Alveolar macrophage phenotypes in severe equine asthma

Publication date: Available online 11 February 2020Source: The Veterinary JournalAuthor(s): M.E. Wilson, E.E. McCandless, M.A. Olszewski, N.Edward RobinsonAbstractBecause the alveolar macrophage (AM) phenotype of horses with severe equine asthma (SEA) is unknown, the cytokines expressed by M1- and M2-polarized AM were determined and the hypothesis that natural hay/straw challenge (NC) induces divergent AM phenotypes in control horses and horses with SEA was tested. Macrophages from control horses were activated either with eIFNγ + lipolysaccharide (LPS) or eIL-4 to characterize M1- or M2-polarized AM gene expression, respectively and determine the response of polarized cells to pathogen-associated molecular patterns (PAMPS): LPS, zymosan, peptidoglycan and hay dust. Subsequently, gene expression was explored in AM of control horses and horses with SEA at pasture and after NC.M1 polarization increased expression of pro-inflammatory cytokines (TNFα, IL-8, IL-12p40), IL-10, and CD80. M2 polarization increased CD206 and down-regulated arginase-II and IL-10. Expression of pro-inflammatory cytokines and CD80 in response to PAMPS was further increased by M1 pre-polarization whereas M2 pre-polarization down-regulated expression of pro-inflammatory cytokines and IL-10 but increased CD206. In horses with SEA, AMs had elevated expression of IL-10 both at pasture and after NC, but only after NC in control horses. CD206 expression increased in both groups during NC. At pasture, stim...
Source: The Veterinary Journal - Category: Veterinary Research Source Type: research