title: Effects of hormones and cysteine protease modulators on infection of HepG2 cells by Plasmodium berghei sporozoites in vitro determined by ELISA immunoassay.
abstract: An enzyme-linked immunosorbent assay (ELISA) detecting a Plasmodium berghei liver-stage-specific protein Pbl-1 is described. The quantitative detection limits ranged from 0.01 to 0.05 microgram of parasite protein. Qualitatively the assay detected as little as 0.001 microgram Pbl-1 per well. Using the ELISA dexamethasone and insulin together was shown to promote higher parasite infections in HepG2 cells compared to unsupplemented medium. Anti-cowpea-protease cysteine inhibitor significantly increased hepatocyte invasion as compared to controls, whereas a significant decrease was recorded in the presence of the protease inhibitor E64. Partial involvement of cysteine proteases in HepG2 invasion by P. berghei sporozoites is therefore suggested.
authors.affiliation: Department of Biology, Imperial College of Science, Technology & Medicine, London, England.
authors.forename: S
authors.initials: S
authors.lastname: Kumar
authors.forename: J F
authors.initials: JF
authors.lastname: van Pelt
authors.forename: C A
authors.initials: CA
authors.lastname: O'Dowd
authors.forename: M R
authors.initials: MR
authors.lastname: Hollingdale
authors.forename: R E
authors.initials: RE
authors.lastname: Sinden
mesh_terms: D000818:Animals; D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000502:physiology; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D003907:Dexamethasone / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D007328:Insulin / Q000494:pharmacology*; D008099:Liver / Q000469:parasitology; D010962:Plasmodium berghei / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D015800:Protozoan Proteins / Q000032:analysis / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000276:immunology
chemical_list: D015853:Cysteine Proteinase Inhibitors; D007328:Insulin; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; D003907:Dexamethasone; D003546:Cysteine Endopeptidases