Phenotypic and genotypic alterations associated with the attenuation of a Theileria annulata vaccine cell line from Turkey.
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.
Somerville
R P
RP
Department of Biology, University of York, UK.
Littlebury
P
P
Pipano
E
E
Brown
C G
CG
Shkap
V
V
Adamson
R E
RE
Oliver
R A
RA
Glass
E J
EJ
Hall
F R
FR
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
D016052:Protozoan Vaccines; D012333:RNA, Messenger; D014613:Vaccines, Attenuated; D008666:Metalloendopeptidases