Investigation of nasal epithelial cells as a surrogate for bronchial epithelial cells in the research of equine asthma.

Equine asthma, previously known as Recurrent Airway Obstruction (RAO) or Inflammatory Airway Disease (IAD), is an often-debilitating condition that may severely affect both performance and quality of life. Research is hindered by the low sample numbers of subjects recruited to studies, a consequence in part of the invasive nature of the sampling methods of bronchial brushing and biopsy. We present an alternative method of sampling equine airway epithelial cells, the 'nasal brush method' (NBM). Obtained by light brushing of the ventral meatus whilst the horse is under standing sedation, these cells express the same markers of differentiation as their deeper counterparts. Grown as 3-D spheroids or as air-liquid interface cultures, nasal epithelial cells are responsive to the inflammatory cytokine interleukin-13. This may be attenuated by modulation of the Notch signalling pathway using the gamma-secretase inhibitor Semagecestat; a previously unreported finding that cements the link between equine and human asthma research and strengthens the case for a One Health approach in researching asthma pathophysiology and therapeutic intervention.

Modelling early events in Mycobacterium bovis infection using a co-culture model of the bovine alveolus.

Bovine tuberculosis (bTB), a zoonosis mainly caused by Mycobacterium bovis has severe socio-economic consequences and impact on animal health. Host-pathogen interactions during M. bovis infection are poorly understood, especially early events which are difficult to follow in vivo. This study describes the utilisation of an in vitro co-culture model, comprising immortalised bovine alveolar type II (BATII) epithelial cells and bovine pulmonary arterial endothelial cells (BPAECs). When cultured at air-liquid interface, it was possible to follow the migration of live M. bovis Bacille Calmette-Guérin (BCG) and to observe interactions with each cell type, alongside cytokine release. Infection with BCG was shown to exert a detrimental effect primarily upon epithelial cells, with corresponding increases in IL8, TNFα, IL22 and IL17a cytokine release, quantified by ELISA. BCG infection increased expression of CD54, MHC Class I and II molecules in endothelial but not epithelial cells, which exhibited constitutive expression. The effect of peripheral blood mononuclear cell conditioned medium from vaccinated cattle upon apical-basolateral migration of BCG was examined by quantifying recovered BCG from the apical, membrane and basolateral fractions over time. The numbers of recovered BCG in each fraction were unaffected by the presence of PBMC conditioned medium, with no observable differences between vaccinated and naïve animals.

Isolation of Alveolar Type II Cells from Adult Bovine Lung.

Alveolar type II (ATII) cells play a key role as part of the distal lung epithelium, including in the innate immune response and as self-renewing progenitors to replace alveolar type I (ATI) cells during epithelial regeneration. Their secretion of surfactant protein helps maintain homeostasis and exerts protective, antimicrobial properties. ATII cells remain difficult to study, partly due to inefficient and expensive isolation methods, a propensity to differentiate into ATI cells, and susceptibility to fibroblast contamination. Published methods of isolation often require specialized technology, negatively impacting the development of in vitro models of disease, including bovine tuberculosis. Presented here is a simple and cost-effective method for generation of bovine primary ATII cells. These cells exhibit an ATII phenotype in 2D and 3D culture and are conducive to further study of the role of ATII cells in bovine respiratory diseases. © 2019 by John Wiley & Sons, Inc.

Isolation and characterisation of alveolar type II pneumocytes from adult bovine lung.

Alveolar type II (ATII) cells play a key role as part of the distal lung epithelium, including roles in the innate immune response and as self-renewing progenitors to replace alveolar type I (ATI) cells during regeneration of the alveolar epithelium. Their secretion of surfactant protein helps to maintain homeostasis in the distal lung and exert protective, antimicrobial properties. Despite the cell's crucial roles, they remain difficult to study, in part due to inefficient and expensive isolation methods, a propensity to differentiate into alveolar type I cells in culture and susceptibility to fibroblast overgrowth from primary isolations. Published methods of isolation often require specialist technology, negatively impacting the development of in vitro models of disease, including bovine tuberculosis (BTB), a serious re-emerging disease in both animals and humans worldwide. We present here a simple and cost-effective method that may be utilised in the generation of bovine primary ATII cells. These exhibit an ATII phenotype in 2D and 3D culture in our studies and are conducive to further study of the role of ATII cells in bovine respiratory diseases.