Standardization of a Multiplex Magnetic Bead-based for Simultaneous Detection of IgG to Plasmodium Antigens

Ronald Perraut (1) , M-L Varela (1) , Babacar Mbengue (1) , M. Guillotte (2) , Odile Mercereau-Puijalon (2) , Inès Vigan‑womas (2)

1 Institut Pasteur de Dakar
2 Immunologie moléculaire des parasites

Background: Multiplex assays are currently used to facilitate the evaluation of antibody (Ab) responses to multiple Plasmodium falciparum antigens from large field-based epidemiological studies. The present study aimed at (i) optimizing parameters of a novel cost-effective, compact and reliable magnetic bead-based multiplex immunoassay (MBA) carried out with the MAGPIX ®-Luminex system and (ii) comparing the results with those obtained using standard ELISA technology. Methods: Several MBA parameters including antigen amount for coupling, plasma dilution, type of plates, buffers, washing procedure to minimize bead loss, and bead quantity for testing were optimized. Antibody responses to two recombinant and two peptidic P. falciparum antigens, one Anopheles gambiae salivary gland peptide gSG6 and Bovine Serum Albumin as negative control were tested by MBA and ELISA using sera from 14 villagers from an hyper-endemic Senegalese village. Results: The MBA procedures were developed to reflect responses observed in the standard ELISA protocols used in previous studies. Using the finalized MBA protocol, a strong significant positive correlation (P<10-3) was observed between ELISA and multiplex-MFI (median fluorescence intensity) antibody readouts (PfMSP1p19, PF13-DBL1α1 recombinant proteins, rho= .77 and .82, respectively; LSA141, CSP and gSG6, synthetic peptides; rho = .86, .61 and .73, respectively). Backgrounds with the negative control BSA or non-immune sera were minimal. There was a good reproducibility of MFI values measured with amounts of 1,500 beads/antigen/well. Conclusion: The MBA protocol offers important advantages over ELISA for measuring antibody responses to multiple Plasmodium antigens, especially in large field studies. Reducing significantly consumables' costs and being more rapid than ELISA, the MBA protocols developed here represents a basis for standardizing assays of humoral responses and enable valid comparisons of results from different laboratories in seroepidemiological surveys or analysis of immunogenicity of vaccine candidates.

Mots clés: Multiplex assay; Magnetic beads; MAGPIX ® technology; Malaria; Plasmodium; Antibodies detection; ELISA

Domaines: Immunologie

Ronald Perraut, M-L Varela, Babacar Mbengue, M. Guillotte, Odile Mercereau-Puijalon, et al.. Standardization of a Multiplex Magnetic Bead-based for Simultaneous Detection of IgG to Plasmodium Antigens. Journal of Immunological Techniques & Infectious Diseases, 2015, 4 (2), pp.1-8. ⟨10.4172/2329-9541.1000134⟩. ⟨hal-01299922⟩