title: Phenotypic and genotypic alterations associated with the attenuation of a Theileria annulata vaccine cell line from Turkey.
abstract: Attenuated vaccines, produced by prolonged in vitro culture of the macroschizont stage of the life-cycle, are the main method of controlling Theileria annulata infections. Little is known about the mechanism(s) of attenuation. Here we present data from a Turkish cell line demonstrating that attenuation is associated with reduced ability to differentiate into microschizonts and a reduction in matrix metalloproteinase activity. We also show that attenuation results in a change in the structure of the parasite population. Using the technique of differential mRNA display, we demonstrate that gene expression profiles differ between non-attenuated and attenuated macroschizont infected leucocytes. One differentially expressed gene is of parasite origin. These data are discussed in the context of a multifactorial model for virulence.
authors.affiliation: Department of Biology, University of York, UK.
authors.forename: R P
authors.initials: RP
authors.lastname: Somerville
authors.forename: P
authors.initials: P
authors.lastname: Littlebury
authors.forename: E
authors.initials: E
authors.lastname: Pipano
authors.forename: C G
authors.initials: CG
authors.lastname: Brown
authors.forename: V
authors.initials: V
authors.lastname: Shkap
authors.forename: R E
authors.initials: RE
authors.lastname: Adamson
authors.forename: R A
authors.initials: RA
authors.lastname: Oliver
authors.forename: E J
authors.initials: EJ
authors.lastname: Glass
authors.forename: F R
authors.initials: FR
authors.lastname: Hall
mesh_terms: D000818:Animals; D002417:Cattle; D015536:Down-Regulation; D005786:Gene Expression Regulation; D005838:Genotype; D008666:Metalloendopeptidases / Q000378:metabolism; D010641:Phenotype; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D016052:Protozoan Vaccines / Q000235:genetics* / Q000276:immunology* / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D016796:Theileria annulata / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D013801:Theileriasis / Q000276:immunology / Q000517:prevention & control; D014158:Transcription, Genetic; D014613:Vaccines, Attenuated / Q000235:genetics / Q000276:immunology / Q000494:pharmacology
chemical_list: D016052:Protozoan Vaccines; D012333:RNA, Messenger; D014613:Vaccines, Attenuated; D008666:Metalloendopeptidases