A new approach to isolation and culture of human Kupffer cells

Macrophages are a diverse population of cells that are able to adapt to specific tissue environments. Kupffer cells are liver resident macrophages and form the largest population of fixed tissue macrophages. Their isolation offers an exciting opportunity to study this subpopulation of uniquely adapted cells. However existing Kupffer cell isolation techniques are tedious and are still largely based on enzymatic digestion to liberate tissue macrophages from the closely associated surrounding tissue. Isolation techniques have continually evolved over the last 3 decades but are neither easily applicable nor user friendly. This is highlighted by a review of current literature which will show that there is a scarcity of published studies employing human Kupffer cells. The other difficulty with Kupffer cells and some other populations of macrophages in culture is the strong tenacity with which they adhere to solid substrate and their resistance to conventional sub-culture dissociation agents. The difficulty with cell dissociation has previously required cells to be grown in suspension culture. This has been achieved by culturing macrophages in Teflon bags but unfortunately this deprives cells of the maturation signals generated by adherence. In this article we have upped the ante by describing a 'user friendly' method for Kupffer cell isolation and new culture techniques that allow Kupffer cells to be grown in adherency whilst at the same time circumventing the difficulties posed by the adherence of these unique cells.