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Comparative transcriptome analysis of equine alveolar macrophages
Author(s) -
Karagianni A.E.,
Kapetanovic R.,
Summers K.M.,
McGorum B.C.,
Hume D.A.,
Pirie R.S.
Publication year - 2017
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/evj.12584
Subject(s) - transcriptome , gene expression , macrophage , alveolar macrophage , bronchoalveolar lavage , biology , lipopolysaccharide , microarray analysis techniques , gene , horse , gene expression profiling , microarray , inflammation , immunology , lung , medicine , in vitro , genetics , paleontology
Summary Reasons for performing study Alveolar macrophages ( AM s) are the first line of defence against pathogens in the lungs of all mammalian species and thus may constitute appropriate therapeutic target cells in the treatment and prevention of opportunistic airway infections. Therefore, acquiring a better understanding of equine macrophage biology is of paramount importance in addressing this issue in relation to the horse. Objectives To compare the transcriptome of equine AM s with that of equine peritoneal macrophages ( PM s) and to investigate the effect of lipopolysaccharide ( LPS ) on equine AM . Study design Gene expression study of equine AM s. Methods Cells from both bronchoalveolar and peritoneal lavage fluid were isolated from systemically healthy horses that had been submitted to euthanasia. Cells were cryopreserved. RNA was extracted and comparative microarray analyses were performed in AM s and PM s, and in AM s treated and untreated with LPS . Comparisons with published data derived from human AM studies were made, with particular focus on LPS ‐induced inflammatory status. Results The comparison between AM s and PM s revealed the differential basal expression of 451 genes. Gene expression analysis revealed an alternative (M2) macrophage polarisation profile in AM s and a hybrid macrophage activation profile in PM s, a phenomenon potentially attributable to a degree of induced endotoxin tolerance. The gene expression profile of equine AM s following LPS stimulation revealed significant changes in the expression of 240 genes, including well‐known upregulated inflammatory genes. This LPS ‐induced gene expression profile of equine AM s more closely resembles that of human rather than murine macrophages. Conclusions This study improves current understanding of equine macrophage biology. These data suggest that the horse may represent a suitable animal model for the study of human macrophage‐associated lung inflammation and data derived from human macrophage studies may have significant relevance to the horse.