A polyclonal but not a monoclonal antibody to an M(r) 52-kD protein responsible for a punctate fluorescence pattern in Plasmodium falciparum merozoites inhibits invasion in vitro.
A monoclonal antibody, MAb H24, recognized a Plasmodium falciparum antigen with a relative molecular mass (M(r)) of 52 kD that appeared to be a rhoptry component by immunofluorescence microscopy. The antigen is synthesized during both ring and schizont stages, but pulse-chase experiments showed that it is not carried through to the next ring stage after reinvasion. It was not labeled by 3H-glucosamine. The purified MAb failed to inhibit parasite invasion in vitro. The antigen was isolated using affinity chromatography, and used to produce a monospecific polyclonal antibody (PAb H24) in mice. Polyclonal antibody H24 recognized the same antigen as MAb H24 as judged by both immunofluorescence microscopy and immunoprecipitation followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and was markedly inhibitory in vitro.
Storey
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Department of Pathology, University of Melbourne, Parkville, Victoria, Australia.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000913:Antibodies, Protozoan / Q000276:immunology*; D000953:Antigens, Protozoan / Q000276:immunology*; D004912:Erythrocytes / Q000469:parasitology; D005455:Fluorescent Antibody Technique; D006801:Humans; D066298:In Vitro Techniques; D008970:Molecular Weight; D010963:Plasmodium falciparum / Q000254:growth & development / Q000276:immunology* / Q000472:pathogenicity; D015800:Protozoan Proteins / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D015800:Protozoan Proteins