Project description:Theileria annulata is an apicomplexan parasite that infects and transforms bovine macrophages that disseminate throughout the animal causing a leukaemia-like disease called tropical theileriosis. Using deep RNAseq of T. annulata-infected B cells and macrophages we identify a set of microRNAs induced by infection, whose expression diminishes upon loss of the hyper-disseminating phenotype of virulent transformed macrophages. We describe how infection-induced upregulation of miR-126-5p ablates JIP-2 expression to release cytosolic JNK to translocate to the nucleus and trans-activate AP-1-driven transcription of mmp9 to promote tumour dissemination. In non-disseminating attenuated macrophages miR-126-5p levels drop, JIP-2 levels increase, JNK1 is retained in the cytosol leading to decreased c-Jun phosphorylation and dampened AP-1-driven mmp9 transcription. We show that variation in miR-126-5p levels depends on the tyrosine phosphorylation status of AGO2 that is regulated by Grb2-recruitment of PTP1B. In attenuated macrophages Grb2 levels drop resulting in less PTP1B recruitment, greater AGO2 phosphorylation, less miR-126-5p associated with AGO2 and a consequent rise in JIP-2 levels. Changes in miR-126-5p levels therefore, underpin both the virulent hyper-dissemination and the attenuated dissemination of T. annulata-infected macrophages.
Project description:Investigation of parasite (T. annulata) gene expression over the course of the life-cycle (sporozoite->macroschizont->merozoite->piroplasm). The study focused on the expression of known and putative transcription factors, in particular members of the ApiAP2 gene family. Up-stream motifs associated with stage-specifically expressed genes were identified during the course of the analysis. The experiment investigates Theileria annulata gene expression over a differentiation time-course - sporozoite through to piroplasm. 20 samples were analyzed - 4 x sporozoite (replicates), 3 x macroschizont (replicates), 3 x day 4, 3 x day 7, 3 x day 9 (replicates) and 4 x piroplasm (replicates)
