Novel indirect co-culture of immortalized hepatocytes with monocyte derived macrophages is supported by pro-inflammatory cytokine networks

The liver is composed of different cell populations. Interactions of different cell populations can be investigated bya newly established indirect co-culture system consisting of immortalised primary human hepatocytes and human monocyte derived macrophages(MDMs). Using the time-dependent cytokine secretion of the co-cultures and singlecultures, correlation networks(includingthe cytokinesG-CSF, CCL3, MCP-1, CCL20, FGF, TGF-β1, GM-CSF, IL-8 IL-6, IL-1β, and IL-18)were generated and the correlationswere validatedbyapplication of IL-8and TNF-α-neutralising antibodies. Thedata reveal that IL-8 is crucial for the interaction between hepatocytes and macrophages in vitro.In addition, transcriptome analyses showedthat a change in the ratio between macrophages and hepatocytes may triggerpro-inflammatory signalling pathways of the acute phase responseand the complement system(release of, e.g., certaincyto-and chemokines).Using diclofenac and LPS showed that the release of cytokines is increasingwith higher ratios of MDMs. Altogether we coulddemonstratethat the current co-culture system is better suited to mirror thein vivosituation when compared to previously established co-culturesystems composed of HepG2and differentiated THP-1cells.Further, our data reveal that the cytokine IL-8 is crucial for the interaction between hepatocytes and macrophages in vitro. Characterization of Fa2N-4 cells under influence of monocyte derived macrophages using the Affymetrix Human Clariom S. Array data was processed by the company ATLAS Biolabs GmbH (Friedrichstraße 147, 10117 Berlin, Germany). Three biological replicates were performed for each condition.