Cell-cell interactions are particularly important for modulating the monocyte to macrophage transition in tissue compartments. Both cell membrane contacts and soluble signals from the environment might be involved in these interactions. The aim of our study was to characterize gene expression profiles of human mononuclear phagocytes induced by a co-culture with epithelial cells
Methods:
Human THP-1 macrophages were co-cultured with A549 epithelial cells either directly or separated by a filter insert. At different time points, THP-1 cells were aspirated and the mRNA expression was evaluated by multiplex Real-time RT-PCR, the release of selected cytokines was evaluated by Luminex technology or ELISA. The phenotype of both cultured cells was evaluated by flow cytometry.
Results:
Co-culture with epithelial cells induced a number of cytokine genes (IL-1 beta, IL-6, IL-10, TNF alpha, IL-19, GM-CSF, ...etc) together with upregulation of genes associated with NFkappaB activation including REL, RELB, transcription co-activator BCL3, MALT gene, and NFKB1 subunit. Our recent study has confirmed the role of NFkB signalling by inhibition of IL-6 release from co-cultured cells by p65 siRNA transfection1. Phenotypic pattern of THP-1 cells co-cultured with epithelial monolayers showed maturation and activation associated changes such as CD14 upregulation associated with higher release of the soluble form (sCD14) from macrophage membrane.
Conclusions:
Our data suggest that properties of human mononuclear phagocytes in tissues are highly influenced by their immediate interactions with other, e.g. epithelial cells. These factors might be of particular importance in final steps of differenciation of monocytes/macrophages into fully competent effector cells.
Reference:
I.Striz, E. Brabcova, L. Kolesar, X.D Liu , I. Brabcova, A. Sekerkova, J.A. Poole, M. Jaresova, A. Slavcev, S.I. Rennard: Epithelial cells modulate genes associated with NF kappaB activation in co-cultured human macrophages. Immunobiology in press - doi:10.1016/j.imbio.2011.04.009
Supported by IGA MZCR grant No.10524-3 and the Institute for Clinical and Experimental Medicine (MZO 0023001)