scholarly journals Characterization of Glycoproteins of Native 19kDa C-Terminal Merozoite Surface Protein-1 from Native Antigen of Plasmodium falciparum

Author(s):  
Sahar Tajik ◽  
Sedigheh Sadeghi ◽  
Ayda Iravani ◽  
Mitra Khalili ◽  
Mohammad Arjmand ◽  
...  

Background: Plasmodium falciparum is the protozoan parasite which causes malignant malaria of medical concern. Prime candidates for recombinant vaccine development are asexual stage antigens of P. falciparum, for example, merozoite surface proteins (MSP1 and MSP2) not given satisfactory results to date. In this study, the 19kDa C-terminal of MSP1, a vaccine candidate was purified in its native form in the ring stage, and its glycoproteins studied. Methods: The study was carried out at the Biochemistry Department of Pasteur Institute of Iran in the years 2015–2016. Large scale culture of P. falciparum was performed in vitro with 80% ring stage parasitemia. Isopycnic ultracentrifuga­tion with 36% sucrose and analytical SDS-PAGE on the supernatant and precipitate performed, and the 19kDa antigen was obtained by cutting it from strips of preparative SDS gels. Purified protein was concentrated and analyzed by SDS-PAGE and immunoblotting, using antibodies raised to recombinant C-terminal MSP1. Results: The purified protein gave a single band of 19kDa antigen as shown by silver staining of SDS-PAGE and a sin­gle bond in immunoblotting. Bioinformatics also confirmed the likelihood of the presence of glycans on the antigen. Conclusion: The presence of N and O-glycoproteins were detected by Q proteome kit. This work was done on the ring stage, and earlier workers confirmed the presence of glycoproteins on MSP1 in the other stages. This glycosylation is present in all stages, and maybe incomplete protection elicited by recombinant MSP1 antigens is due to lack of N and O-glycoproteins.

2003 ◽  
Vol 71 (12) ◽  
pp. 6766-6774 ◽  
Author(s):  
Sanjay Singh ◽  
Michael C. Kennedy ◽  
Carole A. Long ◽  
Allan J. Saul ◽  
Louis H. Miller ◽  
...  

ABSTRACT Protection against Plasmodium falciparum can be induced by vaccination in animal models with merozoite surface protein 1 (MSP1), which makes this protein an attractive vaccine candidate for malaria. In an attempt to produce a product that is easily scaleable and inexpensive, we expressed the C-terminal 42 kDa of MSP1 (MSP142) in Escherichia coli, refolded the protein to its native form from insoluble inclusion bodies, and tested its ability to elicit antibodies with in vitro and in vivo activities. Biochemical, biophysical, and immunological characterization confirmed that refolded E. coli MSP142 was homogeneous and highly immunogenic. In a formulation suitable for human use, rabbit antibodies were raised against refolded E. coli MSP142 and tested in vitro in a P. falciparum growth invasion assay. The antibodies inhibited the growth of parasites expressing either homologous or heterologous forms of P. falciparum MSP142. However, the inhibitory activity was primarily a consequence of antibodies directed against the C- terminal 19 kDa of MSP1 (MSP119). Vaccination of nonhuman primates with E. coli MSP142 in Freund's adjuvant protected six of seven Aotus monkeys from virulent infection with P. falciparum. The protection correlated with antibody-dependent mechanisms. Thus, this new construct, E. coli MSP142, is a viable candidate for human vaccine trials.


2014 ◽  
Vol 21 (6) ◽  
pp. 886-897 ◽  
Author(s):  
Puneet K. Gupta ◽  
Paushali Mukherjee ◽  
Shikha Dhawan ◽  
Alok K. Pandey ◽  
Suman Mazumdar ◽  
...  

ABSTRACTAPlasmodium falciparumchimeric protein, PfMSP-Fu24, was constructed by genetically coupling immunodominant, conserved regions of two merozoite surface proteins, the 19-kDa region C-terminal region of merozoite surface protein 1 (PfMSP-119) and an 11-kDa conserved region of merozoite surface protein 3 (PfMSP-311), to augment the immunogenicity potential of these blood-stage malaria vaccine candidates. Here we describe an improved, efficient, and scalable process to produce high-quality PfMSP-Fu24. The chimeric protein was produced inEscherichia coliSHuffle T7 ExpresslysYcells that express disulfide isomerase DsbC. A two-step purification process comprising metal affinity followed by cation exchange chromatography was developed, and we were able to obtain PfMSP-Fu24with purity above 99% and with a considerable yield of 23 mg/liter. Immunogenicity of PfMSP-Fu24formulated with several adjuvants, including Adjuplex, Alhydrogel, Adjuphos, Alhydrogel plus glucopyranosyl lipid adjuvant, aqueous (GLA-AF), Adjuphos+GLA-AF, glucopyranosyl lipid adjuvant-stable emulsion (GLA-SE), and Freund's adjuvant, was evaluated. PfMSP-Fu24formulated with GLA-SE and Freund's adjuvant in mice and with Alhydrogel and Freund's adjuvant in rabbits produced high titers of PfMSP-119and PfMSP-311-specific functional antibodies. Some of the adjuvant formulations induced inhibitory antibody responses and inhibitedin vitrogrowth ofP. falciparumparasites in the presence as well as in the absence of human monocytes. These results suggest that PfMSP-Fu24can form a constituent of a multistage malaria vaccine.


2019 ◽  
Vol 295 (2) ◽  
pp. 403-414 ◽  
Author(s):  
Susheel K. Singh ◽  
Jordan Plieskatt ◽  
Bishwanath Kumar Chourasia ◽  
Vandana Singh ◽  
Judith M. Bolscher ◽  
...  

The Plasmodium falciparum circumsporozoite protein (PfCSP) is a sporozoite surface protein whose role in sporozoite motility and cell invasion has made it the leading candidate for a pre-erythrocytic malaria vaccine. However, production of high yields of soluble recombinant PfCSP, including its extensive NANP and NVDP repeats, has proven problematic. Here, we report on the development and characterization of a secreted, soluble, and stable full-length PfCSP (containing 4 NVDP and 38 NANP repeats) produced in the Lactococcus lactis expression system. The recombinant full-length PfCSP, denoted PfCSP4/38, was produced initially with a histidine tag and purified by a simple two-step procedure. Importantly, the recombinant PfCSP4/38 retained a conformational epitope for antibodies as confirmed by both in vivo and in vitro characterizations. We characterized this complex protein by HPLC, light scattering, MS analysis, differential scanning fluorimetry, CD, SDS-PAGE, and immunoblotting with conformation-dependent and -independent mAbs, which confirmed it to be both pure and soluble. Moreover, we found that the recombinant protein is stable at both frozen and elevated-temperature storage conditions. When we used L. lactis–derived PfCSP4/38 to immunize mice, it elicited high levels of functional antibodies that had the capacity to modify sporozoite motility in vitro. We concluded that the reported yield, purity, results of biophysical analyses, and stability of PfCSP4/38 warrant further consideration of using the L. lactis system for the production of circumsporozoite proteins for preclinical and clinical applications in malaria vaccine development.


2009 ◽  
Vol 78 (2) ◽  
pp. 872-883 ◽  
Author(s):  
Suman Mazumdar ◽  
Paushali Mukherjee ◽  
Syed Shams Yazdani ◽  
S. K. Jain ◽  
Asif Mohmmed ◽  
...  

ABSTRACT A chimeric gene, MSP-Fu24 , was constructed by genetically coupling immunodominant, conserved regions of the two leading malaria vaccine candidates, Plasmodium falciparum merozoite surface protein 1 (C-terminal 19-kDa region [PfMSP-119]) and merozoite surface protein 3 (11-kDa conserved region [PfMSP-311]). The recombinant MSP-Fu24 protein was produced in Escherichia coli cells and purified to homogeneity by a two-step purification process with a yield of ∼30 mg/liter. Analyses of conformational properties of MSP-Fu24 using PfMSP-119-specific monoclonal antibody showed that the conformational epitopes of PfMSP-119 that may be critical for the generation of the antiparasitic immune response remained intact in the fusion protein. Recombinant MSP-Fu24 was highly immunogenic in mice and in rabbits when formulated with two different human-compatible adjuvants and induced an immune response against both PfMSP-119 and PfMSP-311. Purified anti-MSP-Fu24 antibodies showed invasion inhibition of P. falciparum 3D7 and FCR parasites, and this effect was found to be dependent on antibodies specific for the PfMSP-119 component. The protective potential of MSP-Fu24 was demonstrated by in vitro parasite growth inhibition using an antibody-dependent cell inhibition (ADCI) assay with anti-MSP-Fu24 antibodies. Overall, the antiparasitic activity was mediated by a combination of growth-inhibitory antibodies generated by both the PfMSP-119 and PfMSP-311 components of the MSP-Fu24 protein. The antiparasitic activities elicited by anti-MSP-Fu24 antibodies were comparable to those elicited by antibodies generated with immunization with a physical mixture of two component antigens, PfMSP-119 and PfMSP-311. The fusion protein induces a protective immune response with human-compatible adjuvants and may form a part of a multicomponent malaria vaccine.


2009 ◽  
Vol 77 (3) ◽  
pp. 1165-1174 ◽  
Author(s):  
Danielle I. Stanisic ◽  
Jack S. Richards ◽  
Fiona J. McCallum ◽  
Pascal Michon ◽  
Christopher L. King ◽  
...  

ABSTRACT Substantial evidence indicates that antibodies to Plasmodium falciparum merozoite antigens play a role in protection from malaria, although the precise targets and mechanisms mediating immunity remain unclear. Different malaria antigens induce distinct immunoglobulin G (IgG) subclass responses, but the importance of different responses in protective immunity from malaria is not known and the factors determining subclass responses in vivo are poorly understood. We examined IgG and IgG subclass responses to the merozoite antigens MSP1-19 (the 19-kDa C-terminal region of merozoite surface protein 1), MSP2 (merozoite surface protein 2), and AMA-1 (apical membrane antigen 1), including different polymorphic variants of these antigens, in a longitudinal cohort of children in Papua New Guinea. IgG1 and IgG3 were the predominant subclasses of antibodies to each antigen, and all antibody responses increased in association with age and exposure without evidence of increasing polarization toward one subclass. The profiles of IgG subclasses differed somewhat for different alleles of MSP2 but not for different variants of AMA-1. Individuals did not appear to have a propensity to make a specific subclass response irrespective of the antigen. Instead, data suggest that subclass responses to each antigen are generated independently among individuals and that antigen properties, rather than host factors, are the major determinants of IgG subclass responses. High levels of AMA-1-specific IgG3 and MSP1-19-specific IgG1 were strongly predictive of a reduced risk of symptomatic malaria and high-density P. falciparum infections. However, no antibody response was significantly associated with protection from parasitization per se. Our findings have major implications for understanding human immunity and for malaria vaccine development and evaluation.


2006 ◽  
Vol 13 (7) ◽  
pp. 810-813 ◽  
Author(s):  
Kézia K. G. Scopel ◽  
Cor J. F. Fontes ◽  
Marcelo U. Ferreira ◽  
Érika M. Braga

ABSTRACT We investigated immunoglobulin G (IgG) subclass antibody responses to Plasmodium falciparum merozoite surface protein 1 (MSP-1) and MSP-2 in 112 malaria-exposed subjects in Brazil. IgG3 polarization was primarily epitope driven, being little affected by cumulative or current exposure to malaria and not affected by a subject's age and Fcγ receptor IIA genotype.


2006 ◽  
Vol 74 (2) ◽  
pp. 1313-1322 ◽  
Author(s):  
Ute Woehlbier ◽  
Christian Epp ◽  
Christian W. Kauth ◽  
Rolf Lutz ◽  
Carole A. Long ◽  
...  

ABSTRACT The 190-kDa merozoite surface protein 1 (MSP-1) of Plasmodium falciparum, an essential component in the parasite's life cycle, is a primary candidate for a malaria vaccine. Rabbit antibodies elicited by the heterologously produced MSP-1 processing products p83, p30, p38, and p42, derived from strain 3D7, were analyzed for the potential to inhibit in vitro erythrocyte invasion by the parasite and parasite growth. Our data show that (i) epitopes recognized by antibodies, which inhibit parasite replication, are distributed throughout the entire MSP-1 molecule; (ii) when combined, antibodies specific for different regions of MSP-1 inhibit in a strictly additive manner; (iii) anti-MSP-1 antibodies interfere with erythrocyte invasion as well as with the intraerythrocytic growth of the parasite; and (iv) antibodies raised against MSP-1 of strain 3D7 strongly cross-inhibit replication of the heterologous strain FCB-1. Accordingly, anti-MSP-1 antibodies appear to be capable of interfering with parasite multiplication at more than one level. Since the overall immunogenicity profile of MSP-1 in rabbits closely resembles that found in sera of Aotus monkeys immunized with parasite-derived MSP-1 and of humans semi-immune to malaria from whom highly inhibiting antigen-specific antibodies were recovered, we consider the findings reported here to be relevant for the development of MSP-1-based vaccines against malaria.


2012 ◽  
Vol 80 (12) ◽  
pp. 4177-4185 ◽  
Author(s):  
Christopher G. Adda ◽  
Christopher A. MacRaild ◽  
Linda Reiling ◽  
Kaye Wycherley ◽  
Michelle J. Boyle ◽  
...  

ABSTRACTMerozoite surface protein 2 (MSP2) is an abundant glycosylphosphatidylinositol (GPI)-anchored protein ofPlasmodium falciparum, which is a potential component of a malaria vaccine. As all forms of MSP2 can be categorized into two allelic families, a vaccine containing two representative forms of MSP2 may overcome the problem of diversity in this highly polymorphic protein. Monomeric recombinant MSP2 is an intrinsically unstructured protein, but its conformational properties on the merozoite surface are unknown. This question is addressed here by analyzing the 3D7 and FC27 forms of recombinant and parasite MSP2 using a panel of monoclonal antibodies raised against recombinant MSP2. The epitopes of all antibodies, mapped using both a peptide array and by nuclear magnetic resonance (NMR) spectroscopy on full-length recombinant MSP2, were shown to be linear. The antibodies revealed antigenic differences, which indicate that the conserved N- and C-terminal regions, but not the central variable region, are less accessible in the parasite antigen. This appears to be an intrinsic property of parasite MSP2 and is not dependent on interactions with other merozoite surface proteins as the loss of some conserved-region epitopes seen using the immunofluorescence assay (IFA) on parasite smears was also seen on Western blot analyses of parasite lysates. Further studies of the structural basis of these antigenic differences are required in order to optimize recombinant MSP2 constructs being evaluated as potential vaccine components.


2001 ◽  
Vol 69 (9) ◽  
pp. 5565-5572 ◽  
Author(s):  
William O. Rogers ◽  
J. Kevin Baird ◽  
Anita Kumar ◽  
John A. Tine ◽  
Walter Weiss ◽  
...  

ABSTRACT A nonhuman primate model for malaria vaccine development allowing reliable, stringent sporozoite challenge and evaluation of both cellular and antibody responses is needed. We therefore constructed a multicomponent, multistage DNA vaccine for the simian malaria species Plasmodium knowlesi including two preerythrocytic-stage antigens, the circumsporozoite protein (PkCSP) and sporozoite surface protein 2 (PkSSP2), and two blood stage antigens, apical merozoite antigen 1 (PkAMA1) and merozoite surface protein 1 (PkMSP1p42), as well as recombinant canarypox viruses encoding the four antigens (ALVAC-4). The DNA vaccine plasmids expressed the corresponding antigens in vitro and induced antiparasite antibodies in mice. Groups of four rhesus monkeys received three doses of a mixture of the four DNA vaccine plasmids and a plasmid encoding rhesus granulocyte-monocyte colony-stimulating factor, followed by boosting with a single dose of ALVAC-4. Three groups received the priming DNA doses by different routes, either by intramuscular needle injection, by intramuscular injection with a needleless injection device, the Biojector, or by a combination of intramuscular and intradermal routes by Biojector. Animals immunized by any route developed antibody responses against sporozoites and infected erythrocytes and against a recombinant PkCSP protein, as well as gamma interferon-secreting T-cell responses against peptides from PkCSP. Following challenge with 100 P. knowlesi sporozoites, 1 of 12 experimental monkeys was completely protected and the mean parasitemia in the remaining monkeys was significantly lower than that in 4 control monkeys. This model will be important in preclinical vaccine development.


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.


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