Plasmodium yoelii blood-stage antigens newly identified by immunoaffinity using purified IgG antibodies from malaria-resistant mice.
As the search for an effective human malaria vaccine continues, understanding immune responses to Plasmodium in rodent models is perhaps the key to unlocking new vaccine strategies. The recruitment of parasite-specific antibodies is an important component of natural immunity against infection in blood-stage malaria. Here, we describe the use of sera from naturally surviving ICR mice after infection with lethal doses of Plasmodium yoelii yoelii 17XL to identify highly immunogenic blood-stage antigens. Immobilized protein A/G was used for the affinity-chromatography purification of the IgGs present in pooled sera from surviving mice. These protective IgGs, covalently immobilized on agarose columns, were then used to isolate reactive antigens from whole P. yoelii yoelii 17XL protein extracts obtained from the blood-stage malaria infection. Through proteomics analysis of the recovered parasite antigens, we were able to identify two endoplasmic reticulum lumen proteins: protein disulfide isomerase and a member of the heat shock protein 70 family. Also identified were the digestive protease plasmepsin and the 39 kDa-subunit of eukaryotic translation initiation factor 3, a ribosome associated protein. Of these four proteins, three have not been previously identified as antigenic during blood-stage malaria infection. This procedure of isolating and identifying parasite antigens using serum IgGs from malaria-protected individuals could be a novel strategy for the development of multi-antigen-based vaccine therapies.
Departamento de Bioquímica y Biología Molecular IV, Universidad Complutense de Madrid, Ciudad Universitaria, E28040 Madrid, Spain.
Ali N
AN
Kamali
Patricia
P
Marín-García
Isabel G
IG
Azcárate
Amalia
A
Diez
Antonio
A
Puyet
José M
JM
Bautista
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology* / Q000302:isolation & purification; D000953:Antigens, Protozoan / Q000097:blood / Q000276:immunology*; D016282:Aspartic Acid Endopeptidases / Q000276:immunology / Q000378:metabolism; D015153:Blotting, Western; D002846:Chromatography, Affinity; D060467:Disease Resistance / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D039621:Eukaryotic Initiation Factor-3 / Q000276:immunology / Q000378:metabolism; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology / Q000302:isolation & purification; D008288:Malaria / Q000097:blood / Q000276:immunology* / Q000469:parasitology; D017780:Malaria Vaccines / Q000097:blood / Q000276:immunology; D051379:Mice; D008813:Mice, Inbred ICR; D010967:Plasmodium yoelii / Q000254:growth & development / Q000276:immunology*; D019704:Protein Disulfide-Isomerases / Q000276:immunology / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D039621:Eukaryotic Initiation Factor-3; D018840:HSP70 Heat-Shock Proteins; D007074:Immunoglobulin G; D017780:Malaria Vaccines; D016282:Aspartic Acid Endopeptidases; C089643:plasmepsin; D019704:Protein Disulfide-Isomerases