Characterisation of infection associated microRNA and protein cargo in extracellular vesicles of Theileria annulata infected leukocytes.

Victoria Gillan,Kirsty Maitland,Deborah M Simpson,Jane Kinnaird,Eileen Devaney,Brian Shiels

doi:10.1111/cmi.12969

Victoria Gillan, Kirsty Maitland + Show 4 more

Open Access

https://doi.org/10.1111/cmi.12969

Copy DOI

Abstract

The protozoan parasites Theileria annulata and Theileria parva are unique amongst intracellular eukaryotic pathogens as they induce a transformation‐like phenotype in their bovine host cell. T. annulata causes tropical theileriosis, which is frequently fatal, with infected leukocytes becoming metastatic and forming foci in multiple organs resulting in destruction of the lymphoid system. Exosomes, a subset of extracellular vesicles (EV), are critical in metastatic progression in many cancers. Here, we characterised the cargo of EV from a control bovine lymphosarcoma cell line (BL20) and BL20 infected with T. annulata (TBL20) by comparative mass spectrometry and microRNA (miRNA) profiling (data available via ProteomeXchange, identifier PXD010713 and NCBI GEO, accession number GSE118456, respectively). Ingenuity pathway analysis that many infection‐associated proteins essential to migration and extracellular matrix digestion were upregulated in EV from TBL20 cells compared with BL20 controls. An altered repertoire of host miRNA, many with known roles in tumour and/or infection biology, was also observed. Focusing on the tumour suppressor miRNA, bta‐miR‐181a and bta‐miR‐181b, we identified putative messenger RNA targets and confirmed the interaction of bta‐miR181a with ICAM‐1. We propose that EV and their miRNA cargo play an important role in the manipulation of the host cell phenotype and the pathobiology of Theileria infection.

Highlights

The tick‐borne parasites of ruminants Theileria annulata and Theileria parva are responsible for significant pathology, productivity, and economic loss over large areas of the old world
We isolated a population of vesicles enriched with exosomes from BL20 and TBL20 cells, as judged by their protein composition, high levels of expression of marker proteins and size profile
By labelling with PKH67, TBL20‐extracellular vesicles (EV) were shown to enter uninfected cells, demonstrating a potential means of delivering their content. These observations are pertinent given the pathogenesis of T. annulata infection, where uncontrolled proliferation, metastasis, and destruction of the lymphoid system are hallmarks of acute disease

Summary

| INTRODUCTION

The tick‐borne parasites of ruminants Theileria annulata and Theileria parva are responsible for significant pathology, productivity, and economic loss over large areas of the old world. In sub‐Saharan Africa, T. parva is the causative agent of east coast fever, a condition that is frequently fatal These Theileria spp are unique amongst apicomplexan parasites because of their ability to transform host cells, which, in the case of T. annulata, are myeloid cells, dendritic cells (DC), and B cells. Other classes of EV, such as microvesicles bud from the plasma membrane, while apoptotic bodies occur when cells are undergoing apoptotic fragmentation These subtypes have a larger size range (50 to 2000 nm and 50 to 5000 nm, respectively) and lack the cup‐shape morphology unique to exosomes (reviewed in Edgar, 2016). We compared the protein and miRNA profile of EV from T. annulata infected (TBL20) and control uninfected cells (BL20). Our results indicate that infection‐associated EV proteins and miRNA may play a key role in the pathobiology of this important veterinary pathogen

| RESULTS

| DISCUSSION

Findings

| Experimental procedures