Hepatic Sinusoidal Cells and Liver-Associated Lymphocytes

The liver contains a number of distinct populations of nonparenchymal cells including sinusoidal endothelial cells, Kupffer cells, stellate cells, and natural killer cells, as well as lymphocytes and natural killer T cells, which function to defend the body against blood-borne pathogens and other foreign materials. The unusual structure of the hepatic sinusoids promotes slow blood flow, facilitating the interaction of sinusoidal cells and responding lymphocytes with foreign materials. Whereas under homeostatic conditions, these cells work together to provide immune defense and tolerance, following exposure to hepatotoxicants or infectious agents, they can become over activated, resulting in exacerbation of tissue injury and chronic inflammation, culminating in acute liver failure or fibrosis. In this article the various populations of hepatic sinusoidal cells and liver associated lymphocytes are reviewed, along with their roles in liver homeostasis and disease pathogenesis.