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Up‐regulated expression of the α7 nicotinic acetylcholine receptor subunit on inflammatory infiltrates during Dictyocaulus viviparus infection
Author(s) -
LAZARI O.,
KIPAR A.,
JOHNSON D. R.,
SELKIRK M. E.,
MATTHEWS J. B.
Publication year - 2006
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1111/j.1365-3024.2006.00873.x
Subject(s) - biology , parenchyma , nicotinic acetylcholine receptor , pathology , reverse transcription polymerase chain reaction , immunology , cholinergic , lung , infiltration (hvac) , receptor , immune system , gene expression , acetylcholine receptor , gene , medicine , endocrinology , physics , thermodynamics , biochemistry , botany
SUMMARY Cholinergic signalling is known to affect immune cell function, but few studies have addressed its relevance during nematode infection. We therefore analysed the anatomical distribution and expression pattern of the nicotinic acetylcholine receptor (nAChR) α7 subunit in lungs obtained from Dictyocaulus viviparus ‐infected and uninfected control cattle. The analysis was performed on trachea and lung parenchyma from uninfected animals and animals necropsied at 15, 22 and 43 days post‐infection (DPI). Localization of the α7 nAChR was evaluated by immunohistology and mRNA expression analysed by gene‐specific reverse transcription‐polymerase chain reaction (RT‐PCR). In uninfected animals, tracheal, bronchial and bronchiolar epithelium and smooth muscle cells constitutively expressed the α7 nAChR, as did type I and II alveolar epithelial cells and alveolar macrophages and a few infiltrating leucocytes. By 15 DPI, immunohistology revealed a massive influx of α7 nAChR+ inflammatory cells into the lung parenchyma and tracheal wall. This was reflected in the RT‐PCR results. At later time points, both parenchyma and tracheal wall contained large numbers of α7 nAChR+ leucocytes, but detection of transcript was restricted to the trachea. Recruitment of nAChR‐containing leucocytes to the lungs of D. viviparus ‐infected cattle suggests that these cells may represent possible downstream targets for parasite‐secreted acetylcholinesterases.