SERUM FACTORS INHIBITORY FOR IN-VITRO DEVELOPMENT OF PLASMODIUM-FALCIPARUM BLOOD-STAGE PARASITES

Sera from 29 individuals residing in a malaria-endemic region of Colom bia were evaluated by an inhibition assay for their capacity to retard the growth of Plasmodium falciparum in vitro. The inhibitory activity was found to be independent of antibody activity. Furthermore, the de gree of inhibition of parasite development was variable depending on t he parasite isolate used for the assay and the season of malaria trans mission We selected sera with high inhibitory activity and carried out partial analytical characterization by anion exchange fast protein li quid chromatography (FPLC) to identify the chemical nature of the inhi bitory factor(s). The results suggested that the in vitro inhibitory a ctivity might result from the additive effect of different molecules. It appears that these molecules could be non-specifically induced by s timulation of the immune system, they seem to play a role in the immun ity to malaria.