Fig. 1.

Adenovirus transduction of hepatocytes and Kupffer cells following intravenous administration in naïve mice. After intravenous injection into naïve mice, adenovirus vectors very efficiently transduce liver hepatocytes. This transduction is now thought to be dependent on serum factors such as FX that bridge the virus to hepatic heparan sulfate proteoglycans (HSPGs). Other serum factors (SF), including FIX and complement components, also bind to capsid proteins. However, their role in hepatocyte virus transduction is less clear at this time. Transduction into hepatocytes is followed by robust transgene expression. Kupffer cells (liver macrophages) take up virus mainly through scavenger receptors, complement receptors (CR) and Fc-receptors for immunoglobulin (Fc-R). However, transgene expression is substantially less in Kupffer cells than that observed in transduced hepatocytes.