scholarly journals In Vivo Expression and Immunological Studies of the 42-Kilodalton Carboxyl-Terminal Processing Fragment of Plasmodium falciparum Merozoite Surface Protein 1 in the Baculovirus-Silkworm System

2002 ◽  
Vol 70 (6) ◽  
pp. 2772-2779 ◽  
Author(s):  
Alan L. Y. Pang ◽  
Caryn N. Hashimoto ◽  
Leslie Q. Tam ◽  
Z. Q. Meng ◽  
George S. N. Hui ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
B Cell ◽  
Expression System ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Attractive Alternative ◽  
B Cell Epitopes ◽  
Merozoite Surface Protein 1 ◽  
Carboxyl Terminal

ABSTRACT The 42-kDa carboxyl-terminal processing fragment of Plasmodium falciparum merozoite surface protein 1 (MSP-142) is an anti-erythrocytic stage malaria vaccine candidate. In this study, MSP-142 was expressed by using the Bombyx mori nuclear polyhedrosis virus-silkworm expression system, and the antigenicity and immmunogenicity of the recombinant protein, Bmp42, were evaluated. The average yield of Bmp42, as determined by a sandwich enzyme-linked immunosorbent assay (ELISA), was 379 μg/ml of infected silkworm hemolymph, which was >100-fold higher than the level attainable in cell culture medium. N-terminal amino acid sequencing revealed that Bmp42 was correctly processed in silkworm cells. Data from immunoblotting, as well as from the inhibition ELISA, suggested that the conformational B-cell epitopes of MSP-142 were recreated in Bmp42. Immunization of rabbits with Bmp42 in complete Freund's adjuvant generated high-titer antibody responses against the immunogen. Specificity analyses of the anti-Bmp42 antibodies using several recombinant MSP-119 proteins expressing variant and conserved B-cell epitopes suggested that the anti-Bmp42 antibodies recognized primarily conserved epitopes on MSP-119. Furthermore, the anti-Bmp42 antibodies were highly effective in inhibiting the in vitro growth of parasites carrying homologous or heterologous MSP-142. Our results demonstrated that the baculovirus-silkworm expression system could be employed to express biologically and immunologically active recombinant MSP-142 at elevated levels; thus, it is an attractive alternative for producing a protective MSP-142 vaccine for human use.

scholarly journals Genetic diversity and immunogenicity of the merozoite surface protein 1 C-terminal 19-kDa fragment of Plasmodium ovale imported from Africa into China

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Qinwen Xu ◽  
Sihong Liu ◽  
Kokouvi Kassegne ◽  
Bo Yang ◽  
Jiachen Lu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Immune Responses ◽  
Expression System ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Avidity ◽  
Plasmodium Ovale ◽  
Merozoite Surface Protein 1 ◽  
Proliferation Assays

Abstract Background Merozoite surface protein 1 (MSP1) plays an essential role in erythrocyte invasion by malaria parasites. The C-terminal 19-kDa region of MSP1 has long been considered one of the major candidate antigens for a malaria blood-stage vaccine against Plasmodium falciparum. However, there is limited information on the C-terminal 19-kDa region of Plasmodium ovale MSP1 (PoMSP119). This study aims to analyze the genetic diversity and immunogenicity of PoMSP119. Methods A total of 37 clinical Plasmodium ovale isolates including Plasmodium ovale curtisi and Plasmodium ovale wallikeri imported from Africa into China and collected during the period 2012–2016 were used. Genomic DNA was used to amplify P. ovale curtisi (poc) msp119 (pocmsp119) and P. ovale wallikeri (pow) msp119 (powmsp119) genes by polymerase chain reaction. The genetic diversity of pomsp119 was analyzed using the GeneDoc version 6 programs. Recombinant PoMSP119 (rPoMSP119)-glutathione S-transferase (GST) proteins were expressed in an Escherichia coli expression system and analyzed by western blot. Immune responses in BALB/c mice immunized with rPoMSP119-GST were determined using enzyme-linked immunosorbent assay. In addition, antigen-specific T cell responses were assessed by lymphocyte proliferation assays. A total of 49 serum samples from healthy individuals and individuals infected with P. ovale were used for the evaluation of natural immune responses by using protein microarrays. Results Sequences of pomsp119 were found to be thoroughly conserved in all the clinical isolates. rPoMSP119 proteins were efficiently expressed and purified as ~ 37-kDa proteins. High antibody responses in mice immunized with rPoMSP119-GST were observed. rPoMSP119-GST induced high avidity indexes, with an average of 92.57% and 85.32% for rPocMSP119 and rPowMSP119, respectively. Cross-reactivity between rPocMSP119 and rPowMSP119 was observed. Cellular immune responses to rPocMSP119 (69.51%) and rPowMSP119 (52.17%) induced in rPocMSP119- and rPowMSP119-immunized mice were found in the splenocyte proliferation assays. The sensitivity and specificity of rPoMSP119-GST proteins for the detection of natural immune responses in patients infected with P. ovale were 89.96% and 75%, respectively. Conclusions This study revealed highly conserved gene sequences of pomsp119. In addition, naturally acquired humoral immune responses against rPoMSP1 were observed in P. ovale infections, and high immunogenicity of rPoMSP119 in mice was also identified. These instructive findings should encourage further testing of PoMSP119 for rational vaccine design. Graphical abstract

scholarly journals Characterization of Conserved T- and B-Cell Epitopes in Plasmodium falciparum Major Merozoite Surface Protein 1

2000 ◽  
Vol 68 (5) ◽  
pp. 2685-2691 ◽  
Author(s):  
Marcela Parra ◽  
George Hui ◽  
Armead H. Johnson ◽  
Jay A. Berzofsky ◽  
Theodore Roberts ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Surface Protein ◽  
T Cell Responses ◽  
Merozoite Surface Protein ◽  
B Cell Epitopes ◽  
Conserved Sequence ◽  
Cell Responses ◽  
Merozoite Surface Protein 1

ABSTRACT Vaccines for P. falciparum will need to contain both T- and B-cell epitopes. Conserved epitopes are the most desirable, but they are often poorly immunogenic. The major merozoite surface protein 1 (MSP-1) is currently a leading vaccine candidate antigen. In this study, six peptides from conserved or partly conserved regions of MSP-1 were evaluated for immunogenicity in B10 congenic mice. Following immunization with the peptides, murine T cells were tested for the ability to proliferate in vitro and antibody responses to MSP-1 were evaluated in vivo. The results showed that one highly conserved sequence (MSP-1#1, VTHESYQELVKKLEALEDAV; located at amino acid positions 20 to 39) and one partly conserved sequence (MSP-1#23, GLFHKEKMILNEEEITTKGA; located at positions 44 to 63) contained both T- and B-cell epitopes. Immunization of mice with these peptides resulted in T-cell proliferation and enhanced production of antibody to MSP-1 upon exposure to merozoites. MSP-1#1 stimulated T-cell responses in three of the six strains of mice evaluated, whereas MSP-1#23 was immunogenic in only one strain. Immunization with the other four peptides resulted in T-cell responses to the peptides, but none of the resulting peptide-specific T cells recognized native MSP-1. These results demonstrate that two sequences located in the N terminus of MSP-1 can induce T- and B-cell responses following immunization in a murine model. Clearly, these sequences merit further consideration for inclusion in a vaccine for malaria.

scholarly journals The Clinical-Grade 42-Kilodalton Fragment of Merozoite Surface Protein 1 of Plasmodium falciparum Strain FVO Expressed in Escherichia coli Protects Aotus nancymai against Challenge with Homologous Erythrocytic-Stage Parasites

2005 ◽  
Vol 73 (1) ◽  
pp. 287-297 ◽  
Author(s):  
Christian A. Darko ◽  
Evelina Angov ◽  
William E. Collins ◽  
Elke S. Bergmann-Leitner ◽  
Autumn S. Girouard ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Plasmodium Falciparum ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Clinical Grade ◽  
Erythrocytic Stage ◽  
Malaria Parasites ◽  
E Coli ◽  
Merozoite Surface Protein 1

ABSTRACT A 42-kDa fragment from the C terminus of major merozoite surface protein 1 (MSP1) is among the leading malaria vaccine candidates that target infection by asexual erythrocytic-stage malaria parasites. The MSP142 gene fragment from the Vietnam-Oak Knoll (FVO) strain of Plasmodium falciparum was expressed as a soluble protein in Escherichia coli and purified according to good manufacturing practices. This clinical-grade recombinant protein retained some important elements of correct structure, as it was reactive with several functional, conformation-dependent monoclonal antibodies raised against P. falciparum malaria parasites, it induced antibodies (Abs) that were reactive to parasites in immunofluorescent Ab tests, and it induced strong growth and invasion inhibitory antisera in New Zealand White rabbits. The antigen quality was further evaluated by vaccinating Aotus nancymai monkeys and challenging them with homologous P. falciparum FVO erythrocytic-stage malaria parasites. The trial included two control groups, one vaccinated with the sexual-stage-specific antigen of Plasmodium vivax, Pvs25, as a negative control, and the other vaccinated with baculovirus-expressed MSP142 (FVO) as a positive control. Enzyme-linked immunosorbent assay (ELISA) Ab titers induced by E. coli MSP142 were significantly higher than those induced by the baculovirus-expressed antigen. None of the six monkeys that were vaccinated with the E. coli MSP142 antigen required treatment for uncontrolled parasitemia, but two required treatment for anemia. Protective immunity in these monkeys correlated with the ELISA Ab titer against the p19 fragment and the epidermal growth factor (EGF)-like domain 2 fragment of MSP142, but not the MSP142 protein itself or the EGF-like domain 1 fragment. Soluble MSP142 (FVO) expressed in E. coli offers excellent promise as a component of a vaccine against erythrocytic-stage falciparum malaria.

scholarly journals Inhibitory Antibodies Specific for the 19-Kilodalton Fragment of Merozoite Surface Protein 1 Do Not Correlate with Delayed Appearance of Infection with Plasmodium falciparum in Semi-Immune Individuals in Vietnam

2009 ◽  
Vol 77 (10) ◽  
pp. 4510-4517 ◽  
Author(s):  
E. Elsa Herdiana Murhandarwati ◽  
Lina Wang ◽  
Casilda G. Black ◽  
Doan Hanh Nhan ◽  
Thomas L. Richie ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Plasmodium Yoelii ◽  
Enzyme Linked Immunosorbent Assay ◽  
Acquired Immunity ◽  
Homologous Region ◽  
Significant Component ◽  
Merozoite Surface Protein 1 ◽  
Inhibitory Antibodies

ABSTRACT Inhibitory antibodies specific for the 19-kDa fragment of merozoite surface protein 1 (MSP119) are a significant component of inhibitory responses in individuals immune to malaria. Nevertheless, conflicting results have been obtained in determining whether this antibody specificity correlates with protection in residents of areas where malaria is endemic. In this study, we examined sera collected from a population of semi-immune individuals living in an area of Vietnam with meso-endemicity during a 6-month period. We used two Plasmodium falciparum parasite lines that express either endogenous MSP119 or the homologous region from Plasmodium yoelii to measure the MSP119-specific inhibitory activity. We showed that (i) the level of MSP119-specific inhibitory antibodies was not associated with a delay in P. falciparum infection, (ii) MSP119-specific inhibitory antibodies declined significantly during the convalescent period after infection, and (iii) there was no significant correlation between the MSP119-specific inhibitory antibodies and the total antibodies measured by enzyme-linked immunosorbent assay. These results have implications for understanding naturally acquired immunity to malaria and for the development and evaluation of MSP119-based vaccines.

scholarly journals Kinetics of Humoral and Memory B Cell Response Induced by the Plasmodium falciparum 19-Kilodalton Merozoite Surface Protein 1 in Mice

2011 ◽  
Vol 80 (2) ◽  
pp. 633-642 ◽  
Author(s):  
Mwanaidi Y. Kafuye-Mlwilo ◽  
Paushali Mukherjee ◽  
Virander S. Chauhan
Keyword(s):  
Plasmodium Falciparum ◽  
B Cell ◽  
Plasma Cells ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Cell Memory ◽  
Content Type ◽  
Merozoite Surface Protein 1 ◽  
B Cell Memory ◽  
Protection Against Infection

ABSTRACTThe 19-kDa carboxyl-terminal fragment of the merozoite surface protein-1 (MSP-119) has been shown to regulate antibody (Ab)-mediated protective immunity to blood-stage malaria infection. But the serological memory to this antigen tends to be short-lived, and little is known of the mechanisms that regulate the formation of B cell memory to MSP-119antigen. We studied the formation of B cell memory response after immunization with the recombinant 19-kDaPlasmodium falciparummerozoite surface protein 1 (PfMSP-119). Immunization with PfMSP-119resulted in delayed increase in germinal center (GC) B cell numbers. This poor GC reaction correlated with short-lived PfMSP-119-specific antibodies in serum and the short life of PfMSP-119-specific plasma cells and memory B cells (MBCs) in spleen and bone marrow. PfMSP-119-specific MBCs were capable of producing antigen (Ag)-specific Ab-secreting cell (ASC) responses that were short-lived following challenge immunization of the immune mice with antigen or transgenicPlasmodium bergheiparasite expressing PfMSP-119in place of nativeP. bergheiMSP-119at 8 weeks after the last immunization or following adoptive transfer into naive hosts. However, no protection was achieved in PfMSP-119immune mice or recipient mice with PfMSP-119-specific MBCs following challenge with transgenicP. berghei. Our findings suggest that PfMSP-119-specific IgG production by short-lived plasma cells combined with the poor ability of the PfMSP-119-induced MBCs to maintain the anamnestic IgG responses failed to contribute to protection against infection.

scholarly journals Levels of Antibody to Conserved Parts of Plasmodium falciparum Merozoite Surface Protein 1 in Ghanaian Children Are Not Associated with Protection from Clinical Malaria

1999 ◽  
Vol 67 (5) ◽  
pp. 2131-2137 ◽  
Author(s):  
Daniel Dodoo ◽  
Thor G. Theander ◽  
Jorgen A. L. Kurtzhals ◽  
Kojo Koram ◽  
Eleanor Riley ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Clinical Malaria ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Antibody ◽  
Merozoite Surface Protein 1 ◽  
Egf Domain ◽  
Antibody Specificities

ABSTRACT The 19-kDa conserved C-terminal part of the Plasmodium falciparum merozoite surface protein 1 (PfMSP119) is a malaria vaccine candidate antigen, and human antibody responses to PfMSP119 have been associated with protection against clinical malaria. In this longitudinal study carried out in an area of stable but seasonal malaria transmission with an estimated parasite inoculation of about 20 infective bites/year, we monitored 266 3- to 15-year-old Ghanaian children clinically and parasitologically over a period of 18 months. Blood samples were collected at the beginning of the study before the major malaria season in April and after the season in November. Using enzyme-linked immunosorbent assay, we measured antibody responses to recombinant gluthathioneS-transferase–PfMSP119 fusion proteins corresponding to the Wellcome and MAD20 allelic variants in these samples. Prevalence of antibodies recognizing the Wellcome 19 construct containing both epidermal growth factor (EGF)-like motifs in Wellcome type PfMSP119 was about 30%. Prevalence of antibodies to constructs containing only the first EGF domain from either Wellcome or MAD20 type PfMSP119 was about 15%, whereas antibodies recognizing a construct containing only the second EGF domain of MAD20 type PfMSP119 was found in only about 4% of the donors. Neither the prevalence nor the levels of any of the antibody specificities varied significantly with season, age, or sex. Significantly, and in contrast to previous reports from other parts of West Africa, we found no evidence of an association between antibody responses to PfMSP119and clinical protection against malaria.

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