Pro- and antiinflammatory cytokines are known to be involved in the pathogenesis of septic shock and multiple organ dysfunction, including liver failure. Many lympho- and monokines may alter hepatocellular function. Liver parenchymal cells themselves, in contrast to mononuclears like Kupffer cells, are generally considered only targets but not producers of these important mediators.

In order to investigate whether hepatocellular cells are a potential source of various regulatory cytokines we have estimated the multiple cytokine gene expression in the culture of well differentiated human HepG2 hepatoma cells using RT-PCR.

Our findings demonstrate that HepG2 cells express mRNAs for IFN-γ, TNF-α, TGF-β, M-CSF, oncostatin-M, ICAM-1, IL-4, IL-5, IL-7, IL-10, IL-11, IL-12 and IL-6R. At the same time the expression of IL-1, IL-2, IL-3, IL-6, CD40 ligand and IL-2R genes was not detected.

Hepatocytes are potential producers of a variety of cytokines, some of them being able to regulate hepatocellular functions directly, others are important regulators of leukocyte functions. Thus, on the one hand, hepatocytes may express autoregulatory cytokines and, on the other hand, influence the functions of other liver cells like Kupffer, Ito or endothelial cells. Due to their large amount, liver parenchymal cells could be an important source of systemically acting pro- and anti-inflammatory and other regulatory cytokines.