scholarly journals Biochemical and Immunological Characterization of Bacterially Expressed and Refolded Plasmodium falciparum 42-Kilodalton C-Terminal Merozoite Surface Protein 1

2003 ◽  
Vol 71 (12) ◽  
pp. 6766-6774 ◽  
Author(s):  
Sanjay Singh ◽  
Michael C. Kennedy ◽  
Carole A. Long ◽  
Allan J. Saul ◽  
Louis H. Miller ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Native Form ◽  
Immunological Characterization ◽  
E Coli ◽  
Merozoite Surface Protein 1 ◽  
Vaccine Trials

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.

scholarly journals Efficacy of Two Alternate Vaccines Based on Plasmodium falciparum Merozoite Surface Protein 1 in anAotus Challenge Trial

2001 ◽  
Vol 69 (3) ◽  
pp. 1536-1546 ◽  
Author(s):  
Anthony W. Stowers ◽  
Vittoria Cioce ◽  
Richard L. Shimp ◽  
Mark Lawson ◽  
George Hui ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Vaccine Antigen ◽  
Merozoite Surface Protein 1 ◽  
Adjuvant Vaccine ◽  
New Formulation ◽  
Antibody Levels

ABSTRACT In an attempt to produce a more defined, clinical-grade version of a vaccine based on Plasmodium falciparum merozoite surface protein 1 (MSP1), we evaluated the efficacy of two recombinant forms of MSP1 in an Aotus nancymai challenge model system. One recombinant vaccine, bvMSP142, based on the 42-kDa C-terminal portion of MSP1, was expressed as a secreted protein in baculovirus-infected insect cells. A highly pure baculovirus product could be reproducibly expressed and purified at yields in excess of 8 mg of pure protein per liter of culture. This protein, when tested for efficacy in the Aotus challenge model, gave significant protection, with only one of seven monkeys requiring treatment for uncontrolled parasitemia after challenge with P. falciparum. The second recombinant protein, P30P2MSP119, has been used in previous studies and is based on the smaller, C-terminal 19-kDa portion of MSP1 expressed inSaccharomyces cerevisiae. Substantial changes were made in its production process to optimize expression. The optimum form of this vaccine antigen (as judged by in vitro and in vivo indicators) was then evaluated, along with bvMSP142, for efficacy in theA. nancymai system. The new formulation of P30P3MSP119 performed significantly worse than bvMSP142 and appeared to be less efficacious than we have found in the past, with four of seven monkeys in the vaccinated group requiring treatment for uncontrolled parasitemia. With both antigens, protection was seen only when high antibody levels were obtained by formulation of the vaccines in Freund's adjuvant. Vaccine formulation in an alternate adjuvant, MF59, resulted in significantly lower antibody titers and no protection.

scholarly journals Quantification of Plasmodium falciparum malaria from complex infections in the Peruvian Amazon using quantitative PCR of the merozoite surface protein 1, block 2 (PfMSP1-B2): in vitro dynamics reveal density-dependent interactions

Parasitology ◽  
2012 ◽  
Vol 139 (6) ◽  
pp. 701-708 ◽  
Author(s):  
THOMAS M. ZERVOS ◽  
JEAN N. HERNANDEZ ◽  
PATRICK L. SUTTON ◽  
ORALEE H. BRANCH
Keyword(s):  
Plasmodium Falciparum ◽  
Quantitative Pcr ◽  
Surface Protein ◽  
Plasmodium Falciparum Malaria ◽  
Merozoite Surface Protein ◽  
Peruvian Amazon ◽  
Field Isolates ◽  
Merozoite Surface Protein 1

SUMMARYThe majority of Plasmodium falciparum field isolates are defined as complex infections because they contain multiple genetically distinct clones. Studying interactions between clones in complex infections in vivo and in vitro could elucidate important phenomena in malaria infection, transmission and treatment. Using quantitative PCR (qPCR) of the P. falciparum merozoite surface protein 1, block 2 (PfMSP1-B2), we provide a sensitive and efficient genotyping method. This is important for epidemiological studies because it makes it possible to study genotype-specific growth dynamics. We compared 3 PfMSP1-B2 genotyping methods by analysing 79 field isolates from the Peruvian Amazon. In vivo observations from other studies using these techniques led to the hypothesis that clones within complex infections interact. By co-culturing clones with different PfMSP1-B2 genotypes, and measuring parasitaemia using qPCR, we found that suppression of clonal expansion was a factor of the collective density of all clones present in a culture. PfMSP1-B2 qPCR enabled us to find in vitro evidence for parasite-parasite interactions and could facilitate future investigations of growth trends in naturally occurring complex infections.

scholarly journals Plasmodium falciparum Merozoite Surface Protein 1 (MSP-1)-MSP-3 Chimeric Protein: Immunogenicity Determined with Human-Compatible Adjuvants and Induction of Protective Immune Response

2009 ◽  
Vol 78 (2) ◽  
pp. 872-883 ◽  
Author(s):  
Suman Mazumdar ◽  
Paushali Mukherjee ◽  
Syed Shams Yazdani ◽  
S. K. Jain ◽  
Asif Mohmmed ◽  
...  
Keyword(s):  
Immune Response ◽  
Plasmodium Falciparum ◽  
Fusion Protein ◽  
Malaria Vaccine ◽  
Chimeric Protein ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Protective Immune Response ◽  
Merozoite Surface Protein 1

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.

scholarly journals Immunogenicity and In Vivo Efficacy of Recombinant Plasmodium falciparum Merozoite Surface Protein-1 in Aotus Monkeys

1995 ◽  
Vol 1 (3) ◽  
pp. 325-332 ◽  
Author(s):  
Sanjai Kumar ◽  
Anjali Yadava ◽  
David B. Keister ◽  
Jing Hui Tian ◽  
Michael Ohl ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
In Vivo Efficacy ◽  
Merozoite Surface Protein 1 ◽  
Falciparum Merozoite

scholarly journals Analysis of Antibodies Directed against Merozoite Surface Protein 1 of the Human Malaria Parasite Plasmodium falciparum

2006 ◽  
Vol 74 (2) ◽  
pp. 1313-1322 ◽  
Author(s):  
Ute Woehlbier ◽  
Christian Epp ◽  
Christian W. Kauth ◽  
Rolf Lutz ◽  
Carole A. Long ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Merozoite Surface Protein 1 ◽  
Erythrocyte Invasion ◽  
Parasite Plasmodium ◽  
Parasite Plasmodium Falciparum ◽  
Parasite Multiplication ◽  
Parasite Replication

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.

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.

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