Expression of Toll-like receptor 9 (TLR9) in the lungs and lymphoid tissue of pigs

摘要

The pattern of distribution of Toll-like receptor 9 (TLR9) in different tissues varies between species. The aim of the present study was to describe the distribution of TLR9 expression in selected tissues and organs of healthy pigs at 3 weeks and 3 months of age. Representative formalin-fixed samples of lung, thymus and secondary lymphoid tissues were evaluated by immunohistochemistry. TLR9 positive staining was observed in epithelial cells, vascular endothelium and myoepithelial-like cells, as well as in cells of the alveolar septa of the lung. Antigen presenting cells of perifollicular zones (interdigitating, macrophage and dendritic-like cells) of the Peyer's patches, lymph nodes, spleen and thymus were also immunoreactive for TLR9. No differences were seen in TLR9 protein expression in tissues from the two age groups. (C) 2014 Elsevier Ltd. All rights reserved.