TY - JOUR T1 - Characterisation of a new Daisy cell line representative of human alveolar macrophage (hAM) JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p3859 AU - Yvette Hayman AU - Simon Hart AU - Alyn Morice Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p3859.abstract N2 - Introduction: Techniques used to obtain primary hAM are invasive, often providing low yields which cannot be expanded in vitro. No human cell line exists as an alternative. We characterised a new human cell line capable of expansion and spontaneous differentiation.Methods: Cells were cultured in RPMI1640 with 10% foetal bovine serum and penicillin/streptomycin (100U/ml;0.1mg/ml) in a humidified 5% CO2 atmosphere, passaged every 2 days. Light and transmission electron microscopy comparing Daisy cells with THP-1 cells stimulated with phorbol myristate acetate (PMA;50μg/ml;24h) was performed. Flow cytometric immunophenotype studies were performed analysing CD 11b, 14, 16, 23, 24, 32, 36, 64, 163 and 206 expression. Results were compared with both THP-1 cells and primary hAM obtained by bronchoalveolar lavage. Phagocytic capability by zymosan uptake (mg/ml;1h), mycoplasma screening by fluorescence microscopy and opsonised antigen binding by flow cytometry were also assessed.Results: Microscopy showed Daisy cells to be similar in size, shape and granularity to PMA stimulated THP-1 cells with a higher proportion of heterochromatin, pseudopodia and vesicular inclusions. Daisy cells were shown to express lower levels of CD11b, 14 and 32 compared with PMA stimulated THP-1 cells yet higher levels of CD36, 80, 163 and 206. CD marker expression of Daisy cells more closely resembled that of primary hAM. Zymosan was readily phagocytosed, mycoplasma was not detected and high levels of opsonised antigen binding were seen in Daisy but not THP-1 cells.Conclusions: The new Daisy cell line shows characteristics of mature hAM yet can be maintained and cultured providing a useful tool in respiratory research. ER -