Sialylation pattern in lung epithelial cell line and Siglecs expression in monocytic THP-1 cells as cellular indicators of cigarette smoke – induced pathology in vitro

ABSTRACTPurpose: Cellular response to cigarette smoke (CS) involves activation of recognition receptors resulting in changes in immune status, oxidative stress and cell turnover. We investigated the effects of CS on sialic acid-binding immunoglobulin type lectins (Siglecs) expression and their sialylated ligands in human immune and non-immune cells. Methods: Human monocytes (THP-1) and epithelial cells (A549) were cultured in CS–conditioned medium (CSM). Expression of Siglec-8 and Siglec-5/Siglec-14 was analysed in THP-1 cells using flow cytometry. The effects of CS on immune activity was evaluated flow cytometrically in these cells by assessment of phagocytosis and intracellular expression IL-1β and IL-10. Detection and differentiation of sialic acids was analyzed by dot blot, western blot and flow cytometry using plant lectins and antibodies. Results: Exposure to CS significantly increased expression of Siglec-8 and Siglec-5/Siglec-14 in THP-1 cells. These changes were accompanied by enhanced intracellu...