MiR-126-5p by direct targeting of JNK-interacting protein-2 (JIP-2) plays a key role in Theileria-infected macrophage virulence.

Malak Haidar,Perle Latre De Late,Gordon Langsley,Shahin Tajeri,Fathia Ben-Rached,Arnab Pain,Zineb Rchiad,Hifzur Rahman Ansari,Eric Y Denkers

doi:10.1371/journal.ppat.1006942

Abstract

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.

Highlights

Theileria annulata is an apicomplexan parasite causing a widespread disease called tropical theileriosis that is endemic to North Africa, the Middle East, vast parts of India and China [1]
Deep microRNA sequencing revealed that infection of both B cells and macrophages alters the expression of a large number of host cell microRNAs
We show that miR-126-5p in virulent macrophages directly targets and suppresses a cytosolic scaffold protein called JNK-Interacting Protein-2 (JIP-2), so liberating JNK1 to enter the nucleus and phosphorylate c-Jun

Summary

Introduction

Theileria annulata is an apicomplexan parasite causing a widespread disease called tropical theileriosis that is endemic to North Africa, the Middle East, vast parts of India and China [1]. Since attenuated vaccine lines used to fight tropical theileriosis are derived by long-term culture of virulent infected macrophages, and since many virulence traits can be restored by TGF-β2–stimulation of attenuated macrophages [5], loss of Theileria-infected macrophage virulence such as activation of the Activator Protein 1 (AP-1) transcription factor [6, 7] may have an epigenetic element [8, 9]. Micro-ribonucleic acids (miRNAs) are small (17–25 bases long) single-stranded, non-coding RNAs [10, 11] that modulate diverse biological processes by normally binding to the 30untranslated region (3’-UTR) of target mRNAs, altering the post-transcriptional regulation of numerous genes [12,13,14]. A role for miR-155 in the virulence of T. annulata-infected leukocytes occurs via its suppression of De-Etiolated Homolog 1 (DET-1) expression that diminishes c-Jun ubiquitination [9]

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Conclusion