Expression of nicotinic acetylcholine receptors on murine alveolar macrophages.

Neuronal nicotinic acetylcholine receptors (nAChRs) play an essential role in immunomodulation of macrophages. In particular, the alpha7 subunit confers inhibition of the systemic inflammatory response to bacterial lipopolysaccharide, thereby being the crucial element of the cholinergic anti-inflammatory pathway (Borovikova et al., 2000; Pavlov et al., 2003; Wang et al., 2003). In the murine lung, nicotine also exerts anti-inflammatory effects (Blanchet et al., 2004), but at least in murine alveolar macrophage cell lines the alpha7 subunit has not been detected (Matsunaga et al., 2001). On this background we investigated the expression of the nAChR subunits (alpha2-alpha7, alpha9, alpha10, beta2-beta4) on freshly isolated murine alveolar macrophages by immunohistochemistry and RT-PCR.