Immune response to soluble exoantigens ofPlasmodium falciparummay contribute to both pathogenesis and protection in clinical malaria: evidence from a longitudinal, prospective study of semi‐immune African children

摘要

AbstractSome soluble exoantigens of Plasmodium have lipopolysaccharide (LPS)‐like properties and are believed to contribute to the pathogenesis of acute malaria. We have studied cellular and humoral immune responses to several purified exoantigens ofPlasmodium falciparumin a cohort of children and compared these responses with their subsequent susceptibility to malaria infection and clinical disease. We found no evidence that either lymphoproliferative or interferon‐γ (IFN‐γ) responses to these antigens were associated with protective immunity. On the contrary, children whose cells produced IFN‐γ afterin vitroactivation with one of the soluble antigens (Ag7) were more likely to experience clinical manifestations of malaria infection (fever and malaise) than were children whose cells did not produce IFN‐γ. It is possible that exoantigen‐induced IFN‐γ may exacerbate the LPS‐like effects of these antigens. However, serum antibodies to another antigen (Ag2) were more prevalent in children with asymptomatic infections or low parasitemia than in children with fever and higher parasitemia (confirmed clinical malaria), suggesting that these antibodies may contribute to the development of