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 of virulence. (C) 1998 Elsevier Science Ltd. All rights reserved.
Original language | English |
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Pages (from-to) | 569-575 |
Number of pages | 7 |
Journal | Vaccine |
Volume | 16 |
Issue number | 6 |
Publication status | Published - Apr 1998 |
Keywords
- Theileria annulata
- attenuation
- vaccine
- BABESIA-BOVIS
- SURFACE-ANTIGEN
- SUBPOPULATIONS
- POLYMORPHISM
- EXPRESSION
- MEROZOITE
- SELECTION
- CATTLE
- DNA