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Expression of TLR9 in Horse, Cow, and Human Lung
Author(s) -
Schneberger David,
Caldwell Sarah,
Suri Sarabjeet Singh,
Kanthan Rani,
Singh Baljit
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.929.7
Subject(s) - tlr9 , horse , lung , biology , receptor , toll like receptor 9 , pathology , inflammation , immunology , gene expression , medicine , gene , paleontology , biochemistry , dna methylation
Toll‐like receptor 9 (TLR9) is the receptor used for responding to bacterial DNA in many species. Recent work has shown that this receptor is expressed in a diverse set of cells within the lung. However, much of this work has been done in tumors, explanted cells, or cell cultures. We examined the in situ expression of TLR9 in the lung of cattle, horses and humans. The data show expression of TLR9 in monocytes, airway epithelial cells, and capillary endothelium in the lungs of all the species. Pulmonary intravascular macrophages of the horse and cattle also express TLR9. Immno‐electron microscopy revealed TLR9 expression in the cytoplasm and, more interestingly, in the nucleus of pulmonary intravascular macrophages (PIMs) and other lung cells. Lung inflammation as a result of E. coli LPS (horses), Mannheimia hemolytica infection (calves), or sepsis (human) resulted in an influx of TLR9‐positive cells. Finally, we show that the LPS‐induced increase in TLR9 gene transcription in the horse lung was abrogated by pre‐treatment with gadolinium chloride to deplete PIMs which demonstrates PIMs as a major source of TLR9 in the horse lung. We conclude that TLR9 is constitutively expressed in lungs of horse, cow and human. The implications of TLR9 expression in PIMs in the horse and cow for infections need to be clarified. (NSERC) Grant Funding Source NSERC