title: Recombinant antibodies specific for the Plasmodium falciparum histidine-rich protein 2.
abstract: Early diagnosis and appropriate treatment are key elements of malaria control programs in endemic areas. A major step forward in recent years has been the production and use of rapid diagnostic tests (RDTs) in settings where microscopy is impracticable. Many current RDTs target the Plasmodium falciparum histidine-rich protein 2 (PfHRP2) released in the plasma of infected individuals. These RDTs have had an indisputably positive effect on malaria management, but still present several limitations, including the poor characterization of the commercial monoclonal antibodies (mAbs) used for PfHRP2 detection, variable sensitivity and specificity, and high costs. RDT use is further limited by impaired stability caused by temperature fluctuations during transport and uncontrolled storage in field-based facilities. To circumvent such drawbacks, an alternative could be the development of well-characterized, stabilized recombinant antibodies, with high binding affinity and specificity. Here, we report the characterization of the cDNA sequences encoding the Fab fragment of F1110 and F1546, two novels anti-PfHRP2 mAbs. FabF1546 was produced in the Escherichia coli periplasm. Its properties of binding to the parasite and to a recombinant PfHRP-2 antigen were similar to those of the parental mAb. As the affinity and stability of recombinant antibodies can be improved by protein engineering, our results open a novel approach for the development of an improved RDT for malaria diagnosis.
authors.affiliation: Institut Pasteur de Madagascar; Institut Pasteur.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ravaoarisoa
authors.affiliation: Institut Pasteur; Centre d'Etude et de Recherche Médicale et Sanitaire.
authors.forename: Halima
authors.initials: H
authors.lastname: Zamanka
authors.affiliation: Institut de Médecine Tropicale du Service de Santé des Armées.
authors.forename: Thierry
authors.initials: T
authors.lastname: Fusai
authors.affiliation: Institut Pasteur.
authors.forename: Jacques
authors.initials: J
authors.lastname: Bellalou
authors.affiliation: Institut Pasteur.
authors.forename: Hugues
authors.initials: H
authors.lastname: Bedouelle
authors.affiliation: Institut Pasteur.
authors.forename: Odile
authors.initials: O
authors.lastname: Mercereau-Puijalon
authors.affiliation: Institut Pasteur; Centre d'Etude et de Recherche Médicale et Sanitaire.
authors.forename: Thierry
authors.initials: T
authors.lastname: Fandeur
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000737:chemistry / Q000235:genetics*; D000953:Antigens, Protozoan / Q000276:immunology; D018076:DNA, Complementary / Q000032:analysis; D042241:Early Diagnosis; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D006403:Hematologic Tests; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000235:genetics*; D016778:Malaria, Falciparum / Q000175:diagnosis* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000276:immunology*; D015202:Protein Engineering; D015800:Protozoan Proteins / Q000276:immunology; D011994:Recombinant Proteins / Q000235:genetics*; D012680:Sensitivity and Specificity
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D018076:DNA, Complementary; C514457:HRP-2 antigen, Plasmodium falciparum; D007140:Immunoglobulin Fab Fragments; D015800:Protozoan Proteins; D011994:Recombinant Proteins