Antigenic diversity and size diversity of Plasmodium falciparum antigens in isolates from Gambian patients. I. S-antigens

摘要: Summary Ring-stage asexual parasites of P. falciparum were collected from six Gambian children and the S-antigens radiolabeled by 3H-glycine uptake during in vitro culture up to rupture infected cells merozoite release. Ouchterlony double diffusion boiled supernatants against a panel adult sera identified one S-antigen precipitin arc for five isolates two arcs isolate. Five serologically distinct. Analysis comparison SDS-polyacrylamide gel electrophoresis patterns heat-treated soluble proteins revealed more complex pattern 3H-labelled that was different each There between bands isolate size range molecular weight 137 000 285 000. This result confirms large with adapted falciparum. Several relatively weakly labelled 3H-glycine, suggesting natural contain or predominant phenotypes several other expressed minor parasite subpopulations. Immunoprecipitation performed using adults, or, acute 3 week convalescent same patients used radiolabelling. Adult generally immunoprecipitated some isolate, including antigens must represent extremely subpopulations since they could not be seen non-immunoprecipitated heat-stable proteins. Sera negative on immunoprecipitation, even homologous In case we observed acquisition specific immuoprecipitating antibody period. The antigenic structural complexity have been submitted selection pressure adaptation is clearly greater than