Читать книгу Principles of Virology, Volume 2 - Jane Flint, S. Jane Flint - Страница 89

Organs such as the liver, spleen, bone marrow, and adrenal glands are characterized by the presence of sinusoids, a type of capillary that has a large pore size to allow free exchange between the blood and the tissue. These capillaries are lined with macrophages, known somewhat misleadingly as the reticuloendothelial system (these macrophages are neither endothelial nor a “system”). These cells function to filter the blood and remove foreign particles, similar to a HEPA filter purifying incoming air. However, the macrophages in organs that possess sinusoids often provide the portal for entry of viral particles into tissues. For example, hepatitis viruses that infect the liver, the major filtering and detoxifying organ of the body, usually enter from the blood. The presence of virus particles in the blood can lead to the infection of Kupffer cells, the macrophages that line liver sinusoids (Fig. 2.19). Virus particles may be transcytosed across kupffer and endothelial cells without reproduction to reach the underlying hepatocytes. Alternatively, viruses may multiply in the kupffer cells, and then be released to infect hepatocytes. Either mechanism may induce inflammation and necrosis of liver tissue, a condition termed hepatitis.