Schistosoma mansoni: effect of transferrin and growth factors on development of schistosomula in vitro.
We have studied the role of human transferrin and of exogenous iron on early growth and development of schistosomula of Schistosoma mansoni in vitro, as determined by developmental achievement and thymidine incorporation. To help define an adequate serumless medium we also utilized fibroblast growth factor, platelet-derived growth factor, epidermal growth factor, and multiplication-stimulating activity, all present in the hepatic environment of developing schistosomula, as well as certain commercial serum substitutes. Supplementation of basal medium with transferrin in the range of 250-1,000 micrograms/ml provided development equal or superior to serum-supplemented medium, at least within the first 2 wk of culture. Serum-free medium supplemented with Nutridoma-HU or -SP stimulated development to a lesser extent. The stimulatory effect of iron (as ferric sulfate) on thymidine incorporation was removed by deferroxamine, a chelating agent. Competitive inhibition studies with 125I-labeled and unlabeled transferrin indicated the presence of nonsaturable binding sites on schistosomula.
Clemens
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LE
Department of Health Research and Policy, Stanford University School of Medicine, California 94305.
Basch
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PF
D000818:Animals; D001665:Binding Sites; D003470:Culture Media; D003676:Deferoxamine / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005290:Ferric Compounds / Q000494:pharmacology; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology*; D007335:Insulin-Like Growth Factor II / Q000494:pharmacology; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D012550:Schistosoma mansoni / Q000254:growth & development* / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism; D014168:Transferrin / Q000378:metabolism / Q000494:pharmacology*
D003470:Culture Media; D005290:Ferric Compounds; D006133:Growth Substances; D010982:Platelet-Derived Growth Factor; D014168:Transferrin; C024823:ferric sulfate; D005346:Fibroblast Growth Factors; D004815:Epidermal Growth Factor; D007335:Insulin-Like Growth Factor II; D003676:Deferoxamine; D013936:Thymidine