Mycoplasma hyopneumoniae resides intracellularly within porcine epithelial cells. Issue 1 (December 2018)

• Record Type: Journal Article
• Authors: Raymond, B.; Turnbull, L.; Jenkins, C.; Madhkoor, R.; Schleicher, I.; Uphoff, C.; Whitchurch, C.; Rohde, M.; Djordjevic, S.
• Is Part Of: Scientific reports. Volume 8:Issue 1(2018)
• Page Start: 1
• Page End: 13
• Publication Date: 2018-12
• Subjects: Natural history -- Research -- Periodicals; Biology -- Research -- Periodicals; Physical sciences -- Research -- Periodicals; Earth sciences -- Research -- Periodicals; Environmental sciences -- Research -- Periodicals; 502.85
• DOI: 10.1038/s41598-018-36054-3
• Languages: English
• ISSNs: 2045-2322

Abstract

Abstract Enzootic pneumonia incurs major economic losses to pork production globally. The primary pathogen and causative agent, Mycoplasma hyopneumoniae, colonises ciliated epithelium and disrupts mucociliary function predisposing the upper respiratory tract to secondary pathogens. Alleviation of disease is reliant on antibiotics, vaccination, and sound animal husbandry, but none are effective at eliminatingM. hyopneumoniae from large production systems. Sustainable pork production systems strive to lower reliance on antibiotics but lack of a detailed understanding of the pathobiology ofM. hyopneumoniae has curtailed efforts to develop effective mitigation strategies.M. hyopneumoniae is considered an extracellular pathogen. Here we show thatM. hyopneumoniae associates with integrin β1 on the surface of epithelial cells via interactions with surface-bound fibronectin and initiates signalling events that stimulate pathogen uptake into clathrin-coated vesicles (CCVs) and caveosomes. These early events allowM. hyopneumoniae to exploit an intracellular lifestyle by commandeering the endosomal pathway. Specifically, we show: (i) using a modified gentamicin protection assay that approximately 8% ofM. hyopneumoniae cells reside intracellularly; (ii) integrin β1 expression specifically co-localises with the deposition of fibronectin precisely whereM. hyopneumoniae cells assemble extracellularly; (iii) anti-integrin β1 antibodies block entry ofM. hyopneumoniae into porcine cells; and (iv)M. hyopneumoniae survives phagolysosomal fusion, and resides within recycling endosomes that are trafficked to the cell membrane. Our data creates a paradigm shift by challenging the long-held view thatM. hyopneumoniae is a strict extracellular pathogen and calls forin vivo studies to determine ifM. hyopneumoniae can traffic to extrapulmonary sites in commercially-reared pigs.