upon stimulation with PvMSP-1 p42; the cytokines interleukin 2 (IL-2), gamma interferon, IL-4, and IL-10 were detected in the culture supernatants. These results indicate that PvMSP-1 p42 in combination with both of the adjuvants elicited cellular and humoral responses in mice.


2020 ◽  
Author(s):  
Fei-hu Shen ◽  
Jessica Jie Ying Ong ◽  
Yi-fan Sun ◽  
Yao Lei ◽  
Rui-lin Chu ◽  
...  

Research on erythrocytic Plasmodium vivax merozoite antigens is critical for identifying potential vaccine candidates in reducing vivax disease. However, many P. vivax studies are constrained by its inability to undergo long-term culture in vitro. Conserved across all Plasmodium spp, merozoite surface proteins are essential for invasion into erythrocytes and highly expressed on erythrocytic merozoites, thus making it an ideal vaccine candidate. In clinical trials, the P. vivax merozoite surface protein 1 (PvMSP1-19) vaccine candidate alone has shown to have limited immunogenicity in patients, hence we incorporate the highly conserved and immunogenic C-terminus of both P. vivax merozoite surface protein 8 (PvMSP8) and PvMSP1-19 to develop a multicomponent chimeric protein rPvMSP8+1 for immunization into mice. The resulted chimeric rPvMSP8+1 antibody was shown to recognize native protein MSP8 and MSP1-19 of mature P. vivax schizonts. In the immunized mice, elevated antibody response was observed in the rPvMSP8+1-immunized group as compared to that immunized with single antigen components. In addition, we examined the growth inhibition of these antibodies against P. cynomolgi (Berok strain) parasites, which is phylogenetically close to P. vivax and sustains long term culture in vitro. Similarly, the chimeric anti-rPvMSP8+1 antibodies recognises P. cynomolgi MSP8 and MSP1-19 on mature schizonts, and showed strong inhibition in vitro via growth inhibition assay. This study provides support for a new multi-antigen-based paradigm rPvMSP8+1 to explore potential chimeric vaccine candidates against P. vivax malaria using sister species, P. cynomolgi.


2017 ◽  
Vol 24 (11) ◽  
Author(s):  
Anja Jäschke ◽  
Boubacar Coulibaly ◽  
Edmond J. Remarque ◽  
Hermann Bujard ◽  
Christian Epp

ABSTRACT Naturally acquired immunity against malaria is largely mediated by serum antibodies controlling levels of blood-stage parasites. A limited understanding of the antigenic targets and functional mechanisms of protective antibodies has hampered the development of efficient malaria vaccines. Besides directly inhibiting the growth of Plasmodium parasites, antibodies can opsonize merozoites and recruit immune effector cells such as monocytes and neutrophils. Antibodies against the vaccine candidate merozoite surface protein 1 (MSP-1) are acquired during natural infections and have been associated with protection against malaria in several epidemiological studies. Here we analyzed serum antibodies from semi-immune individuals from Burkina Faso for their potential (i) to directly inhibit the growth of P. falciparum blood stages in vitro and (ii) to opsonize merozoites and to induce the antibody-dependent respiratory burst (ADRB) activity of neutrophils. While a few sera that directly inhibited the growth of P. falciparum blood stages were identified, immunoglobulin G (IgG) from all individuals clearly mediated the activation of neutrophils. The level of neutrophil activation correlated with levels of antibodies to MSP-1, and affinity-purified MSP-1-specific antibodies elicited ADRB activity. Furthermore, immunization of nonhuman primates with recombinant full-size MSP-1 induced antibodies that efficiently opsonized P. falciparum merozoites. Reversing the function by preincubation with recombinant antigens allowed us to quantify the contribution of MSP-1 to the antiparasitic effect of serum antibodies. Our data suggest that MSP-1, especially the partially conserved subunit MSP-183, is a major target of opsonizing antibodies acquired during natural exposure to malaria. Induction of opsonizing antibodies might be a crucial effector mechanism for MSP-1-based malaria vaccines.


2002 ◽  
Vol 99 (25) ◽  
pp. 16348-16353 ◽  
Author(s):  
C. Putaporntip ◽  
S. Jongwutiwes ◽  
N. Sakihama ◽  
M. U. Ferreira ◽  
W.-G. Kho ◽  
...  

Parasitology ◽  
2009 ◽  
Vol 136 (12) ◽  
pp. 1445-1456 ◽  
Author(s):  
A. A. HOLDER

SUMMARYOver the last 30 years, evidence has been gathered suggesting that merozoite surface protein 1 (MSP1) is a target of protective immunity against malaria. In a variety of experimental approaches usingin vitromethodology, animal models and sero-epidemiological techniques, the importance of antibody against MSP1 has been established but we are still finding out what are the mechanisms involved. Now that clinical trials of MSP1 vaccines are underway and the early results have been disappointing, it is increasingly clear that we need to know more about the mechanisms of immunity, because a better understanding will highlight the limitations of our current assays and identify the improvements required. Understanding the structure of MSP1 will help us design and engineer better antigens that are more effective than the first generation of vaccine candidates. This review is focused on the carboxy-terminus of MSP1.


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