Thrombospondin-related adhesive protein (TRAP) of Plasmodium falciparum: Expression during sporozoite ontogeny and binding to human hepatocytes

Abstract Background Thrombospondin-related adhesive protein (TRAP) is a transmembrane protein that plays a crucial role during the invasion of Plasmodium falciparum into liver cells. As a potential malaria vaccine candidate, the genetic diversity and natural selection of PfTRAP was assessed and the global PfTRAP polymorphism pattern was described. Methods 153 blood spot samples from Bioko malaria patients were collected during 2016–2018 and the target TRAP gene was amplified. Together with the sequences from database, nucleotide diversity and natural selection analysis, and the structural prediction were preformed using bioinformatical tools. Results A total of 119 Bioko PfTRAP sequences were amplified successfully. On Bioko Island, PfTRAP shows its high degree of genetic diversity and heterogeneity, with π value for 0.01046 and Hd for 0.99. The value of dN–dS (6.2231, p < 0.05) hinted at natural selection of PfTRAP on Bioko Island. Globally, the African PfTRAPs showed more diverse than the Asian ones, and significant genetic differentiation was discovered by the fixation index between African and Asian countries (Fst > 0.15, p < 0.05). 667 Asian isolates clustered in 136 haplotypes and 739 African isolates clustered in 528 haplotypes by network analysis. The mutations I116T, L221I, Y128F, G228V and P299S were predicted as probably damaging by PolyPhen online service, while mutations L49V, R285G, R285S, P299S and K421N would lead to a significant increase of free energy difference (ΔΔG > 1) indicated a destabilization of protein structure. Conclusions Evidences in the present investigation supported that PfTRAP gene from Bioko Island and other malaria endemic countries is highly polymorphic (especially at T cell epitopes), which provided the genetic information background for developing an PfTRAP-based universal effective vaccine. Moreover, some mutations have been shown to be detrimental to the protein structure or function and deserve further study and continuous monitoring.

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Molecular detection and quantification of Plasmodium falciparum-infected human hepatocytes in chimeric immune-deficient mice

Malaria Journal ◽

10.1186/1475-2875-12-430 ◽

2013 ◽

Vol 12 (1) ◽

pp. 430 ◽

Cited By ~ 14

Author(s):

Lander Foquet ◽

Cornelus C Hermsen ◽

Geert-Jan van Gemert ◽

Louis Libbrecht ◽

Robert Sauerwein ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Molecular Detection ◽

Human Hepatocytes ◽

Deficient Mice ◽

Detection And Quantification

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Diversifying Selection on the Thrombospondin-Related Adhesive Protein (TRAP) Gene of Plasmodium falciparum in Thailand

PLoS ONE ◽

10.1371/journal.pone.0090522 ◽

2014 ◽

Vol 9 (2) ◽

pp. e90522 ◽

Cited By ~ 5

Author(s):

Jun Ohashi ◽

Yuji Suzuki ◽

Izumi Naka ◽

Hathairad Hananantachai ◽

Jintana Patarapotikul

Keyword(s):

Plasmodium Falciparum ◽

Diversifying Selection ◽

Adhesive Protein ◽

Trap Gene

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Gene Disruption of Plasmodium falciparum p52 Results in Attenuation of Malaria Liver Stage Development in Cultured Primary Human Hepatocytes

PLoS ONE ◽

10.1371/journal.pone.0003549 ◽

2008 ◽

Vol 3 (10) ◽

pp. e3549 ◽

Cited By ~ 70

Author(s):

Ben C. L. van Schaijk ◽

Chris J. Janse ◽

Geert-Jan van Gemert ◽

Melissa R. van Dijk ◽

Audrey Gego ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Gene Disruption ◽

Human Hepatocytes ◽

Liver Stage ◽

Primary Human Hepatocytes ◽

Stage Development

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Gamma Interferon Responses to Plasmodium falciparum Liver-Stage Antigen 1 and Thrombospondin-Related Adhesive Protein and Their Relationship to Age, Transmission Intensity, and Protection against Malaria

Infection and Immunity ◽

10.1128/iai.72.9.5135-5142.2004 ◽

2004 ◽

Vol 72 (9) ◽

pp. 5135-5142 ◽

Cited By ~ 39

Author(s):

Chandy C. John ◽

Ann M. Moormann ◽

Peter O. Sumba ◽

Ayub V. Ofulla ◽

Daniel C. Pregibon ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Clinical Malaria ◽

Gamma Interferon ◽

Transmission Intensity ◽

Liver Stage ◽

Adhesive Protein ◽

Transmission Area ◽

Ifn Γ ◽

Stable Transmission ◽

Unstable Transmission

ABSTRACT Gamma interferon (IFN-γ) responses to the Plasmodium falciparum antigens liver-stage antigen 1 (LSA-1) and thrombospondin-related adhesive protein (TRAP) are thought to be important in protection against malaria. Optimal methods of testing and the effects of age and transmission intensity on these responses are unknown. IFN-γ responses to LSA-1 and TRAP peptides were assessed by the enzyme-linked immunospot assay (ELISPOT) and enzyme-linked immunosorbent assay (ELISA) in children and adults from areas of stable and unstable malaria transmission in Kenya. Adults in the areas of stable and unstable transmission had similar frequencies and levels of IFN-γ responses to LSA-1 and TRAP as determined by ELISPOT and ELISA. In contrast, IFN-γ responses to the LSA-1 T3 peptide (assessed by ELISPOT) and to any LSA-1 peptide (assessed by ELISA) were less frequent in children in the area of unstable transmission than in children in the area of stable transmission. IFN-γ responses to LSA-1 were more frequently detected by ELISA than by ELISPOT in the stable-transmission area. IFN-γ responses detected by ELISA and ELISPOT did not correlate with each other. In children in the stable-transmission area, IFN-γ responses to LSA-1 peptides assessed by ELISA, but not by ELISPOT, were associated with protection against clinical malaria and anemia. IFN-γ responses to LSA-1 appear to require repeated P. falciparum exposure and/or increased age and, as measured by ELISA, are associated with protection against clinical malaria and anemia.

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Antibodies to the Plasmodium falciparum Antigens Circumsporozoite Protein, Thrombospondin-Related Adhesive Protein, and Liver-Stage Antigen 1 Vary by Ages of Subjects and by Season in a Highland Area of Kenya

Infection and Immunity ◽

10.1128/iai.71.8.4320-4325.2003 ◽

2003 ◽

Vol 71 (8) ◽

pp. 4320-4325 ◽

Cited By ~ 39

Author(s):

Chandy C. John ◽

Joseph S. Zickafoose ◽

P. Odada Sumba ◽

Christopher L. King ◽

James W. Kazura

Keyword(s):

Plasmodium Falciparum ◽

Dry Season ◽

Circumsporozoite Protein ◽

Protective Effects ◽

Igg Antibodies ◽

Liver Stage ◽

Highland Area ◽

Adhesive Protein ◽

Adults And Children ◽

Dry Seasons

ABSTRACT Immunoglobulin G (IgG) antibodies to three vaccine candidate preerythrocytic Plasmodium falciparum antigens were evaluated in children and adults in an epidemic-prone highland area of Kenya during rainy (high-transmission) and dry (low-transmission) seasons. The frequencies and median levels of IgG antibodies to circumsporozoite protein (CSP) and thrombospondin-related adhesive protein (TRAP) were compared to the frequencies and median levels of IgG antibodies to liver-stage antigen 1 (LSA-1) reported previously. The frequencies and median levels of IgG antibodies to CSP and TRAP were similar in children and adults in the rainy season, but they were lower in children than in adults in the dry season. The frequencies and median levels of antibodies to LSA-1 were lower in children than in adults in both the rainy and dry seasons. Antibodies to CSP and LSA-1 were primarily members of the IgG1 and IgG3 subclasses, while antibodies to TRAP were primarily members of the IgG3 and IgG4 subclasses. In a treatment-reinfection study following dry season testing, antibodies to TRAP were associated with a trend toward protection from infection in children (P = 0.051) but not in adults. Antibodies to LSA-1 and CSP did not correlate with protection in children or adults. In this highland area of Kenya with unstable transmission, IgG antibodies to preerythrocytic P. falciparum antigens vary in subjects by age and season, and the protective effects of these antibodies against infection may be different in adults and children.

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Developmental Stage- and Cell Cycle Number-Dependent Changes in Characteristics of Plasmodium falciparum-Infected Erythrocyte Adherence to Placental Chondroitin-4-Sulfate Proteoglycan

Infection and Immunity ◽

10.1128/iai.00478-07 ◽

2007 ◽

Vol 75 (9) ◽

pp. 4409-4415 ◽

Cited By ~ 7

Author(s):

SubbaRao V. Madhunapantula ◽

Rajeshwara N. Achur ◽

D. Channe Gowda

Keyword(s):

Plasmodium Falciparum ◽

Binding Capacity ◽

Protein S ◽

Parasite Development ◽

Trypsin Treatment ◽

Cycle Number ◽

Adhesive Protein ◽

Parasite Stage ◽

Selection For ◽

Successive Generations

ABSTRACTThe adherence ofPlasmodium falciparum-infected red blood cells (IRBCs) in the human placenta is mediated by chondroitin-4-sulfate (C4S). Although IRBC binding to C4S has been unequivocally established, the adherence characteristics of IRBCs at different stages of parasite development and through successive parasite generations after selection for C4S adherence are not known. Here we show that IRBCs acquire a significant capacity to bind to C4S at as early as 14 h and exhibit maximum binding at 22 to 26 h postinvasion. Surprisingly, the IRBC binding ability decreases by ∼50% at the late trophozoite and schizont stages. The binding strength of the IRBCs also gradually decreases during successive generations after selection for C4S binding, and at the 32nd generation, the binding capacity was only ∼31% of that of IRBCs at the 2nd generation, suggesting that IRBCs eventually lose their C4S-adherent capacity. We also tested the susceptibility of the adhesive protein(s) on the IRBC surface to trypsin treatment at different stages of parasite development. The data show that IRBCs with late trophozoites are more resistant to trypsin treatment than those containing early trophozoites, indicating that parasite proteins expressed on the IRBC surface during trophozoite maturation partially mask accessibility of adhesive protein for binding to C4S. These data provide important insights into the expression pattern of the C4S-adhesive protein(s) on the IRBC surface, emphasizing the need for understanding the regulation of genes involved in IRBC binding to C4S. Our data also define the parasite stage at which IRBCs are suitable for studying structural interactions with C4S.

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